@end table
-All expressions default to "val".
+@subsection Examples
-Some examples:
+@itemize
+@item
+List all available plugins within amp (LADSPA example plugin) library:
@example
-# Negate input video
-lutrgb="r=maxval+minval-val:g=maxval+minval-val:b=maxval+minval-val"
-lutyuv="y=maxval+minval-val:u=maxval+minval-val:v=maxval+minval-val"
+ladspa=file=amp
+@end example
-# The above is the same as
-lutrgb="r=negval:g=negval:b=negval"
-lutyuv="y=negval:u=negval:v=negval"
+@item
+List all available controls and their valid ranges for @code{vcf_notch}
+plugin from @code{VCF} library:
+@example
+ladspa=f=vcf:p=vcf_notch:c=help
+@end example
-# Negate luminance
-lutyuv=negval
+@item
+Simulate low quality audio equipment using @code{Computer Music Toolkit} (CMT)
+plugin library:
+@example
+ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
+@end example
-# Remove chroma components, turning the video into a graytone image
-lutyuv="u=128:v=128"
+@item
+Add reverberation to the audio using TAP-plugins
+(Tom's Audio Processing plugins):
+@example
+ladspa=file=tap_reverb:tap_reverb
+@end example
-# Apply a luma burning effect
-lutyuv="y=2*val"
+@item
+Generate white noise, with 0.2 amplitude:
+@example
+ladspa=file=cmt:noise_source_white:c=c0=.2
+@end example
-# Remove green and blue components
-lutrgb="g=0:b=0"
+@item
+Generate 20 bpm clicks using plugin @code{C* Click - Metronome} from the
+@code{C* Audio Plugin Suite} (CAPS) library:
+@example
+ladspa=file=caps:Click:c=c1=20'
+@end example
-# Set a constant alpha channel value on input
-format=rgba,lutrgb=a="maxval-minval/2"
+@item
+Apply @code{C* Eq10X2 - Stereo 10-band equaliser} effect:
+@example
+ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
+@end example
-# Correct luminance gamma by a factor of 0.5
-lutyuv=y=gammaval(0.5)
+@item
+Increase volume by 20dB using fast lookahead limiter from Steve Harris
+@code{SWH Plugins} collection:
+@example
+ladspa=fast_lookahead_limiter_1913:fastLookaheadLimiter:20|0|2
@end example
-@section negate
+@item
+Attenuate low frequencies using Multiband EQ from Steve Harris
+@code{SWH Plugins} collection:
+@example
+ladspa=mbeq_1197:mbeq:-24|-24|-24|0|0|0|0|0|0|0|0|0|0|0|0
+@end example
+@end itemize
-Negate input video.
+@subsection Commands
-It accepts an integer in input; if non-zero it negates the
-alpha component (if available). The default value in input is 0.
+This filter supports the following commands:
+@table @option
+@item cN
+Modify the @var{N}-th control value.
-@section noformat
+If the specified value is not valid, it is ignored and prior one is kept.
+@end table
-Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
+@section lowpass
+
+Apply a low-pass filter with 3dB point frequency.
+The filter can be either single-pole or double-pole (the default).
+The filter roll off at 6dB per pole per octave (20dB per pole per decade).
+
+The filter accepts the following options:
-It accepts the following parameters:
@table @option
+@item frequency, f
+Set frequency in Hz. Default is 500.
-@item pix_fmts
-A '|'-separated list of pixel format names, such as
-apix_fmts=yuv420p|monow|rgb24".
+@item poles, p
+Set number of poles. Default is 2.
+@item width_type
+Set method to specify band-width of filter.
+@table @option
+@item h
+Hz
+@item q
+Q-Factor
+@item o
+octave
+@item s
+slope
@end table
-Some examples:
-@example
-# Force libavfilter to use a format different from "yuv420p" for the
-# input to the vflip filter
-noformat=pix_fmts=yuv420p,vflip
+@item width, w
+Specify the band-width of a filter in width_type units.
+Applies only to double-pole filter.
+The default is 0.707q and gives a Butterworth response.
+@end table
-# Convert the input video to any of the formats not contained in the list
-noformat=yuv420p|yuv444p|yuv410p
-@end example
+@anchor{pan}
+@section pan
-@section null
+Mix channels with specific gain levels. The filter accepts the output
+channel layout followed by a set of channels definitions.
-Pass the video source unchanged to the output.
+This filter is also designed to efficiently remap the channels of an audio
+stream.
-@section ocv
+The filter accepts parameters of the form:
+"@var{l}|@var{outdef}|@var{outdef}|..."
-Apply a video transform using libopencv.
+@table @option
+@item l
+output channel layout or number of channels
-To enable this filter, install the libopencv library and headers and
-configure Libav with --enable-libopencv.
+@item outdef
+output channel specification, of the form:
+"@var{out_name}=[@var{gain}*]@var{in_name}[+[@var{gain}*]@var{in_name}...]"
-It accepts the following parameters:
+@item out_name
+output channel to define, either a channel name (FL, FR, etc.) or a channel
+number (c0, c1, etc.)
-@table @option
-
-@item filter_name
-The name of the libopencv filter to apply.
-
-@item filter_params
-The parameters to pass to the libopencv filter. If not specified, the default
-values are assumed.
+@item gain
+multiplicative coefficient for the channel, 1 leaving the volume unchanged
+@item in_name
+input channel to use, see out_name for details; it is not possible to mix
+named and numbered input channels
@end table
-Refer to the official libopencv documentation for more precise
-information:
-@url{http://opencv.willowgarage.com/documentation/c/image_filtering.html}
+If the `=' in a channel specification is replaced by `<', then the gains for
+that specification will be renormalized so that the total is 1, thus
+avoiding clipping noise.
-Several libopencv filters are supported; see the following subsections.
+@subsection Mixing examples
-@anchor{dilate}
-@subsection dilate
+For example, if you want to down-mix from stereo to mono, but with a bigger
+factor for the left channel:
+@example
+pan=1c|c0=0.9*c0+0.1*c1
+@end example
-Dilate an image by using a specific structuring element.
-It corresponds to the libopencv function @code{cvDilate}.
+A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
+7-channels surround:
+@example
+pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
+@end example
-It accepts the parameters: @var{struct_el}|@var{nb_iterations}.
+Note that @command{ffmpeg} integrates a default down-mix (and up-mix) system
+that should be preferred (see "-ac" option) unless you have very specific
+needs.
-@var{struct_el} represents a structuring element, and has the syntax:
-@var{cols}x@var{rows}+@var{anchor_x}x@var{anchor_y}/@var{shape}
+@subsection Remapping examples
-@var{cols} and @var{rows} represent the number of columns and rows of
-the structuring element, @var{anchor_x} and @var{anchor_y} the anchor
-point, and @var{shape} the shape for the structuring element. @var{shape}
-must be "rect", "cross", "ellipse", or "custom".
+The channel remapping will be effective if, and only if:
-If the value for @var{shape} is "custom", it must be followed by a
-string of the form "=@var{filename}". The file with name
-@var{filename} is assumed to represent a binary image, with each
-printable character corresponding to a bright pixel. When a custom
-@var{shape} is used, @var{cols} and @var{rows} are ignored, the number
-or columns and rows of the read file are assumed instead.
+@itemize
+@item gain coefficients are zeroes or ones,
+@item only one input per channel output,
+@end itemize
-The default value for @var{struct_el} is "3x3+0x0/rect".
+If all these conditions are satisfied, the filter will notify the user ("Pure
+channel mapping detected"), and use an optimized and lossless method to do the
+remapping.
-@var{nb_iterations} specifies the number of times the transform is
-applied to the image, and defaults to 1.
+For example, if you have a 5.1 source and want a stereo audio stream by
+dropping the extra channels:
+@example
+pan="stereo| c0=FL | c1=FR"
+@end example
-Some examples:
+Given the same source, you can also switch front left and front right channels
+and keep the input channel layout:
@example
-# Use the default values
-ocv=dilate
+pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
+@end example
-# Dilate using a structuring element with a 5x5 cross, iterating two times
-ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
+If the input is a stereo audio stream, you can mute the front left channel (and
+still keep the stereo channel layout) with:
+@example
+pan="stereo|c1=c1"
+@end example
-# Read the shape from the file diamond.shape, iterating two times.
-# The file diamond.shape may contain a pattern of characters like this
-# *
-# ***
-# *****
-# ***
-# *
-# The specified columns and rows are ignored
-# but the anchor point coordinates are not
-ocv=dilate:0x0+2x2/custom=diamond.shape|2
+Still with a stereo audio stream input, you can copy the right channel in both
+front left and right:
+@example
+pan="stereo| c0=FR | c1=FR"
@end example
-@subsection erode
+@section replaygain
-Erode an image by using a specific structuring element.
-It corresponds to the libopencv function @code{cvErode}.
+ReplayGain scanner filter. This filter takes an audio stream as an input and
+outputs it unchanged.
+At end of filtering it displays @code{track_gain} and @code{track_peak}.
-It accepts the parameters: @var{struct_el}:@var{nb_iterations},
-with the same syntax and semantics as the @ref{dilate} filter.
+@section resample
-@subsection smooth
+Convert the audio sample format, sample rate and channel layout. It is
+not meant to be used directly.
-Smooth the input video.
+@section rubberband
+Apply time-stretching and pitch-shifting with librubberband.
-The filter takes the following parameters:
-@var{type}|@var{param1}|@var{param2}|@var{param3}|@var{param4}.
+The filter accepts the following options:
-@var{type} is the type of smooth filter to apply, and must be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-or "bilateral". The default value is "gaussian".
+@table @option
+@item tempo
+Set tempo scale factor.
-The meaning of @var{param1}, @var{param2}, @var{param3}, and @var{param4}
-depend on the smooth type. @var{param1} and
-@var{param2} accept integer positive values or 0. @var{param3} and
-@var{param4} accept floating point values.
+@item pitch
+Set pitch scale factor.
-The default value for @var{param1} is 3. The default value for the
-other parameters is 0.
+@item transients
+Set transients detector.
+Possible values are:
+@table @var
+@item crisp
+@item mixed
+@item smooth
+@end table
-These parameters correspond to the parameters assigned to the
-libopencv function @code{cvSmooth}.
+@item detector
+Set detector.
+Possible values are:
+@table @var
+@item compound
+@item percussive
+@item soft
+@end table
-@anchor{overlay}
-@section overlay
+@item phase
+Set phase.
+Possible values are:
+@table @var
+@item laminar
+@item independent
+@end table
-Overlay one video on top of another.
+@item window
+Set processing window size.
+Possible values are:
+@table @var
+@item standard
+@item short
+@item long
+@end table
-It takes two inputs and has one output. The first input is the "main"
-video on which the second input is overlayed.
+@item smoothing
+Set smoothing.
+Possible values are:
+@table @var
+@item off
+@item on
+@end table
-It accepts the following parameters:
+@item formant
+Enable formant preservation when shift pitching.
+Possible values are:
+@table @var
+@item shifted
+@item preserved
+@end table
-@table @option
+@item pitchq
+Set pitch quality.
+Possible values are:
+@table @var
+@item quality
+@item speed
+@item consistency
+@end table
-@item x
-The horizontal position of the left edge of the overlaid video on the main video.
+@item channels
+Set channels.
+Possible values are:
+@table @var
+@item apart
+@item together
+@end table
+@end table
-@item y
-The vertical position of the top edge of the overlaid video on the main video.
+@section sidechaincompress
-@end table
+This filter acts like normal compressor but has the ability to compress
+detected signal using second input signal.
+It needs two input streams and returns one output stream.
+First input stream will be processed depending on second stream signal.
+The filtered signal then can be filtered with other filters in later stages of
+processing. See @ref{pan} and @ref{amerge} filter.
-The parameters are expressions containing the following parameters:
+The filter accepts the following options:
@table @option
-@item main_w, main_h
-The main input width and height.
+@item level_in
+Set input gain. Default is 1. Range is between 0.015625 and 64.
-@item W, H
-These are the same as @var{main_w} and @var{main_h}.
+@item threshold
+If a signal of second stream raises above this level it will affect the gain
+reduction of first stream.
+By default is 0.125. Range is between 0.00097563 and 1.
+
+@item ratio
+Set a ratio about which the signal is reduced. 1:2 means that if the level
+raised 4dB above the threshold, it will be only 2dB above after the reduction.
+Default is 2. Range is between 1 and 20.
+
+@item attack
+Amount of milliseconds the signal has to rise above the threshold before gain
+reduction starts. Default is 20. Range is between 0.01 and 2000.
+
+@item release
+Amount of milliseconds the signal has to fall below the threshold before
+reduction is decreased again. Default is 250. Range is between 0.01 and 9000.
+
+@item makeup
+Set the amount by how much signal will be amplified after processing.
+Default is 2. Range is from 1 and 64.
+
+@item knee
+Curve the sharp knee around the threshold to enter gain reduction more softly.
+Default is 2.82843. Range is between 1 and 8.
+
+@item link
+Choose if the @code{average} level between all channels of side-chain stream
+or the louder(@code{maximum}) channel of side-chain stream affects the
+reduction. Default is @code{average}.
+
+@item detection
+Should the exact signal be taken in case of @code{peak} or an RMS one in case
+of @code{rms}. Default is @code{rms} which is mainly smoother.
+
+@item level_sc
+Set sidechain gain. Default is 1. Range is between 0.015625 and 64.
+
+@item mix
+How much to use compressed signal in output. Default is 1.
+Range is between 0 and 1.
+@end table
-@item overlay_w, overlay_h
-The overlay input width and height.
+@subsection Examples
-@item w, h
-These are the same as @var{overlay_w} and @var{overlay_h}.
+@itemize
+@item
+Full ffmpeg example taking 2 audio inputs, 1st input to be compressed
+depending on the signal of 2nd input and later compressed signal to be
+merged with 2nd input:
+@example
+ffmpeg -i main.flac -i sidechain.flac -filter_complex "[1:a]asplit=2[sc][mix];[0:a][sc]sidechaincompress[compr];[compr][mix]amerge"
+@end example
+@end itemize
-@item eof_action
-The action to take when EOF is encountered on the secondary input; it accepts
-one of the following values:
+@section sidechaingate
+
+A sidechain gate acts like a normal (wideband) gate but has the ability to
+filter the detected signal before sending it to the gain reduction stage.
+Normally a gate uses the full range signal to detect a level above the
+threshold.
+For example: If you cut all lower frequencies from your sidechain signal
+the gate will decrease the volume of your track only if not enough highs
+appear. With this technique you are able to reduce the resonation of a
+natural drum or remove "rumbling" of muted strokes from a heavily distorted
+guitar.
+It needs two input streams and returns one output stream.
+First input stream will be processed depending on second stream signal.
+
+The filter accepts the following options:
@table @option
-@item repeat
-Repeat the last frame (the default).
-@item endall
-End both streams.
-@item pass
-Pass the main input through.
-@end table
+@item level_in
+Set input level before filtering.
+Default is 1. Allowed range is from 0.015625 to 64.
+
+@item range
+Set the level of gain reduction when the signal is below the threshold.
+Default is 0.06125. Allowed range is from 0 to 1.
+@item threshold
+If a signal rises above this level the gain reduction is released.
+Default is 0.125. Allowed range is from 0 to 1.
+
+@item ratio
+Set a ratio about which the signal is reduced.
+Default is 2. Allowed range is from 1 to 9000.
+
+@item attack
+Amount of milliseconds the signal has to rise above the threshold before gain
+reduction stops.
+Default is 20 milliseconds. Allowed range is from 0.01 to 9000.
+
+@item release
+Amount of milliseconds the signal has to fall below the threshold before the
+reduction is increased again. Default is 250 milliseconds.
+Allowed range is from 0.01 to 9000.
+
+@item makeup
+Set amount of amplification of signal after processing.
+Default is 1. Allowed range is from 1 to 64.
+
+@item knee
+Curve the sharp knee around the threshold to enter gain reduction more softly.
+Default is 2.828427125. Allowed range is from 1 to 8.
+
+@item detection
+Choose if exact signal should be taken for detection or an RMS like one.
+Default is rms. Can be peak or rms.
+
+@item link
+Choose if the average level between all channels or the louder channel affects
+the reduction.
+Default is average. Can be average or maximum.
+
+@item level_sc
+Set sidechain gain. Default is 1. Range is from 0.015625 to 64.
@end table
-Be aware that frames are taken from each input video in timestamp
-order, hence, if their initial timestamps differ, it is a a good idea
-to pass the two inputs through a @var{setpts=PTS-STARTPTS} filter to
-have them begin in the same zero timestamp, as the example for
-the @var{movie} filter does.
+@section silencedetect
-Some examples:
-@example
-# Draw the overlay at 10 pixels from the bottom right
-# corner of the main video
-overlay=x=main_w-overlay_w-10:y=main_h-overlay_h-10
+Detect silence in an audio stream.
-# Insert a transparent PNG logo in the bottom left corner of the input
-avconv -i input -i logo -filter_complex 'overlay=x=10:y=main_h-overlay_h-10' output
+This filter logs a message when it detects that the input audio volume is less
+or equal to a noise tolerance value for a duration greater or equal to the
+minimum detected noise duration.
-# Insert 2 different transparent PNG logos (second logo on bottom
-# right corner)
-avconv -i input -i logo1 -i logo2 -filter_complex
-'overlay=x=10:y=H-h-10,overlay=x=W-w-10:y=H-h-10' output
+The printed times and duration are expressed in seconds.
-# Add a transparent color layer on top of the main video;
-# WxH specifies the size of the main input to the overlay filter
-color=red@.3:WxH [over]; [in][over] overlay [out]
+The filter accepts the following options:
-# Mask 10-20 seconds of a video by applying the delogo filter to a section
-avconv -i test.avi -codec:v:0 wmv2 -ar 11025 -b:v 9000k
--vf '[in]split[split_main][split_delogo];[split_delogo]trim=start=360:end=371,delogo=0:0:640:480[delogoed];[split_main][delogoed]overlay=eof_action=pass[out]'
-masked.avi
+@table @option
+@item duration, d
+Set silence duration until notification (default is 2 seconds).
+
+@item noise, n
+Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
+specified value) or amplitude ratio. Default is -60dB, or 0.001.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Detect 5 seconds of silence with -50dB noise tolerance:
+@example
+silencedetect=n=-50dB:d=5
@end example
-You can chain together more overlays but the efficiency of such
-approach is yet to be tested.
+@item
+Complete example with @command{ffmpeg} to detect silence with 0.0001 noise
+tolerance in @file{silence.mp3}:
+@example
+ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
+@end example
+@end itemize
-@section pad
+@section silenceremove
-Add paddings to the input image, and place the original input at the
-provided @var{x}, @var{y} coordinates.
+Remove silence from the beginning, middle or end of the audio.
-It accepts the following parameters:
+The filter accepts the following options:
@table @option
-@item width, height
+@item start_periods
+This value is used to indicate if audio should be trimmed at beginning of
+the audio. A value of zero indicates no silence should be trimmed from the
+beginning. When specifying a non-zero value, it trims audio up until it
+finds non-silence. Normally, when trimming silence from beginning of audio
+the @var{start_periods} will be @code{1} but it can be increased to higher
+values to trim all audio up to specific count of non-silence periods.
+Default value is @code{0}.
+
+@item start_duration
+Specify the amount of time that non-silence must be detected before it stops
+trimming audio. By increasing the duration, bursts of noises can be treated
+as silence and trimmed off. Default value is @code{0}.
+
+@item start_threshold
+This indicates what sample value should be treated as silence. For digital
+audio, a value of @code{0} may be fine but for audio recorded from analog,
+you may wish to increase the value to account for background noise.
+Can be specified in dB (in case "dB" is appended to the specified value)
+or amplitude ratio. Default value is @code{0}.
+
+@item stop_periods
+Set the count for trimming silence from the end of audio.
+To remove silence from the middle of a file, specify a @var{stop_periods}
+that is negative. This value is then treated as a positive value and is
+used to indicate the effect should restart processing as specified by
+@var{start_periods}, making it suitable for removing periods of silence
+in the middle of the audio.
+Default value is @code{0}.
+
+@item stop_duration
+Specify a duration of silence that must exist before audio is not copied any
+more. By specifying a higher duration, silence that is wanted can be left in
+the audio.
+Default value is @code{0}.
+
+@item stop_threshold
+This is the same as @option{start_threshold} but for trimming silence from
+the end of audio.
+Can be specified in dB (in case "dB" is appended to the specified value)
+or amplitude ratio. Default value is @code{0}.
+
+@item leave_silence
+This indicate that @var{stop_duration} length of audio should be left intact
+at the beginning of each period of silence.
+For example, if you want to remove long pauses between words but do not want
+to remove the pauses completely. Default value is @code{0}.
+
+@item detection
+Set how is silence detected. Can be @code{rms} or @code{peak}. Second is faster
+and works better with digital silence which is exactly 0.
+Default value is @code{rms}.
+
+@item window
+Set ratio used to calculate size of window for detecting silence.
+Default value is @code{0.02}. Allowed range is from @code{0} to @code{10}.
+@end table
-Specify the size of the output image with the paddings added. If the
-value for @var{width} or @var{height} is 0, the corresponding input size
-is used for the output.
+@subsection Examples
-The @var{width} expression can reference the value set by the
-@var{height} expression, and vice versa.
+@itemize
+@item
+The following example shows how this filter can be used to start a recording
+that does not contain the delay at the start which usually occurs between
+pressing the record button and the start of the performance:
+@example
+silenceremove=1:5:0.02
+@end example
-The default value of @var{width} and @var{height} is 0.
+@item
+Trim all silence encountered from begining to end where there is more than 1
+second of silence in audio:
+@example
+silenceremove=0:0:0:-1:1:-90dB
+@end example
+@end itemize
-@item x, y
+@section sofalizer
-Specify the offsets to place the input image at within the padded area,
-with respect to the top/left border of the output image.
+SOFAlizer uses head-related transfer functions (HRTFs) to create virtual
+loudspeakers around the user for binaural listening via headphones (audio
+formats up to 9 channels supported).
+The HRTFs are stored in SOFA files (see @url{http://www.sofacoustics.org/} for a database).
+SOFAlizer is developed at the Acoustics Research Institute (ARI) of the
+Austrian Academy of Sciences.
-The @var{x} expression can reference the value set by the @var{y}
-expression, and vice versa.
+To enable compilation of this filter you need to configure FFmpeg with
+@code{--enable-netcdf}.
-The default value of @var{x} and @var{y} is 0.
+The filter accepts the following options:
-@item color
+@table @option
+@item sofa
+Set the SOFA file used for rendering.
+
+@item gain
+Set gain applied to audio. Value is in dB. Default is 0.
-Specify the color of the padded area. It can be the name of a color
-(case insensitive match) or an 0xRRGGBB[AA] sequence.
+@item rotation
+Set rotation of virtual loudspeakers in deg. Default is 0.
-The default value of @var{color} is "black".
+@item elevation
+Set elevation of virtual speakers in deg. Default is 0.
+
+@item radius
+Set distance in meters between loudspeakers and the listener with near-field
+HRTFs. Default is 1.
+@item type
+Set processing type. Can be @var{time} or @var{freq}. @var{time} is
+processing audio in time domain which is slow but gives high quality output.
+@var{freq} is processing audio in frequency domain which is fast but gives
+mediocre output. Default is @var{freq}.
@end table
-The parameters @var{width}, @var{height}, @var{x}, and @var{y} are
-expressions containing the following constants:
+@section stereotools
+
+This filter has some handy utilities to manage stereo signals, for converting
+M/S stereo recordings to L/R signal while having control over the parameters
+or spreading the stereo image of master track.
+
+The filter accepts the following options:
@table @option
-@item E, PI, PHI
-These are approximated values for the mathematical constants e
-(Euler's number), pi (Greek pi), and phi (the golden ratio).
+@item level_in
+Set input level before filtering for both channels. Defaults is 1.
+Allowed range is from 0.015625 to 64.
-@item in_w, in_h
-The input video width and height.
+@item level_out
+Set output level after filtering for both channels. Defaults is 1.
+Allowed range is from 0.015625 to 64.
-@item iw, ih
-These are the same as @var{in_w} and @var{in_h}.
+@item balance_in
+Set input balance between both channels. Default is 0.
+Allowed range is from -1 to 1.
-@item out_w, out_h
-The output width and height (the size of the padded area), as
-specified by the @var{width} and @var{height} expressions.
+@item balance_out
+Set output balance between both channels. Default is 0.
+Allowed range is from -1 to 1.
-@item ow, oh
-These are the same as @var{out_w} and @var{out_h}.
+@item softclip
+Enable softclipping. Results in analog distortion instead of harsh digital 0dB
+clipping. Disabled by default.
-@item x, y
-The x and y offsets as specified by the @var{x} and @var{y}
-expressions, or NAN if not yet specified.
+@item mutel
+Mute the left channel. Disabled by default.
-@item a
-The input display aspect ratio, same as @var{iw} / @var{ih}.
+@item muter
+Mute the right channel. Disabled by default.
-@item hsub, vsub
-The horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
-@end table
+@item phasel
+Change the phase of the left channel. Disabled by default.
-Some examples:
+@item phaser
+Change the phase of the right channel. Disabled by default.
-@example
-# Add paddings with the color "violet" to the input video. The output video
-# size is 640x480, and the top-left corner of the input video is placed at
-# column 0, row 40
-pad=width=640:height=480:x=0:y=40:color=violet
+@item mode
+Set stereo mode. Available values are:
-# Pad the input to get an output with dimensions increased by 3/2,
-# and put the input video at the center of the padded area
-pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"
+@table @samp
+@item lr>lr
+Left/Right to Left/Right, this is default.
-# Pad the input to get a squared output with size equal to the maximum
-# value between the input width and height, and put the input video at
-# the center of the padded area
-pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"
+@item lr>ms
+Left/Right to Mid/Side.
-# Pad the input to get a final w/h ratio of 16:9
-pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
+@item ms>lr
+Mid/Side to Left/Right.
-# Double the output size and put the input video in the bottom-right
-# corner of the output padded area
-pad="2*iw:2*ih:ow-iw:oh-ih"
-@end example
+@item lr>ll
+Left/Right to Left/Left.
-@section pixdesctest
+@item lr>rr
+Left/Right to Right/Right.
-Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
+@item lr>l+r
+Left/Right to Left + Right.
-For example:
-@example
-format=monow, pixdesctest
-@end example
+@item lr>rl
+Left/Right to Right/Left.
+@end table
-can be used to test the monowhite pixel format descriptor definition.
+@item slev
+Set level of side signal. Default is 1.
+Allowed range is from 0.015625 to 64.
-@anchor{scale}
-@section scale
+@item sbal
+Set balance of side signal. Default is 0.
+Allowed range is from -1 to 1.
-Scale the input video and/or convert the image format.
+@item mlev
+Set level of the middle signal. Default is 1.
+Allowed range is from 0.015625 to 64.
-It accepts the following parameters:
+@item mpan
+Set middle signal pan. Default is 0. Allowed range is from -1 to 1.
-@table @option
+@item base
+Set stereo base between mono and inversed channels. Default is 0.
+Allowed range is from -1 to 1.
-@item w
-The output video width.
+@item delay
+Set delay in milliseconds how much to delay left from right channel and
+vice versa. Default is 0. Allowed range is from -20 to 20.
-@item h
-The output video height.
+@item sclevel
+Set S/C level. Default is 1. Allowed range is from 1 to 100.
+@item phase
+Set the stereo phase in degrees. Default is 0. Allowed range is from 0 to 360.
@end table
-The parameters @var{w} and @var{h} are expressions containing
-the following constants:
+@section stereowiden
+
+This filter enhance the stereo effect by suppressing signal common to both
+channels and by delaying the signal of left into right and vice versa,
+thereby widening the stereo effect.
+
+The filter accepts the following options:
@table @option
-@item E, PI, PHI
-These are approximated values for the mathematical constants e
-(Euler's number), pi (Greek pi), and phi (the golden ratio).
+@item delay
+Time in milliseconds of the delay of left signal into right and vice versa.
+Default is 20 milliseconds.
-@item in_w, in_h
-The input width and height.
+@item feedback
+Amount of gain in delayed signal into right and vice versa. Gives a delay
+effect of left signal in right output and vice versa which gives widening
+effect. Default is 0.3.
-@item iw, ih
-These are the same as @var{in_w} and @var{in_h}.
+@item crossfeed
+Cross feed of left into right with inverted phase. This helps in suppressing
+the mono. If the value is 1 it will cancel all the signal common to both
+channels. Default is 0.3.
-@item out_w, out_h
-The output (cropped) width and height.
+@item drymix
+Set level of input signal of original channel. Default is 0.8.
+@end table
-@item ow, oh
-These are the same as @var{out_w} and @var{out_h}.
+@section treble
-@item a
-This is the same as @var{iw} / @var{ih}.
+Boost or cut treble (upper) frequencies of the audio using a two-pole
+shelving filter with a response similar to that of a standard
+hi-fi's tone-controls. This is also known as shelving equalisation (EQ).
-@item sar
-input sample aspect ratio
+The filter accepts the following options:
-@item dar
-The input display aspect ratio; it is the same as
-(@var{iw} / @var{ih}) * @var{sar}.
+@table @option
+@item gain, g
+Give the gain at whichever is the lower of ~22 kHz and the
+Nyquist frequency. Its useful range is about -20 (for a large cut)
+to +20 (for a large boost). Beware of clipping when using a positive gain.
+
+@item frequency, f
+Set the filter's central frequency and so can be used
+to extend or reduce the frequency range to be boosted or cut.
+The default value is @code{3000} Hz.
+
+@item width_type
+Set method to specify band-width of filter.
+@table @option
+@item h
+Hz
+@item q
+Q-Factor
+@item o
+octave
+@item s
+slope
+@end table
-@item hsub, vsub
-The horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+@item width, w
+Determine how steep is the filter's shelf transition.
@end table
-If the input image format is different from the format requested by
-the next filter, the scale filter will convert the input to the
-requested format.
+@section tremolo
-If the value for @var{w} or @var{h} is 0, the respective input
-size is used for the output.
+Sinusoidal amplitude modulation.
-If the value for @var{w} or @var{h} is -1, the scale filter will use, for the
-respective output size, a value that maintains the aspect ratio of the input
+The filter accepts the following options:
+
+@table @option
+@item f
+Modulation frequency in Hertz. Modulation frequencies in the subharmonic range
+(20 Hz or lower) will result in a tremolo effect.
+This filter may also be used as a ring modulator by specifying
+a modulation frequency higher than 20 Hz.
+Range is 0.1 - 20000.0. Default value is 5.0 Hz.
+
+@item d
+Depth of modulation as a percentage. Range is 0.0 - 1.0.
+Default value is 0.5.
+@end table
+
+@section vibrato
+
+Sinusoidal phase modulation.
+
+The filter accepts the following options:
+
+@table @option
+@item f
+Modulation frequency in Hertz.
+Range is 0.1 - 20000.0. Default value is 5.0 Hz.
+
+@item d
+Depth of modulation as a percentage. Range is 0.0 - 1.0.
+Default value is 0.5.
+@end table
+
+@section volume
+
+Adjust the input audio volume.
+
+It accepts the following parameters:
+@table @option
+
+@item volume
+Set audio volume expression.
+
+Output values are clipped to the maximum value.
+
+The output audio volume is given by the relation:
+@example
+@var{output_volume} = @var{volume} * @var{input_volume}
+@end example
+
+The default value for @var{volume} is "1.0".
+
+@item precision
+This parameter represents the mathematical precision.
+
+It determines which input sample formats will be allowed, which affects the
+precision of the volume scaling.
+
+@table @option
+@item fixed
+8-bit fixed-point; this limits input sample format to U8, S16, and S32.
+@item float
+32-bit floating-point; this limits input sample format to FLT. (default)
+@item double
+64-bit floating-point; this limits input sample format to DBL.
+@end table
+
+@item replaygain
+Choose the behaviour on encountering ReplayGain side data in input frames.
+
+@table @option
+@item drop
+Remove ReplayGain side data, ignoring its contents (the default).
+
+@item ignore
+Ignore ReplayGain side data, but leave it in the frame.
+
+@item track
+Prefer the track gain, if present.
+
+@item album
+Prefer the album gain, if present.
+@end table
+
+@item replaygain_preamp
+Pre-amplification gain in dB to apply to the selected replaygain gain.
+
+Default value for @var{replaygain_preamp} is 0.0.
+
+@item eval
+Set when the volume expression is evaluated.
+
+It accepts the following values:
+@table @samp
+@item once
+only evaluate expression once during the filter initialization, or
+when the @samp{volume} command is sent
+
+@item frame
+evaluate expression for each incoming frame
+@end table
+
+Default value is @samp{once}.
+@end table
+
+The volume expression can contain the following parameters.
+
+@table @option
+@item n
+frame number (starting at zero)
+@item nb_channels
+number of channels
+@item nb_consumed_samples
+number of samples consumed by the filter
+@item nb_samples
+number of samples in the current frame
+@item pos
+original frame position in the file
+@item pts
+frame PTS
+@item sample_rate
+sample rate
+@item startpts
+PTS at start of stream
+@item startt
+time at start of stream
+@item t
+frame time
+@item tb
+timestamp timebase
+@item volume
+last set volume value
+@end table
+
+Note that when @option{eval} is set to @samp{once} only the
+@var{sample_rate} and @var{tb} variables are available, all other
+variables will evaluate to NAN.
+
+@subsection Commands
+
+This filter supports the following commands:
+@table @option
+@item volume
+Modify the volume expression.
+The command accepts the same syntax of the corresponding option.
+
+If the specified expression is not valid, it is kept at its current
+value.
+@item replaygain_noclip
+Prevent clipping by limiting the gain applied.
+
+Default value for @var{replaygain_noclip} is 1.
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Halve the input audio volume:
+@example
+volume=volume=0.5
+volume=volume=1/2
+volume=volume=-6.0206dB
+@end example
+
+In all the above example the named key for @option{volume} can be
+omitted, for example like in:
+@example
+volume=0.5
+@end example
+
+@item
+Increase input audio power by 6 decibels using fixed-point precision:
+@example
+volume=volume=6dB:precision=fixed
+@end example
+
+@item
+Fade volume after time 10 with an annihilation period of 5 seconds:
+@example
+volume='if(lt(t,10),1,max(1-(t-10)/5,0))':eval=frame
+@end example
+@end itemize
+
+@section volumedetect
+
+Detect the volume of the input video.
+
+The filter has no parameters. The input is not modified. Statistics about
+the volume will be printed in the log when the input stream end is reached.
+
+In particular it will show the mean volume (root mean square), maximum
+volume (on a per-sample basis), and the beginning of a histogram of the
+registered volume values (from the maximum value to a cumulated 1/1000 of
+the samples).
+
+All volumes are in decibels relative to the maximum PCM value.
+
+@subsection Examples
+
+Here is an excerpt of the output:
+@example
+[Parsed_volumedetect_0 @ 0xa23120] mean_volume: -27 dB
+[Parsed_volumedetect_0 @ 0xa23120] max_volume: -4 dB
+[Parsed_volumedetect_0 @ 0xa23120] histogram_4db: 6
+[Parsed_volumedetect_0 @ 0xa23120] histogram_5db: 62
+[Parsed_volumedetect_0 @ 0xa23120] histogram_6db: 286
+[Parsed_volumedetect_0 @ 0xa23120] histogram_7db: 1042
+[Parsed_volumedetect_0 @ 0xa23120] histogram_8db: 2551
+[Parsed_volumedetect_0 @ 0xa23120] histogram_9db: 4609
+[Parsed_volumedetect_0 @ 0xa23120] histogram_10db: 8409
+@end example
+
+It means that:
+@itemize
+@item
+The mean square energy is approximately -27 dB, or 10^-2.7.
+@item
+The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
+@item
+There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
+@end itemize
+
+In other words, raising the volume by +4 dB does not cause any clipping,
+raising it by +5 dB causes clipping for 6 samples, etc.
+
+@c man end AUDIO FILTERS
+
+@chapter Audio Sources
+@c man begin AUDIO SOURCES
+
+Below is a description of the currently available audio sources.
+
+@section abuffer
+
+Buffer audio frames, and make them available to the filter chain.
+
+This source is mainly intended for a programmatic use, in particular
+through the interface defined in @file{libavfilter/asrc_abuffer.h}.
+
+It accepts the following parameters:
+@table @option
+
+@item time_base
+The timebase which will be used for timestamps of submitted frames. It must be
+either a floating-point number or in @var{numerator}/@var{denominator} form.
+
+@item sample_rate
+The sample rate of the incoming audio buffers.
+
+@item sample_fmt
+The sample format of the incoming audio buffers.
+Either a sample format name or its corresponding integer representation from
+the enum AVSampleFormat in @file{libavutil/samplefmt.h}
+
+@item channel_layout
+The channel layout of the incoming audio buffers.
+Either a channel layout name from channel_layout_map in
+@file{libavutil/channel_layout.c} or its corresponding integer representation
+from the AV_CH_LAYOUT_* macros in @file{libavutil/channel_layout.h}
+
+@item channels
+The number of channels of the incoming audio buffers.
+If both @var{channels} and @var{channel_layout} are specified, then they
+must be consistent.
+
+@end table
+
+@subsection Examples
+
+@example
+abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
+@end example
+
+will instruct the source to accept planar 16bit signed stereo at 44100Hz.
+Since the sample format with name "s16p" corresponds to the number
+6 and the "stereo" channel layout corresponds to the value 0x3, this is
+equivalent to:
+@example
+abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
+@end example
+
+@section aevalsrc
+
+Generate an audio signal specified by an expression.
+
+This source accepts in input one or more expressions (one for each
+channel), which are evaluated and used to generate a corresponding
+audio signal.
+
+This source accepts the following options:
+
+@table @option
+@item exprs
+Set the '|'-separated expressions list for each separate channel. In case the
+@option{channel_layout} option is not specified, the selected channel layout
+depends on the number of provided expressions. Otherwise the last
+specified expression is applied to the remaining output channels.
+
+@item channel_layout, c
+Set the channel layout. The number of channels in the specified layout
+must be equal to the number of specified expressions.
+
+@item duration, d
+Set the minimum duration of the sourced audio. See
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
+Note that the resulting duration may be greater than the specified
+duration, as the generated audio is always cut at the end of a
+complete frame.
+
+If not specified, or the expressed duration is negative, the audio is
+supposed to be generated forever.
+
+@item nb_samples, n
+Set the number of samples per channel per each output frame,
+default to 1024.
+
+@item sample_rate, s
+Specify the sample rate, default to 44100.
+@end table
+
+Each expression in @var{exprs} can contain the following constants:
+
+@table @option
+@item n
+number of the evaluated sample, starting from 0
+
+@item t
+time of the evaluated sample expressed in seconds, starting from 0
+
+@item s
+sample rate
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Generate silence:
+@example
+aevalsrc=0
+@end example
+
+@item
+Generate a sin signal with frequency of 440 Hz, set sample rate to
+8000 Hz:
+@example
+aevalsrc="sin(440*2*PI*t):s=8000"
+@end example
+
+@item
+Generate a two channels signal, specify the channel layout (Front
+Center + Back Center) explicitly:
+@example
+aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
+@end example
+
+@item
+Generate white noise:
+@example
+aevalsrc="-2+random(0)"
+@end example
+
+@item
+Generate an amplitude modulated signal:
+@example
+aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
+@end example
+
+@item
+Generate 2.5 Hz binaural beats on a 360 Hz carrier:
+@example
+aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
+@end example
+
+@end itemize
+
+@section anullsrc
+
+The null audio source, return unprocessed audio frames. It is mainly useful
+as a template and to be employed in analysis / debugging tools, or as
+the source for filters which ignore the input data (for example the sox
+synth filter).
+
+This source accepts the following options:
+
+@table @option
+
+@item channel_layout, cl
+
+Specifies the channel layout, and can be either an integer or a string
+representing a channel layout. The default value of @var{channel_layout}
+is "stereo".
+
+Check the channel_layout_map definition in
+@file{libavutil/channel_layout.c} for the mapping between strings and
+channel layout values.
+
+@item sample_rate, r
+Specifies the sample rate, and defaults to 44100.
+
+@item nb_samples, n
+Set the number of samples per requested frames.
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
+@example
+anullsrc=r=48000:cl=4
+@end example
+
+@item
+Do the same operation with a more obvious syntax:
+@example
+anullsrc=r=48000:cl=mono
+@end example
+@end itemize
+
+All the parameters need to be explicitly defined.
+
+@section flite
+
+Synthesize a voice utterance using the libflite library.
+
+To enable compilation of this filter you need to configure FFmpeg with
+@code{--enable-libflite}.
+
+Note that the flite library is not thread-safe.
+
+The filter accepts the following options:
+
+@table @option
+
+@item list_voices
+If set to 1, list the names of the available voices and exit
+immediately. Default value is 0.
+
+@item nb_samples, n
+Set the maximum number of samples per frame. Default value is 512.
+
+@item textfile
+Set the filename containing the text to speak.
+
+@item text
+Set the text to speak.
+
+@item voice, v
+Set the voice to use for the speech synthesis. Default value is
+@code{kal}. See also the @var{list_voices} option.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Read from file @file{speech.txt}, and synthesize the text using the
+standard flite voice:
+@example
+flite=textfile=speech.txt
+@end example
+
+@item
+Read the specified text selecting the @code{slt} voice:
+@example
+flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
+@end example
+
+@item
+Input text to ffmpeg:
+@example
+ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
+@end example
+
+@item
+Make @file{ffplay} speak the specified text, using @code{flite} and
+the @code{lavfi} device:
+@example
+ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
+@end example
+@end itemize
+
+For more information about libflite, check:
+@url{http://www.speech.cs.cmu.edu/flite/}
+
+@section anoisesrc
+
+Generate a noise audio signal.
+
+The filter accepts the following options:
+
+@table @option
+@item sample_rate, r
+Specify the sample rate. Default value is 48000 Hz.
+
+@item amplitude, a
+Specify the amplitude (0.0 - 1.0) of the generated audio stream. Default value
+is 1.0.
+
+@item duration, d
+Specify the duration of the generated audio stream. Not specifying this option
+results in noise with an infinite length.
+
+@item color, colour, c
+Specify the color of noise. Available noise colors are white, pink, and brown.
+Default color is white.
+
+@item seed, s
+Specify a value used to seed the PRNG.
+
+@item nb_samples, n
+Set the number of samples per each output frame, default is 1024.
+@end table
+
+@subsection Examples
+
+@itemize
+
+@item
+Generate 60 seconds of pink noise, with a 44.1 kHz sampling rate and an amplitude of 0.5:
+@example
+anoisesrc=d=60:c=pink:r=44100:a=0.5
+@end example
+@end itemize
+
+@section sine
+
+Generate an audio signal made of a sine wave with amplitude 1/8.
+
+The audio signal is bit-exact.
+
+The filter accepts the following options:
+
+@table @option
+
+@item frequency, f
+Set the carrier frequency. Default is 440 Hz.
+
+@item beep_factor, b
+Enable a periodic beep every second with frequency @var{beep_factor} times
+the carrier frequency. Default is 0, meaning the beep is disabled.
+
+@item sample_rate, r
+Specify the sample rate, default is 44100.
+
+@item duration, d
+Specify the duration of the generated audio stream.
+
+@item samples_per_frame
+Set the number of samples per output frame.
+
+The expression can contain the following constants:
+
+@table @option
+@item n
+The (sequential) number of the output audio frame, starting from 0.
+
+@item pts
+The PTS (Presentation TimeStamp) of the output audio frame,
+expressed in @var{TB} units.
+
+@item t
+The PTS of the output audio frame, expressed in seconds.
+
+@item TB
+The timebase of the output audio frames.
+@end table
+
+Default is @code{1024}.
+@end table
+
+@subsection Examples
+
+@itemize
+
+@item
+Generate a simple 440 Hz sine wave:
+@example
+sine
+@end example
+
+@item
+Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
+@example
+sine=220:4:d=5
+sine=f=220:b=4:d=5
+sine=frequency=220:beep_factor=4:duration=5
+@end example
+
+@item
+Generate a 1 kHz sine wave following @code{1602,1601,1602,1601,1602} NTSC
+pattern:
+@example
+sine=1000:samples_per_frame='st(0,mod(n,5)); 1602-not(not(eq(ld(0),1)+eq(ld(0),3)))'
+@end example
+@end itemize
+
+@c man end AUDIO SOURCES
+
+@chapter Audio Sinks
+@c man begin AUDIO SINKS
+
+Below is a description of the currently available audio sinks.
+
+@section abuffersink
+
+Buffer audio frames, and make them available to the end of filter chain.
+
+This sink is mainly intended for programmatic use, in particular
+through the interface defined in @file{libavfilter/buffersink.h}
+or the options system.
+
+It accepts a pointer to an AVABufferSinkContext structure, which
+defines the incoming buffers' formats, to be passed as the opaque
+parameter to @code{avfilter_init_filter} for initialization.
+@section anullsink
+
+Null audio sink; do absolutely nothing with the input audio. It is
+mainly useful as a template and for use in analysis / debugging
+tools.
+
+@c man end AUDIO SINKS
+
+@chapter Video Filters
+@c man begin VIDEO FILTERS
+
+When you configure your FFmpeg build, you can disable any of the
+existing filters using @code{--disable-filters}.
+The configure output will show the video filters included in your
+build.
+
+Below is a description of the currently available video filters.
+
+@section alphaextract
+
+Extract the alpha component from the input as a grayscale video. This
+is especially useful with the @var{alphamerge} filter.
+
+@section alphamerge
+
+Add or replace the alpha component of the primary input with the
+grayscale value of a second input. This is intended for use with
+@var{alphaextract} to allow the transmission or storage of frame
+sequences that have alpha in a format that doesn't support an alpha
+channel.
+
+For example, to reconstruct full frames from a normal YUV-encoded video
+and a separate video created with @var{alphaextract}, you might use:
+@example
+movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
+@end example
+
+Since this filter is designed for reconstruction, it operates on frame
+sequences without considering timestamps, and terminates when either
+input reaches end of stream. This will cause problems if your encoding
+pipeline drops frames. If you're trying to apply an image as an
+overlay to a video stream, consider the @var{overlay} filter instead.
+
+@section ass
+
+Same as the @ref{subtitles} filter, except that it doesn't require libavcodec
+and libavformat to work. On the other hand, it is limited to ASS (Advanced
+Substation Alpha) subtitles files.
+
+This filter accepts the following option in addition to the common options from
+the @ref{subtitles} filter:
+
+@table @option
+@item shaping
+Set the shaping engine
+
+Available values are:
+@table @samp
+@item auto
+The default libass shaping engine, which is the best available.
+@item simple
+Fast, font-agnostic shaper that can do only substitutions
+@item complex
+Slower shaper using OpenType for substitutions and positioning
+@end table
+
+The default is @code{auto}.
+@end table
+
+@section atadenoise
+Apply an Adaptive Temporal Averaging Denoiser to the video input.
+
+The filter accepts the following options:
+
+@table @option
+@item 0a
+Set threshold A for 1st plane. Default is 0.02.
+Valid range is 0 to 0.3.
+
+@item 0b
+Set threshold B for 1st plane. Default is 0.04.
+Valid range is 0 to 5.
+
+@item 1a
+Set threshold A for 2nd plane. Default is 0.02.
+Valid range is 0 to 0.3.
+
+@item 1b
+Set threshold B for 2nd plane. Default is 0.04.
+Valid range is 0 to 5.
+
+@item 2a
+Set threshold A for 3rd plane. Default is 0.02.
+Valid range is 0 to 0.3.
+
+@item 2b
+Set threshold B for 3rd plane. Default is 0.04.
+Valid range is 0 to 5.
+
+Threshold A is designed to react on abrupt changes in the input signal and
+threshold B is designed to react on continuous changes in the input signal.
+
+@item s
+Set number of frames filter will use for averaging. Default is 33. Must be odd
+number in range [5, 129].
+@end table
+
+@section bbox
+
+Compute the bounding box for the non-black pixels in the input frame
+luminance plane.
+
+This filter computes the bounding box containing all the pixels with a
+luminance value greater than the minimum allowed value.
+The parameters describing the bounding box are printed on the filter
+log.
+
+The filter accepts the following option:
+
+@table @option
+@item min_val
+Set the minimal luminance value. Default is @code{16}.
+@end table
+
+@section blackdetect
+
+Detect video intervals that are (almost) completely black. Can be
+useful to detect chapter transitions, commercials, or invalid
+recordings. Output lines contains the time for the start, end and
+duration of the detected black interval expressed in seconds.
+
+In order to display the output lines, you need to set the loglevel at
+least to the AV_LOG_INFO value.
+
+The filter accepts the following options:
+
+@table @option
+@item black_min_duration, d
+Set the minimum detected black duration expressed in seconds. It must
+be a non-negative floating point number.
+
+Default value is 2.0.
+
+@item picture_black_ratio_th, pic_th
+Set the threshold for considering a picture "black".
+Express the minimum value for the ratio:
+@example
+@var{nb_black_pixels} / @var{nb_pixels}
+@end example
+
+for which a picture is considered black.
+Default value is 0.98.
+
+@item pixel_black_th, pix_th
+Set the threshold for considering a pixel "black".
+
+The threshold expresses the maximum pixel luminance value for which a
+pixel is considered "black". The provided value is scaled according to
+the following equation:
+@example
+@var{absolute_threshold} = @var{luminance_minimum_value} + @var{pixel_black_th} * @var{luminance_range_size}
+@end example
+
+@var{luminance_range_size} and @var{luminance_minimum_value} depend on
+the input video format, the range is [0-255] for YUV full-range
+formats and [16-235] for YUV non full-range formats.
+
+Default value is 0.10.
+@end table
+
+The following example sets the maximum pixel threshold to the minimum
+value, and detects only black intervals of 2 or more seconds:
+@example
+blackdetect=d=2:pix_th=0.00
+@end example
+
+@section blackframe
+
+Detect frames that are (almost) completely black. Can be useful to
+detect chapter transitions or commercials. Output lines consist of
+the frame number of the detected frame, the percentage of blackness,
+the position in the file if known or -1 and the timestamp in seconds.
+
+In order to display the output lines, you need to set the loglevel at
+least to the AV_LOG_INFO value.
+
+It accepts the following parameters:
+
+@table @option
+
+@item amount
+The percentage of the pixels that have to be below the threshold; it defaults to
+@code{98}.
+
+@item threshold, thresh
+The threshold below which a pixel value is considered black; it defaults to
+@code{32}.
+
+@end table
+
+@section blend, tblend
+
+Blend two video frames into each other.
+
+The @code{blend} filter takes two input streams and outputs one
+stream, the first input is the "top" layer and second input is
+"bottom" layer. Output terminates when shortest input terminates.
+
+The @code{tblend} (time blend) filter takes two consecutive frames
+from one single stream, and outputs the result obtained by blending
+the new frame on top of the old frame.
+
+A description of the accepted options follows.
+
+@table @option
+@item c0_mode
+@item c1_mode
+@item c2_mode
+@item c3_mode
+@item all_mode
+Set blend mode for specific pixel component or all pixel components in case
+of @var{all_mode}. Default value is @code{normal}.
+
+Available values for component modes are:
+@table @samp
+@item addition
+@item addition128
+@item and
+@item average
+@item burn
+@item darken
+@item difference
+@item difference128
+@item divide
+@item dodge
+@item exclusion
+@item glow
+@item hardlight
+@item hardmix
+@item lighten
+@item linearlight
+@item multiply
+@item multiply128
+@item negation
+@item normal
+@item or
+@item overlay
+@item phoenix
+@item pinlight
+@item reflect
+@item screen
+@item softlight
+@item subtract
+@item vividlight
+@item xor
+@end table
+
+@item c0_opacity
+@item c1_opacity
+@item c2_opacity
+@item c3_opacity
+@item all_opacity
+Set blend opacity for specific pixel component or all pixel components in case
+of @var{all_opacity}. Only used in combination with pixel component blend modes.
+
+@item c0_expr
+@item c1_expr
+@item c2_expr
+@item c3_expr
+@item all_expr
+Set blend expression for specific pixel component or all pixel components in case
+of @var{all_expr}. Note that related mode options will be ignored if those are set.
+
+The expressions can use the following variables:
+
+@table @option
+@item N
+The sequential number of the filtered frame, starting from @code{0}.
+
+@item X
+@item Y
+the coordinates of the current sample
+
+@item W
+@item H
+the width and height of currently filtered plane
+
+@item SW
+@item SH
+Width and height scale depending on the currently filtered plane. It is the
+ratio between the corresponding luma plane number of pixels and the current
+plane ones. E.g. for YUV4:2:0 the values are @code{1,1} for the luma plane, and
+@code{0.5,0.5} for chroma planes.
+
+@item T
+Time of the current frame, expressed in seconds.
+
+@item TOP, A
+Value of pixel component at current location for first video frame (top layer).
+
+@item BOTTOM, B
+Value of pixel component at current location for second video frame (bottom layer).
+@end table
+
+@item shortest
+Force termination when the shortest input terminates. Default is
+@code{0}. This option is only defined for the @code{blend} filter.
+
+@item repeatlast
+Continue applying the last bottom frame after the end of the stream. A value of
+@code{0} disable the filter after the last frame of the bottom layer is reached.
+Default is @code{1}. This option is only defined for the @code{blend} filter.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Apply transition from bottom layer to top layer in first 10 seconds:
+@example
+blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
+@end example
+
+@item
+Apply 1x1 checkerboard effect:
+@example
+blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
+@end example
+
+@item
+Apply uncover left effect:
+@example
+blend=all_expr='if(gte(N*SW+X,W),A,B)'
+@end example
+
+@item
+Apply uncover down effect:
+@example
+blend=all_expr='if(gte(Y-N*SH,0),A,B)'
+@end example
+
+@item
+Apply uncover up-left effect:
+@example
+blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
+@end example
+
+@item
+Split diagonally video and shows top and bottom layer on each side:
+@example
+blend=all_expr=if(gt(X,Y*(W/H)),A,B)
+@end example
+
+@item
+Display differences between the current and the previous frame:
+@example
+tblend=all_mode=difference128
+@end example
+@end itemize
+
+@section bwdif
+
+Deinterlace the input video ("bwdif" stands for "Bob Weaver
+Deinterlacing Filter").
+
+Motion adaptive deinterlacing based on yadif with the use of w3fdif and cubic
+interpolation algorithms.
+It accepts the following parameters:
+
+@table @option
+@item mode
+The interlacing mode to adopt. It accepts one of the following values:
+
+@table @option
+@item 0, send_frame
+Output one frame for each frame.
+@item 1, send_field
+Output one frame for each field.
+@end table
+
+The default value is @code{send_field}.
+
+@item parity
+The picture field parity assumed for the input interlaced video. It accepts one
+of the following values:
+
+@table @option
+@item 0, tff
+Assume the top field is first.
+@item 1, bff
+Assume the bottom field is first.
+@item -1, auto
+Enable automatic detection of field parity.
+@end table
+
+The default value is @code{auto}.
+If the interlacing is unknown or the decoder does not export this information,
+top field first will be assumed.
+
+@item deint
+Specify which frames to deinterlace. Accept one of the following
+values:
+
+@table @option
+@item 0, all
+Deinterlace all frames.
+@item 1, interlaced
+Only deinterlace frames marked as interlaced.
+@end table
+
+The default value is @code{all}.
+@end table
+
+@section boxblur
+
+Apply a boxblur algorithm to the input video.
+
+It accepts the following parameters:
+
+@table @option
+
+@item luma_radius, lr
+@item luma_power, lp
+@item chroma_radius, cr
+@item chroma_power, cp
+@item alpha_radius, ar
+@item alpha_power, ap
+
+@end table
+
+A description of the accepted options follows.
+
+@table @option
+@item luma_radius, lr
+@item chroma_radius, cr
+@item alpha_radius, ar
+Set an expression for the box radius in pixels used for blurring the
+corresponding input plane.
+
+The radius value must be a non-negative number, and must not be
+greater than the value of the expression @code{min(w,h)/2} for the
+luma and alpha planes, and of @code{min(cw,ch)/2} for the chroma
+planes.
+
+Default value for @option{luma_radius} is "2". If not specified,
+@option{chroma_radius} and @option{alpha_radius} default to the
+corresponding value set for @option{luma_radius}.
+
+The expressions can contain the following constants:
+@table @option
+@item w
+@item h
+The input width and height in pixels.
+
+@item cw
+@item ch
+The input chroma image width and height in pixels.
+
+@item hsub
+@item vsub
+The horizontal and vertical chroma subsample values. For example, for the
+pixel format "yuv422p", @var{hsub} is 2 and @var{vsub} is 1.
+@end table
+
+@item luma_power, lp
+@item chroma_power, cp
+@item alpha_power, ap
+Specify how many times the boxblur filter is applied to the
+corresponding plane.
+
+Default value for @option{luma_power} is 2. If not specified,
+@option{chroma_power} and @option{alpha_power} default to the
+corresponding value set for @option{luma_power}.
+
+A value of 0 will disable the effect.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Apply a boxblur filter with the luma, chroma, and alpha radii
+set to 2:
+@example
+boxblur=luma_radius=2:luma_power=1
+boxblur=2:1
+@end example
+
+@item
+Set the luma radius to 2, and alpha and chroma radius to 0:
+@example
+boxblur=2:1:cr=0:ar=0
+@end example
+
+@item
+Set the luma and chroma radii to a fraction of the video dimension:
+@example
+boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
+@end example
+@end itemize
+
+@section chromakey
+YUV colorspace color/chroma keying.
+
+The filter accepts the following options:
+
+@table @option
+@item color
+The color which will be replaced with transparency.
+
+@item similarity
+Similarity percentage with the key color.
+
+0.01 matches only the exact key color, while 1.0 matches everything.
+
+@item blend
+Blend percentage.
+
+0.0 makes pixels either fully transparent, or not transparent at all.
+
+Higher values result in semi-transparent pixels, with a higher transparency
+the more similar the pixels color is to the key color.
+
+@item yuv
+Signals that the color passed is already in YUV instead of RGB.
+
+Litteral colors like "green" or "red" don't make sense with this enabled anymore.
+This can be used to pass exact YUV values as hexadecimal numbers.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Make every green pixel in the input image transparent:
+@example
+ffmpeg -i input.png -vf chromakey=green out.png
+@end example
+
+@item
+Overlay a greenscreen-video on top of a static black background.
+@example
+ffmpeg -f lavfi -i color=c=black:s=1280x720 -i video.mp4 -shortest -filter_complex "[1:v]chromakey=0x70de77:0.1:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.mkv
+@end example
+@end itemize
+
+@section codecview
+
+Visualize information exported by some codecs.
+
+Some codecs can export information through frames using side-data or other
+means. For example, some MPEG based codecs export motion vectors through the
+@var{export_mvs} flag in the codec @option{flags2} option.
+
+The filter accepts the following option:
+
+@table @option
+@item mv
+Set motion vectors to visualize.
+
+Available flags for @var{mv} are:
+
+@table @samp
+@item pf
+forward predicted MVs of P-frames
+@item bf
+forward predicted MVs of B-frames
+@item bb
+backward predicted MVs of B-frames
+@end table
+
+@item qp
+Display quantization parameters using the chroma planes
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Visualizes multi-directionals MVs from P and B-Frames using @command{ffplay}:
+@example
+ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
+@end example
+@end itemize
+
+@section colorbalance
+Modify intensity of primary colors (red, green and blue) of input frames.
+
+The filter allows an input frame to be adjusted in the shadows, midtones or highlights
+regions for the red-cyan, green-magenta or blue-yellow balance.
+
+A positive adjustment value shifts the balance towards the primary color, a negative
+value towards the complementary color.
+
+The filter accepts the following options:
+
+@table @option
+@item rs
+@item gs
+@item bs
+Adjust red, green and blue shadows (darkest pixels).
+
+@item rm
+@item gm
+@item bm
+Adjust red, green and blue midtones (medium pixels).
+
+@item rh
+@item gh
+@item bh
+Adjust red, green and blue highlights (brightest pixels).
+
+Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{0}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Add red color cast to shadows:
+@example
+colorbalance=rs=.3
+@end example
+@end itemize
+
+@section colorkey
+RGB colorspace color keying.
+
+The filter accepts the following options:
+
+@table @option
+@item color
+The color which will be replaced with transparency.
+
+@item similarity
+Similarity percentage with the key color.
+
+0.01 matches only the exact key color, while 1.0 matches everything.
+
+@item blend
+Blend percentage.
+
+0.0 makes pixels either fully transparent, or not transparent at all.
+
+Higher values result in semi-transparent pixels, with a higher transparency
+the more similar the pixels color is to the key color.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Make every green pixel in the input image transparent:
+@example
+ffmpeg -i input.png -vf colorkey=green out.png
+@end example
+
+@item
+Overlay a greenscreen-video on top of a static background image.
+@example
+ffmpeg -i background.png -i video.mp4 -filter_complex "[1:v]colorkey=0x3BBD1E:0.3:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.flv
+@end example
+@end itemize
+
+@section colorlevels
+
+Adjust video input frames using levels.
+
+The filter accepts the following options:
+
+@table @option
+@item rimin
+@item gimin
+@item bimin
+@item aimin
+Adjust red, green, blue and alpha input black point.
+Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{0}.
+
+@item rimax
+@item gimax
+@item bimax
+@item aimax
+Adjust red, green, blue and alpha input white point.
+Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{1}.
+
+Input levels are used to lighten highlights (bright tones), darken shadows
+(dark tones), change the balance of bright and dark tones.
+
+@item romin
+@item gomin
+@item bomin
+@item aomin
+Adjust red, green, blue and alpha output black point.
+Allowed ranges for options are @code{[0, 1.0]}. Defaults are @code{0}.
+
+@item romax
+@item gomax
+@item bomax
+@item aomax
+Adjust red, green, blue and alpha output white point.
+Allowed ranges for options are @code{[0, 1.0]}. Defaults are @code{1}.
+
+Output levels allows manual selection of a constrained output level range.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Make video output darker:
+@example
+colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
+@end example
+
+@item
+Increase contrast:
+@example
+colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
+@end example
+
+@item
+Make video output lighter:
+@example
+colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
+@end example
+
+@item
+Increase brightness:
+@example
+colorlevels=romin=0.5:gomin=0.5:bomin=0.5
+@end example
+@end itemize
+
+@section colorchannelmixer
+
+Adjust video input frames by re-mixing color channels.
+
+This filter modifies a color channel by adding the values associated to
+the other channels of the same pixels. For example if the value to
+modify is red, the output value will be:
+@example
+@var{red}=@var{red}*@var{rr} + @var{blue}*@var{rb} + @var{green}*@var{rg} + @var{alpha}*@var{ra}
+@end example
+
+The filter accepts the following options:
+
+@table @option
+@item rr
+@item rg
+@item rb
+@item ra
+Adjust contribution of input red, green, blue and alpha channels for output red channel.
+Default is @code{1} for @var{rr}, and @code{0} for @var{rg}, @var{rb} and @var{ra}.
+
+@item gr
+@item gg
+@item gb
+@item ga
+Adjust contribution of input red, green, blue and alpha channels for output green channel.
+Default is @code{1} for @var{gg}, and @code{0} for @var{gr}, @var{gb} and @var{ga}.
+
+@item br
+@item bg
+@item bb
+@item ba
+Adjust contribution of input red, green, blue and alpha channels for output blue channel.
+Default is @code{1} for @var{bb}, and @code{0} for @var{br}, @var{bg} and @var{ba}.
+
+@item ar
+@item ag
+@item ab
+@item aa
+Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
+Default is @code{1} for @var{aa}, and @code{0} for @var{ar}, @var{ag} and @var{ab}.
+
+Allowed ranges for options are @code{[-2.0, 2.0]}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Convert source to grayscale:
+@example
+colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
+@end example
+@item
+Simulate sepia tones:
+@example
+colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
+@end example
+@end itemize
+
+@section colormatrix
+
+Convert color matrix.
+
+The filter accepts the following options:
+
+@table @option
+@item src
+@item dst
+Specify the source and destination color matrix. Both values must be
+specified.
+
+The accepted values are:
+@table @samp
+@item bt709
+BT.709
+
+@item bt601
+BT.601
+
+@item smpte240m
+SMPTE-240M
+
+@item fcc
+FCC
+@end table
+@end table
+
+For example to convert from BT.601 to SMPTE-240M, use the command:
+@example
+colormatrix=bt601:smpte240m
+@end example
+
+@section convolution
+
+Apply convolution 3x3 or 5x5 filter.
+
+The filter accepts the following options:
+
+@table @option
+@item 0m
+@item 1m
+@item 2m
+@item 3m
+Set matrix for each plane.
+Matrix is sequence of 9 or 25 signed integers.
+
+@item 0rdiv
+@item 1rdiv
+@item 2rdiv
+@item 3rdiv
+Set multiplier for calculated value for each plane.
+
+@item 0bias
+@item 1bias
+@item 2bias
+@item 3bias
+Set bias for each plane. This value is added to the result of the multiplication.
+Useful for making the overall image brighter or darker. Default is 0.0.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Apply sharpen:
+@example
+convolution="0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0"
+@end example
+
+@item
+Apply blur:
+@example
+convolution="1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1 1 1 1 1 1 1 1 1:1/9:1/9:1/9:1/9"
+@end example
+
+@item
+Apply edge enhance:
+@example
+convolution="0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:0 0 0 -1 1 0 0 0 0:5:1:1:1:0:128:128:128"
+@end example
+
+@item
+Apply edge detect:
+@example
+convolution="0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:0 1 0 1 -4 1 0 1 0:5:5:5:1:0:128:128:128"
+@end example
+
+@item
+Apply emboss:
+@example
+convolution="-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2:-2 -1 0 -1 1 1 0 1 2"
+@end example
+@end itemize
+
+@section copy
+
+Copy the input source unchanged to the output. This is mainly useful for
+testing purposes.
+
+@section crop
+
+Crop the input video to given dimensions.
+
+It accepts the following parameters:
+
+@table @option
+@item w, out_w
+The width of the output video. It defaults to @code{iw}.
+This expression is evaluated only once during the filter
+configuration, or when the @samp{w} or @samp{out_w} command is sent.
+
+@item h, out_h
+The height of the output video. It defaults to @code{ih}.
+This expression is evaluated only once during the filter
+configuration, or when the @samp{h} or @samp{out_h} command is sent.
+
+@item x
+The horizontal position, in the input video, of the left edge of the output
+video. It defaults to @code{(in_w-out_w)/2}.
+This expression is evaluated per-frame.
+
+@item y
+The vertical position, in the input video, of the top edge of the output video.
+It defaults to @code{(in_h-out_h)/2}.
+This expression is evaluated per-frame.
+
+@item keep_aspect
+If set to 1 will force the output display aspect ratio
+to be the same of the input, by changing the output sample aspect
+ratio. It defaults to 0.
+@end table
+
+The @var{out_w}, @var{out_h}, @var{x}, @var{y} parameters are
+expressions containing the following constants:
+
+@table @option
+@item x
+@item y
+The computed values for @var{x} and @var{y}. They are evaluated for
+each new frame.
+
+@item in_w
+@item in_h
+The input width and height.
+
+@item iw
+@item ih
+These are the same as @var{in_w} and @var{in_h}.
+
+@item out_w
+@item out_h
+The output (cropped) width and height.
+
+@item ow
+@item oh
+These are the same as @var{out_w} and @var{out_h}.
+
+@item a
+same as @var{iw} / @var{ih}
+
+@item sar
+input sample aspect ratio
+
+@item dar
+input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
+
+@item hsub
+@item vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
+@item n
+The number of the input frame, starting from 0.
+
+@item pos
+the position in the file of the input frame, NAN if unknown
+
+@item t
+The timestamp expressed in seconds. It's NAN if the input timestamp is unknown.
+
+@end table
+
+The expression for @var{out_w} may depend on the value of @var{out_h},
+and the expression for @var{out_h} may depend on @var{out_w}, but they
+cannot depend on @var{x} and @var{y}, as @var{x} and @var{y} are
+evaluated after @var{out_w} and @var{out_h}.
+
+The @var{x} and @var{y} parameters specify the expressions for the
+position of the top-left corner of the output (non-cropped) area. They
+are evaluated for each frame. If the evaluated value is not valid, it
+is approximated to the nearest valid value.
+
+The expression for @var{x} may depend on @var{y}, and the expression
+for @var{y} may depend on @var{x}.
+
+@subsection Examples
+
+@itemize
+@item
+Crop area with size 100x100 at position (12,34).
+@example
+crop=100:100:12:34
+@end example
+
+Using named options, the example above becomes:
+@example
+crop=w=100:h=100:x=12:y=34
+@end example
+
+@item
+Crop the central input area with size 100x100:
+@example
+crop=100:100
+@end example
+
+@item
+Crop the central input area with size 2/3 of the input video:
+@example
+crop=2/3*in_w:2/3*in_h
+@end example
+
+@item
+Crop the input video central square:
+@example
+crop=out_w=in_h
+crop=in_h
+@end example
+
+@item
+Delimit the rectangle with the top-left corner placed at position
+100:100 and the right-bottom corner corresponding to the right-bottom
+corner of the input image.
+@example
+crop=in_w-100:in_h-100:100:100
+@end example
+
+@item
+Crop 10 pixels from the left and right borders, and 20 pixels from
+the top and bottom borders
+@example
+crop=in_w-2*10:in_h-2*20
+@end example
+
+@item
+Keep only the bottom right quarter of the input image:
+@example
+crop=in_w/2:in_h/2:in_w/2:in_h/2
+@end example
+
+@item
+Crop height for getting Greek harmony:
+@example
+crop=in_w:1/PHI*in_w
+@end example
+
+@item
+Apply trembling effect:
+@example
+crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(n/10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(n/7)
+@end example
+
+@item
+Apply erratic camera effect depending on timestamp:
+@example
+crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)"
+@end example
+
+@item
+Set x depending on the value of y:
+@example
+crop=in_w/2:in_h/2:y:10+10*sin(n/10)
+@end example
+@end itemize
+
+@subsection Commands
+
+This filter supports the following commands:
+@table @option
+@item w, out_w
+@item h, out_h
+@item x
+@item y
+Set width/height of the output video and the horizontal/vertical position
+in the input video.
+The command accepts the same syntax of the corresponding option.
+
+If the specified expression is not valid, it is kept at its current
+value.
+@end table
+
+@section cropdetect
+
+Auto-detect the crop size.
+
+It calculates the necessary cropping parameters and prints the
+recommended parameters via the logging system. The detected dimensions
+correspond to the non-black area of the input video.
+
+It accepts the following parameters:
+
+@table @option
+
+@item limit
+Set higher black value threshold, which can be optionally specified
+from nothing (0) to everything (255 for 8bit based formats). An intensity
+value greater to the set value is considered non-black. It defaults to 24.
+You can also specify a value between 0.0 and 1.0 which will be scaled depending
+on the bitdepth of the pixel format.
+
+@item round
+The value which the width/height should be divisible by. It defaults to
+16. The offset is automatically adjusted to center the video. Use 2 to
+get only even dimensions (needed for 4:2:2 video). 16 is best when
+encoding to most video codecs.
+
+@item reset_count, reset
+Set the counter that determines after how many frames cropdetect will
+reset the previously detected largest video area and start over to
+detect the current optimal crop area. Default value is 0.
+
+This can be useful when channel logos distort the video area. 0
+indicates 'never reset', and returns the largest area encountered during
+playback.
+@end table
+
+@anchor{curves}
+@section curves
+
+Apply color adjustments using curves.
+
+This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
+component (red, green and blue) has its values defined by @var{N} key points
+tied from each other using a smooth curve. The x-axis represents the pixel
+values from the input frame, and the y-axis the new pixel values to be set for
+the output frame.
+
+By default, a component curve is defined by the two points @var{(0;0)} and
+@var{(1;1)}. This creates a straight line where each original pixel value is
+"adjusted" to its own value, which means no change to the image.
+
+The filter allows you to redefine these two points and add some more. A new
+curve (using a natural cubic spline interpolation) will be define to pass
+smoothly through all these new coordinates. The new defined points needs to be
+strictly increasing over the x-axis, and their @var{x} and @var{y} values must
+be in the @var{[0;1]} interval. If the computed curves happened to go outside
+the vector spaces, the values will be clipped accordingly.
+
+If there is no key point defined in @code{x=0}, the filter will automatically
+insert a @var{(0;0)} point. In the same way, if there is no key point defined
+in @code{x=1}, the filter will automatically insert a @var{(1;1)} point.
+
+The filter accepts the following options:
+
+@table @option
+@item preset
+Select one of the available color presets. This option can be used in addition
+to the @option{r}, @option{g}, @option{b} parameters; in this case, the later
+options takes priority on the preset values.
+Available presets are:
+@table @samp
+@item none
+@item color_negative
+@item cross_process
+@item darker
+@item increase_contrast
+@item lighter
+@item linear_contrast
+@item medium_contrast
+@item negative
+@item strong_contrast
+@item vintage
+@end table
+Default is @code{none}.
+@item master, m
+Set the master key points. These points will define a second pass mapping. It
+is sometimes called a "luminance" or "value" mapping. It can be used with
+@option{r}, @option{g}, @option{b} or @option{all} since it acts like a
+post-processing LUT.
+@item red, r
+Set the key points for the red component.
+@item green, g
+Set the key points for the green component.
+@item blue, b
+Set the key points for the blue component.
+@item all
+Set the key points for all components (not including master).
+Can be used in addition to the other key points component
+options. In this case, the unset component(s) will fallback on this
+@option{all} setting.
+@item psfile
+Specify a Photoshop curves file (@code{.acv}) to import the settings from.
+@end table
+
+To avoid some filtergraph syntax conflicts, each key points list need to be
+defined using the following syntax: @code{x0/y0 x1/y1 x2/y2 ...}.
+
+@subsection Examples
+
+@itemize
+@item
+Increase slightly the middle level of blue:
+@example
+curves=blue='0.5/0.58'
+@end example
+
+@item
+Vintage effect:
+@example
+curves=r='0/0.11 .42/.51 1/0.95':g='0.50/0.48':b='0/0.22 .49/.44 1/0.8'
+@end example
+Here we obtain the following coordinates for each components:
+@table @var
+@item red
+@code{(0;0.11) (0.42;0.51) (1;0.95)}
+@item green
+@code{(0;0) (0.50;0.48) (1;1)}
+@item blue
+@code{(0;0.22) (0.49;0.44) (1;0.80)}
+@end table
+
+@item
+The previous example can also be achieved with the associated built-in preset:
+@example
+curves=preset=vintage
+@end example
+
+@item
+Or simply:
+@example
+curves=vintage
+@end example
+
+@item
+Use a Photoshop preset and redefine the points of the green component:
+@example
+curves=psfile='MyCurvesPresets/purple.acv':green='0.45/0.53'
+@end example
+@end itemize
+
+@section dctdnoiz
+
+Denoise frames using 2D DCT (frequency domain filtering).
+
+This filter is not designed for real time.
+
+The filter accepts the following options:
+
+@table @option
+@item sigma, s
+Set the noise sigma constant.
+
+This @var{sigma} defines a hard threshold of @code{3 * sigma}; every DCT
+coefficient (absolute value) below this threshold with be dropped.
+
+If you need a more advanced filtering, see @option{expr}.
+
+Default is @code{0}.
+
+@item overlap
+Set number overlapping pixels for each block. Since the filter can be slow, you
+may want to reduce this value, at the cost of a less effective filter and the
+risk of various artefacts.
+
+If the overlapping value doesn't permit processing the whole input width or
+height, a warning will be displayed and according borders won't be denoised.
+
+Default value is @var{blocksize}-1, which is the best possible setting.
+
+@item expr, e
+Set the coefficient factor expression.
+
+For each coefficient of a DCT block, this expression will be evaluated as a
+multiplier value for the coefficient.
+
+If this is option is set, the @option{sigma} option will be ignored.
+
+The absolute value of the coefficient can be accessed through the @var{c}
+variable.
+
+@item n
+Set the @var{blocksize} using the number of bits. @code{1<<@var{n}} defines the
+@var{blocksize}, which is the width and height of the processed blocks.
+
+The default value is @var{3} (8x8) and can be raised to @var{4} for a
+@var{blocksize} of 16x16. Note that changing this setting has huge consequences
+on the speed processing. Also, a larger block size does not necessarily means a
+better de-noising.
+@end table
+
+@subsection Examples
+
+Apply a denoise with a @option{sigma} of @code{4.5}:
+@example
+dctdnoiz=4.5
+@end example
+
+The same operation can be achieved using the expression system:
+@example
+dctdnoiz=e='gte(c, 4.5*3)'
+@end example
+
+Violent denoise using a block size of @code{16x16}:
+@example
+dctdnoiz=15:n=4
+@end example
+
+@section deband
+
+Remove banding artifacts from input video.
+It works by replacing banded pixels with average value of referenced pixels.
+
+The filter accepts the following options:
+
+@table @option
+@item 1thr
+@item 2thr
+@item 3thr
+@item 4thr
+Set banding detection threshold for each plane. Default is 0.02.
+Valid range is 0.00003 to 0.5.
+If difference between current pixel and reference pixel is less than threshold,
+it will be considered as banded.
+
+@item range, r
+Banding detection range in pixels. Default is 16. If positive, random number
+in range 0 to set value will be used. If negative, exact absolute value
+will be used.
+The range defines square of four pixels around current pixel.
+
+@item direction, d
+Set direction in radians from which four pixel will be compared. If positive,
+random direction from 0 to set direction will be picked. If negative, exact of
+absolute value will be picked. For example direction 0, -PI or -2*PI radians
+will pick only pixels on same row and -PI/2 will pick only pixels on same
+column.
+
+@item blur
+If enabled, current pixel is compared with average value of all four
+surrounding pixels. The default is enabled. If disabled current pixel is
+compared with all four surrounding pixels. The pixel is considered banded
+if only all four differences with surrounding pixels are less than threshold.
+@end table
+
+@anchor{decimate}
+@section decimate
+
+Drop duplicated frames at regular intervals.
+
+The filter accepts the following options:
+
+@table @option
+@item cycle
+Set the number of frames from which one will be dropped. Setting this to
+@var{N} means one frame in every batch of @var{N} frames will be dropped.
+Default is @code{5}.
+
+@item dupthresh
+Set the threshold for duplicate detection. If the difference metric for a frame
+is less than or equal to this value, then it is declared as duplicate. Default
+is @code{1.1}
+
+@item scthresh
+Set scene change threshold. Default is @code{15}.
+
+@item blockx
+@item blocky
+Set the size of the x and y-axis blocks used during metric calculations.
+Larger blocks give better noise suppression, but also give worse detection of
+small movements. Must be a power of two. Default is @code{32}.
+
+@item ppsrc
+Mark main input as a pre-processed input and activate clean source input
+stream. This allows the input to be pre-processed with various filters to help
+the metrics calculation while keeping the frame selection lossless. When set to
+@code{1}, the first stream is for the pre-processed input, and the second
+stream is the clean source from where the kept frames are chosen. Default is
+@code{0}.
+
+@item chroma
+Set whether or not chroma is considered in the metric calculations. Default is
+@code{1}.
+@end table
+
+@section deflate
+
+Apply deflate effect to the video.
+
+This filter replaces the pixel by the local(3x3) average by taking into account
+only values lower than the pixel.
+
+It accepts the following options:
+
+@table @option
+@item threshold0
+@item threshold1
+@item threshold2
+@item threshold3
+Limit the maximum change for each plane, default is 65535.
+If 0, plane will remain unchanged.
+@end table
+
+@section dejudder
+
+Remove judder produced by partially interlaced telecined content.
+
+Judder can be introduced, for instance, by @ref{pullup} filter. If the original
+source was partially telecined content then the output of @code{pullup,dejudder}
+will have a variable frame rate. May change the recorded frame rate of the
+container. Aside from that change, this filter will not affect constant frame
+rate video.
+
+The option available in this filter is:
+@table @option
+
+@item cycle
+Specify the length of the window over which the judder repeats.
+
+Accepts any integer greater than 1. Useful values are:
+@table @samp
+
+@item 4
+If the original was telecined from 24 to 30 fps (Film to NTSC).
+
+@item 5
+If the original was telecined from 25 to 30 fps (PAL to NTSC).
+
+@item 20
+If a mixture of the two.
+@end table
+
+The default is @samp{4}.
+@end table
+
+@section delogo
+
+Suppress a TV station logo by a simple interpolation of the surrounding
+pixels. Just set a rectangle covering the logo and watch it disappear
+(and sometimes something even uglier appear - your mileage may vary).
+
+It accepts the following parameters:
+@table @option
+
+@item x
+@item y
+Specify the top left corner coordinates of the logo. They must be
+specified.
+
+@item w
+@item h
+Specify the width and height of the logo to clear. They must be
+specified.
+
+@item band, t
+Specify the thickness of the fuzzy edge of the rectangle (added to
+@var{w} and @var{h}). The default value is 1. This option is
+deprecated, setting higher values should no longer be necessary and
+is not recommended.
+
+@item show
+When set to 1, a green rectangle is drawn on the screen to simplify
+finding the right @var{x}, @var{y}, @var{w}, and @var{h} parameters.
+The default value is 0.
+
+The rectangle is drawn on the outermost pixels which will be (partly)
+replaced with interpolated values. The values of the next pixels
+immediately outside this rectangle in each direction will be used to
+compute the interpolated pixel values inside the rectangle.
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Set a rectangle covering the area with top left corner coordinates 0,0
+and size 100x77, and a band of size 10:
+@example
+delogo=x=0:y=0:w=100:h=77:band=10
+@end example
+
+@end itemize
+
+@section deshake
+
+Attempt to fix small changes in horizontal and/or vertical shift. This
+filter helps remove camera shake from hand-holding a camera, bumping a
+tripod, moving on a vehicle, etc.
+
+The filter accepts the following options:
+
+@table @option
+
+@item x
+@item y
+@item w
+@item h
+Specify a rectangular area where to limit the search for motion
+vectors.
+If desired the search for motion vectors can be limited to a
+rectangular area of the frame defined by its top left corner, width
+and height. These parameters have the same meaning as the drawbox
+filter which can be used to visualise the position of the bounding
+box.
+
+This is useful when simultaneous movement of subjects within the frame
+might be confused for camera motion by the motion vector search.
+
+If any or all of @var{x}, @var{y}, @var{w} and @var{h} are set to -1
+then the full frame is used. This allows later options to be set
+without specifying the bounding box for the motion vector search.
+
+Default - search the whole frame.
+
+@item rx
+@item ry
+Specify the maximum extent of movement in x and y directions in the
+range 0-64 pixels. Default 16.
+
+@item edge
+Specify how to generate pixels to fill blanks at the edge of the
+frame. Available values are:
+@table @samp
+@item blank, 0
+Fill zeroes at blank locations
+@item original, 1
+Original image at blank locations
+@item clamp, 2
+Extruded edge value at blank locations
+@item mirror, 3
+Mirrored edge at blank locations
+@end table
+Default value is @samp{mirror}.
+
+@item blocksize
+Specify the blocksize to use for motion search. Range 4-128 pixels,
+default 8.
+
+@item contrast
+Specify the contrast threshold for blocks. Only blocks with more than
+the specified contrast (difference between darkest and lightest
+pixels) will be considered. Range 1-255, default 125.
+
+@item search
+Specify the search strategy. Available values are:
+@table @samp
+@item exhaustive, 0
+Set exhaustive search
+@item less, 1
+Set less exhaustive search.
+@end table
+Default value is @samp{exhaustive}.
+
+@item filename
+If set then a detailed log of the motion search is written to the
+specified file.
+
+@item opencl
+If set to 1, specify using OpenCL capabilities, only available if
+FFmpeg was configured with @code{--enable-opencl}. Default value is 0.
+
+@end table
+
+@section detelecine
+
+Apply an exact inverse of the telecine operation. It requires a predefined
+pattern specified using the pattern option which must be the same as that passed
+to the telecine filter.
+
+This filter accepts the following options:
+
+@table @option
+@item first_field
+@table @samp
+@item top, t
+top field first
+@item bottom, b
+bottom field first
+The default value is @code{top}.
+@end table
+
+@item pattern
+A string of numbers representing the pulldown pattern you wish to apply.
+The default value is @code{23}.
+
+@item start_frame
+A number representing position of the first frame with respect to the telecine
+pattern. This is to be used if the stream is cut. The default value is @code{0}.
+@end table
+
+@section dilation
+
+Apply dilation effect to the video.
+
+This filter replaces the pixel by the local(3x3) maximum.
+
+It accepts the following options:
+
+@table @option
+@item threshold0
+@item threshold1
+@item threshold2
+@item threshold3
+Limit the maximum change for each plane, default is 65535.
+If 0, plane will remain unchanged.
+
+@item coordinates
+Flag which specifies the pixel to refer to. Default is 255 i.e. all eight
+pixels are used.
+
+Flags to local 3x3 coordinates maps like this:
+
+ 1 2 3
+ 4 5
+ 6 7 8
+@end table
+
+@section displace
+
+Displace pixels as indicated by second and third input stream.
+
+It takes three input streams and outputs one stream, the first input is the
+source, and second and third input are displacement maps.
+
+The second input specifies how much to displace pixels along the
+x-axis, while the third input specifies how much to displace pixels
+along the y-axis.
+If one of displacement map streams terminates, last frame from that
+displacement map will be used.
+
+Note that once generated, displacements maps can be reused over and over again.
+
+A description of the accepted options follows.
+
+@table @option
+@item edge
+Set displace behavior for pixels that are out of range.
+
+Available values are:
+@table @samp
+@item blank
+Missing pixels are replaced by black pixels.
+
+@item smear
+Adjacent pixels will spread out to replace missing pixels.
+
+@item wrap
+Out of range pixels are wrapped so they point to pixels of other side.
+@end table
+Default is @samp{smear}.
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Add ripple effect to rgb input of video size hd720:
+@example
+ffmpeg -i INPUT -f lavfi -i nullsrc=s=hd720,lutrgb=128:128:128 -f lavfi -i nullsrc=s=hd720,geq='r=128+30*sin(2*PI*X/400+T):g=128+30*sin(2*PI*X/400+T):b=128+30*sin(2*PI*X/400+T)' -lavfi '[0][1][2]displace' OUTPUT
+@end example
+
+@item
+Add wave effect to rgb input of video size hd720:
+@example
+ffmpeg -i INPUT -f lavfi -i nullsrc=hd720,geq='r=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):g=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T)):b=128+80*(sin(sqrt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2))/220*2*PI+T))' -lavfi '[1]split[x][y],[0][x][y]displace' OUTPUT
+@end example
+@end itemize
+
+@section drawbox
+
+Draw a colored box on the input image.
+
+It accepts the following parameters:
+
+@table @option
+@item x
+@item y
+The expressions which specify the top left corner coordinates of the box. It defaults to 0.
+
+@item width, w
+@item height, h
+The expressions which specify the width and height of the box; if 0 they are interpreted as
+the input width and height. It defaults to 0.
+
+@item color, c
+Specify the color of the box to write. For the general syntax of this option,
+check the "Color" section in the ffmpeg-utils manual. If the special
+value @code{invert} is used, the box edge color is the same as the
+video with inverted luma.
+
+@item thickness, t
+The expression which sets the thickness of the box edge. Default value is @code{3}.
+
+See below for the list of accepted constants.
+@end table
+
+The parameters for @var{x}, @var{y}, @var{w} and @var{h} and @var{t} are expressions containing the
+following constants:
+
+@table @option
+@item dar
+The input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}.
+
+@item hsub
+@item vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
+@item in_h, ih
+@item in_w, iw
+The input width and height.
+
+@item sar
+The input sample aspect ratio.
+
+@item x
+@item y
+The x and y offset coordinates where the box is drawn.
+
+@item w
+@item h
+The width and height of the drawn box.
+
+@item t
+The thickness of the drawn box.
+
+These constants allow the @var{x}, @var{y}, @var{w}, @var{h} and @var{t} expressions to refer to
+each other, so you may for example specify @code{y=x/dar} or @code{h=w/dar}.
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Draw a black box around the edge of the input image:
+@example
+drawbox
+@end example
+
+@item
+Draw a box with color red and an opacity of 50%:
+@example
+drawbox=10:20:200:60:red@@0.5
+@end example
+
+The previous example can be specified as:
+@example
+drawbox=x=10:y=20:w=200:h=60:color=red@@0.5
+@end example
+
+@item
+Fill the box with pink color:
+@example
+drawbox=x=10:y=10:w=100:h=100:color=pink@@0.5:t=max
+@end example
+
+@item
+Draw a 2-pixel red 2.40:1 mask:
+@example
+drawbox=x=-t:y=0.5*(ih-iw/2.4)-t:w=iw+t*2:h=iw/2.4+t*2:t=2:c=red
+@end example
+@end itemize
+
+@section drawgraph, adrawgraph
+
+Draw a graph using input video or audio metadata.
+
+It accepts the following parameters:
+
+@table @option
+@item m1
+Set 1st frame metadata key from which metadata values will be used to draw a graph.
+
+@item fg1
+Set 1st foreground color expression.
+
+@item m2
+Set 2nd frame metadata key from which metadata values will be used to draw a graph.
+
+@item fg2
+Set 2nd foreground color expression.
+
+@item m3
+Set 3rd frame metadata key from which metadata values will be used to draw a graph.
+
+@item fg3
+Set 3rd foreground color expression.
+
+@item m4
+Set 4th frame metadata key from which metadata values will be used to draw a graph.
+
+@item fg4
+Set 4th foreground color expression.
+
+@item min
+Set minimal value of metadata value.
+
+@item max
+Set maximal value of metadata value.
+
+@item bg
+Set graph background color. Default is white.
+
+@item mode
+Set graph mode.
+
+Available values for mode is:
+@table @samp
+@item bar
+@item dot
+@item line
+@end table
+
+Default is @code{line}.
+
+@item slide
+Set slide mode.
+
+Available values for slide is:
+@table @samp
+@item frame
+Draw new frame when right border is reached.
+
+@item replace
+Replace old columns with new ones.
+
+@item scroll
+Scroll from right to left.
+
+@item rscroll
+Scroll from left to right.
+@end table
+
+Default is @code{frame}.
+
+@item size
+Set size of graph video. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+The default value is @code{900x256}.
+
+The foreground color expressions can use the following variables:
+@table @option
+@item MIN
+Minimal value of metadata value.
+
+@item MAX
+Maximal value of metadata value.
+
+@item VAL
+Current metadata key value.
+@end table
+
+The color is defined as 0xAABBGGRR.
+@end table
+
+Example using metadata from @ref{signalstats} filter:
+@example
+signalstats,drawgraph=lavfi.signalstats.YAVG:min=0:max=255
+@end example
+
+Example using metadata from @ref{ebur128} filter:
+@example
+ebur128=metadata=1,adrawgraph=lavfi.r128.M:min=-120:max=5
+@end example
+
+@section drawgrid
+
+Draw a grid on the input image.
+
+It accepts the following parameters:
+
+@table @option
+@item x
+@item y
+The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
+
+@item width, w
+@item height, h
+The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
+input width and height, respectively, minus @code{thickness}, so image gets
+framed. Default to 0.
+
+@item color, c
+Specify the color of the grid. For the general syntax of this option,
+check the "Color" section in the ffmpeg-utils manual. If the special
+value @code{invert} is used, the grid color is the same as the
+video with inverted luma.
+
+@item thickness, t
+The expression which sets the thickness of the grid line. Default value is @code{1}.
+
+See below for the list of accepted constants.
+@end table
+
+The parameters for @var{x}, @var{y}, @var{w} and @var{h} and @var{t} are expressions containing the
+following constants:
+
+@table @option
+@item dar
+The input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}.
+
+@item hsub
+@item vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
+@item in_h, ih
+@item in_w, iw
+The input grid cell width and height.
+
+@item sar
+The input sample aspect ratio.
+
+@item x
+@item y
+The x and y coordinates of some point of grid intersection (meant to configure offset).
+
+@item w
+@item h
+The width and height of the drawn cell.
+
+@item t
+The thickness of the drawn cell.
+
+These constants allow the @var{x}, @var{y}, @var{w}, @var{h} and @var{t} expressions to refer to
+each other, so you may for example specify @code{y=x/dar} or @code{h=w/dar}.
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
+@example
+drawgrid=width=100:height=100:thickness=2:color=red@@0.5
+@end example
+
+@item
+Draw a white 3x3 grid with an opacity of 50%:
+@example
+drawgrid=w=iw/3:h=ih/3:t=2:c=white@@0.5
+@end example
+@end itemize
+
+@anchor{drawtext}
+@section drawtext
+
+Draw a text string or text from a specified file on top of a video, using the
+libfreetype library.
+
+To enable compilation of this filter, you need to configure FFmpeg with
+@code{--enable-libfreetype}.
+To enable default font fallback and the @var{font} option you need to
+configure FFmpeg with @code{--enable-libfontconfig}.
+To enable the @var{text_shaping} option, you need to configure FFmpeg with
+@code{--enable-libfribidi}.
+
+@subsection Syntax
+
+It accepts the following parameters:
+
+@table @option
+
+@item box
+Used to draw a box around text using the background color.
+The value must be either 1 (enable) or 0 (disable).
+The default value of @var{box} is 0.
+
+@item boxborderw
+Set the width of the border to be drawn around the box using @var{boxcolor}.
+The default value of @var{boxborderw} is 0.
+
+@item boxcolor
+The color to be used for drawing box around text. For the syntax of this
+option, check the "Color" section in the ffmpeg-utils manual.
+
+The default value of @var{boxcolor} is "white".
+
+@item borderw
+Set the width of the border to be drawn around the text using @var{bordercolor}.
+The default value of @var{borderw} is 0.
+
+@item bordercolor
+Set the color to be used for drawing border around text. For the syntax of this
+option, check the "Color" section in the ffmpeg-utils manual.
+
+The default value of @var{bordercolor} is "black".
+
+@item expansion
+Select how the @var{text} is expanded. Can be either @code{none},
+@code{strftime} (deprecated) or
+@code{normal} (default). See the @ref{drawtext_expansion, Text expansion} section
+below for details.
+
+@item fix_bounds
+If true, check and fix text coords to avoid clipping.
+
+@item fontcolor
+The color to be used for drawing fonts. For the syntax of this option, check
+the "Color" section in the ffmpeg-utils manual.
+
+The default value of @var{fontcolor} is "black".
+
+@item fontcolor_expr
+String which is expanded the same way as @var{text} to obtain dynamic
+@var{fontcolor} value. By default this option has empty value and is not
+processed. When this option is set, it overrides @var{fontcolor} option.
+
+@item font
+The font family to be used for drawing text. By default Sans.
+
+@item fontfile
+The font file to be used for drawing text. The path must be included.
+This parameter is mandatory if the fontconfig support is disabled.
+
+@item draw
+This option does not exist, please see the timeline system
+
+@item alpha
+Draw the text applying alpha blending. The value can
+be either a number between 0.0 and 1.0
+The expression accepts the same variables @var{x, y} do.
+The default value is 1.
+Please see fontcolor_expr
+
+@item fontsize
+The font size to be used for drawing text.
+The default value of @var{fontsize} is 16.
+
+@item text_shaping
+If set to 1, attempt to shape the text (for example, reverse the order of
+right-to-left text and join Arabic characters) before drawing it.
+Otherwise, just draw the text exactly as given.
+By default 1 (if supported).
+
+@item ft_load_flags
+The flags to be used for loading the fonts.
+
+The flags map the corresponding flags supported by libfreetype, and are
+a combination of the following values:
+@table @var
+@item default
+@item no_scale
+@item no_hinting
+@item render
+@item no_bitmap
+@item vertical_layout
+@item force_autohint
+@item crop_bitmap
+@item pedantic
+@item ignore_global_advance_width
+@item no_recurse
+@item ignore_transform
+@item monochrome
+@item linear_design
+@item no_autohint
+@end table
+
+Default value is "default".
+
+For more information consult the documentation for the FT_LOAD_*
+libfreetype flags.
+
+@item shadowcolor
+The color to be used for drawing a shadow behind the drawn text. For the
+syntax of this option, check the "Color" section in the ffmpeg-utils manual.
+
+The default value of @var{shadowcolor} is "black".
+
+@item shadowx
+@item shadowy
+The x and y offsets for the text shadow position with respect to the
+position of the text. They can be either positive or negative
+values. The default value for both is "0".
+
+@item start_number
+The starting frame number for the n/frame_num variable. The default value
+is "0".
+
+@item tabsize
+The size in number of spaces to use for rendering the tab.
+Default value is 4.
+
+@item timecode
+Set the initial timecode representation in "hh:mm:ss[:;.]ff"
+format. It can be used with or without text parameter. @var{timecode_rate}
+option must be specified.
+
+@item timecode_rate, rate, r
+Set the timecode frame rate (timecode only).
+
+@item text
+The text string to be drawn. The text must be a sequence of UTF-8
+encoded characters.
+This parameter is mandatory if no file is specified with the parameter
+@var{textfile}.
+
+@item textfile
+A text file containing text to be drawn. The text must be a sequence
+of UTF-8 encoded characters.
+
+This parameter is mandatory if no text string is specified with the
+parameter @var{text}.
+
+If both @var{text} and @var{textfile} are specified, an error is thrown.
+
+@item reload
+If set to 1, the @var{textfile} will be reloaded before each frame.
+Be sure to update it atomically, or it may be read partially, or even fail.
+
+@item x
+@item y
+The expressions which specify the offsets where text will be drawn
+within the video frame. They are relative to the top/left border of the
+output image.
+
+The default value of @var{x} and @var{y} is "0".
+
+See below for the list of accepted constants and functions.
+@end table
+
+The parameters for @var{x} and @var{y} are expressions containing the
+following constants and functions:
+
+@table @option
+@item dar
+input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
+
+@item hsub
+@item vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
+@item line_h, lh
+the height of each text line
+
+@item main_h, h, H
+the input height
+
+@item main_w, w, W
+the input width
+
+@item max_glyph_a, ascent
+the maximum distance from the baseline to the highest/upper grid
+coordinate used to place a glyph outline point, for all the rendered
+glyphs.
+It is a positive value, due to the grid's orientation with the Y axis
+upwards.
+
+@item max_glyph_d, descent
+the maximum distance from the baseline to the lowest grid coordinate
+used to place a glyph outline point, for all the rendered glyphs.
+This is a negative value, due to the grid's orientation, with the Y axis
+upwards.
+
+@item max_glyph_h
+maximum glyph height, that is the maximum height for all the glyphs
+contained in the rendered text, it is equivalent to @var{ascent} -
+@var{descent}.
+
+@item max_glyph_w
+maximum glyph width, that is the maximum width for all the glyphs
+contained in the rendered text
+
+@item n
+the number of input frame, starting from 0
+
+@item rand(min, max)
+return a random number included between @var{min} and @var{max}
+
+@item sar
+The input sample aspect ratio.
+
+@item t
+timestamp expressed in seconds, NAN if the input timestamp is unknown
+
+@item text_h, th
+the height of the rendered text
+
+@item text_w, tw
+the width of the rendered text
+
+@item x
+@item y
+the x and y offset coordinates where the text is drawn.
+
+These parameters allow the @var{x} and @var{y} expressions to refer
+each other, so you can for example specify @code{y=x/dar}.
+@end table
+
+@anchor{drawtext_expansion}
+@subsection Text expansion
+
+If @option{expansion} is set to @code{strftime},
+the filter recognizes strftime() sequences in the provided text and
+expands them accordingly. Check the documentation of strftime(). This
+feature is deprecated.
+
+If @option{expansion} is set to @code{none}, the text is printed verbatim.
+
+If @option{expansion} is set to @code{normal} (which is the default),
+the following expansion mechanism is used.
+
+The backslash character @samp{\}, followed by any character, always expands to
+the second character.
+
+Sequence of the form @code{%@{...@}} are expanded. The text between the
+braces is a function name, possibly followed by arguments separated by ':'.
+If the arguments contain special characters or delimiters (':' or '@}'),
+they should be escaped.
+
+Note that they probably must also be escaped as the value for the
+@option{text} option in the filter argument string and as the filter
+argument in the filtergraph description, and possibly also for the shell,
+that makes up to four levels of escaping; using a text file avoids these
+problems.
+
+The following functions are available:
+
+@table @command
+
+@item expr, e
+The expression evaluation result.
+
+It must take one argument specifying the expression to be evaluated,
+which accepts the same constants and functions as the @var{x} and
+@var{y} values. Note that not all constants should be used, for
+example the text size is not known when evaluating the expression, so
+the constants @var{text_w} and @var{text_h} will have an undefined
+value.
+
+@item expr_int_format, eif
+Evaluate the expression's value and output as formatted integer.
+
+The first argument is the expression to be evaluated, just as for the @var{expr} function.
+The second argument specifies the output format. Allowed values are @samp{x},
+@samp{X}, @samp{d} and @samp{u}. They are treated exactly as in the
+@code{printf} function.
+The third parameter is optional and sets the number of positions taken by the output.
+It can be used to add padding with zeros from the left.
+
+@item gmtime
+The time at which the filter is running, expressed in UTC.
+It can accept an argument: a strftime() format string.
+
+@item localtime
+The time at which the filter is running, expressed in the local time zone.
+It can accept an argument: a strftime() format string.
+
+@item metadata
+Frame metadata. It must take one argument specifying metadata key.
+
+@item n, frame_num
+The frame number, starting from 0.
+
+@item pict_type
+A 1 character description of the current picture type.
+
+@item pts
+The timestamp of the current frame.
+It can take up to three arguments.
+
+The first argument is the format of the timestamp; it defaults to @code{flt}
+for seconds as a decimal number with microsecond accuracy; @code{hms} stands
+for a formatted @var{[-]HH:MM:SS.mmm} timestamp with millisecond accuracy.
+@code{gmtime} stands for the timestamp of the frame formatted as UTC time;
+@code{localtime} stands for the timestamp of the frame formatted as
+local time zone time.
+
+The second argument is an offset added to the timestamp.
+
+If the format is set to @code{localtime} or @code{gmtime},
+a third argument may be supplied: a strftime() format string.
+By default, @var{YYYY-MM-DD HH:MM:SS} format will be used.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Draw "Test Text" with font FreeSerif, using the default values for the
+optional parameters.
+
+@example
+drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text'"
+@end example
+
+@item
+Draw 'Test Text' with font FreeSerif of size 24 at position x=100
+and y=50 (counting from the top-left corner of the screen), text is
+yellow with a red box around it. Both the text and the box have an
+opacity of 20%.
+
+@example
+drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text':\
+ x=100: y=50: fontsize=24: fontcolor=yellow@@0.2: box=1: boxcolor=red@@0.2"
+@end example
+
+Note that the double quotes are not necessary if spaces are not used
+within the parameter list.
+
+@item
+Show the text at the center of the video frame:
+@example
+drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=(w-text_w)/2:y=(h-text_h)/2"
+@end example
+
+@item
+Show a text line sliding from right to left in the last row of the video
+frame. The file @file{LONG_LINE} is assumed to contain a single line
+with no newlines.
+@example
+drawtext="fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t"
+@end example
+
+@item
+Show the content of file @file{CREDITS} off the bottom of the frame and scroll up.
+@example
+drawtext="fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t"
+@end example
+
+@item
+Draw a single green letter "g", at the center of the input video.
+The glyph baseline is placed at half screen height.
+@example
+drawtext="fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent"
+@end example
+
+@item
+Show text for 1 second every 3 seconds:
+@example
+drawtext="fontfile=FreeSerif.ttf:fontcolor=white:x=100:y=x/dar:enable=lt(mod(t\,3)\,1):text='blink'"
+@end example
+
+@item
+Use fontconfig to set the font. Note that the colons need to be escaped.
+@example
+drawtext='fontfile=Linux Libertine O-40\:style=Semibold:text=FFmpeg'
+@end example
+
+@item
+Print the date of a real-time encoding (see strftime(3)):
+@example
+drawtext='fontfile=FreeSans.ttf:text=%@{localtime\:%a %b %d %Y@}'
+@end example
+
+@item
+Show text fading in and out (appearing/disappearing):
+@example
+#!/bin/sh
+DS=1.0 # display start
+DE=10.0 # display end
+FID=1.5 # fade in duration
+FOD=5 # fade out duration
+ffplay -f lavfi "color,drawtext=text=TEST:fontsize=50:fontfile=FreeSerif.ttf:fontcolor_expr=ff0000%@{eif\\\\: clip(255*(1*between(t\\, $DS + $FID\\, $DE - $FOD) + ((t - $DS)/$FID)*between(t\\, $DS\\, $DS + $FID) + (-(t - $DE)/$FOD)*between(t\\, $DE - $FOD\\, $DE) )\\, 0\\, 255) \\\\: x\\\\: 2 @}"
+@end example
+
+@end itemize
+
+For more information about libfreetype, check:
+@url{http://www.freetype.org/}.
+
+For more information about fontconfig, check:
+@url{http://freedesktop.org/software/fontconfig/fontconfig-user.html}.
+
+For more information about libfribidi, check:
+@url{http://fribidi.org/}.
+
+@section edgedetect
+
+Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
+
+The filter accepts the following options:
+
+@table @option
+@item low
+@item high
+Set low and high threshold values used by the Canny thresholding
+algorithm.
+
+The high threshold selects the "strong" edge pixels, which are then
+connected through 8-connectivity with the "weak" edge pixels selected
+by the low threshold.
+
+@var{low} and @var{high} threshold values must be chosen in the range
+[0,1], and @var{low} should be lesser or equal to @var{high}.
+
+Default value for @var{low} is @code{20/255}, and default value for @var{high}
+is @code{50/255}.
+
+@item mode
+Define the drawing mode.
+
+@table @samp
+@item wires
+Draw white/gray wires on black background.
+
+@item colormix
+Mix the colors to create a paint/cartoon effect.
+@end table
+
+Default value is @var{wires}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Standard edge detection with custom values for the hysteresis thresholding:
+@example
+edgedetect=low=0.1:high=0.4
+@end example
+
+@item
+Painting effect without thresholding:
+@example
+edgedetect=mode=colormix:high=0
+@end example
+@end itemize
+
+@section eq
+Set brightness, contrast, saturation and approximate gamma adjustment.
+
+The filter accepts the following options:
+
+@table @option
+@item contrast
+Set the contrast expression. The value must be a float value in range
+@code{-2.0} to @code{2.0}. The default value is "1".
+
+@item brightness
+Set the brightness expression. The value must be a float value in
+range @code{-1.0} to @code{1.0}. The default value is "0".
+
+@item saturation
+Set the saturation expression. The value must be a float in
+range @code{0.0} to @code{3.0}. The default value is "1".
+
+@item gamma
+Set the gamma expression. The value must be a float in range
+@code{0.1} to @code{10.0}. The default value is "1".
+
+@item gamma_r
+Set the gamma expression for red. The value must be a float in
+range @code{0.1} to @code{10.0}. The default value is "1".
+
+@item gamma_g
+Set the gamma expression for green. The value must be a float in range
+@code{0.1} to @code{10.0}. The default value is "1".
+
+@item gamma_b
+Set the gamma expression for blue. The value must be a float in range
+@code{0.1} to @code{10.0}. The default value is "1".
+
+@item gamma_weight
+Set the gamma weight expression. It can be used to reduce the effect
+of a high gamma value on bright image areas, e.g. keep them from
+getting overamplified and just plain white. The value must be a float
+in range @code{0.0} to @code{1.0}. A value of @code{0.0} turns the
+gamma correction all the way down while @code{1.0} leaves it at its
+full strength. Default is "1".
+
+@item eval
+Set when the expressions for brightness, contrast, saturation and
+gamma expressions are evaluated.
+
+It accepts the following values:
+@table @samp
+@item init
+only evaluate expressions once during the filter initialization or
+when a command is processed
+
+@item frame
+evaluate expressions for each incoming frame
+@end table
+
+Default value is @samp{init}.
+@end table
+
+The expressions accept the following parameters:
+@table @option
+@item n
+frame count of the input frame starting from 0
+
+@item pos
+byte position of the corresponding packet in the input file, NAN if
+unspecified
+
+@item r
+frame rate of the input video, NAN if the input frame rate is unknown
+
+@item t
+timestamp expressed in seconds, NAN if the input timestamp is unknown
+@end table
+
+@subsection Commands
+The filter supports the following commands:
+
+@table @option
+@item contrast
+Set the contrast expression.
+
+@item brightness
+Set the brightness expression.
+
+@item saturation
+Set the saturation expression.
+
+@item gamma
+Set the gamma expression.
+
+@item gamma_r
+Set the gamma_r expression.
+
+@item gamma_g
+Set gamma_g expression.
+
+@item gamma_b
+Set gamma_b expression.
+
+@item gamma_weight
+Set gamma_weight expression.
+
+The command accepts the same syntax of the corresponding option.
+
+If the specified expression is not valid, it is kept at its current
+value.
+
+@end table
+
+@section erosion
+
+Apply erosion effect to the video.
+
+This filter replaces the pixel by the local(3x3) minimum.
+
+It accepts the following options:
+
+@table @option
+@item threshold0
+@item threshold1
+@item threshold2
+@item threshold3
+Limit the maximum change for each plane, default is 65535.
+If 0, plane will remain unchanged.
+
+@item coordinates
+Flag which specifies the pixel to refer to. Default is 255 i.e. all eight
+pixels are used.
+
+Flags to local 3x3 coordinates maps like this:
+
+ 1 2 3
+ 4 5
+ 6 7 8
+@end table
+
+@section extractplanes
+
+Extract color channel components from input video stream into
+separate grayscale video streams.
+
+The filter accepts the following option:
+
+@table @option
+@item planes
+Set plane(s) to extract.
+
+Available values for planes are:
+@table @samp
+@item y
+@item u
+@item v
+@item a
+@item r
+@item g
+@item b
+@end table
+
+Choosing planes not available in the input will result in an error.
+That means you cannot select @code{r}, @code{g}, @code{b} planes
+with @code{y}, @code{u}, @code{v} planes at same time.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Extract luma, u and v color channel component from input video frame
+into 3 grayscale outputs:
+@example
+ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
+@end example
+@end itemize
+
+@section elbg
+
+Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
+
+For each input image, the filter will compute the optimal mapping from
+the input to the output given the codebook length, that is the number
+of distinct output colors.
+
+This filter accepts the following options.
+
+@table @option
+@item codebook_length, l
+Set codebook length. The value must be a positive integer, and
+represents the number of distinct output colors. Default value is 256.
+
+@item nb_steps, n
+Set the maximum number of iterations to apply for computing the optimal
+mapping. The higher the value the better the result and the higher the
+computation time. Default value is 1.
+
+@item seed, s
+Set a random seed, must be an integer included between 0 and
+UINT32_MAX. If not specified, or if explicitly set to -1, the filter
+will try to use a good random seed on a best effort basis.
+
+@item pal8
+Set pal8 output pixel format. This option does not work with codebook
+length greater than 256.
+@end table
+
+@section fade
+
+Apply a fade-in/out effect to the input video.
+
+It accepts the following parameters:
+
+@table @option
+@item type, t
+The effect type can be either "in" for a fade-in, or "out" for a fade-out
+effect.
+Default is @code{in}.
+
+@item start_frame, s
+Specify the number of the frame to start applying the fade
+effect at. Default is 0.
+
+@item nb_frames, n
+The number of frames that the fade effect lasts. At the end of the
+fade-in effect, the output video will have the same intensity as the input video.
+At the end of the fade-out transition, the output video will be filled with the
+selected @option{color}.
+Default is 25.
+
+@item alpha
+If set to 1, fade only alpha channel, if one exists on the input.
+Default value is 0.
+
+@item start_time, st
+Specify the timestamp (in seconds) of the frame to start to apply the fade
+effect. If both start_frame and start_time are specified, the fade will start at
+whichever comes last. Default is 0.
+
+@item duration, d
+The number of seconds for which the fade effect has to last. At the end of the
+fade-in effect the output video will have the same intensity as the input video,
+at the end of the fade-out transition the output video will be filled with the
+selected @option{color}.
+If both duration and nb_frames are specified, duration is used. Default is 0
+(nb_frames is used by default).
+
+@item color, c
+Specify the color of the fade. Default is "black".
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Fade in the first 30 frames of video:
+@example
+fade=in:0:30
+@end example
+
+The command above is equivalent to:
+@example
+fade=t=in:s=0:n=30
+@end example
+
+@item
+Fade out the last 45 frames of a 200-frame video:
+@example
+fade=out:155:45
+fade=type=out:start_frame=155:nb_frames=45
+@end example
+
+@item
+Fade in the first 25 frames and fade out the last 25 frames of a 1000-frame video:
+@example
+fade=in:0:25, fade=out:975:25
+@end example
+
+@item
+Make the first 5 frames yellow, then fade in from frame 5-24:
+@example
+fade=in:5:20:color=yellow
+@end example
+
+@item
+Fade in alpha over first 25 frames of video:
+@example
+fade=in:0:25:alpha=1
+@end example
+
+@item
+Make the first 5.5 seconds black, then fade in for 0.5 seconds:
+@example
+fade=t=in:st=5.5:d=0.5
+@end example
+
+@end itemize
+
+@section fftfilt
+Apply arbitrary expressions to samples in frequency domain
+
+@table @option
+@item dc_Y
+Adjust the dc value (gain) of the luma plane of the image. The filter
+accepts an integer value in range @code{0} to @code{1000}. The default
+value is set to @code{0}.
+
+@item dc_U
+Adjust the dc value (gain) of the 1st chroma plane of the image. The
+filter accepts an integer value in range @code{0} to @code{1000}. The
+default value is set to @code{0}.
+
+@item dc_V
+Adjust the dc value (gain) of the 2nd chroma plane of the image. The
+filter accepts an integer value in range @code{0} to @code{1000}. The
+default value is set to @code{0}.
+
+@item weight_Y
+Set the frequency domain weight expression for the luma plane.
+
+@item weight_U
+Set the frequency domain weight expression for the 1st chroma plane.
+
+@item weight_V
+Set the frequency domain weight expression for the 2nd chroma plane.
+
+The filter accepts the following variables:
+@item X
+@item Y
+The coordinates of the current sample.
+
+@item W
+@item H
+The width and height of the image.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+High-pass:
+@example
+fftfilt=dc_Y=128:weight_Y='squish(1-(Y+X)/100)'
+@end example
+
+@item
+Low-pass:
+@example
+fftfilt=dc_Y=0:weight_Y='squish((Y+X)/100-1)'
+@end example
+
+@item
+Sharpen:
+@example
+fftfilt=dc_Y=0:weight_Y='1+squish(1-(Y+X)/100)'
+@end example
+
+@item
+Blur:
+@example
+fftfilt=dc_Y=0:weight_Y='exp(-4 * ((Y+X)/(W+H)))'
+@end example
+
+@end itemize
+
+@section field
+
+Extract a single field from an interlaced image using stride
+arithmetic to avoid wasting CPU time. The output frames are marked as
+non-interlaced.
+
+The filter accepts the following options:
+
+@table @option
+@item type
+Specify whether to extract the top (if the value is @code{0} or
+@code{top}) or the bottom field (if the value is @code{1} or
+@code{bottom}).
+@end table
+
+@section fieldhint
+
+Create new frames by copying the top and bottom fields from surrounding frames
+supplied as numbers by the hint file.
+
+@table @option
+@item hint
+Set file containing hints: absolute/relative frame numbers.
+
+There must be one line for each frame in a clip. Each line must contain two
+numbers separated by the comma, optionally followed by @code{-} or @code{+}.
+Numbers supplied on each line of file can not be out of [N-1,N+1] where N
+is current frame number for @code{absolute} mode or out of [-1, 1] range
+for @code{relative} mode. First number tells from which frame to pick up top
+field and second number tells from which frame to pick up bottom field.
+
+If optionally followed by @code{+} output frame will be marked as interlaced,
+else if followed by @code{-} output frame will be marked as progressive, else
+it will be marked same as input frame.
+If line starts with @code{#} or @code{;} that line is skipped.
+
+@item mode
+Can be item @code{absolute} or @code{relative}. Default is @code{absolute}.
+@end table
+
+Example of first several lines of @code{hint} file for @code{relative} mode:
+@example
+0,0 - # first frame
+1,0 - # second frame, use third's frame top field and second's frame bottom field
+1,0 - # third frame, use fourth's frame top field and third's frame bottom field
+1,0 -
+0,0 -
+0,0 -
+1,0 -
+1,0 -
+1,0 -
+0,0 -
+0,0 -
+1,0 -
+1,0 -
+1,0 -
+0,0 -
+@end example
+
+@section fieldmatch
+
+Field matching filter for inverse telecine. It is meant to reconstruct the
+progressive frames from a telecined stream. The filter does not drop duplicated
+frames, so to achieve a complete inverse telecine @code{fieldmatch} needs to be
+followed by a decimation filter such as @ref{decimate} in the filtergraph.
+
+The separation of the field matching and the decimation is notably motivated by
+the possibility of inserting a de-interlacing filter fallback between the two.
+If the source has mixed telecined and real interlaced content,
+@code{fieldmatch} will not be able to match fields for the interlaced parts.
+But these remaining combed frames will be marked as interlaced, and thus can be
+de-interlaced by a later filter such as @ref{yadif} before decimation.
+
+In addition to the various configuration options, @code{fieldmatch} can take an
+optional second stream, activated through the @option{ppsrc} option. If
+enabled, the frames reconstruction will be based on the fields and frames from
+this second stream. This allows the first input to be pre-processed in order to
+help the various algorithms of the filter, while keeping the output lossless
+(assuming the fields are matched properly). Typically, a field-aware denoiser,
+or brightness/contrast adjustments can help.
+
+Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
+and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
+which @code{fieldmatch} is based on. While the semantic and usage are very
+close, some behaviour and options names can differ.
+
+The @ref{decimate} filter currently only works for constant frame rate input.
+If your input has mixed telecined (30fps) and progressive content with a lower
+framerate like 24fps use the following filterchain to produce the necessary cfr
+stream: @code{dejudder,fps=30000/1001,fieldmatch,decimate}.
+
+The filter accepts the following options:
+
+@table @option
+@item order
+Specify the assumed field order of the input stream. Available values are:
+
+@table @samp
+@item auto
+Auto detect parity (use FFmpeg's internal parity value).
+@item bff
+Assume bottom field first.
+@item tff
+Assume top field first.
+@end table
+
+Note that it is sometimes recommended not to trust the parity announced by the
+stream.
+
+Default value is @var{auto}.
+
+@item mode
+Set the matching mode or strategy to use. @option{pc} mode is the safest in the
+sense that it won't risk creating jerkiness due to duplicate frames when
+possible, but if there are bad edits or blended fields it will end up
+outputting combed frames when a good match might actually exist. On the other
+hand, @option{pcn_ub} mode is the most risky in terms of creating jerkiness,
+but will almost always find a good frame if there is one. The other values are
+all somewhere in between @option{pc} and @option{pcn_ub} in terms of risking
+jerkiness and creating duplicate frames versus finding good matches in sections
+with bad edits, orphaned fields, blended fields, etc.
+
+More details about p/c/n/u/b are available in @ref{p/c/n/u/b meaning} section.
+
+Available values are:
+
+@table @samp
+@item pc
+2-way matching (p/c)
+@item pc_n
+2-way matching, and trying 3rd match if still combed (p/c + n)
+@item pc_u
+2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
+@item pc_n_ub
+2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
+still combed (p/c + n + u/b)
+@item pcn
+3-way matching (p/c/n)
+@item pcn_ub
+3-way matching, and trying 4th/5th matches if all 3 of the original matches are
+detected as combed (p/c/n + u/b)
+@end table
+
+The parenthesis at the end indicate the matches that would be used for that
+mode assuming @option{order}=@var{tff} (and @option{field} on @var{auto} or
+@var{top}).
+
+In terms of speed @option{pc} mode is by far the fastest and @option{pcn_ub} is
+the slowest.
+
+Default value is @var{pc_n}.
+
+@item ppsrc
+Mark the main input stream as a pre-processed input, and enable the secondary
+input stream as the clean source to pick the fields from. See the filter
+introduction for more details. It is similar to the @option{clip2} feature from
+VFM/TFM.
+
+Default value is @code{0} (disabled).
+
+@item field
+Set the field to match from. It is recommended to set this to the same value as
+@option{order} unless you experience matching failures with that setting. In
+certain circumstances changing the field that is used to match from can have a
+large impact on matching performance. Available values are:
+
+@table @samp
+@item auto
+Automatic (same value as @option{order}).
+@item bottom
+Match from the bottom field.
+@item top
+Match from the top field.
+@end table
+
+Default value is @var{auto}.
+
+@item mchroma
+Set whether or not chroma is included during the match comparisons. In most
+cases it is recommended to leave this enabled. You should set this to @code{0}
+only if your clip has bad chroma problems such as heavy rainbowing or other
+artifacts. Setting this to @code{0} could also be used to speed things up at
+the cost of some accuracy.
+
+Default value is @code{1}.
+
+@item y0
+@item y1
+These define an exclusion band which excludes the lines between @option{y0} and
+@option{y1} from being included in the field matching decision. An exclusion
+band can be used to ignore subtitles, a logo, or other things that may
+interfere with the matching. @option{y0} sets the starting scan line and
+@option{y1} sets the ending line; all lines in between @option{y0} and
+@option{y1} (including @option{y0} and @option{y1}) will be ignored. Setting
+@option{y0} and @option{y1} to the same value will disable the feature.
+@option{y0} and @option{y1} defaults to @code{0}.
+
+@item scthresh
+Set the scene change detection threshold as a percentage of maximum change on
+the luma plane. Good values are in the @code{[8.0, 14.0]} range. Scene change
+detection is only relevant in case @option{combmatch}=@var{sc}. The range for
+@option{scthresh} is @code{[0.0, 100.0]}.
+
+Default value is @code{12.0}.
+
+@item combmatch
+When @option{combatch} is not @var{none}, @code{fieldmatch} will take into
+account the combed scores of matches when deciding what match to use as the
+final match. Available values are:
+
+@table @samp
+@item none
+No final matching based on combed scores.
+@item sc
+Combed scores are only used when a scene change is detected.
+@item full
+Use combed scores all the time.
+@end table
+
+Default is @var{sc}.
+
+@item combdbg
+Force @code{fieldmatch} to calculate the combed metrics for certain matches and
+print them. This setting is known as @option{micout} in TFM/VFM vocabulary.
+Available values are:
+
+@table @samp
+@item none
+No forced calculation.
+@item pcn
+Force p/c/n calculations.
+@item pcnub
+Force p/c/n/u/b calculations.
+@end table
+
+Default value is @var{none}.
+
+@item cthresh
+This is the area combing threshold used for combed frame detection. This
+essentially controls how "strong" or "visible" combing must be to be detected.
+Larger values mean combing must be more visible and smaller values mean combing
+can be less visible or strong and still be detected. Valid settings are from
+@code{-1} (every pixel will be detected as combed) to @code{255} (no pixel will
+be detected as combed). This is basically a pixel difference value. A good
+range is @code{[8, 12]}.
+
+Default value is @code{9}.
+
+@item chroma
+Sets whether or not chroma is considered in the combed frame decision. Only
+disable this if your source has chroma problems (rainbowing, etc.) that are
+causing problems for the combed frame detection with chroma enabled. Actually,
+using @option{chroma}=@var{0} is usually more reliable, except for the case
+where there is chroma only combing in the source.
+
+Default value is @code{0}.
+
+@item blockx
+@item blocky
+Respectively set the x-axis and y-axis size of the window used during combed
+frame detection. This has to do with the size of the area in which
+@option{combpel} pixels are required to be detected as combed for a frame to be
+declared combed. See the @option{combpel} parameter description for more info.
+Possible values are any number that is a power of 2 starting at 4 and going up
+to 512.
+
+Default value is @code{16}.
+
+@item combpel
+The number of combed pixels inside any of the @option{blocky} by
+@option{blockx} size blocks on the frame for the frame to be detected as
+combed. While @option{cthresh} controls how "visible" the combing must be, this
+setting controls "how much" combing there must be in any localized area (a
+window defined by the @option{blockx} and @option{blocky} settings) on the
+frame. Minimum value is @code{0} and maximum is @code{blocky x blockx} (at
+which point no frames will ever be detected as combed). This setting is known
+as @option{MI} in TFM/VFM vocabulary.
+
+Default value is @code{80}.
+@end table
+
+@anchor{p/c/n/u/b meaning}
+@subsection p/c/n/u/b meaning
+
+@subsubsection p/c/n
+
+We assume the following telecined stream:
+
+@example
+Top fields: 1 2 2 3 4
+Bottom fields: 1 2 3 4 4
+@end example
+
+The numbers correspond to the progressive frame the fields relate to. Here, the
+first two frames are progressive, the 3rd and 4th are combed, and so on.
+
+When @code{fieldmatch} is configured to run a matching from bottom
+(@option{field}=@var{bottom}) this is how this input stream get transformed:
+
+@example
+Input stream:
+ T 1 2 2 3 4
+ B 1 2 3 4 4 <-- matching reference
+
+Matches: c c n n c
+
+Output stream:
+ T 1 2 3 4 4
+ B 1 2 3 4 4
+@end example
+
+As a result of the field matching, we can see that some frames get duplicated.
+To perform a complete inverse telecine, you need to rely on a decimation filter
+after this operation. See for instance the @ref{decimate} filter.
+
+The same operation now matching from top fields (@option{field}=@var{top})
+looks like this:
+
+@example
+Input stream:
+ T 1 2 2 3 4 <-- matching reference
+ B 1 2 3 4 4
+
+Matches: c c p p c
+
+Output stream:
+ T 1 2 2 3 4
+ B 1 2 2 3 4
+@end example
+
+In these examples, we can see what @var{p}, @var{c} and @var{n} mean;
+basically, they refer to the frame and field of the opposite parity:
+
+@itemize
+@item @var{p} matches the field of the opposite parity in the previous frame
+@item @var{c} matches the field of the opposite parity in the current frame
+@item @var{n} matches the field of the opposite parity in the next frame
+@end itemize
+
+@subsubsection u/b
+
+The @var{u} and @var{b} matching are a bit special in the sense that they match
+from the opposite parity flag. In the following examples, we assume that we are
+currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
+'x' is placed above and below each matched fields.
+
+With bottom matching (@option{field}=@var{bottom}):
+@example
+Match: c p n b u
+
+ x x x x x
+ Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
+ Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
+ x x x x x
+
+Output frames:
+ 2 1 2 2 2
+ 2 2 2 1 3
+@end example
+
+With top matching (@option{field}=@var{top}):
+@example
+Match: c p n b u
+
+ x x x x x
+ Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
+ Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
+ x x x x x
+
+Output frames:
+ 2 2 2 1 2
+ 2 1 3 2 2
+@end example
+
+@subsection Examples
+
+Simple IVTC of a top field first telecined stream:
+@example
+fieldmatch=order=tff:combmatch=none, decimate
+@end example
+
+Advanced IVTC, with fallback on @ref{yadif} for still combed frames:
+@example
+fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
+@end example
+
+@section fieldorder
+
+Transform the field order of the input video.
+
+It accepts the following parameters:
+
+@table @option
+
+@item order
+The output field order. Valid values are @var{tff} for top field first or @var{bff}
+for bottom field first.
+@end table
+
+The default value is @samp{tff}.
+
+The transformation is done by shifting the picture content up or down
+by one line, and filling the remaining line with appropriate picture content.
+This method is consistent with most broadcast field order converters.
+
+If the input video is not flagged as being interlaced, or it is already
+flagged as being of the required output field order, then this filter does
+not alter the incoming video.
+
+It is very useful when converting to or from PAL DV material,
+which is bottom field first.
+
+For example:
+@example
+ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
+@end example
+
+@section fifo, afifo
+
+Buffer input images and send them when they are requested.
+
+It is mainly useful when auto-inserted by the libavfilter
+framework.
+
+It does not take parameters.
+
+@section find_rect
+
+Find a rectangular object
+
+It accepts the following options:
+
+@table @option
+@item object
+Filepath of the object image, needs to be in gray8.
+
+@item threshold
+Detection threshold, default is 0.5.
+
+@item mipmaps
+Number of mipmaps, default is 3.
+
+@item xmin, ymin, xmax, ymax
+Specifies the rectangle in which to search.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Generate a representative palette of a given video using @command{ffmpeg}:
+@example
+ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
+@end example
+@end itemize
+
+@section cover_rect
+
+Cover a rectangular object
+
+It accepts the following options:
+
+@table @option
+@item cover
+Filepath of the optional cover image, needs to be in yuv420.
+
+@item mode
+Set covering mode.
+
+It accepts the following values:
+@table @samp
+@item cover
+cover it by the supplied image
+@item blur
+cover it by interpolating the surrounding pixels
+@end table
+
+Default value is @var{blur}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Generate a representative palette of a given video using @command{ffmpeg}:
+@example
+ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
+@end example
+@end itemize
+
+@anchor{format}
+@section format
+
+Convert the input video to one of the specified pixel formats.
+Libavfilter will try to pick one that is suitable as input to
+the next filter.
+
+It accepts the following parameters:
+@table @option
+
+@item pix_fmts
+A '|'-separated list of pixel format names, such as
+"pix_fmts=yuv420p|monow|rgb24".
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Convert the input video to the @var{yuv420p} format
+@example
+format=pix_fmts=yuv420p
+@end example
+
+Convert the input video to any of the formats in the list
+@example
+format=pix_fmts=yuv420p|yuv444p|yuv410p
+@end example
+@end itemize
+
+@anchor{fps}
+@section fps
+
+Convert the video to specified constant frame rate by duplicating or dropping
+frames as necessary.
+
+It accepts the following parameters:
+@table @option
+
+@item fps
+The desired output frame rate. The default is @code{25}.
+
+@item round
+Rounding method.
+
+Possible values are:
+@table @option
+@item zero
+zero round towards 0
+@item inf
+round away from 0
+@item down
+round towards -infinity
+@item up
+round towards +infinity
+@item near
+round to nearest
+@end table
+The default is @code{near}.
+
+@item start_time
+Assume the first PTS should be the given value, in seconds. This allows for
+padding/trimming at the start of stream. By default, no assumption is made
+about the first frame's expected PTS, so no padding or trimming is done.
+For example, this could be set to 0 to pad the beginning with duplicates of
+the first frame if a video stream starts after the audio stream or to trim any
+frames with a negative PTS.
+
+@end table
+
+Alternatively, the options can be specified as a flat string:
+@var{fps}[:@var{round}].
+
+See also the @ref{setpts} filter.
+
+@subsection Examples
+
+@itemize
+@item
+A typical usage in order to set the fps to 25:
+@example
+fps=fps=25
+@end example
+
+@item
+Sets the fps to 24, using abbreviation and rounding method to round to nearest:
+@example
+fps=fps=film:round=near
+@end example
+@end itemize
+
+@section framepack
+
+Pack two different video streams into a stereoscopic video, setting proper
+metadata on supported codecs. The two views should have the same size and
+framerate and processing will stop when the shorter video ends. Please note
+that you may conveniently adjust view properties with the @ref{scale} and
+@ref{fps} filters.
+
+It accepts the following parameters:
+@table @option
+
+@item format
+The desired packing format. Supported values are:
+
+@table @option
+
+@item sbs
+The views are next to each other (default).
+
+@item tab
+The views are on top of each other.
+
+@item lines
+The views are packed by line.
+
+@item columns
+The views are packed by column.
+
+@item frameseq
+The views are temporally interleaved.
+
+@end table
+
+@end table
+
+Some examples:
+
+@example
+# Convert left and right views into a frame-sequential video
+ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
+
+# Convert views into a side-by-side video with the same output resolution as the input
+ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
+@end example
+
+@section framerate
+
+Change the frame rate by interpolating new video output frames from the source
+frames.
+
+This filter is not designed to function correctly with interlaced media. If
+you wish to change the frame rate of interlaced media then you are required
+to deinterlace before this filter and re-interlace after this filter.
+
+A description of the accepted options follows.
+
+@table @option
+@item fps
+Specify the output frames per second. This option can also be specified
+as a value alone. The default is @code{50}.
+
+@item interp_start
+Specify the start of a range where the output frame will be created as a
+linear interpolation of two frames. The range is [@code{0}-@code{255}],
+the default is @code{15}.
+
+@item interp_end
+Specify the end of a range where the output frame will be created as a
+linear interpolation of two frames. The range is [@code{0}-@code{255}],
+the default is @code{240}.
+
+@item scene
+Specify the level at which a scene change is detected as a value between
+0 and 100 to indicate a new scene; a low value reflects a low
+probability for the current frame to introduce a new scene, while a higher
+value means the current frame is more likely to be one.
+The default is @code{7}.
+
+@item flags
+Specify flags influencing the filter process.
+
+Available value for @var{flags} is:
+
+@table @option
+@item scene_change_detect, scd
+Enable scene change detection using the value of the option @var{scene}.
+This flag is enabled by default.
+@end table
+@end table
+
+@section framestep
+
+Select one frame every N-th frame.
+
+This filter accepts the following option:
+@table @option
+@item step
+Select frame after every @code{step} frames.
+Allowed values are positive integers higher than 0. Default value is @code{1}.
+@end table
+
+@anchor{frei0r}
+@section frei0r
+
+Apply a frei0r effect to the input video.
+
+To enable the compilation of this filter, you need to install the frei0r
+header and configure FFmpeg with @code{--enable-frei0r}.
+
+It accepts the following parameters:
+
+@table @option
+
+@item filter_name
+The name of the frei0r effect to load. If the environment variable
+@env{FREI0R_PATH} is defined, the frei0r effect is searched for in each of the
+directories specified by the colon-separated list in @env{FREIOR_PATH}.
+Otherwise, the standard frei0r paths are searched, in this order:
+@file{HOME/.frei0r-1/lib/}, @file{/usr/local/lib/frei0r-1/},
+@file{/usr/lib/frei0r-1/}.
+
+@item filter_params
+A '|'-separated list of parameters to pass to the frei0r effect.
+
+@end table
+
+A frei0r effect parameter can be a boolean (its value is either
+"y" or "n"), a double, a color (specified as
+@var{R}/@var{G}/@var{B}, where @var{R}, @var{G}, and @var{B} are floating point
+numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
+section in the ffmpeg-utils manual), a position (specified as @var{X}/@var{Y}, where
+@var{X} and @var{Y} are floating point numbers) and/or a string.
+
+The number and types of parameters depend on the loaded effect. If an
+effect parameter is not specified, the default value is set.
+
+@subsection Examples
+
+@itemize
+@item
+Apply the distort0r effect, setting the first two double parameters:
+@example
+frei0r=filter_name=distort0r:filter_params=0.5|0.01
+@end example
+
+@item
+Apply the colordistance effect, taking a color as the first parameter:
+@example
+frei0r=colordistance:0.2/0.3/0.4
+frei0r=colordistance:violet
+frei0r=colordistance:0x112233
+@end example
+
+@item
+Apply the perspective effect, specifying the top left and top right image
+positions:
+@example
+frei0r=perspective:0.2/0.2|0.8/0.2
+@end example
+@end itemize
+
+For more information, see
+@url{http://frei0r.dyne.org}
+
+@section fspp
+
+Apply fast and simple postprocessing. It is a faster version of @ref{spp}.
+
+It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
+processing filter, one of them is performed once per block, not per pixel.
+This allows for much higher speed.
+
+The filter accepts the following options:
+
+@table @option
+@item quality
+Set quality. This option defines the number of levels for averaging. It accepts
+an integer in the range 4-5. Default value is @code{4}.
+
+@item qp
+Force a constant quantization parameter. It accepts an integer in range 0-63.
+If not set, the filter will use the QP from the video stream (if available).
+
+@item strength
+Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
+more details but also more artifacts, while higher values make the image smoother
+but also blurrier. Default value is @code{0} − PSNR optimal.
+
+@item use_bframe_qp
+Enable the use of the QP from the B-Frames if set to @code{1}. Using this
+option may cause flicker since the B-Frames have often larger QP. Default is
+@code{0} (not enabled).
+
+@end table
+
+@section geq
+
+The filter accepts the following options:
+
+@table @option
+@item lum_expr, lum
+Set the luminance expression.
+@item cb_expr, cb
+Set the chrominance blue expression.
+@item cr_expr, cr
+Set the chrominance red expression.
+@item alpha_expr, a
+Set the alpha expression.
+@item red_expr, r
+Set the red expression.
+@item green_expr, g
+Set the green expression.
+@item blue_expr, b
+Set the blue expression.
+@end table
+
+The colorspace is selected according to the specified options. If one
+of the @option{lum_expr}, @option{cb_expr}, or @option{cr_expr}
+options is specified, the filter will automatically select a YCbCr
+colorspace. If one of the @option{red_expr}, @option{green_expr}, or
+@option{blue_expr} options is specified, it will select an RGB
+colorspace.
+
+If one of the chrominance expression is not defined, it falls back on the other
+one. If no alpha expression is specified it will evaluate to opaque value.
+If none of chrominance expressions are specified, they will evaluate
+to the luminance expression.
+
+The expressions can use the following variables and functions:
+
+@table @option
+@item N
+The sequential number of the filtered frame, starting from @code{0}.
+
+@item X
+@item Y
+The coordinates of the current sample.
+
+@item W
+@item H
+The width and height of the image.
+
+@item SW
+@item SH
+Width and height scale depending on the currently filtered plane. It is the
+ratio between the corresponding luma plane number of pixels and the current
+plane ones. E.g. for YUV4:2:0 the values are @code{1,1} for the luma plane, and
+@code{0.5,0.5} for chroma planes.
+
+@item T
+Time of the current frame, expressed in seconds.
+
+@item p(x, y)
+Return the value of the pixel at location (@var{x},@var{y}) of the current
+plane.
+
+@item lum(x, y)
+Return the value of the pixel at location (@var{x},@var{y}) of the luminance
+plane.
+
+@item cb(x, y)
+Return the value of the pixel at location (@var{x},@var{y}) of the
+blue-difference chroma plane. Return 0 if there is no such plane.
+
+@item cr(x, y)
+Return the value of the pixel at location (@var{x},@var{y}) of the
+red-difference chroma plane. Return 0 if there is no such plane.
+
+@item r(x, y)
+@item g(x, y)
+@item b(x, y)
+Return the value of the pixel at location (@var{x},@var{y}) of the
+red/green/blue component. Return 0 if there is no such component.
+
+@item alpha(x, y)
+Return the value of the pixel at location (@var{x},@var{y}) of the alpha
+plane. Return 0 if there is no such plane.
+@end table
+
+For functions, if @var{x} and @var{y} are outside the area, the value will be
+automatically clipped to the closer edge.
+
+@subsection Examples
+
+@itemize
+@item
+Flip the image horizontally:
+@example
+geq=p(W-X\,Y)
+@end example
+
+@item
+Generate a bidimensional sine wave, with angle @code{PI/3} and a
+wavelength of 100 pixels:
+@example
+geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
+@end example
+
+@item
+Generate a fancy enigmatic moving light:
+@example
+nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
+@end example
+
+@item
+Generate a quick emboss effect:
+@example
+format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
+@end example
+
+@item
+Modify RGB components depending on pixel position:
+@example
+geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
+@end example
+
+@item
+Create a radial gradient that is the same size as the input (also see
+the @ref{vignette} filter):
+@example
+geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
+@end example
+@end itemize
+
+@section gradfun
+
+Fix the banding artifacts that are sometimes introduced into nearly flat
+regions by truncation to 8bit color depth.
+Interpolate the gradients that should go where the bands are, and
+dither them.
+
+It is designed for playback only. Do not use it prior to
+lossy compression, because compression tends to lose the dither and
+bring back the bands.
+
+It accepts the following parameters:
+
+@table @option
+
+@item strength
+The maximum amount by which the filter will change any one pixel. This is also
+the threshold for detecting nearly flat regions. Acceptable values range from
+.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
+valid range.
+
+@item radius
+The neighborhood to fit the gradient to. A larger radius makes for smoother
+gradients, but also prevents the filter from modifying the pixels near detailed
+regions. Acceptable values are 8-32; the default value is 16. Out-of-range
+values will be clipped to the valid range.
+
+@end table
+
+Alternatively, the options can be specified as a flat string:
+@var{strength}[:@var{radius}]
+
+@subsection Examples
+
+@itemize
+@item
+Apply the filter with a @code{3.5} strength and radius of @code{8}:
+@example
+gradfun=3.5:8
+@end example
+
+@item
+Specify radius, omitting the strength (which will fall-back to the default
+value):
+@example
+gradfun=radius=8
+@end example
+
+@end itemize
+
+@anchor{haldclut}
+@section haldclut
+
+Apply a Hald CLUT to a video stream.
+
+First input is the video stream to process, and second one is the Hald CLUT.
+The Hald CLUT input can be a simple picture or a complete video stream.
+
+The filter accepts the following options:
+
+@table @option
+@item shortest
+Force termination when the shortest input terminates. Default is @code{0}.
+@item repeatlast
+Continue applying the last CLUT after the end of the stream. A value of
+@code{0} disable the filter after the last frame of the CLUT is reached.
+Default is @code{1}.
+@end table
+
+@code{haldclut} also has the same interpolation options as @ref{lut3d} (both
+filters share the same internals).
+
+More information about the Hald CLUT can be found on Eskil Steenberg's website
+(Hald CLUT author) at @url{http://www.quelsolaar.com/technology/clut.html}.
+
+@subsection Workflow examples
+
+@subsubsection Hald CLUT video stream
+
+Generate an identity Hald CLUT stream altered with various effects:
+@example
+ffmpeg -f lavfi -i @ref{haldclutsrc}=8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
+@end example
+
+Note: make sure you use a lossless codec.
+
+Then use it with @code{haldclut} to apply it on some random stream:
+@example
+ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
+@end example
+
+The Hald CLUT will be applied to the 10 first seconds (duration of
+@file{clut.nut}), then the latest picture of that CLUT stream will be applied
+to the remaining frames of the @code{mandelbrot} stream.
+
+@subsubsection Hald CLUT with preview
+
+A Hald CLUT is supposed to be a squared image of @code{Level*Level*Level} by
+@code{Level*Level*Level} pixels. For a given Hald CLUT, FFmpeg will select the
+biggest possible square starting at the top left of the picture. The remaining
+padding pixels (bottom or right) will be ignored. This area can be used to add
+a preview of the Hald CLUT.
+
+Typically, the following generated Hald CLUT will be supported by the
+@code{haldclut} filter:
+
+@example
+ffmpeg -f lavfi -i @ref{haldclutsrc}=8 -vf "
+ pad=iw+320 [padded_clut];
+ smptebars=s=320x256, split [a][b];
+ [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
+ [main][b] overlay=W-320" -frames:v 1 clut.png
+@end example
+
+It contains the original and a preview of the effect of the CLUT: SMPTE color
+bars are displayed on the right-top, and below the same color bars processed by
+the color changes.
+
+Then, the effect of this Hald CLUT can be visualized with:
+@example
+ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
+@end example
+
+@section hflip
+
+Flip the input video horizontally.
+
+For example, to horizontally flip the input video with @command{ffmpeg}:
+@example
+ffmpeg -i in.avi -vf "hflip" out.avi
+@end example
+
+@section histeq
+This filter applies a global color histogram equalization on a
+per-frame basis.
+
+It can be used to correct video that has a compressed range of pixel
+intensities. The filter redistributes the pixel intensities to
+equalize their distribution across the intensity range. It may be
+viewed as an "automatically adjusting contrast filter". This filter is
+useful only for correcting degraded or poorly captured source
+video.
+
+The filter accepts the following options:
+
+@table @option
+@item strength
+Determine the amount of equalization to be applied. As the strength
+is reduced, the distribution of pixel intensities more-and-more
+approaches that of the input frame. The value must be a float number
+in the range [0,1] and defaults to 0.200.
+
+@item intensity
+Set the maximum intensity that can generated and scale the output
+values appropriately. The strength should be set as desired and then
+the intensity can be limited if needed to avoid washing-out. The value
+must be a float number in the range [0,1] and defaults to 0.210.
+
+@item antibanding
+Set the antibanding level. If enabled the filter will randomly vary
+the luminance of output pixels by a small amount to avoid banding of
+the histogram. Possible values are @code{none}, @code{weak} or
+@code{strong}. It defaults to @code{none}.
+@end table
+
+@section histogram
+
+Compute and draw a color distribution histogram for the input video.
+
+The computed histogram is a representation of the color component
+distribution in an image.
+
+Standard histogram displays the color components distribution in an image.
+Displays color graph for each color component. Shows distribution of
+the Y, U, V, A or R, G, B components, depending on input format, in the
+current frame. Below each graph a color component scale meter is shown.
+
+The filter accepts the following options:
+
+@table @option
+@item level_height
+Set height of level. Default value is @code{200}.
+Allowed range is [50, 2048].
+
+@item scale_height
+Set height of color scale. Default value is @code{12}.
+Allowed range is [0, 40].
+
+@item display_mode
+Set display mode.
+It accepts the following values:
+@table @samp
+@item parade
+Per color component graphs are placed below each other.
+
+@item overlay
+Presents information identical to that in the @code{parade}, except
+that the graphs representing color components are superimposed directly
+over one another.
+@end table
+Default is @code{parade}.
+
+@item levels_mode
+Set mode. Can be either @code{linear}, or @code{logarithmic}.
+Default is @code{linear}.
+
+@item components
+Set what color components to display.
+Default is @code{7}.
+@end table
+
+@subsection Examples
+
+@itemize
+
+@item
+Calculate and draw histogram:
+@example
+ffplay -i input -vf histogram
+@end example
+
+@end itemize
+
+@anchor{hqdn3d}
+@section hqdn3d
+
+This is a high precision/quality 3d denoise filter. It aims to reduce
+image noise, producing smooth images and making still images really
+still. It should enhance compressibility.
+
+It accepts the following optional parameters:
+
+@table @option
+@item luma_spatial
+A non-negative floating point number which specifies spatial luma strength.
+It defaults to 4.0.
+
+@item chroma_spatial
+A non-negative floating point number which specifies spatial chroma strength.
+It defaults to 3.0*@var{luma_spatial}/4.0.
+
+@item luma_tmp
+A floating point number which specifies luma temporal strength. It defaults to
+6.0*@var{luma_spatial}/4.0.
+
+@item chroma_tmp
+A floating point number which specifies chroma temporal strength. It defaults to
+@var{luma_tmp}*@var{chroma_spatial}/@var{luma_spatial}.
+@end table
+
++@anchor{hwupload_cuda}
++@section hwupload_cuda
++
++Upload system memory frames to a CUDA device.
++
++It accepts the following optional parameters:
++
++@table @option
++@item device
++The number of the CUDA device to use
++@end table
++
+@section hqx
+
+Apply a high-quality magnification filter designed for pixel art. This filter
+was originally created by Maxim Stepin.
+
+It accepts the following option:
+
+@table @option
+@item n
+Set the scaling dimension: @code{2} for @code{hq2x}, @code{3} for
+@code{hq3x} and @code{4} for @code{hq4x}.
+Default is @code{3}.
+@end table
+
+@section hstack
+Stack input videos horizontally.
+
+All streams must be of same pixel format and of same height.
+
+Note that this filter is faster than using @ref{overlay} and @ref{pad} filter
+to create same output.
+
+The filter accept the following option:
+
+@table @option
+@item inputs
+Set number of input streams. Default is 2.
+
+@item shortest
+If set to 1, force the output to terminate when the shortest input
+terminates. Default value is 0.
+@end table
+
+@section hue
+
+Modify the hue and/or the saturation of the input.
+
+It accepts the following parameters:
+
+@table @option
+@item h
+Specify the hue angle as a number of degrees. It accepts an expression,
+and defaults to "0".
+
+@item s
+Specify the saturation in the [-10,10] range. It accepts an expression and
+defaults to "1".
+
+@item H
+Specify the hue angle as a number of radians. It accepts an
+expression, and defaults to "0".
+
+@item b
+Specify the brightness in the [-10,10] range. It accepts an expression and
+defaults to "0".
+@end table
+
+@option{h} and @option{H} are mutually exclusive, and can't be
+specified at the same time.
+
+The @option{b}, @option{h}, @option{H} and @option{s} option values are
+expressions containing the following constants:
+
+@table @option
+@item n
+frame count of the input frame starting from 0
+
+@item pts
+presentation timestamp of the input frame expressed in time base units
+
+@item r
+frame rate of the input video, NAN if the input frame rate is unknown
+
+@item t
+timestamp expressed in seconds, NAN if the input timestamp is unknown
+
+@item tb
+time base of the input video
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Set the hue to 90 degrees and the saturation to 1.0:
+@example
+hue=h=90:s=1
+@end example
+
+@item
+Same command but expressing the hue in radians:
+@example
+hue=H=PI/2:s=1
+@end example
+
+@item
+Rotate hue and make the saturation swing between 0
+and 2 over a period of 1 second:
+@example
+hue="H=2*PI*t: s=sin(2*PI*t)+1"
+@end example
+
+@item
+Apply a 3 seconds saturation fade-in effect starting at 0:
+@example
+hue="s=min(t/3\,1)"
+@end example
+
+The general fade-in expression can be written as:
+@example
+hue="s=min(0\, max((t-START)/DURATION\, 1))"
+@end example
+
+@item
+Apply a 3 seconds saturation fade-out effect starting at 5 seconds:
+@example
+hue="s=max(0\, min(1\, (8-t)/3))"
+@end example
+
+The general fade-out expression can be written as:
+@example
+hue="s=max(0\, min(1\, (START+DURATION-t)/DURATION))"
+@end example
+
+@end itemize
+
+@subsection Commands
+
+This filter supports the following commands:
+@table @option
+@item b
+@item s
+@item h
+@item H
+Modify the hue and/or the saturation and/or brightness of the input video.
+The command accepts the same syntax of the corresponding option.
+
+If the specified expression is not valid, it is kept at its current
+value.
+@end table
+
+@section idet
+
+Detect video interlacing type.
+
+This filter tries to detect if the input frames as interlaced, progressive,
+top or bottom field first. It will also try and detect fields that are
+repeated between adjacent frames (a sign of telecine).
+
+Single frame detection considers only immediately adjacent frames when classifying each frame.
+Multiple frame detection incorporates the classification history of previous frames.
+
+The filter will log these metadata values:
+
+@table @option
+@item single.current_frame
+Detected type of current frame using single-frame detection. One of:
+``tff'' (top field first), ``bff'' (bottom field first),
+``progressive'', or ``undetermined''
+
+@item single.tff
+Cumulative number of frames detected as top field first using single-frame detection.
+
+@item multiple.tff
+Cumulative number of frames detected as top field first using multiple-frame detection.
+
+@item single.bff
+Cumulative number of frames detected as bottom field first using single-frame detection.
+
+@item multiple.current_frame
+Detected type of current frame using multiple-frame detection. One of:
+``tff'' (top field first), ``bff'' (bottom field first),
+``progressive'', or ``undetermined''
+
+@item multiple.bff
+Cumulative number of frames detected as bottom field first using multiple-frame detection.
+
+@item single.progressive
+Cumulative number of frames detected as progressive using single-frame detection.
+
+@item multiple.progressive
+Cumulative number of frames detected as progressive using multiple-frame detection.
+
+@item single.undetermined
+Cumulative number of frames that could not be classified using single-frame detection.
+
+@item multiple.undetermined
+Cumulative number of frames that could not be classified using multiple-frame detection.
+
+@item repeated.current_frame
+Which field in the current frame is repeated from the last. One of ``neither'', ``top'', or ``bottom''.
+
+@item repeated.neither
+Cumulative number of frames with no repeated field.
+
+@item repeated.top
+Cumulative number of frames with the top field repeated from the previous frame's top field.
+
+@item repeated.bottom
+Cumulative number of frames with the bottom field repeated from the previous frame's bottom field.
+@end table
+
+The filter accepts the following options:
+
+@table @option
+@item intl_thres
+Set interlacing threshold.
+@item prog_thres
+Set progressive threshold.
+@item repeat_thres
+Threshold for repeated field detection.
+@item half_life
+Number of frames after which a given frame's contribution to the
+statistics is halved (i.e., it contributes only 0.5 to it's
+classification). The default of 0 means that all frames seen are given
+full weight of 1.0 forever.
+@item analyze_interlaced_flag
+When this is not 0 then idet will use the specified number of frames to determine
+if the interlaced flag is accurate, it will not count undetermined frames.
+If the flag is found to be accurate it will be used without any further
+computations, if it is found to be inaccurate it will be cleared without any
+further computations. This allows inserting the idet filter as a low computational
+method to clean up the interlaced flag
+@end table
+
+@section il
+
+Deinterleave or interleave fields.
+
+This filter allows one to process interlaced images fields without
+deinterlacing them. Deinterleaving splits the input frame into 2
+fields (so called half pictures). Odd lines are moved to the top
+half of the output image, even lines to the bottom half.
+You can process (filter) them independently and then re-interleave them.
+
+The filter accepts the following options:
+
+@table @option
+@item luma_mode, l
+@item chroma_mode, c
+@item alpha_mode, a
+Available values for @var{luma_mode}, @var{chroma_mode} and
+@var{alpha_mode} are:
+
+@table @samp
+@item none
+Do nothing.
+
+@item deinterleave, d
+Deinterleave fields, placing one above the other.
+
+@item interleave, i
+Interleave fields. Reverse the effect of deinterleaving.
+@end table
+Default value is @code{none}.
+
+@item luma_swap, ls
+@item chroma_swap, cs
+@item alpha_swap, as
+Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is @code{0}.
+@end table
+
+@section inflate
+
+Apply inflate effect to the video.
+
+This filter replaces the pixel by the local(3x3) average by taking into account
+only values higher than the pixel.
+
+It accepts the following options:
+
+@table @option
+@item threshold0
+@item threshold1
+@item threshold2
+@item threshold3
+Limit the maximum change for each plane, default is 65535.
+If 0, plane will remain unchanged.
+@end table
+
+@section interlace
+
+Simple interlacing filter from progressive contents. This interleaves upper (or
+lower) lines from odd frames with lower (or upper) lines from even frames,
+halving the frame rate and preserving image height.
+
+@example
+ Original Original New Frame
+ Frame 'j' Frame 'j+1' (tff)
+ ========== =========== ==================
+ Line 0 --------------------> Frame 'j' Line 0
+ Line 1 Line 1 ----> Frame 'j+1' Line 1
+ Line 2 ---------------------> Frame 'j' Line 2
+ Line 3 Line 3 ----> Frame 'j+1' Line 3
+ ... ... ...
+New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
+@end example
+
+It accepts the following optional parameters:
+
+@table @option
+@item scan
+This determines whether the interlaced frame is taken from the even
+(tff - default) or odd (bff) lines of the progressive frame.
+
+@item lowpass
+Enable (default) or disable the vertical lowpass filter to avoid twitter
+interlacing and reduce moire patterns.
+@end table
+
+@section kerndeint
+
+Deinterlace input video by applying Donald Graft's adaptive kernel
+deinterling. Work on interlaced parts of a video to produce
+progressive frames.
+
+The description of the accepted parameters follows.
+
+@table @option
+@item thresh
+Set the threshold which affects the filter's tolerance when
+determining if a pixel line must be processed. It must be an integer
+in the range [0,255] and defaults to 10. A value of 0 will result in
+applying the process on every pixels.
+
+@item map
+Paint pixels exceeding the threshold value to white if set to 1.
+Default is 0.
+
+@item order
+Set the fields order. Swap fields if set to 1, leave fields alone if
+0. Default is 0.
+
+@item sharp
+Enable additional sharpening if set to 1. Default is 0.
+
+@item twoway
+Enable twoway sharpening if set to 1. Default is 0.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Apply default values:
+@example
+kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
+@end example
+
+@item
+Enable additional sharpening:
+@example
+kerndeint=sharp=1
+@end example
+
+@item
+Paint processed pixels in white:
+@example
+kerndeint=map=1
+@end example
+@end itemize
+
+@section lenscorrection
+
+Correct radial lens distortion
+
+This filter can be used to correct for radial distortion as can result from the use
+of wide angle lenses, and thereby re-rectify the image. To find the right parameters
+one can use tools available for example as part of opencv or simply trial-and-error.
+To use opencv use the calibration sample (under samples/cpp) from the opencv sources
+and extract the k1 and k2 coefficients from the resulting matrix.
+
+Note that effectively the same filter is available in the open-source tools Krita and
+Digikam from the KDE project.
+
+In contrast to the @ref{vignette} filter, which can also be used to compensate lens errors,
+this filter corrects the distortion of the image, whereas @ref{vignette} corrects the
+brightness distribution, so you may want to use both filters together in certain
+cases, though you will have to take care of ordering, i.e. whether vignetting should
+be applied before or after lens correction.
+
+@subsection Options
+
+The filter accepts the following options:
+
+@table @option
+@item cx
+Relative x-coordinate of the focal point of the image, and thereby the center of the
+distortion. This value has a range [0,1] and is expressed as fractions of the image
+width.
+@item cy
+Relative y-coordinate of the focal point of the image, and thereby the center of the
+distortion. This value has a range [0,1] and is expressed as fractions of the image
+height.
+@item k1
+Coefficient of the quadratic correction term. 0.5 means no correction.
+@item k2
+Coefficient of the double quadratic correction term. 0.5 means no correction.
+@end table
+
+The formula that generates the correction is:
+
+@var{r_src} = @var{r_tgt} * (1 + @var{k1} * (@var{r_tgt} / @var{r_0})^2 + @var{k2} * (@var{r_tgt} / @var{r_0})^4)
+
+where @var{r_0} is halve of the image diagonal and @var{r_src} and @var{r_tgt} are the
+distances from the focal point in the source and target images, respectively.
+
+@section loop, aloop
+
+Loop video frames or audio samples.
+
+Those filters accepts the following options:
+
+@table @option
+@item loop
+Set the number of loops.
+
+@item size
+Set maximal size in number of frames for @code{loop} filter or maximal number
+of samples in case of @code{aloop} filter.
+
+@item start
+Set first frame of loop for @code{loop} filter or first sample of loop in case
+of @code{aloop} filter.
+@end table
+
+@anchor{lut3d}
+@section lut3d
+
+Apply a 3D LUT to an input video.
+
+The filter accepts the following options:
+
+@table @option
+@item file
+Set the 3D LUT file name.
+
+Currently supported formats:
+@table @samp
+@item 3dl
+AfterEffects
+@item cube
+Iridas
+@item dat
+DaVinci
+@item m3d
+Pandora
+@end table
+@item interp
+Select interpolation mode.
+
+Available values are:
+
+@table @samp
+@item nearest
+Use values from the nearest defined point.
+@item trilinear
+Interpolate values using the 8 points defining a cube.
+@item tetrahedral
+Interpolate values using a tetrahedron.
+@end table
+@end table
+
+@section lut, lutrgb, lutyuv
+
+Compute a look-up table for binding each pixel component input value
+to an output value, and apply it to the input video.
+
+@var{lutyuv} applies a lookup table to a YUV input video, @var{lutrgb}
+to an RGB input video.
+
+These filters accept the following parameters:
+@table @option
+@item c0
+set first pixel component expression
+@item c1
+set second pixel component expression
+@item c2
+set third pixel component expression
+@item c3
+set fourth pixel component expression, corresponds to the alpha component
+
+@item r
+set red component expression
+@item g
+set green component expression
+@item b
+set blue component expression
+@item a
+alpha component expression
+
+@item y
+set Y/luminance component expression
+@item u
+set U/Cb component expression
+@item v
+set V/Cr component expression
+@end table
+
+Each of them specifies the expression to use for computing the lookup table for
+the corresponding pixel component values.
+
+The exact component associated to each of the @var{c*} options depends on the
+format in input.
+
+The @var{lut} filter requires either YUV or RGB pixel formats in input,
+@var{lutrgb} requires RGB pixel formats in input, and @var{lutyuv} requires YUV.
+
+The expressions can contain the following constants and functions:
+
+@table @option
+@item w
+@item h
+The input width and height.
+
+@item val
+The input value for the pixel component.
+
+@item clipval
+The input value, clipped to the @var{minval}-@var{maxval} range.
+
+@item maxval
+The maximum value for the pixel component.
+
+@item minval
+The minimum value for the pixel component.
+
+@item negval
+The negated value for the pixel component value, clipped to the
+@var{minval}-@var{maxval} range; it corresponds to the expression
+"maxval-clipval+minval".
+
+@item clip(val)
+The computed value in @var{val}, clipped to the
+@var{minval}-@var{maxval} range.
+
+@item gammaval(gamma)
+The computed gamma correction value of the pixel component value,
+clipped to the @var{minval}-@var{maxval} range. It corresponds to the
+expression
+"pow((clipval-minval)/(maxval-minval)\,@var{gamma})*(maxval-minval)+minval"
+
+@end table
+
+All expressions default to "val".
+
+@subsection Examples
+
+@itemize
+@item
+Negate input video:
+@example
+lutrgb="r=maxval+minval-val:g=maxval+minval-val:b=maxval+minval-val"
+lutyuv="y=maxval+minval-val:u=maxval+minval-val:v=maxval+minval-val"
+@end example
+
+The above is the same as:
+@example
+lutrgb="r=negval:g=negval:b=negval"
+lutyuv="y=negval:u=negval:v=negval"
+@end example
+
+@item
+Negate luminance:
+@example
+lutyuv=y=negval
+@end example
+
+@item
+Remove chroma components, turning the video into a graytone image:
+@example
+lutyuv="u=128:v=128"
+@end example
+
+@item
+Apply a luma burning effect:
+@example
+lutyuv="y=2*val"
+@end example
+
+@item
+Remove green and blue components:
+@example
+lutrgb="g=0:b=0"
+@end example
+
+@item
+Set a constant alpha channel value on input:
+@example
+format=rgba,lutrgb=a="maxval-minval/2"
+@end example
+
+@item
+Correct luminance gamma by a factor of 0.5:
+@example
+lutyuv=y=gammaval(0.5)
+@end example
+
+@item
+Discard least significant bits of luma:
+@example
+lutyuv=y='bitand(val, 128+64+32)'
+@end example
+@end itemize
+
+@section maskedmerge
+
+Merge the first input stream with the second input stream using per pixel
+weights in the third input stream.
+
+A value of 0 in the third stream pixel component means that pixel component
+from first stream is returned unchanged, while maximum value (eg. 255 for
+8-bit videos) means that pixel component from second stream is returned
+unchanged. Intermediate values define the amount of merging between both
+input stream's pixel components.
+
+This filter accepts the following options:
+@table @option
+@item planes
+Set which planes will be processed as bitmap, unprocessed planes will be
+copied from first stream.
+By default value 0xf, all planes will be processed.
+@end table
+
+@section mcdeint
+
+Apply motion-compensation deinterlacing.
+
+It needs one field per frame as input and must thus be used together
+with yadif=1/3 or equivalent.
+
+This filter accepts the following options:
+@table @option
+@item mode
+Set the deinterlacing mode.
+
+It accepts one of the following values:
+@table @samp
+@item fast
+@item medium
+@item slow
+use iterative motion estimation
+@item extra_slow
+like @samp{slow}, but use multiple reference frames.
+@end table
+Default value is @samp{fast}.
+
+@item parity
+Set the picture field parity assumed for the input video. It must be
+one of the following values:
+
+@table @samp
+@item 0, tff
+assume top field first
+@item 1, bff
+assume bottom field first
+@end table
+
+Default value is @samp{bff}.
+
+@item qp
+Set per-block quantization parameter (QP) used by the internal
+encoder.
+
+Higher values should result in a smoother motion vector field but less
+optimal individual vectors. Default value is 1.
+@end table
+
+@section mergeplanes
+
+Merge color channel components from several video streams.
+
+The filter accepts up to 4 input streams, and merge selected input
+planes to the output video.
+
+This filter accepts the following options:
+@table @option
+@item mapping
+Set input to output plane mapping. Default is @code{0}.
+
+The mappings is specified as a bitmap. It should be specified as a
+hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. 'Aa' describes the
+mapping for the first plane of the output stream. 'A' sets the number of
+the input stream to use (from 0 to 3), and 'a' the plane number of the
+corresponding input to use (from 0 to 3). The rest of the mappings is
+similar, 'Bb' describes the mapping for the output stream second
+plane, 'Cc' describes the mapping for the output stream third plane and
+'Dd' describes the mapping for the output stream fourth plane.
+
+@item format
+Set output pixel format. Default is @code{yuva444p}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Merge three gray video streams of same width and height into single video stream:
+@example
+[a0][a1][a2]mergeplanes=0x001020:yuv444p
+@end example
+
+@item
+Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
+@example
+[a0][a1]mergeplanes=0x00010210:yuva444p
+@end example
+
+@item
+Swap Y and A plane in yuva444p stream:
+@example
+format=yuva444p,mergeplanes=0x03010200:yuva444p
+@end example
+
+@item
+Swap U and V plane in yuv420p stream:
+@example
+format=yuv420p,mergeplanes=0x000201:yuv420p
+@end example
+
+@item
+Cast a rgb24 clip to yuv444p:
+@example
+format=rgb24,mergeplanes=0x000102:yuv444p
+@end example
+@end itemize
+
+@section metadata, ametadata
+
+Manipulate frame metadata.
+
+This filter accepts the following options:
+
+@table @option
+@item mode
+Set mode of operation of the filter.
+
+Can be one of the following:
+
+@table @samp
+@item select
+If both @code{value} and @code{key} is set, select frames
+which have such metadata. If only @code{key} is set, select
+every frame that has such key in metadata.
+
+@item add
+Add new metadata @code{key} and @code{value}. If key is already available
+do nothing.
+
+@item modify
+Modify value of already present key.
+
+@item delete
+If @code{value} is set, delete only keys that have such value.
+Otherwise, delete key.
+
+@item print
+Print key and its value if metadata was found. If @code{key} is not set print all
+metadata values available in frame.
+@end table
+
+@item key
+Set key used with all modes. Must be set for all modes except @code{print}.
+
+@item value
+Set metadata value which will be used. This option is mandatory for
+@code{modify} and @code{add} mode.
+
+@item function
+Which function to use when comparing metadata value and @code{value}.
+
+Can be one of following:
+
+@table @samp
+@item same_str
+Values are interpreted as strings, returns true if metadata value is same as @code{value}.
+
+@item starts_with
+Values are interpreted as strings, returns true if metadata value starts with
+the @code{value} option string.
+
+@item less
+Values are interpreted as floats, returns true if metadata value is less than @code{value}.
+
+@item equal
+Values are interpreted as floats, returns true if @code{value} is equal with metadata value.
+
+@item greater
+Values are interpreted as floats, returns true if metadata value is greater than @code{value}.
+
+@item expr
+Values are interpreted as floats, returns true if expression from option @code{expr}
+evaluates to true.
+@end table
+
+@item expr
+Set expression which is used when @code{function} is set to @code{expr}.
+The expression is evaluated through the eval API and can contain the following
+constants:
+
+@table @option
+@item VALUE1
+Float representation of @code{value} from metadata key.
+
+@item VALUE2
+Float representation of @code{value} as supplied by user in @code{value} option.
+@end table
+
+@item file
+If specified in @code{print} mode, output is written to the named file. When
+filename equals "-" data is written to standard output.
+If @code{file} option is not set, output is written to the log with AV_LOG_INFO
+loglevel.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Print all metadata values for frames with key @code{lavfi.singnalstats.YDIF} with values
+between 0 and 1.
+@example
+@end example
+signalstats,metadata=print:key=lavfi.signalstats.YDIF:value=0:function=expr:expr='between(VALUE1,0,1)'
+@end itemize
+
+@section mpdecimate
+
+Drop frames that do not differ greatly from the previous frame in
+order to reduce frame rate.
+
+The main use of this filter is for very-low-bitrate encoding
+(e.g. streaming over dialup modem), but it could in theory be used for
+fixing movies that were inverse-telecined incorrectly.
+
+A description of the accepted options follows.
+
+@table @option
+@item max
+Set the maximum number of consecutive frames which can be dropped (if
+positive), or the minimum interval between dropped frames (if
+negative). If the value is 0, the frame is dropped unregarding the
+number of previous sequentially dropped frames.
+
+Default value is 0.
+
+@item hi
+@item lo
+@item frac
+Set the dropping threshold values.
+
+Values for @option{hi} and @option{lo} are for 8x8 pixel blocks and
+represent actual pixel value differences, so a threshold of 64
+corresponds to 1 unit of difference for each pixel, or the same spread
+out differently over the block.
+
+A frame is a candidate for dropping if no 8x8 blocks differ by more
+than a threshold of @option{hi}, and if no more than @option{frac} blocks (1
+meaning the whole image) differ by more than a threshold of @option{lo}.
+
+Default value for @option{hi} is 64*12, default value for @option{lo} is
+64*5, and default value for @option{frac} is 0.33.
+@end table
+
+
+@section negate
+
+Negate input video.
+
+It accepts an integer in input; if non-zero it negates the
+alpha component (if available). The default value in input is 0.
+
+@section nnedi
+
+Deinterlace video using neural network edge directed interpolation.
+
+This filter accepts the following options:
+
+@table @option
+@item weights
+Mandatory option, without binary file filter can not work.
+Currently file can be found here:
+https://github.com/dubhater/vapoursynth-nnedi3/blob/master/src/nnedi3_weights.bin
+
+@item deint
+Set which frames to deinterlace, by default it is @code{all}.
+Can be @code{all} or @code{interlaced}.
+
+@item field
+Set mode of operation.
+
+Can be one of the following:
+
+@table @samp
+@item af
+Use frame flags, both fields.
+@item a
+Use frame flags, single field.
+@item t
+Use top field only.
+@item b
+Use bottom field only.
+@item tf
+Use both fields, top first.
+@item bf
+Use both fields, bottom first.
+@end table
+
+@item planes
+Set which planes to process, by default filter process all frames.
+
+@item nsize
+Set size of local neighborhood around each pixel, used by the predictor neural
+network.
+
+Can be one of the following:
+
+@table @samp
+@item s8x6
+@item s16x6
+@item s32x6
+@item s48x6
+@item s8x4
+@item s16x4
+@item s32x4
+@end table
+
+@item nns
+Set the number of neurons in predicctor neural network.
+Can be one of the following:
+
+@table @samp
+@item n16
+@item n32
+@item n64
+@item n128
+@item n256
+@end table
+
+@item qual
+Controls the number of different neural network predictions that are blended
+together to compute the final output value. Can be @code{fast}, default or
+@code{slow}.
+
+@item etype
+Set which set of weights to use in the predictor.
+Can be one of the following:
+
+@table @samp
+@item a
+weights trained to minimize absolute error
+@item s
+weights trained to minimize squared error
+@end table
+
+@item pscrn
+Controls whether or not the prescreener neural network is used to decide
+which pixels should be processed by the predictor neural network and which
+can be handled by simple cubic interpolation.
+The prescreener is trained to know whether cubic interpolation will be
+sufficient for a pixel or whether it should be predicted by the predictor nn.
+The computational complexity of the prescreener nn is much less than that of
+the predictor nn. Since most pixels can be handled by cubic interpolation,
+using the prescreener generally results in much faster processing.
+The prescreener is pretty accurate, so the difference between using it and not
+using it is almost always unnoticeable.
+
+Can be one of the following:
+
+@table @samp
+@item none
+@item original
+@item new
+@end table
+
+Default is @code{new}.
+
+@item fapprox
+Set various debugging flags.
+@end table
+
+@section noformat
+
+Force libavfilter not to use any of the specified pixel formats for the
+input to the next filter.
+
+It accepts the following parameters:
+@table @option
+
+@item pix_fmts
+A '|'-separated list of pixel format names, such as
+apix_fmts=yuv420p|monow|rgb24".
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Force libavfilter to use a format different from @var{yuv420p} for the
+input to the vflip filter:
+@example
+noformat=pix_fmts=yuv420p,vflip
+@end example
+
+@item
+Convert the input video to any of the formats not contained in the list:
+@example
+noformat=yuv420p|yuv444p|yuv410p
+@end example
+@end itemize
+
+@section noise
+
+Add noise on video input frame.
+
+The filter accepts the following options:
+
+@table @option
+@item all_seed
+@item c0_seed
+@item c1_seed
+@item c2_seed
+@item c3_seed
+Set noise seed for specific pixel component or all pixel components in case
+of @var{all_seed}. Default value is @code{123457}.
+
+@item all_strength, alls
+@item c0_strength, c0s
+@item c1_strength, c1s
+@item c2_strength, c2s
+@item c3_strength, c3s
+Set noise strength for specific pixel component or all pixel components in case
+@var{all_strength}. Default value is @code{0}. Allowed range is [0, 100].
+
+@item all_flags, allf
+@item c0_flags, c0f
+@item c1_flags, c1f
+@item c2_flags, c2f
+@item c3_flags, c3f
+Set pixel component flags or set flags for all components if @var{all_flags}.
+Available values for component flags are:
+@table @samp
+@item a
+averaged temporal noise (smoother)
+@item p
+mix random noise with a (semi)regular pattern
+@item t
+temporal noise (noise pattern changes between frames)
+@item u
+uniform noise (gaussian otherwise)
+@end table
+@end table
+
+@subsection Examples
+
+Add temporal and uniform noise to input video:
+@example
+noise=alls=20:allf=t+u
+@end example
+
+@section null
+
+Pass the video source unchanged to the output.
+
+@section ocr
+Optical Character Recognition
+
+This filter uses Tesseract for optical character recognition.
+
+It accepts the following options:
+
+@table @option
+@item datapath
+Set datapath to tesseract data. Default is to use whatever was
+set at installation.
+
+@item language
+Set language, default is "eng".
+
+@item whitelist
+Set character whitelist.
+
+@item blacklist
+Set character blacklist.
+@end table
+
+The filter exports recognized text as the frame metadata @code{lavfi.ocr.text}.
+
+@section ocv
+
+Apply a video transform using libopencv.
+
+To enable this filter, install the libopencv library and headers and
+configure FFmpeg with @code{--enable-libopencv}.
+
+It accepts the following parameters:
+
+@table @option
+
+@item filter_name
+The name of the libopencv filter to apply.
+
+@item filter_params
+The parameters to pass to the libopencv filter. If not specified, the default
+values are assumed.
+
+@end table
+
+Refer to the official libopencv documentation for more precise
+information:
+@url{http://docs.opencv.org/master/modules/imgproc/doc/filtering.html}
+
+Several libopencv filters are supported; see the following subsections.
+
+@anchor{dilate}
+@subsection dilate
+
+Dilate an image by using a specific structuring element.
+It corresponds to the libopencv function @code{cvDilate}.
+
+It accepts the parameters: @var{struct_el}|@var{nb_iterations}.
+
+@var{struct_el} represents a structuring element, and has the syntax:
+@var{cols}x@var{rows}+@var{anchor_x}x@var{anchor_y}/@var{shape}
+
+@var{cols} and @var{rows} represent the number of columns and rows of
+the structuring element, @var{anchor_x} and @var{anchor_y} the anchor
+point, and @var{shape} the shape for the structuring element. @var{shape}
+must be "rect", "cross", "ellipse", or "custom".
+
+If the value for @var{shape} is "custom", it must be followed by a
+string of the form "=@var{filename}". The file with name
+@var{filename} is assumed to represent a binary image, with each
+printable character corresponding to a bright pixel. When a custom
+@var{shape} is used, @var{cols} and @var{rows} are ignored, the number
+or columns and rows of the read file are assumed instead.
+
+The default value for @var{struct_el} is "3x3+0x0/rect".
+
+@var{nb_iterations} specifies the number of times the transform is
+applied to the image, and defaults to 1.
+
+Some examples:
+@example
+# Use the default values
+ocv=dilate
+
+# Dilate using a structuring element with a 5x5 cross, iterating two times
+ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
+
+# Read the shape from the file diamond.shape, iterating two times.
+# The file diamond.shape may contain a pattern of characters like this
+# *
+# ***
+# *****
+# ***
+# *
+# The specified columns and rows are ignored
+# but the anchor point coordinates are not
+ocv=dilate:0x0+2x2/custom=diamond.shape|2
+@end example
+
+@subsection erode
+
+Erode an image by using a specific structuring element.
+It corresponds to the libopencv function @code{cvErode}.
+
+It accepts the parameters: @var{struct_el}:@var{nb_iterations},
+with the same syntax and semantics as the @ref{dilate} filter.
+
+@subsection smooth
+
+Smooth the input video.
+
+The filter takes the following parameters:
+@var{type}|@var{param1}|@var{param2}|@var{param3}|@var{param4}.
+
+@var{type} is the type of smooth filter to apply, and must be one of
+the following values: "blur", "blur_no_scale", "median", "gaussian",
+or "bilateral". The default value is "gaussian".
+
+The meaning of @var{param1}, @var{param2}, @var{param3}, and @var{param4}
+depend on the smooth type. @var{param1} and
+@var{param2} accept integer positive values or 0. @var{param3} and
+@var{param4} accept floating point values.
+
+The default value for @var{param1} is 3. The default value for the
+other parameters is 0.
+
+These parameters correspond to the parameters assigned to the
+libopencv function @code{cvSmooth}.
+
+@anchor{overlay}
+@section overlay
+
+Overlay one video on top of another.
+
+It takes two inputs and has one output. The first input is the "main"
+video on which the second input is overlaid.
+
+It accepts the following parameters:
+
+A description of the accepted options follows.
+
+@table @option
+@item x
+@item y
+Set the expression for the x and y coordinates of the overlaid video
+on the main video. Default value is "0" for both expressions. In case
+the expression is invalid, it is set to a huge value (meaning that the
+overlay will not be displayed within the output visible area).
+
+@item eof_action
+The action to take when EOF is encountered on the secondary input; it accepts
+one of the following values:
+
+@table @option
+@item repeat
+Repeat the last frame (the default).
+@item endall
+End both streams.
+@item pass
+Pass the main input through.
+@end table
+
+@item eval
+Set when the expressions for @option{x}, and @option{y} are evaluated.
+
+It accepts the following values:
+@table @samp
+@item init
+only evaluate expressions once during the filter initialization or
+when a command is processed
+
+@item frame
+evaluate expressions for each incoming frame
+@end table
+
+Default value is @samp{frame}.
+
+@item shortest
+If set to 1, force the output to terminate when the shortest input
+terminates. Default value is 0.
+
+@item format
+Set the format for the output video.
+
+It accepts the following values:
+@table @samp
+@item yuv420
+force YUV420 output
+
+@item yuv422
+force YUV422 output
+
+@item yuv444
+force YUV444 output
+
+@item rgb
+force RGB output
+@end table
+
+Default value is @samp{yuv420}.
+
+@item rgb @emph{(deprecated)}
+If set to 1, force the filter to accept inputs in the RGB
+color space. Default value is 0. This option is deprecated, use
+@option{format} instead.
+
+@item repeatlast
+If set to 1, force the filter to draw the last overlay frame over the
+main input until the end of the stream. A value of 0 disables this
+behavior. Default value is 1.
+@end table
+
+The @option{x}, and @option{y} expressions can contain the following
+parameters.
+
+@table @option
+@item main_w, W
+@item main_h, H
+The main input width and height.
+
+@item overlay_w, w
+@item overlay_h, h
+The overlay input width and height.
+
+@item x
+@item y
+The computed values for @var{x} and @var{y}. They are evaluated for
+each new frame.
+
+@item hsub
+@item vsub
+horizontal and vertical chroma subsample values of the output
+format. For example for the pixel format "yuv422p" @var{hsub} is 2 and
+@var{vsub} is 1.
+
+@item n
+the number of input frame, starting from 0
+
+@item pos
+the position in the file of the input frame, NAN if unknown
+
+@item t
+The timestamp, expressed in seconds. It's NAN if the input timestamp is unknown.
+
+@end table
+
+Note that the @var{n}, @var{pos}, @var{t} variables are available only
+when evaluation is done @emph{per frame}, and will evaluate to NAN
+when @option{eval} is set to @samp{init}.
+
+Be aware that frames are taken from each input video in timestamp
+order, hence, if their initial timestamps differ, it is a good idea
+to pass the two inputs through a @var{setpts=PTS-STARTPTS} filter to
+have them begin in the same zero timestamp, as the example for
+the @var{movie} filter does.
+
+You can chain together more overlays but you should test the
+efficiency of such approach.
+
+@subsection Commands
+
+This filter supports the following commands:
+@table @option
+@item x
+@item y
+Modify the x and y of the overlay input.
+The command accepts the same syntax of the corresponding option.
+
+If the specified expression is not valid, it is kept at its current
+value.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Draw the overlay at 10 pixels from the bottom right corner of the main
+video:
+@example
+overlay=main_w-overlay_w-10:main_h-overlay_h-10
+@end example
+
+Using named options the example above becomes:
+@example
+overlay=x=main_w-overlay_w-10:y=main_h-overlay_h-10
+@end example
+
+@item
+Insert a transparent PNG logo in the bottom left corner of the input,
+using the @command{ffmpeg} tool with the @code{-filter_complex} option:
+@example
+ffmpeg -i input -i logo -filter_complex 'overlay=10:main_h-overlay_h-10' output
+@end example
+
+@item
+Insert 2 different transparent PNG logos (second logo on bottom
+right corner) using the @command{ffmpeg} tool:
+@example
+ffmpeg -i input -i logo1 -i logo2 -filter_complex 'overlay=x=10:y=H-h-10,overlay=x=W-w-10:y=H-h-10' output
+@end example
+
+@item
+Add a transparent color layer on top of the main video; @code{WxH}
+must specify the size of the main input to the overlay filter:
+@example
+color=color=red@@.3:size=WxH [over]; [in][over] overlay [out]
+@end example
+
+@item
+Play an original video and a filtered version (here with the deshake
+filter) side by side using the @command{ffplay} tool:
+@example
+ffplay input.avi -vf 'split[a][b]; [a]pad=iw*2:ih[src]; [b]deshake[filt]; [src][filt]overlay=w'
+@end example
+
+The above command is the same as:
+@example
+ffplay input.avi -vf 'split[b], pad=iw*2[src], [b]deshake, [src]overlay=w'
+@end example
+
+@item
+Make a sliding overlay appearing from the left to the right top part of the
+screen starting since time 2:
+@example
+overlay=x='if(gte(t,2), -w+(t-2)*20, NAN)':y=0
+@end example
+
+@item
+Compose output by putting two input videos side to side:
+@example
+ffmpeg -i left.avi -i right.avi -filter_complex "
+nullsrc=size=200x100 [background];
+[0:v] setpts=PTS-STARTPTS, scale=100x100 [left];
+[1:v] setpts=PTS-STARTPTS, scale=100x100 [right];
+[background][left] overlay=shortest=1 [background+left];
+[background+left][right] overlay=shortest=1:x=100 [left+right]
+"
+@end example
+
+@item
+Mask 10-20 seconds of a video by applying the delogo filter to a section
+@example
+ffmpeg -i test.avi -codec:v:0 wmv2 -ar 11025 -b:v 9000k
+-vf '[in]split[split_main][split_delogo];[split_delogo]trim=start=360:end=371,delogo=0:0:640:480[delogoed];[split_main][delogoed]overlay=eof_action=pass[out]'
+masked.avi
+@end example
+
+@item
+Chain several overlays in cascade:
+@example
+nullsrc=s=200x200 [bg];
+testsrc=s=100x100, split=4 [in0][in1][in2][in3];
+[in0] lutrgb=r=0, [bg] overlay=0:0 [mid0];
+[in1] lutrgb=g=0, [mid0] overlay=100:0 [mid1];
+[in2] lutrgb=b=0, [mid1] overlay=0:100 [mid2];
+[in3] null, [mid2] overlay=100:100 [out0]
+@end example
+
+@end itemize
+
+@section owdenoise
+
+Apply Overcomplete Wavelet denoiser.
+
+The filter accepts the following options:
+
+@table @option
+@item depth
+Set depth.
+
+Larger depth values will denoise lower frequency components more, but
+slow down filtering.
+
+Must be an int in the range 8-16, default is @code{8}.
+
+@item luma_strength, ls
+Set luma strength.
+
+Must be a double value in the range 0-1000, default is @code{1.0}.
+
+@item chroma_strength, cs
+Set chroma strength.
+
+Must be a double value in the range 0-1000, default is @code{1.0}.
+@end table
+
+@anchor{pad}
+@section pad
+
+Add paddings to the input image, and place the original input at the
+provided @var{x}, @var{y} coordinates.
+
+It accepts the following parameters:
+
+@table @option
+@item width, w
+@item height, h
+Specify an expression for the size of the output image with the
+paddings added. If the value for @var{width} or @var{height} is 0, the
+corresponding input size is used for the output.
+
+The @var{width} expression can reference the value set by the
+@var{height} expression, and vice versa.
+
+The default value of @var{width} and @var{height} is 0.
+
+@item x
+@item y
+Specify the offsets to place the input image at within the padded area,
+with respect to the top/left border of the output image.
+
+The @var{x} expression can reference the value set by the @var{y}
+expression, and vice versa.
+
+The default value of @var{x} and @var{y} is 0.
+
+@item color
+Specify the color of the padded area. For the syntax of this option,
+check the "Color" section in the ffmpeg-utils manual.
+
+The default value of @var{color} is "black".
+@end table
+
+The value for the @var{width}, @var{height}, @var{x}, and @var{y}
+options are expressions containing the following constants:
+
+@table @option
+@item in_w
+@item in_h
+The input video width and height.
+
+@item iw
+@item ih
+These are the same as @var{in_w} and @var{in_h}.
+
+@item out_w
+@item out_h
+The output width and height (the size of the padded area), as
+specified by the @var{width} and @var{height} expressions.
+
+@item ow
+@item oh
+These are the same as @var{out_w} and @var{out_h}.
+
+@item x
+@item y
+The x and y offsets as specified by the @var{x} and @var{y}
+expressions, or NAN if not yet specified.
+
+@item a
+same as @var{iw} / @var{ih}
+
+@item sar
+input sample aspect ratio
+
+@item dar
+input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
+
+@item hsub
+@item vsub
+The horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Add paddings with the color "violet" to the input video. The output video
+size is 640x480, and the top-left corner of the input video is placed at
+column 0, row 40
+@example
+pad=640:480:0:40:violet
+@end example
+
+The example above is equivalent to the following command:
+@example
+pad=width=640:height=480:x=0:y=40:color=violet
+@end example
+
+@item
+Pad the input to get an output with dimensions increased by 3/2,
+and put the input video at the center of the padded area:
+@example
+pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"
+@end example
+
+@item
+Pad the input to get a squared output with size equal to the maximum
+value between the input width and height, and put the input video at
+the center of the padded area:
+@example
+pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"
+@end example
+
+@item
+Pad the input to get a final w/h ratio of 16:9:
+@example
+pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
+@end example
+
+@item
+In case of anamorphic video, in order to set the output display aspect
+correctly, it is necessary to use @var{sar} in the expression,
+according to the relation:
+@example
+(ih * X / ih) * sar = output_dar
+X = output_dar / sar
+@end example
+
+Thus the previous example needs to be modified to:
+@example
+pad="ih*16/9/sar:ih:(ow-iw)/2:(oh-ih)/2"
+@end example
+
+@item
+Double the output size and put the input video in the bottom-right
+corner of the output padded area:
+@example
+pad="2*iw:2*ih:ow-iw:oh-ih"
+@end example
+@end itemize
+
+@anchor{palettegen}
+@section palettegen
+
+Generate one palette for a whole video stream.
+
+It accepts the following options:
+
+@table @option
+@item max_colors
+Set the maximum number of colors to quantize in the palette.
+Note: the palette will still contain 256 colors; the unused palette entries
+will be black.
+
+@item reserve_transparent
+Create a palette of 255 colors maximum and reserve the last one for
+transparency. Reserving the transparency color is useful for GIF optimization.
+If not set, the maximum of colors in the palette will be 256. You probably want
+to disable this option for a standalone image.
+Set by default.
+
+@item stats_mode
+Set statistics mode.
+
+It accepts the following values:
+@table @samp
+@item full
+Compute full frame histograms.
+@item diff
+Compute histograms only for the part that differs from previous frame. This
+might be relevant to give more importance to the moving part of your input if
+the background is static.
+@end table
+
+Default value is @var{full}.
+@end table
+
+The filter also exports the frame metadata @code{lavfi.color_quant_ratio}
+(@code{nb_color_in / nb_color_out}) which you can use to evaluate the degree of
+color quantization of the palette. This information is also visible at
+@var{info} logging level.
+
+@subsection Examples
+
+@itemize
+@item
+Generate a representative palette of a given video using @command{ffmpeg}:
+@example
+ffmpeg -i input.mkv -vf palettegen palette.png
+@end example
+@end itemize
+
+@section paletteuse
+
+Use a palette to downsample an input video stream.
+
+The filter takes two inputs: one video stream and a palette. The palette must
+be a 256 pixels image.
+
+It accepts the following options:
+
+@table @option
+@item dither
+Select dithering mode. Available algorithms are:
+@table @samp
+@item bayer
+Ordered 8x8 bayer dithering (deterministic)
+@item heckbert
+Dithering as defined by Paul Heckbert in 1982 (simple error diffusion).
+Note: this dithering is sometimes considered "wrong" and is included as a
+reference.
+@item floyd_steinberg
+Floyd and Steingberg dithering (error diffusion)
+@item sierra2
+Frankie Sierra dithering v2 (error diffusion)
+@item sierra2_4a
+Frankie Sierra dithering v2 "Lite" (error diffusion)
+@end table
+
+Default is @var{sierra2_4a}.
+
+@item bayer_scale
+When @var{bayer} dithering is selected, this option defines the scale of the
+pattern (how much the crosshatch pattern is visible). A low value means more
+visible pattern for less banding, and higher value means less visible pattern
+at the cost of more banding.
+
+The option must be an integer value in the range [0,5]. Default is @var{2}.
+
+@item diff_mode
+If set, define the zone to process
+
+@table @samp
+@item rectangle
+Only the changing rectangle will be reprocessed. This is similar to GIF
+cropping/offsetting compression mechanism. This option can be useful for speed
+if only a part of the image is changing, and has use cases such as limiting the
+scope of the error diffusal @option{dither} to the rectangle that bounds the
+moving scene (it leads to more deterministic output if the scene doesn't change
+much, and as a result less moving noise and better GIF compression).
+@end table
+
+Default is @var{none}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Use a palette (generated for example with @ref{palettegen}) to encode a GIF
+using @command{ffmpeg}:
+@example
+ffmpeg -i input.mkv -i palette.png -lavfi paletteuse output.gif
+@end example
+@end itemize
+
+@section perspective
+
+Correct perspective of video not recorded perpendicular to the screen.
+
+A description of the accepted parameters follows.
+
+@table @option
+@item x0
+@item y0
+@item x1
+@item y1
+@item x2
+@item y2
+@item x3
+@item y3
+Set coordinates expression for top left, top right, bottom left and bottom right corners.
+Default values are @code{0:0:W:0:0:H:W:H} with which perspective will remain unchanged.
+If the @code{sense} option is set to @code{source}, then the specified points will be sent
+to the corners of the destination. If the @code{sense} option is set to @code{destination},
+then the corners of the source will be sent to the specified coordinates.
+
+The expressions can use the following variables:
+
+@table @option
+@item W
+@item H
+the width and height of video frame.
+@end table
+
+@item interpolation
+Set interpolation for perspective correction.
+
+It accepts the following values:
+@table @samp
+@item linear
+@item cubic
+@end table
+
+Default value is @samp{linear}.
+
+@item sense
+Set interpretation of coordinate options.
+
+It accepts the following values:
+@table @samp
+@item 0, source
+
+Send point in the source specified by the given coordinates to
+the corners of the destination.
+
+@item 1, destination
+
+Send the corners of the source to the point in the destination specified
+by the given coordinates.
+
+Default value is @samp{source}.
+@end table
+@end table
+
+@section phase
+
+Delay interlaced video by one field time so that the field order changes.
+
+The intended use is to fix PAL movies that have been captured with the
+opposite field order to the film-to-video transfer.
+
+A description of the accepted parameters follows.
+
+@table @option
+@item mode
+Set phase mode.
+
+It accepts the following values:
+@table @samp
+@item t
+Capture field order top-first, transfer bottom-first.
+Filter will delay the bottom field.
+
+@item b
+Capture field order bottom-first, transfer top-first.
+Filter will delay the top field.
+
+@item p
+Capture and transfer with the same field order. This mode only exists
+for the documentation of the other options to refer to, but if you
+actually select it, the filter will faithfully do nothing.
+
+@item a
+Capture field order determined automatically by field flags, transfer
+opposite.
+Filter selects among @samp{t} and @samp{b} modes on a frame by frame
+basis using field flags. If no field information is available,
+then this works just like @samp{u}.
+
+@item u
+Capture unknown or varying, transfer opposite.
+Filter selects among @samp{t} and @samp{b} on a frame by frame basis by
+analyzing the images and selecting the alternative that produces best
+match between the fields.
+
+@item T
+Capture top-first, transfer unknown or varying.
+Filter selects among @samp{t} and @samp{p} using image analysis.
+
+@item B
+Capture bottom-first, transfer unknown or varying.
+Filter selects among @samp{b} and @samp{p} using image analysis.
+
+@item A
+Capture determined by field flags, transfer unknown or varying.
+Filter selects among @samp{t}, @samp{b} and @samp{p} using field flags and
+image analysis. If no field information is available, then this works just
+like @samp{U}. This is the default mode.
+
+@item U
+Both capture and transfer unknown or varying.
+Filter selects among @samp{t}, @samp{b} and @samp{p} using image analysis only.
+@end table
+@end table
+
+@section pixdesctest
+
+Pixel format descriptor test filter, mainly useful for internal
+testing. The output video should be equal to the input video.
+
+For example:
+@example
+format=monow, pixdesctest
+@end example
+
+can be used to test the monowhite pixel format descriptor definition.
+
+@section pp
+
+Enable the specified chain of postprocessing subfilters using libpostproc. This
+library should be automatically selected with a GPL build (@code{--enable-gpl}).
+Subfilters must be separated by '/' and can be disabled by prepending a '-'.
+Each subfilter and some options have a short and a long name that can be used
+interchangeably, i.e. dr/dering are the same.
+
+The filters accept the following options:
+
+@table @option
+@item subfilters
+Set postprocessing subfilters string.
+@end table
+
+All subfilters share common options to determine their scope:
+
+@table @option
+@item a/autoq
+Honor the quality commands for this subfilter.
+
+@item c/chrom
+Do chrominance filtering, too (default).
+
+@item y/nochrom
+Do luminance filtering only (no chrominance).
+
+@item n/noluma
+Do chrominance filtering only (no luminance).
+@end table
+
+These options can be appended after the subfilter name, separated by a '|'.
+
+Available subfilters are:
+
+@table @option
+@item hb/hdeblock[|difference[|flatness]]
+Horizontal deblocking filter
+@table @option
+@item difference
+Difference factor where higher values mean more deblocking (default: @code{32}).
+@item flatness
+Flatness threshold where lower values mean more deblocking (default: @code{39}).
+@end table
+
+@item vb/vdeblock[|difference[|flatness]]
+Vertical deblocking filter
+@table @option
+@item difference
+Difference factor where higher values mean more deblocking (default: @code{32}).
+@item flatness
+Flatness threshold where lower values mean more deblocking (default: @code{39}).
+@end table
+
+@item ha/hadeblock[|difference[|flatness]]
+Accurate horizontal deblocking filter
+@table @option
+@item difference
+Difference factor where higher values mean more deblocking (default: @code{32}).
+@item flatness
+Flatness threshold where lower values mean more deblocking (default: @code{39}).
+@end table
+
+@item va/vadeblock[|difference[|flatness]]
+Accurate vertical deblocking filter
+@table @option
+@item difference
+Difference factor where higher values mean more deblocking (default: @code{32}).
+@item flatness
+Flatness threshold where lower values mean more deblocking (default: @code{39}).
+@end table
+@end table
+
+The horizontal and vertical deblocking filters share the difference and
+flatness values so you cannot set different horizontal and vertical
+thresholds.
+
+@table @option
+@item h1/x1hdeblock
+Experimental horizontal deblocking filter
+
+@item v1/x1vdeblock
+Experimental vertical deblocking filter
+
+@item dr/dering
+Deringing filter
+
+@item tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
+@table @option
+@item threshold1
+larger -> stronger filtering
+@item threshold2
+larger -> stronger filtering
+@item threshold3
+larger -> stronger filtering
+@end table
+
+@item al/autolevels[:f/fullyrange], automatic brightness / contrast correction
+@table @option
+@item f/fullyrange
+Stretch luminance to @code{0-255}.
+@end table
+
+@item lb/linblenddeint
+Linear blend deinterlacing filter that deinterlaces the given block by
+filtering all lines with a @code{(1 2 1)} filter.
+
+@item li/linipoldeint
+Linear interpolating deinterlacing filter that deinterlaces the given block by
+linearly interpolating every second line.
+
+@item ci/cubicipoldeint
+Cubic interpolating deinterlacing filter deinterlaces the given block by
+cubically interpolating every second line.
+
+@item md/mediandeint
+Median deinterlacing filter that deinterlaces the given block by applying a
+median filter to every second line.
+
+@item fd/ffmpegdeint
+FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
+second line with a @code{(-1 4 2 4 -1)} filter.
+
+@item l5/lowpass5
+Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
+block by filtering all lines with a @code{(-1 2 6 2 -1)} filter.
+
+@item fq/forceQuant[|quantizer]
+Overrides the quantizer table from the input with the constant quantizer you
+specify.
+@table @option
+@item quantizer
+Quantizer to use
+@end table
+
+@item de/default
+Default pp filter combination (@code{hb|a,vb|a,dr|a})
+
+@item fa/fast
+Fast pp filter combination (@code{h1|a,v1|a,dr|a})
+
+@item ac
+High quality pp filter combination (@code{ha|a|128|7,va|a,dr|a})
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Apply horizontal and vertical deblocking, deringing and automatic
+brightness/contrast:
+@example
+pp=hb/vb/dr/al
+@end example
+
+@item
+Apply default filters without brightness/contrast correction:
+@example
+pp=de/-al
+@end example
+
+@item
+Apply default filters and temporal denoiser:
+@example
+pp=default/tmpnoise|1|2|3
+@end example
+
+@item
+Apply deblocking on luminance only, and switch vertical deblocking on or off
+automatically depending on available CPU time:
+@example
+pp=hb|y/vb|a
+@end example
+@end itemize
+
+@section pp7
+Apply Postprocessing filter 7. It is variant of the @ref{spp} filter,
+similar to spp = 6 with 7 point DCT, where only the center sample is
+used after IDCT.
+
+The filter accepts the following options:
+
+@table @option
+@item qp
+Force a constant quantization parameter. It accepts an integer in range
+0 to 63. If not set, the filter will use the QP from the video stream
+(if available).
+
+@item mode
+Set thresholding mode. Available modes are:
+
+@table @samp
+@item hard
+Set hard thresholding.
+@item soft
+Set soft thresholding (better de-ringing effect, but likely blurrier).
+@item medium
+Set medium thresholding (good results, default).
+@end table
+@end table
+
+@section psnr
+
+Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
+Ratio) between two input videos.
+
+This filter takes in input two input videos, the first input is
+considered the "main" source and is passed unchanged to the
+output. The second input is used as a "reference" video for computing
+the PSNR.
+
+Both video inputs must have the same resolution and pixel format for
+this filter to work correctly. Also it assumes that both inputs
+have the same number of frames, which are compared one by one.
+
+The obtained average PSNR is printed through the logging system.
+
+The filter stores the accumulated MSE (mean squared error) of each
+frame, and at the end of the processing it is averaged across all frames
+equally, and the following formula is applied to obtain the PSNR:
+
+@example
+PSNR = 10*log10(MAX^2/MSE)
+@end example
+
+Where MAX is the average of the maximum values of each component of the
image.
-The default value of @var{w} and @var{h} is 0.
+The description of the accepted parameters follows.
+
+@table @option
+@item stats_file, f
+If specified the filter will use the named file to save the PSNR of
+each individual frame. When filename equals "-" the data is sent to
+standard output.
+@end table
+
+The file printed if @var{stats_file} is selected, contains a sequence of
+key/value pairs of the form @var{key}:@var{value} for each compared
+couple of frames.
+
+A description of each shown parameter follows:
+
+@table @option
+@item n
+sequential number of the input frame, starting from 1
+
+@item mse_avg
+Mean Square Error pixel-by-pixel average difference of the compared
+frames, averaged over all the image components.
+
+@item mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a
+Mean Square Error pixel-by-pixel average difference of the compared
+frames for the component specified by the suffix.
+
+@item psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a
+Peak Signal to Noise ratio of the compared frames for the component
+specified by the suffix.
+@end table
+
+For example:
+@example
+movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
+[main][ref] psnr="stats_file=stats.log" [out]
+@end example
+
+On this example the input file being processed is compared with the
+reference file @file{ref_movie.mpg}. The PSNR of each individual frame
+is stored in @file{stats.log}.
+
+@anchor{pullup}
+@section pullup
+
+Pulldown reversal (inverse telecine) filter, capable of handling mixed
+hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
+content.
+
+The pullup filter is designed to take advantage of future context in making
+its decisions. This filter is stateless in the sense that it does not lock
+onto a pattern to follow, but it instead looks forward to the following
+fields in order to identify matches and rebuild progressive frames.
+
+To produce content with an even framerate, insert the fps filter after
+pullup, use @code{fps=24000/1001} if the input frame rate is 29.97fps,
+@code{fps=24} for 30fps and the (rare) telecined 25fps input.
+
+The filter accepts the following options:
+
+@table @option
+@item jl
+@item jr
+@item jt
+@item jb
+These options set the amount of "junk" to ignore at the left, right, top, and
+bottom of the image, respectively. Left and right are in units of 8 pixels,
+while top and bottom are in units of 2 lines.
+The default is 8 pixels on each side.
+
+@item sb
+Set the strict breaks. Setting this option to 1 will reduce the chances of
+filter generating an occasional mismatched frame, but it may also cause an
+excessive number of frames to be dropped during high motion sequences.
+Conversely, setting it to -1 will make filter match fields more easily.
+This may help processing of video where there is slight blurring between
+the fields, but may also cause there to be interlaced frames in the output.
+Default value is @code{0}.
+
+@item mp
+Set the metric plane to use. It accepts the following values:
+@table @samp
+@item l
+Use luma plane.
+
+@item u
+Use chroma blue plane.
+
+@item v
+Use chroma red plane.
+@end table
+
+This option may be set to use chroma plane instead of the default luma plane
+for doing filter's computations. This may improve accuracy on very clean
+source material, but more likely will decrease accuracy, especially if there
+is chroma noise (rainbow effect) or any grayscale video.
+The main purpose of setting @option{mp} to a chroma plane is to reduce CPU
+load and make pullup usable in realtime on slow machines.
+@end table
+
+For best results (without duplicated frames in the output file) it is
+necessary to change the output frame rate. For example, to inverse
+telecine NTSC input:
+@example
+ffmpeg -i input -vf pullup -r 24000/1001 ...
+@end example
+
+@section qp
+
+Change video quantization parameters (QP).
+
+The filter accepts the following option:
+
+@table @option
+@item qp
+Set expression for quantization parameter.
+@end table
+
+The expression is evaluated through the eval API and can contain, among others,
+the following constants:
+
+@table @var
+@item known
+1 if index is not 129, 0 otherwise.
+
+@item qp
+Sequentional index starting from -129 to 128.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Some equation like:
+@example
+qp=2+2*sin(PI*qp)
+@end example
+@end itemize
+
+@section random
+
+Flush video frames from internal cache of frames into a random order.
+No frame is discarded.
+Inspired by @ref{frei0r} nervous filter.
+
+@table @option
+@item frames
+Set size in number of frames of internal cache, in range from @code{2} to
+@code{512}. Default is @code{30}.
+
+@item seed
+Set seed for random number generator, must be an integer included between
+@code{0} and @code{UINT32_MAX}. If not specified, or if explicitly set to
+less than @code{0}, the filter will try to use a good random seed on a
+best effort basis.
+@end table
+
+@section removegrain
+
+The removegrain filter is a spatial denoiser for progressive video.
+
+@table @option
+@item m0
+Set mode for the first plane.
+
+@item m1
+Set mode for the second plane.
+
+@item m2
+Set mode for the third plane.
+
+@item m3
+Set mode for the fourth plane.
+@end table
+
+Range of mode is from 0 to 24. Description of each mode follows:
+
+@table @var
+@item 0
+Leave input plane unchanged. Default.
+
+@item 1
+Clips the pixel with the minimum and maximum of the 8 neighbour pixels.
+
+@item 2
+Clips the pixel with the second minimum and maximum of the 8 neighbour pixels.
+
+@item 3
+Clips the pixel with the third minimum and maximum of the 8 neighbour pixels.
+
+@item 4
+Clips the pixel with the fourth minimum and maximum of the 8 neighbour pixels.
+This is equivalent to a median filter.
+
+@item 5
+Line-sensitive clipping giving the minimal change.
+
+@item 6
+Line-sensitive clipping, intermediate.
+
+@item 7
+Line-sensitive clipping, intermediate.
+
+@item 8
+Line-sensitive clipping, intermediate.
+
+@item 9
+Line-sensitive clipping on a line where the neighbours pixels are the closest.
+
+@item 10
+Replaces the target pixel with the closest neighbour.
+
+@item 11
+[1 2 1] horizontal and vertical kernel blur.
+
+@item 12
+Same as mode 11.
+
+@item 13
+Bob mode, interpolates top field from the line where the neighbours
+pixels are the closest.
+
+@item 14
+Bob mode, interpolates bottom field from the line where the neighbours
+pixels are the closest.
+
+@item 15
+Bob mode, interpolates top field. Same as 13 but with a more complicated
+interpolation formula.
+
+@item 16
+Bob mode, interpolates bottom field. Same as 14 but with a more complicated
+interpolation formula.
+
+@item 17
+Clips the pixel with the minimum and maximum of respectively the maximum and
+minimum of each pair of opposite neighbour pixels.
+
+@item 18
+Line-sensitive clipping using opposite neighbours whose greatest distance from
+the current pixel is minimal.
+
+@item 19
+Replaces the pixel with the average of its 8 neighbours.
+
+@item 20
+Averages the 9 pixels ([1 1 1] horizontal and vertical blur).
+
+@item 21
+Clips pixels using the averages of opposite neighbour.
+
+@item 22
+Same as mode 21 but simpler and faster.
+
+@item 23
+Small edge and halo removal, but reputed useless.
+
+@item 24
+Similar as 23.
+@end table
+
+@section removelogo
+
+Suppress a TV station logo, using an image file to determine which
+pixels comprise the logo. It works by filling in the pixels that
+comprise the logo with neighboring pixels.
+
+The filter accepts the following options:
+
+@table @option
+@item filename, f
+Set the filter bitmap file, which can be any image format supported by
+libavformat. The width and height of the image file must match those of the
+video stream being processed.
+@end table
+
+Pixels in the provided bitmap image with a value of zero are not
+considered part of the logo, non-zero pixels are considered part of
+the logo. If you use white (255) for the logo and black (0) for the
+rest, you will be safe. For making the filter bitmap, it is
+recommended to take a screen capture of a black frame with the logo
+visible, and then using a threshold filter followed by the erode
+filter once or twice.
+
+If needed, little splotches can be fixed manually. Remember that if
+logo pixels are not covered, the filter quality will be much
+reduced. Marking too many pixels as part of the logo does not hurt as
+much, but it will increase the amount of blurring needed to cover over
+the image and will destroy more information than necessary, and extra
+pixels will slow things down on a large logo.
+
+@section repeatfields
+
+This filter uses the repeat_field flag from the Video ES headers and hard repeats
+fields based on its value.
+
+@section reverse, areverse
+
+Reverse a clip.
+
+Warning: This filter requires memory to buffer the entire clip, so trimming
+is suggested.
+
+@subsection Examples
+
+@itemize
+@item
+Take the first 5 seconds of a clip, and reverse it.
+@example
+trim=end=5,reverse
+@end example
+@end itemize
+
+@section rotate
+
+Rotate video by an arbitrary angle expressed in radians.
+
+The filter accepts the following options:
+
+A description of the optional parameters follows.
+@table @option
+@item angle, a
+Set an expression for the angle by which to rotate the input video
+clockwise, expressed as a number of radians. A negative value will
+result in a counter-clockwise rotation. By default it is set to "0".
+
+This expression is evaluated for each frame.
+
+@item out_w, ow
+Set the output width expression, default value is "iw".
+This expression is evaluated just once during configuration.
+
+@item out_h, oh
+Set the output height expression, default value is "ih".
+This expression is evaluated just once during configuration.
+
+@item bilinear
+Enable bilinear interpolation if set to 1, a value of 0 disables
+it. Default value is 1.
+
+@item fillcolor, c
+Set the color used to fill the output area not covered by the rotated
+image. For the general syntax of this option, check the "Color" section in the
+ffmpeg-utils manual. If the special value "none" is selected then no
+background is printed (useful for example if the background is never shown).
+
+Default value is "black".
+@end table
+
+The expressions for the angle and the output size can contain the
+following constants and functions:
+
+@table @option
+@item n
+sequential number of the input frame, starting from 0. It is always NAN
+before the first frame is filtered.
+
+@item t
+time in seconds of the input frame, it is set to 0 when the filter is
+configured. It is always NAN before the first frame is filtered.
+
+@item hsub
+@item vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
+@item in_w, iw
+@item in_h, ih
+the input video width and height
+
+@item out_w, ow
+@item out_h, oh
+the output width and height, that is the size of the padded area as
+specified by the @var{width} and @var{height} expressions
+
+@item rotw(a)
+@item roth(a)
+the minimal width/height required for completely containing the input
+video rotated by @var{a} radians.
+
+These are only available when computing the @option{out_w} and
+@option{out_h} expressions.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Rotate the input by PI/6 radians clockwise:
+@example
+rotate=PI/6
+@end example
+
+@item
+Rotate the input by PI/6 radians counter-clockwise:
+@example
+rotate=-PI/6
+@end example
+
+@item
+Rotate the input by 45 degrees clockwise:
+@example
+rotate=45*PI/180
+@end example
+
+@item
+Apply a constant rotation with period T, starting from an angle of PI/3:
+@example
+rotate=PI/3+2*PI*t/T
+@end example
+
+@item
+Make the input video rotation oscillating with a period of T
+seconds and an amplitude of A radians:
+@example
+rotate=A*sin(2*PI/T*t)
+@end example
+
+@item
+Rotate the video, output size is chosen so that the whole rotating
+input video is always completely contained in the output:
+@example
+rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
+@end example
+
+@item
+Rotate the video, reduce the output size so that no background is ever
+shown:
+@example
+rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
+@end example
+@end itemize
+
+@subsection Commands
+
+The filter supports the following commands:
+
+@table @option
+@item a, angle
+Set the angle expression.
+The command accepts the same syntax of the corresponding option.
+
+If the specified expression is not valid, it is kept at its current
+value.
+@end table
+
+@section sab
+
+Apply Shape Adaptive Blur.
+
+The filter accepts the following options:
+
+@table @option
+@item luma_radius, lr
+Set luma blur filter strength, must be a value in range 0.1-4.0, default
+value is 1.0. A greater value will result in a more blurred image, and
+in slower processing.
+
+@item luma_pre_filter_radius, lpfr
+Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
+value is 1.0.
+
+@item luma_strength, ls
+Set luma maximum difference between pixels to still be considered, must
+be a value in the 0.1-100.0 range, default value is 1.0.
+
+@item chroma_radius, cr
+Set chroma blur filter strength, must be a value in range 0.1-4.0. A
+greater value will result in a more blurred image, and in slower
+processing.
+
+@item chroma_pre_filter_radius, cpfr
+Set chroma pre-filter radius, must be a value in the 0.1-2.0 range.
+
+@item chroma_strength, cs
+Set chroma maximum difference between pixels to still be considered,
+must be a value in the 0.1-100.0 range.
+@end table
+
+Each chroma option value, if not explicitly specified, is set to the
+corresponding luma option value.
+
+@anchor{scale}
+@section scale
+
+Scale (resize) the input video, using the libswscale library.
+
+The scale filter forces the output display aspect ratio to be the same
+of the input, by changing the output sample aspect ratio.
+
+If the input image format is different from the format requested by
+the next filter, the scale filter will convert the input to the
+requested format.
+
+@subsection Options
+The filter accepts the following options, or any of the options
+supported by the libswscale scaler.
+
+See @ref{scaler_options,,the ffmpeg-scaler manual,ffmpeg-scaler} for
+the complete list of scaler options.
+
+@table @option
+@item width, w
+@item height, h
+Set the output video dimension expression. Default value is the input
+dimension.
+
+If the value is 0, the input width is used for the output.
+
+If one of the values is -1, the scale filter will use a value that
+maintains the aspect ratio of the input image, calculated from the
+other specified dimension. If both of them are -1, the input size is
+used
+
+If one of the values is -n with n > 1, the scale filter will also use a value
+that maintains the aspect ratio of the input image, calculated from the other
+specified dimension. After that it will, however, make sure that the calculated
+dimension is divisible by n and adjust the value if necessary.
+
+See below for the list of accepted constants for use in the dimension
+expression.
+
+@item eval
+Specify when to evaluate @var{width} and @var{height} expression. It accepts the following values:
+
+@table @samp
+@item init
+Only evaluate expressions once during the filter initialization or when a command is processed.
+
+@item frame
+Evaluate expressions for each incoming frame.
+
+@end table
+
+Default value is @samp{init}.
+
+
+@item interl
+Set the interlacing mode. It accepts the following values:
+
+@table @samp
+@item 1
+Force interlaced aware scaling.
+
+@item 0
+Do not apply interlaced scaling.
+
+@item -1
+Select interlaced aware scaling depending on whether the source frames
+are flagged as interlaced or not.
+@end table
+
+Default value is @samp{0}.
+
+@item flags
+Set libswscale scaling flags. See
+@ref{sws_flags,,the ffmpeg-scaler manual,ffmpeg-scaler} for the
+complete list of values. If not explicitly specified the filter applies
+the default flags.
+
+
+@item param0, param1
+Set libswscale input parameters for scaling algorithms that need them. See
+@ref{sws_params,,the ffmpeg-scaler manual,ffmpeg-scaler} for the
+complete documentation. If not explicitly specified the filter applies
+empty parameters.
+
+
+
+@item size, s
+Set the video size. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+
+@item in_color_matrix
+@item out_color_matrix
+Set in/output YCbCr color space type.
+
+This allows the autodetected value to be overridden as well as allows forcing
+a specific value used for the output and encoder.
+
+If not specified, the color space type depends on the pixel format.
+
+Possible values:
+
+@table @samp
+@item auto
+Choose automatically.
+
+@item bt709
+Format conforming to International Telecommunication Union (ITU)
+Recommendation BT.709.
+
+@item fcc
+Set color space conforming to the United States Federal Communications
+Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
+
+@item bt601
+Set color space conforming to:
+
+@itemize
+@item
+ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
+
+@item
+ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
+
+@item
+Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
+
+@end itemize
+
+@item smpte240m
+Set color space conforming to SMPTE ST 240:1999.
+@end table
+
+@item in_range
+@item out_range
+Set in/output YCbCr sample range.
+
+This allows the autodetected value to be overridden as well as allows forcing
+a specific value used for the output and encoder. If not specified, the
+range depends on the pixel format. Possible values:
+
+@table @samp
+@item auto
+Choose automatically.
+
+@item jpeg/full/pc
+Set full range (0-255 in case of 8-bit luma).
+
+@item mpeg/tv
+Set "MPEG" range (16-235 in case of 8-bit luma).
+@end table
+
+@item force_original_aspect_ratio
+Enable decreasing or increasing output video width or height if necessary to
+keep the original aspect ratio. Possible values:
+
+@table @samp
+@item disable
+Scale the video as specified and disable this feature.
+
+@item decrease
+The output video dimensions will automatically be decreased if needed.
+
+@item increase
+The output video dimensions will automatically be increased if needed.
+
+@end table
+
+One useful instance of this option is that when you know a specific device's
+maximum allowed resolution, you can use this to limit the output video to
+that, while retaining the aspect ratio. For example, device A allows
+1280x720 playback, and your video is 1920x800. Using this option (set it to
+decrease) and specifying 1280x720 to the command line makes the output
+1280x533.
+
+Please note that this is a different thing than specifying -1 for @option{w}
+or @option{h}, you still need to specify the output resolution for this option
+to work.
+
+@end table
+
+The values of the @option{w} and @option{h} options are expressions
+containing the following constants:
+
+@table @var
+@item in_w
+@item in_h
+The input width and height
+
+@item iw
+@item ih
+These are the same as @var{in_w} and @var{in_h}.
+
+@item out_w
+@item out_h
+The output (scaled) width and height
+
+@item ow
+@item oh
+These are the same as @var{out_w} and @var{out_h}
+
+@item a
+The same as @var{iw} / @var{ih}
+
+@item sar
+input sample aspect ratio
+
+@item dar
+The input display aspect ratio. Calculated from @code{(iw / ih) * sar}.
+
+@item hsub
+@item vsub
+horizontal and vertical input chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
+@item ohsub
+@item ovsub
+horizontal and vertical output chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Scale the input video to a size of 200x100
+@example
+scale=w=200:h=100
+@end example
+
+This is equivalent to:
+@example
+scale=200:100
+@end example
+
+or:
+@example
+scale=200x100
+@end example
+
+@item
+Specify a size abbreviation for the output size:
+@example
+scale=qcif
+@end example
+
+which can also be written as:
+@example
+scale=size=qcif
+@end example
+
+@item
+Scale the input to 2x:
+@example
+scale=w=2*iw:h=2*ih
+@end example
+
+@item
+The above is the same as:
+@example
+scale=2*in_w:2*in_h
+@end example
+
+@item
+Scale the input to 2x with forced interlaced scaling:
+@example
+scale=2*iw:2*ih:interl=1
+@end example
+
+@item
+Scale the input to half size:
+@example
+scale=w=iw/2:h=ih/2
+@end example
+
+@item
+Increase the width, and set the height to the same size:
+@example
+scale=3/2*iw:ow
+@end example
+
+@item
+Seek Greek harmony:
+@example
+scale=iw:1/PHI*iw
+scale=ih*PHI:ih
+@end example
+
+@item
+Increase the height, and set the width to 3/2 of the height:
+@example
+scale=w=3/2*oh:h=3/5*ih
+@end example
+
+@item
+Increase the size, making the size a multiple of the chroma
+subsample values:
+@example
+scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
+@end example
+
+@item
+Increase the width to a maximum of 500 pixels,
+keeping the same aspect ratio as the input:
+@example
+scale=w='min(500\, iw*3/2):h=-1'
+@end example
+@end itemize
+
+@subsection Commands
+
+This filter supports the following commands:
+@table @option
+@item width, w
+@item height, h
+Set the output video dimension expression.
+The command accepts the same syntax of the corresponding option.
+
+If the specified expression is not valid, it is kept at its current
+value.
+@end table
+
+@section scale2ref
+
+Scale (resize) the input video, based on a reference video.
+
+See the scale filter for available options, scale2ref supports the same but
+uses the reference video instead of the main input as basis.
+
+@subsection Examples
+
+@itemize
+@item
+Scale a subtitle stream to match the main video in size before overlaying
+@example
+'scale2ref[b][a];[a][b]overlay'
+@end example
+@end itemize
+
+@section selectivecolor
+
+Adjust cyan, magenta, yellow and black (CMYK) to certain ranges of colors (such
+as "reds", "yellows", "greens", "cyans", ...). The adjustment range is defined
+by the "purity" of the color (that is, how saturated it already is).
+
+This filter is similar to the Adobe Photoshop Selective Color tool.
+
+The filter accepts the following options:
+
+@table @option
+@item correction_method
+Select color correction method.
+
+Available values are:
+@table @samp
+@item absolute
+Specified adjustments are applied "as-is" (added/subtracted to original pixel
+component value).
+@item relative
+Specified adjustments are relative to the original component value.
+@end table
+Default is @code{absolute}.
+@item reds
+Adjustments for red pixels (pixels where the red component is the maximum)
+@item yellows
+Adjustments for yellow pixels (pixels where the blue component is the minimum)
+@item greens
+Adjustments for green pixels (pixels where the green component is the maximum)
+@item cyans
+Adjustments for cyan pixels (pixels where the red component is the minimum)
+@item blues
+Adjustments for blue pixels (pixels where the blue component is the maximum)
+@item magentas
+Adjustments for magenta pixels (pixels where the green component is the minimum)
+@item whites
+Adjustments for white pixels (pixels where all components are greater than 128)
+@item neutrals
+Adjustments for all pixels except pure black and pure white
+@item blacks
+Adjustments for black pixels (pixels where all components are lesser than 128)
+@item psfile
+Specify a Photoshop selective color file (@code{.asv}) to import the settings from.
+@end table
+
+All the adjustment settings (@option{reds}, @option{yellows}, ...) accept up to
+4 space separated floating point adjustment values in the [-1,1] range,
+respectively to adjust the amount of cyan, magenta, yellow and black for the
+pixels of its range.
+
+@subsection Examples
+
+@itemize
+@item
+Increase cyan by 50% and reduce yellow by 33% in every green areas, and
+increase magenta by 27% in blue areas:
+@example
+selectivecolor=greens=.5 0 -.33 0:blues=0 .27
+@end example
+
+@item
+Use a Photoshop selective color preset:
+@example
+selectivecolor=psfile=MySelectiveColorPresets/Misty.asv
+@end example
+@end itemize
+
+@section separatefields
+
+The @code{separatefields} takes a frame-based video input and splits
+each frame into its components fields, producing a new half height clip
+with twice the frame rate and twice the frame count.
+
+This filter use field-dominance information in frame to decide which
+of each pair of fields to place first in the output.
+If it gets it wrong use @ref{setfield} filter before @code{separatefields} filter.
+
+@section setdar, setsar
+
+The @code{setdar} filter sets the Display Aspect Ratio for the filter
+output video.
+
+This is done by changing the specified Sample (aka Pixel) Aspect
+Ratio, according to the following equation:
+@example
+@var{DAR} = @var{HORIZONTAL_RESOLUTION} / @var{VERTICAL_RESOLUTION} * @var{SAR}
+@end example
+
+Keep in mind that the @code{setdar} filter does not modify the pixel
+dimensions of the video frame. Also, the display aspect ratio set by
+this filter may be changed by later filters in the filterchain,
+e.g. in case of scaling or if another "setdar" or a "setsar" filter is
+applied.
+
+The @code{setsar} filter sets the Sample (aka Pixel) Aspect Ratio for
+the filter output video.
+
+Note that as a consequence of the application of this filter, the
+output display aspect ratio will change according to the equation
+above.
+
+Keep in mind that the sample aspect ratio set by the @code{setsar}
+filter may be changed by later filters in the filterchain, e.g. if
+another "setsar" or a "setdar" filter is applied.
+
+It accepts the following parameters:
+
+@table @option
+@item r, ratio, dar (@code{setdar} only), sar (@code{setsar} only)
+Set the aspect ratio used by the filter.
+
+The parameter can be a floating point number string, an expression, or
+a string of the form @var{num}:@var{den}, where @var{num} and
+@var{den} are the numerator and denominator of the aspect ratio. If
+the parameter is not specified, it is assumed the value "0".
+In case the form "@var{num}:@var{den}" is used, the @code{:} character
+should be escaped.
+
+@item max
+Set the maximum integer value to use for expressing numerator and
+denominator when reducing the expressed aspect ratio to a rational.
+Default value is @code{100}.
+
+@end table
+
+The parameter @var{sar} is an expression containing
+the following constants:
+
+@table @option
+@item E, PI, PHI
+These are approximated values for the mathematical constants e
+(Euler's number), pi (Greek pi), and phi (the golden ratio).
+
+@item w, h
+The input width and height.
+
+@item a
+These are the same as @var{w} / @var{h}.
+
+@item sar
+The input sample aspect ratio.
+
+@item dar
+The input display aspect ratio. It is the same as
+(@var{w} / @var{h}) * @var{sar}.
+
+@item hsub, vsub
+Horizontal and vertical chroma subsample values. For example, for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+@end table
+
+@subsection Examples
+
+@itemize
+
+@item
+To change the display aspect ratio to 16:9, specify one of the following:
+@example
+setdar=dar=1.77777
+setdar=dar=16/9
+setdar=dar=1.77777
+@end example
+
+@item
+To change the sample aspect ratio to 10:11, specify:
+@example
+setsar=sar=10/11
+@end example
+
+@item
+To set a display aspect ratio of 16:9, and specify a maximum integer value of
+1000 in the aspect ratio reduction, use the command:
+@example
+setdar=ratio=16/9:max=1000
+@end example
+
+@end itemize
+
+@anchor{setfield}
+@section setfield
+
+Force field for the output video frame.
+
+The @code{setfield} filter marks the interlace type field for the
+output frames. It does not change the input frame, but only sets the
+corresponding property, which affects how the frame is treated by
+following filters (e.g. @code{fieldorder} or @code{yadif}).
+
+The filter accepts the following options:
+
+@table @option
+
+@item mode
+Available values are:
+
+@table @samp
+@item auto
+Keep the same field property.
+
+@item bff
+Mark the frame as bottom-field-first.
+
+@item tff
+Mark the frame as top-field-first.
+
+@item prog
+Mark the frame as progressive.
+@end table
+@end table
+
+@section showinfo
+
+Show a line containing various information for each input video frame.
+The input video is not modified.
+
+The shown line contains a sequence of key/value pairs of the form
+@var{key}:@var{value}.
+
+The following values are shown in the output:
+
+@table @option
+@item n
+The (sequential) number of the input frame, starting from 0.
+
+@item pts
+The Presentation TimeStamp of the input frame, expressed as a number of
+time base units. The time base unit depends on the filter input pad.
+
+@item pts_time
+The Presentation TimeStamp of the input frame, expressed as a number of
+seconds.
+
+@item pos
+The position of the frame in the input stream, or -1 if this information is
+unavailable and/or meaningless (for example in case of synthetic video).
+
+@item fmt
+The pixel format name.
+
+@item sar
+The sample aspect ratio of the input frame, expressed in the form
+@var{num}/@var{den}.
+
+@item s
+The size of the input frame. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+
+@item i
+The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
+for bottom field first).
+
+@item iskey
+This is 1 if the frame is a key frame, 0 otherwise.
+
+@item type
+The picture type of the input frame ("I" for an I-frame, "P" for a
+P-frame, "B" for a B-frame, or "?" for an unknown type).
+Also refer to the documentation of the @code{AVPictureType} enum and of
+the @code{av_get_picture_type_char} function defined in
+@file{libavutil/avutil.h}.
+
+@item checksum
+The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
+
+@item plane_checksum
+The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
+expressed in the form "[@var{c0} @var{c1} @var{c2} @var{c3}]".
+@end table
+
+@section showpalette
+
+Displays the 256 colors palette of each frame. This filter is only relevant for
+@var{pal8} pixel format frames.
+
+It accepts the following option:
+
+@table @option
+@item s
+Set the size of the box used to represent one palette color entry. Default is
+@code{30} (for a @code{30x30} pixel box).
+@end table
+
+@section shuffleframes
+
+Reorder and/or duplicate video frames.
+
+It accepts the following parameters:
+
+@table @option
+@item mapping
+Set the destination indexes of input frames.
+This is space or '|' separated list of indexes that maps input frames to output
+frames. Number of indexes also sets maximal value that each index may have.
+@end table
+
+The first frame has the index 0. The default is to keep the input unchanged.
+
+Swap second and third frame of every three frames of the input:
+@example
+ffmpeg -i INPUT -vf "shuffleframes=0 2 1" OUTPUT
+@end example
+
+@section shuffleplanes
+
+Reorder and/or duplicate video planes.
+
+It accepts the following parameters:
+
+@table @option
+
+@item map0
+The index of the input plane to be used as the first output plane.
+
+@item map1
+The index of the input plane to be used as the second output plane.
+
+@item map2
+The index of the input plane to be used as the third output plane.
+
+@item map3
+The index of the input plane to be used as the fourth output plane.
+
+@end table
+
+The first plane has the index 0. The default is to keep the input unchanged.
+
+Swap the second and third planes of the input:
+@example
+ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
+@end example
+
+@anchor{signalstats}
+@section signalstats
+Evaluate various visual metrics that assist in determining issues associated
+with the digitization of analog video media.
+
+By default the filter will log these metadata values:
+
+@table @option
+@item YMIN
+Display the minimal Y value contained within the input frame. Expressed in
+range of [0-255].
+
+@item YLOW
+Display the Y value at the 10% percentile within the input frame. Expressed in
+range of [0-255].
+
+@item YAVG
+Display the average Y value within the input frame. Expressed in range of
+[0-255].
+
+@item YHIGH
+Display the Y value at the 90% percentile within the input frame. Expressed in
+range of [0-255].
+
+@item YMAX
+Display the maximum Y value contained within the input frame. Expressed in
+range of [0-255].
+
+@item UMIN
+Display the minimal U value contained within the input frame. Expressed in
+range of [0-255].
+
+@item ULOW
+Display the U value at the 10% percentile within the input frame. Expressed in
+range of [0-255].
+
+@item UAVG
+Display the average U value within the input frame. Expressed in range of
+[0-255].
+
+@item UHIGH
+Display the U value at the 90% percentile within the input frame. Expressed in
+range of [0-255].
+
+@item UMAX
+Display the maximum U value contained within the input frame. Expressed in
+range of [0-255].
+
+@item VMIN
+Display the minimal V value contained within the input frame. Expressed in
+range of [0-255].
+
+@item VLOW
+Display the V value at the 10% percentile within the input frame. Expressed in
+range of [0-255].
+
+@item VAVG
+Display the average V value within the input frame. Expressed in range of
+[0-255].
+
+@item VHIGH
+Display the V value at the 90% percentile within the input frame. Expressed in
+range of [0-255].
+
+@item VMAX
+Display the maximum V value contained within the input frame. Expressed in
+range of [0-255].
+
+@item SATMIN
+Display the minimal saturation value contained within the input frame.
+Expressed in range of [0-~181.02].
+
+@item SATLOW
+Display the saturation value at the 10% percentile within the input frame.
+Expressed in range of [0-~181.02].
+
+@item SATAVG
+Display the average saturation value within the input frame. Expressed in range
+of [0-~181.02].
+
+@item SATHIGH
+Display the saturation value at the 90% percentile within the input frame.
+Expressed in range of [0-~181.02].
+
+@item SATMAX
+Display the maximum saturation value contained within the input frame.
+Expressed in range of [0-~181.02].
+
+@item HUEMED
+Display the median value for hue within the input frame. Expressed in range of
+[0-360].
+
+@item HUEAVG
+Display the average value for hue within the input frame. Expressed in range of
+[0-360].
+
+@item YDIF
+Display the average of sample value difference between all values of the Y
+plane in the current frame and corresponding values of the previous input frame.
+Expressed in range of [0-255].
+
+@item UDIF
+Display the average of sample value difference between all values of the U
+plane in the current frame and corresponding values of the previous input frame.
+Expressed in range of [0-255].
+
+@item VDIF
+Display the average of sample value difference between all values of the V
+plane in the current frame and corresponding values of the previous input frame.
+Expressed in range of [0-255].
+@end table
+
+The filter accepts the following options:
+
+@table @option
+@item stat
+@item out
+
+@option{stat} specify an additional form of image analysis.
+@option{out} output video with the specified type of pixel highlighted.
+
+Both options accept the following values:
+
+@table @samp
+@item tout
+Identify @var{temporal outliers} pixels. A @var{temporal outlier} is a pixel
+unlike the neighboring pixels of the same field. Examples of temporal outliers
+include the results of video dropouts, head clogs, or tape tracking issues.
+
+@item vrep
+Identify @var{vertical line repetition}. Vertical line repetition includes
+similar rows of pixels within a frame. In born-digital video vertical line
+repetition is common, but this pattern is uncommon in video digitized from an
+analog source. When it occurs in video that results from the digitization of an
+analog source it can indicate concealment from a dropout compensator.
+
+@item brng
+Identify pixels that fall outside of legal broadcast range.
+@end table
+
+@item color, c
+Set the highlight color for the @option{out} option. The default color is
+yellow.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Output data of various video metrics:
+@example
+ffprobe -f lavfi movie=example.mov,signalstats="stat=tout+vrep+brng" -show_frames
+@end example
+
+@item
+Output specific data about the minimum and maximum values of the Y plane per frame:
+@example
+ffprobe -f lavfi movie=example.mov,signalstats -show_entries frame_tags=lavfi.signalstats.YMAX,lavfi.signalstats.YMIN
+@end example
+
+@item
+Playback video while highlighting pixels that are outside of broadcast range in red.
+@example
+ffplay example.mov -vf signalstats="out=brng:color=red"
+@end example
+
+@item
+Playback video with signalstats metadata drawn over the frame.
+@example
+ffplay example.mov -vf signalstats=stat=brng+vrep+tout,drawtext=fontfile=FreeSerif.ttf:textfile=signalstat_drawtext.txt
+@end example
+
+The contents of signalstat_drawtext.txt used in the command are:
+@example
+time %@{pts:hms@}
+Y (%@{metadata:lavfi.signalstats.YMIN@}-%@{metadata:lavfi.signalstats.YMAX@})
+U (%@{metadata:lavfi.signalstats.UMIN@}-%@{metadata:lavfi.signalstats.UMAX@})
+V (%@{metadata:lavfi.signalstats.VMIN@}-%@{metadata:lavfi.signalstats.VMAX@})
+saturation maximum: %@{metadata:lavfi.signalstats.SATMAX@}
+
+@end example
+@end itemize
+
+@anchor{smartblur}
+@section smartblur
+
+Blur the input video without impacting the outlines.
+
+It accepts the following options:
+
+@table @option
+@item luma_radius, lr
+Set the luma radius. The option value must be a float number in
+the range [0.1,5.0] that specifies the variance of the gaussian filter
+used to blur the image (slower if larger). Default value is 1.0.
+
+@item luma_strength, ls
+Set the luma strength. The option value must be a float number
+in the range [-1.0,1.0] that configures the blurring. A value included
+in [0.0,1.0] will blur the image whereas a value included in
+[-1.0,0.0] will sharpen the image. Default value is 1.0.
+
+@item luma_threshold, lt
+Set the luma threshold used as a coefficient to determine
+whether a pixel should be blurred or not. The option value must be an
+integer in the range [-30,30]. A value of 0 will filter all the image,
+a value included in [0,30] will filter flat areas and a value included
+in [-30,0] will filter edges. Default value is 0.
+
+@item chroma_radius, cr
+Set the chroma radius. The option value must be a float number in
+the range [0.1,5.0] that specifies the variance of the gaussian filter
+used to blur the image (slower if larger). Default value is 1.0.
+
+@item chroma_strength, cs
+Set the chroma strength. The option value must be a float number
+in the range [-1.0,1.0] that configures the blurring. A value included
+in [0.0,1.0] will blur the image whereas a value included in
+[-1.0,0.0] will sharpen the image. Default value is 1.0.
+
+@item chroma_threshold, ct
+Set the chroma threshold used as a coefficient to determine
+whether a pixel should be blurred or not. The option value must be an
+integer in the range [-30,30]. A value of 0 will filter all the image,
+a value included in [0,30] will filter flat areas and a value included
+in [-30,0] will filter edges. Default value is 0.
+@end table
+
+If a chroma option is not explicitly set, the corresponding luma value
+is set.
+
+@section ssim
+
+Obtain the SSIM (Structural SImilarity Metric) between two input videos.
+
+This filter takes in input two input videos, the first input is
+considered the "main" source and is passed unchanged to the
+output. The second input is used as a "reference" video for computing
+the SSIM.
+
+Both video inputs must have the same resolution and pixel format for
+this filter to work correctly. Also it assumes that both inputs
+have the same number of frames, which are compared one by one.
+
+The filter stores the calculated SSIM of each frame.
+
+The description of the accepted parameters follows.
+
+@table @option
+@item stats_file, f
+If specified the filter will use the named file to save the SSIM of
+each individual frame. When filename equals "-" the data is sent to
+standard output.
+@end table
+
+The file printed if @var{stats_file} is selected, contains a sequence of
+key/value pairs of the form @var{key}:@var{value} for each compared
+couple of frames.
+
+A description of each shown parameter follows:
+
+@table @option
+@item n
+sequential number of the input frame, starting from 1
+
+@item Y, U, V, R, G, B
+SSIM of the compared frames for the component specified by the suffix.
+
+@item All
+SSIM of the compared frames for the whole frame.
+
+@item dB
+Same as above but in dB representation.
+@end table
+
+For example:
+@example
+movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
+[main][ref] ssim="stats_file=stats.log" [out]
+@end example
+
+On this example the input file being processed is compared with the
+reference file @file{ref_movie.mpg}. The SSIM of each individual frame
+is stored in @file{stats.log}.
+
+Another example with both psnr and ssim at same time:
+@example
+ffmpeg -i main.mpg -i ref.mpg -lavfi "ssim;[0:v][1:v]psnr" -f null -
+@end example
+
+@section stereo3d
+
+Convert between different stereoscopic image formats.
+
+The filters accept the following options:
+
+@table @option
+@item in
+Set stereoscopic image format of input.
+
+Available values for input image formats are:
+@table @samp
+@item sbsl
+side by side parallel (left eye left, right eye right)
+
+@item sbsr
+side by side crosseye (right eye left, left eye right)
+
+@item sbs2l
+side by side parallel with half width resolution
+(left eye left, right eye right)
+
+@item sbs2r
+side by side crosseye with half width resolution
+(right eye left, left eye right)
+
+@item abl
+above-below (left eye above, right eye below)
+
+@item abr
+above-below (right eye above, left eye below)
+
+@item ab2l
+above-below with half height resolution
+(left eye above, right eye below)
+
+@item ab2r
+above-below with half height resolution
+(right eye above, left eye below)
+
+@item al
+alternating frames (left eye first, right eye second)
+
+@item ar
+alternating frames (right eye first, left eye second)
+
+@item irl
+interleaved rows (left eye has top row, right eye starts on next row)
+
+@item irr
+interleaved rows (right eye has top row, left eye starts on next row)
+
+@item icl
+interleaved columns, left eye first
+
+@item icr
+interleaved columns, right eye first
+
+Default value is @samp{sbsl}.
+@end table
+
+@item out
+Set stereoscopic image format of output.
+
+@table @samp
+@item sbsl
+side by side parallel (left eye left, right eye right)
+
+@item sbsr
+side by side crosseye (right eye left, left eye right)
+
+@item sbs2l
+side by side parallel with half width resolution
+(left eye left, right eye right)
+
+@item sbs2r
+side by side crosseye with half width resolution
+(right eye left, left eye right)
+
+@item abl
+above-below (left eye above, right eye below)
+
+@item abr
+above-below (right eye above, left eye below)
+
+@item ab2l
+above-below with half height resolution
+(left eye above, right eye below)
+
+@item ab2r
+above-below with half height resolution
+(right eye above, left eye below)
+
+@item al
+alternating frames (left eye first, right eye second)
+
+@item ar
+alternating frames (right eye first, left eye second)
+
+@item irl
+interleaved rows (left eye has top row, right eye starts on next row)
+
+@item irr
+interleaved rows (right eye has top row, left eye starts on next row)
+
+@item arbg
+anaglyph red/blue gray
+(red filter on left eye, blue filter on right eye)
+
+@item argg
+anaglyph red/green gray
+(red filter on left eye, green filter on right eye)
+
+@item arcg
+anaglyph red/cyan gray
+(red filter on left eye, cyan filter on right eye)
+
+@item arch
+anaglyph red/cyan half colored
+(red filter on left eye, cyan filter on right eye)
+
+@item arcc
+anaglyph red/cyan color
+(red filter on left eye, cyan filter on right eye)
+
+@item arcd
+anaglyph red/cyan color optimized with the least squares projection of dubois
+(red filter on left eye, cyan filter on right eye)
+
+@item agmg
+anaglyph green/magenta gray
+(green filter on left eye, magenta filter on right eye)
+
+@item agmh
+anaglyph green/magenta half colored
+(green filter on left eye, magenta filter on right eye)
+
+@item agmc
+anaglyph green/magenta colored
+(green filter on left eye, magenta filter on right eye)
+
+@item agmd
+anaglyph green/magenta color optimized with the least squares projection of dubois
+(green filter on left eye, magenta filter on right eye)
+
+@item aybg
+anaglyph yellow/blue gray
+(yellow filter on left eye, blue filter on right eye)
+
+@item aybh
+anaglyph yellow/blue half colored
+(yellow filter on left eye, blue filter on right eye)
+
+@item aybc
+anaglyph yellow/blue colored
+(yellow filter on left eye, blue filter on right eye)
+
+@item aybd
+anaglyph yellow/blue color optimized with the least squares projection of dubois
+(yellow filter on left eye, blue filter on right eye)
+
+@item ml
+mono output (left eye only)
+
+@item mr
+mono output (right eye only)
+
+@item chl
+checkerboard, left eye first
+
+@item chr
+checkerboard, right eye first
+
+@item icl
+interleaved columns, left eye first
+
+@item icr
+interleaved columns, right eye first
+@end table
+
+Default value is @samp{arcd}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Convert input video from side by side parallel to anaglyph yellow/blue dubois:
+@example
+stereo3d=sbsl:aybd
+@end example
+
+@item
+Convert input video from above below (left eye above, right eye below) to side by side crosseye.
+@example
+stereo3d=abl:sbsr
+@end example
+@end itemize
+
+@section streamselect, astreamselect
+Select video or audio streams.
+
+The filter accepts the following options:
+
+@table @option
+@item inputs
+Set number of inputs. Default is 2.
+
+@item map
+Set input indexes to remap to outputs.
+@end table
+
+@subsection Commands
+
+The @code{streamselect} and @code{astreamselect} filter supports the following
+commands:
+
+@table @option
+@item map
+Set input indexes to remap to outputs.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Select first 5 seconds 1st stream and rest of time 2nd stream:
+@example
+sendcmd='5.0 streamselect map 1',streamselect=inputs=2:map=0
+@end example
+
+@item
+Same as above, but for audio:
+@example
+asendcmd='5.0 astreamselect map 1',astreamselect=inputs=2:map=0
+@end example
+@end itemize
+
+@anchor{spp}
+@section spp
+
+Apply a simple postprocessing filter that compresses and decompresses the image
+at several (or - in the case of @option{quality} level @code{6} - all) shifts
+and average the results.
+
+The filter accepts the following options:
+
+@table @option
+@item quality
+Set quality. This option defines the number of levels for averaging. It accepts
+an integer in the range 0-6. If set to @code{0}, the filter will have no
+effect. A value of @code{6} means the higher quality. For each increment of
+that value the speed drops by a factor of approximately 2. Default value is
+@code{3}.
+
+@item qp
+Force a constant quantization parameter. If not set, the filter will use the QP
+from the video stream (if available).
+
+@item mode
+Set thresholding mode. Available modes are:
+
+@table @samp
+@item hard
+Set hard thresholding (default).
+@item soft
+Set soft thresholding (better de-ringing effect, but likely blurrier).
+@end table
+
+@item use_bframe_qp
+Enable the use of the QP from the B-Frames if set to @code{1}. Using this
+option may cause flicker since the B-Frames have often larger QP. Default is
+@code{0} (not enabled).
+@end table
+
+@anchor{subtitles}
+@section subtitles
+
+Draw subtitles on top of input video using the libass library.
+
+To enable compilation of this filter you need to configure FFmpeg with
+@code{--enable-libass}. This filter also requires a build with libavcodec and
+libavformat to convert the passed subtitles file to ASS (Advanced Substation
+Alpha) subtitles format.
+
+The filter accepts the following options:
+
+@table @option
+@item filename, f
+Set the filename of the subtitle file to read. It must be specified.
+
+@item original_size
+Specify the size of the original video, the video for which the ASS file
+was composed. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+Due to a misdesign in ASS aspect ratio arithmetic, this is necessary to
+correctly scale the fonts if the aspect ratio has been changed.
+
+@item fontsdir
+Set a directory path containing fonts that can be used by the filter.
+These fonts will be used in addition to whatever the font provider uses.
+
+@item charenc
+Set subtitles input character encoding. @code{subtitles} filter only. Only
+useful if not UTF-8.
+
+@item stream_index, si
+Set subtitles stream index. @code{subtitles} filter only.
+
+@item force_style
+Override default style or script info parameters of the subtitles. It accepts a
+string containing ASS style format @code{KEY=VALUE} couples separated by ",".
+@end table
+
+If the first key is not specified, it is assumed that the first value
+specifies the @option{filename}.
+
+For example, to render the file @file{sub.srt} on top of the input
+video, use the command:
+@example
+subtitles=sub.srt
+@end example
+
+which is equivalent to:
+@example
+subtitles=filename=sub.srt
+@end example
+
+To render the default subtitles stream from file @file{video.mkv}, use:
+@example
+subtitles=video.mkv
+@end example
+
+To render the second subtitles stream from that file, use:
+@example
+subtitles=video.mkv:si=1
+@end example
+
+To make the subtitles stream from @file{sub.srt} appear in transparent green
+@code{DejaVu Serif}, use:
+@example
+subtitles=sub.srt:force_style='FontName=DejaVu Serif,PrimaryColour=&HAA00FF00'
+@end example
+
+@section super2xsai
+
+Scale the input by 2x and smooth using the Super2xSaI (Scale and
+Interpolate) pixel art scaling algorithm.
+
+Useful for enlarging pixel art images without reducing sharpness.
+
+@section swaprect
+
+Swap two rectangular objects in video.
+
+This filter accepts the following options:
+
+@table @option
+@item w
+Set object width.
+
+@item h
+Set object height.
+
+@item x1
+Set 1st rect x coordinate.
+
+@item y1
+Set 1st rect y coordinate.
+
+@item x2
+Set 2nd rect x coordinate.
+
+@item y2
+Set 2nd rect y coordinate.
+
+All expressions are evaluated once for each frame.
+@end table
+
+The all options are expressions containing the following constants:
+
+@table @option
+@item w
+@item h
+The input width and height.
+
+@item a
+same as @var{w} / @var{h}
+
+@item sar
+input sample aspect ratio
+
+@item dar
+input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
+
+@item n
+The number of the input frame, starting from 0.
+
+@item t
+The timestamp expressed in seconds. It's NAN if the input timestamp is unknown.
+
+@item pos
+the position in the file of the input frame, NAN if unknown
+@end table
+
+@section swapuv
+Swap U & V plane.
+
+@section telecine
+
+Apply telecine process to the video.
+
+This filter accepts the following options:
+
+@table @option
+@item first_field
+@table @samp
+@item top, t
+top field first
+@item bottom, b
+bottom field first
+The default value is @code{top}.
+@end table
+
+@item pattern
+A string of numbers representing the pulldown pattern you wish to apply.
+The default value is @code{23}.
+@end table
+
+@example
+Some typical patterns:
+
+NTSC output (30i):
+27.5p: 32222
+24p: 23 (classic)
+24p: 2332 (preferred)
+20p: 33
+18p: 334
+16p: 3444
+
+PAL output (25i):
+27.5p: 12222
+24p: 222222222223 ("Euro pulldown")
+16.67p: 33
+16p: 33333334
+@end example
+
+@section thumbnail
+Select the most representative frame in a given sequence of consecutive frames.
+
+The filter accepts the following options:
+
+@table @option
+@item n
+Set the frames batch size to analyze; in a set of @var{n} frames, the filter
+will pick one of them, and then handle the next batch of @var{n} frames until
+the end. Default is @code{100}.
+@end table
+
+Since the filter keeps track of the whole frames sequence, a bigger @var{n}
+value will result in a higher memory usage, so a high value is not recommended.
+
+@subsection Examples
+
+@itemize
+@item
+Extract one picture each 50 frames:
+@example
+thumbnail=50
+@end example
+
+@item
+Complete example of a thumbnail creation with @command{ffmpeg}:
+@example
+ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
+@end example
+@end itemize
+
+@section tile
+
+Tile several successive frames together.
+
+The filter accepts the following options:
+
+@table @option
+
+@item layout
+Set the grid size (i.e. the number of lines and columns). For the syntax of
+this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+
+@item nb_frames
+Set the maximum number of frames to render in the given area. It must be less
+than or equal to @var{w}x@var{h}. The default value is @code{0}, meaning all
+the area will be used.
+
+@item margin
+Set the outer border margin in pixels.
+
+@item padding
+Set the inner border thickness (i.e. the number of pixels between frames). For
+more advanced padding options (such as having different values for the edges),
+refer to the pad video filter.
+
+@item color
+Specify the color of the unused area. For the syntax of this option, check the
+"Color" section in the ffmpeg-utils manual. The default value of @var{color}
+is "black".
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Produce 8x8 PNG tiles of all keyframes (@option{-skip_frame nokey}) in a movie:
+@example
+ffmpeg -skip_frame nokey -i file.avi -vf 'scale=128:72,tile=8x8' -an -vsync 0 keyframes%03d.png
+@end example
+The @option{-vsync 0} is necessary to prevent @command{ffmpeg} from
+duplicating each output frame to accommodate the originally detected frame
+rate.
+
+@item
+Display @code{5} pictures in an area of @code{3x2} frames,
+with @code{7} pixels between them, and @code{2} pixels of initial margin, using
+mixed flat and named options:
+@example
+tile=3x2:nb_frames=5:padding=7:margin=2
+@end example
+@end itemize
+
+@section tinterlace
+
+Perform various types of temporal field interlacing.
+
+Frames are counted starting from 1, so the first input frame is
+considered odd.
+
+The filter accepts the following options:
+
+@table @option
+
+@item mode
+Specify the mode of the interlacing. This option can also be specified
+as a value alone. See below for a list of values for this option.
+
+Available values are:
+
+@table @samp
+@item merge, 0
+Move odd frames into the upper field, even into the lower field,
+generating a double height frame at half frame rate.
+@example
+ ------> time
+Input:
+Frame 1 Frame 2 Frame 3 Frame 4
+
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+
+Output:
+11111 33333
+22222 44444
+11111 33333
+22222 44444
+11111 33333
+22222 44444
+11111 33333
+22222 44444
+@end example
+
+@item drop_odd, 1
+Only output even frames, odd frames are dropped, generating a frame with
+unchanged height at half frame rate.
+
+@example
+ ------> time
+Input:
+Frame 1 Frame 2 Frame 3 Frame 4
+
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+
+Output:
+ 22222 44444
+ 22222 44444
+ 22222 44444
+ 22222 44444
+@end example
+
+@item drop_even, 2
+Only output odd frames, even frames are dropped, generating a frame with
+unchanged height at half frame rate.
+
+@example
+ ------> time
+Input:
+Frame 1 Frame 2 Frame 3 Frame 4
+
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+
+Output:
+11111 33333
+11111 33333
+11111 33333
+11111 33333
+@end example
+
+@item pad, 3
+Expand each frame to full height, but pad alternate lines with black,
+generating a frame with double height at the same input frame rate.
+
+@example
+ ------> time
+Input:
+Frame 1 Frame 2 Frame 3 Frame 4
+
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+
+Output:
+11111 ..... 33333 .....
+..... 22222 ..... 44444
+11111 ..... 33333 .....
+..... 22222 ..... 44444
+11111 ..... 33333 .....
+..... 22222 ..... 44444
+11111 ..... 33333 .....
+..... 22222 ..... 44444
+@end example
+
+
+@item interleave_top, 4
+Interleave the upper field from odd frames with the lower field from
+even frames, generating a frame with unchanged height at half frame rate.
+
+@example
+ ------> time
+Input:
+Frame 1 Frame 2 Frame 3 Frame 4
+
+11111<- 22222 33333<- 44444
+11111 22222<- 33333 44444<-
+11111<- 22222 33333<- 44444
+11111 22222<- 33333 44444<-
+
+Output:
+11111 33333
+22222 44444
+11111 33333
+22222 44444
+@end example
+
+
+@item interleave_bottom, 5
+Interleave the lower field from odd frames with the upper field from
+even frames, generating a frame with unchanged height at half frame rate.
+
+@example
+ ------> time
+Input:
+Frame 1 Frame 2 Frame 3 Frame 4
+
+11111 22222<- 33333 44444<-
+11111<- 22222 33333<- 44444
+11111 22222<- 33333 44444<-
+11111<- 22222 33333<- 44444
+
+Output:
+22222 44444
+11111 33333
+22222 44444
+11111 33333
+@end example
+
+
+@item interlacex2, 6
+Double frame rate with unchanged height. Frames are inserted each
+containing the second temporal field from the previous input frame and
+the first temporal field from the next input frame. This mode relies on
+the top_field_first flag. Useful for interlaced video displays with no
+field synchronisation.
+
+@example
+ ------> time
+Input:
+Frame 1 Frame 2 Frame 3 Frame 4
+
+11111 22222 33333 44444
+ 11111 22222 33333 44444
+11111 22222 33333 44444
+ 11111 22222 33333 44444
+
+Output:
+11111 22222 22222 33333 33333 44444 44444
+ 11111 11111 22222 22222 33333 33333 44444
+11111 22222 22222 33333 33333 44444 44444
+ 11111 11111 22222 22222 33333 33333 44444
+@end example
+
+@item mergex2, 7
+Move odd frames into the upper field, even into the lower field,
+generating a double height frame at same frame rate.
+@example
+ ------> time
+Input:
+Frame 1 Frame 2 Frame 3 Frame 4
+
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+11111 22222 33333 44444
+
+Output:
+11111 33333 33333 55555
+22222 22222 44444 44444
+11111 33333 33333 55555
+22222 22222 44444 44444
+11111 33333 33333 55555
+22222 22222 44444 44444
+11111 33333 33333 55555
+22222 22222 44444 44444
+@end example
+
+@end table
+
+Numeric values are deprecated but are accepted for backward
+compatibility reasons.
+
+Default mode is @code{merge}.
+
+@item flags
+Specify flags influencing the filter process.
+
+Available value for @var{flags} is:
+
+@table @option
+@item low_pass_filter, vlfp
+Enable vertical low-pass filtering in the filter.
+Vertical low-pass filtering is required when creating an interlaced
+destination from a progressive source which contains high-frequency
+vertical detail. Filtering will reduce interlace 'twitter' and Moire
+patterning.
+
+Vertical low-pass filtering can only be enabled for @option{mode}
+@var{interleave_top} and @var{interleave_bottom}.
+
+@end table
+@end table
+
+@section transpose
+
+Transpose rows with columns in the input video and optionally flip it.
+
+It accepts the following parameters:
+
+@table @option
+
+@item dir
+Specify the transposition direction.
+
+Can assume the following values:
+@table @samp
+@item 0, 4, cclock_flip
+Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
+@example
+L.R L.l
+. . -> . .
+l.r R.r
+@end example
+
+@item 1, 5, clock
+Rotate by 90 degrees clockwise, that is:
+@example
+L.R l.L
+. . -> . .
+l.r r.R
+@end example
+
+@item 2, 6, cclock
+Rotate by 90 degrees counterclockwise, that is:
+@example
+L.R R.r
+. . -> . .
+l.r L.l
+@end example
+
+@item 3, 7, clock_flip
+Rotate by 90 degrees clockwise and vertically flip, that is:
+@example
+L.R r.R
+. . -> . .
+l.r l.L
+@end example
+@end table
+
+For values between 4-7, the transposition is only done if the input
+video geometry is portrait and not landscape. These values are
+deprecated, the @code{passthrough} option should be used instead.
+
+Numerical values are deprecated, and should be dropped in favor of
+symbolic constants.
+
+@item passthrough
+Do not apply the transposition if the input geometry matches the one
+specified by the specified value. It accepts the following values:
+@table @samp
+@item none
+Always apply transposition.
+@item portrait
+Preserve portrait geometry (when @var{height} >= @var{width}).
+@item landscape
+Preserve landscape geometry (when @var{width} >= @var{height}).
+@end table
+
+Default value is @code{none}.
+@end table
+
+For example to rotate by 90 degrees clockwise and preserve portrait
+layout:
+@example
+transpose=dir=1:passthrough=portrait
+@end example
+
+The command above can also be specified as:
+@example
+transpose=1:portrait
+@end example
+
+@section trim
+Trim the input so that the output contains one continuous subpart of the input.
+
+It accepts the following parameters:
+@table @option
+@item start
+Specify the time of the start of the kept section, i.e. the frame with the
+timestamp @var{start} will be the first frame in the output.
+
+@item end
+Specify the time of the first frame that will be dropped, i.e. the frame
+immediately preceding the one with the timestamp @var{end} will be the last
+frame in the output.
+
+@item start_pts
+This is the same as @var{start}, except this option sets the start timestamp
+in timebase units instead of seconds.
+
+@item end_pts
+This is the same as @var{end}, except this option sets the end timestamp
+in timebase units instead of seconds.
+
+@item duration
+The maximum duration of the output in seconds.
+
+@item start_frame
+The number of the first frame that should be passed to the output.
+
+@item end_frame
+The number of the first frame that should be dropped.
+@end table
+
+@option{start}, @option{end}, and @option{duration} are expressed as time
+duration specifications; see
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
+
+Note that the first two sets of the start/end options and the @option{duration}
+option look at the frame timestamp, while the _frame variants simply count the
+frames that pass through the filter. Also note that this filter does not modify
+the timestamps. If you wish for the output timestamps to start at zero, insert a
+setpts filter after the trim filter.
+
+If multiple start or end options are set, this filter tries to be greedy and
+keep all the frames that match at least one of the specified constraints. To keep
+only the part that matches all the constraints at once, chain multiple trim
+filters.
+
+The defaults are such that all the input is kept. So it is possible to set e.g.
+just the end values to keep everything before the specified time.
+
+Examples:
+@itemize
+@item
+Drop everything except the second minute of input:
+@example
+ffmpeg -i INPUT -vf trim=60:120
+@end example
+
+@item
+Keep only the first second:
+@example
+ffmpeg -i INPUT -vf trim=duration=1
+@end example
+
+@end itemize
+
+
+@anchor{unsharp}
+@section unsharp
+
+Sharpen or blur the input video.
+
+It accepts the following parameters:
+
+@table @option
+@item luma_msize_x, lx
+Set the luma matrix horizontal size. It must be an odd integer between
+3 and 63. The default value is 5.
+
+@item luma_msize_y, ly
+Set the luma matrix vertical size. It must be an odd integer between 3
+and 63. The default value is 5.
+
+@item luma_amount, la
+Set the luma effect strength. It must be a floating point number, reasonable
+values lay between -1.5 and 1.5.
+
+Negative values will blur the input video, while positive values will
+sharpen it, a value of zero will disable the effect.
+
+Default value is 1.0.
+
+@item chroma_msize_x, cx
+Set the chroma matrix horizontal size. It must be an odd integer
+between 3 and 63. The default value is 5.
+
+@item chroma_msize_y, cy
+Set the chroma matrix vertical size. It must be an odd integer
+between 3 and 63. The default value is 5.
+
+@item chroma_amount, ca
+Set the chroma effect strength. It must be a floating point number, reasonable
+values lay between -1.5 and 1.5.
+
+Negative values will blur the input video, while positive values will
+sharpen it, a value of zero will disable the effect.
+
+Default value is 0.0.
+
+@item opencl
+If set to 1, specify using OpenCL capabilities, only available if
+FFmpeg was configured with @code{--enable-opencl}. Default value is 0.
+
+@end table
+
+All parameters are optional and default to the equivalent of the
+string '5:5:1.0:5:5:0.0'.
+
+@subsection Examples
+
+@itemize
+@item
+Apply strong luma sharpen effect:
+@example
+unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
+@end example
+
+@item
+Apply a strong blur of both luma and chroma parameters:
+@example
+unsharp=7:7:-2:7:7:-2
+@end example
+@end itemize
+
+@section uspp
+
+Apply ultra slow/simple postprocessing filter that compresses and decompresses
+the image at several (or - in the case of @option{quality} level @code{8} - all)
+shifts and average the results.
+
+The way this differs from the behavior of spp is that uspp actually encodes &
+decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
+DCT similar to MJPEG.
+
+The filter accepts the following options:
+
+@table @option
+@item quality
+Set quality. This option defines the number of levels for averaging. It accepts
+an integer in the range 0-8. If set to @code{0}, the filter will have no
+effect. A value of @code{8} means the higher quality. For each increment of
+that value the speed drops by a factor of approximately 2. Default value is
+@code{3}.
+
+@item qp
+Force a constant quantization parameter. If not set, the filter will use the QP
+from the video stream (if available).
+@end table
+
+@section vectorscope
+
+Display 2 color component values in the two dimensional graph (which is called
+a vectorscope).
+
+This filter accepts the following options:
+
+@table @option
+@item mode, m
+Set vectorscope mode.
+
+It accepts the following values:
+@table @samp
+@item gray
+Gray values are displayed on graph, higher brightness means more pixels have
+same component color value on location in graph. This is the default mode.
+
+@item color
+Gray values are displayed on graph. Surrounding pixels values which are not
+present in video frame are drawn in gradient of 2 color components which are
+set by option @code{x} and @code{y}.
+
+@item color2
+Actual color components values present in video frame are displayed on graph.
+
+@item color3
+Similar as color2 but higher frequency of same values @code{x} and @code{y}
+on graph increases value of another color component, which is luminance by
+default values of @code{x} and @code{y}.
+
+@item color4
+Actual colors present in video frame are displayed on graph. If two different
+colors map to same position on graph then color with higher value of component
+not present in graph is picked.
+@end table
+
+@item x
+Set which color component will be represented on X-axis. Default is @code{1}.
+
+@item y
+Set which color component will be represented on Y-axis. Default is @code{2}.
+
+@item intensity, i
+Set intensity, used by modes: gray, color and color3 for increasing brightness
+of color component which represents frequency of (X, Y) location in graph.
+
+@item envelope, e
+@table @samp
+@item none
+No envelope, this is default.
+
+@item instant
+Instant envelope, even darkest single pixel will be clearly highlighted.
+
+@item peak
+Hold maximum and minimum values presented in graph over time. This way you
+can still spot out of range values without constantly looking at vectorscope.
+
+@item peak+instant
+Peak and instant envelope combined together.
+@end table
+@end table
+
+@anchor{vidstabdetect}
+@section vidstabdetect
+
+Analyze video stabilization/deshaking. Perform pass 1 of 2, see
+@ref{vidstabtransform} for pass 2.
+
+This filter generates a file with relative translation and rotation
+transform information about subsequent frames, which is then used by
+the @ref{vidstabtransform} filter.
+
+To enable compilation of this filter you need to configure FFmpeg with
+@code{--enable-libvidstab}.
+
+This filter accepts the following options:
+
+@table @option
+@item result
+Set the path to the file used to write the transforms information.
+Default value is @file{transforms.trf}.
+
+@item shakiness
+Set how shaky the video is and how quick the camera is. It accepts an
+integer in the range 1-10, a value of 1 means little shakiness, a
+value of 10 means strong shakiness. Default value is 5.
+
+@item accuracy
+Set the accuracy of the detection process. It must be a value in the
+range 1-15. A value of 1 means low accuracy, a value of 15 means high
+accuracy. Default value is 15.
+
+@item stepsize
+Set stepsize of the search process. The region around minimum is
+scanned with 1 pixel resolution. Default value is 6.
+
+@item mincontrast
+Set minimum contrast. Below this value a local measurement field is
+discarded. Must be a floating point value in the range 0-1. Default
+value is 0.3.
+
+@item tripod
+Set reference frame number for tripod mode.
+
+If enabled, the motion of the frames is compared to a reference frame
+in the filtered stream, identified by the specified number. The idea
+is to compensate all movements in a more-or-less static scene and keep
+the camera view absolutely still.
+
+If set to 0, it is disabled. The frames are counted starting from 1.
+
+@item show
+Show fields and transforms in the resulting frames. It accepts an
+integer in the range 0-2. Default value is 0, which disables any
+visualization.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Use default values:
+@example
+vidstabdetect
+@end example
+
+@item
+Analyze strongly shaky movie and put the results in file
+@file{mytransforms.trf}:
+@example
+vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
+@end example
+
+@item
+Visualize the result of internal transformations in the resulting
+video:
+@example
+vidstabdetect=show=1
+@end example
+
+@item
+Analyze a video with medium shakiness using @command{ffmpeg}:
+@example
+ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
+@end example
+@end itemize
+
+@anchor{vidstabtransform}
+@section vidstabtransform
+
+Video stabilization/deshaking: pass 2 of 2,
+see @ref{vidstabdetect} for pass 1.
+
+Read a file with transform information for each frame and
+apply/compensate them. Together with the @ref{vidstabdetect}
+filter this can be used to deshake videos. See also
+@url{http://public.hronopik.de/vid.stab}. It is important to also use
+the @ref{unsharp} filter, see below.
+
+To enable compilation of this filter you need to configure FFmpeg with
+@code{--enable-libvidstab}.
+
+@subsection Options
+
+@table @option
+@item input
+Set path to the file used to read the transforms. Default value is
+@file{transforms.trf}.
+
+@item smoothing
+Set the number of frames (value*2 + 1) used for lowpass filtering the
+camera movements. Default value is 10.
+
+For example a number of 10 means that 21 frames are used (10 in the
+past and 10 in the future) to smoothen the motion in the video. A
+larger value leads to a smoother video, but limits the acceleration of
+the camera (pan/tilt movements). 0 is a special case where a static
+camera is simulated.
+
+@item optalgo
+Set the camera path optimization algorithm.
+
+Accepted values are:
+@table @samp
+@item gauss
+gaussian kernel low-pass filter on camera motion (default)
+@item avg
+averaging on transformations
+@end table
+
+@item maxshift
+Set maximal number of pixels to translate frames. Default value is -1,
+meaning no limit.
+
+@item maxangle
+Set maximal angle in radians (degree*PI/180) to rotate frames. Default
+value is -1, meaning no limit.
+
+@item crop
+Specify how to deal with borders that may be visible due to movement
+compensation.
+
+Available values are:
+@table @samp
+@item keep
+keep image information from previous frame (default)
+@item black
+fill the border black
+@end table
+
+@item invert
+Invert transforms if set to 1. Default value is 0.
+
+@item relative
+Consider transforms as relative to previous frame if set to 1,
+absolute if set to 0. Default value is 0.
+
+@item zoom
+Set percentage to zoom. A positive value will result in a zoom-in
+effect, a negative value in a zoom-out effect. Default value is 0 (no
+zoom).
+
+@item optzoom
+Set optimal zooming to avoid borders.
+
+Accepted values are:
+@table @samp
+@item 0
+disabled
+@item 1
+optimal static zoom value is determined (only very strong movements
+will lead to visible borders) (default)
+@item 2
+optimal adaptive zoom value is determined (no borders will be
+visible), see @option{zoomspeed}
+@end table
+
+Note that the value given at zoom is added to the one calculated here.
+
+@item zoomspeed
+Set percent to zoom maximally each frame (enabled when
+@option{optzoom} is set to 2). Range is from 0 to 5, default value is
+0.25.
+
+@item interpol
+Specify type of interpolation.
+
+Available values are:
+@table @samp
+@item no
+no interpolation
+@item linear
+linear only horizontal
+@item bilinear
+linear in both directions (default)
+@item bicubic
+cubic in both directions (slow)
+@end table
+
+@item tripod
+Enable virtual tripod mode if set to 1, which is equivalent to
+@code{relative=0:smoothing=0}. Default value is 0.
+
+Use also @code{tripod} option of @ref{vidstabdetect}.
+
+@item debug
+Increase log verbosity if set to 1. Also the detected global motions
+are written to the temporary file @file{global_motions.trf}. Default
+value is 0.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Use @command{ffmpeg} for a typical stabilization with default values:
+@example
+ffmpeg -i inp.mpeg -vf vidstabtransform,unsharp=5:5:0.8:3:3:0.4 inp_stabilized.mpeg
+@end example
+
+Note the use of the @ref{unsharp} filter which is always recommended.
+
+@item
+Zoom in a bit more and load transform data from a given file:
+@example
+vidstabtransform=zoom=5:input="mytransforms.trf"
+@end example
+
+@item
+Smoothen the video even more:
+@example
+vidstabtransform=smoothing=30
+@end example
+@end itemize
+
+@section vflip
+
+Flip the input video vertically.
+
+For example, to vertically flip a video with @command{ffmpeg}:
+@example
+ffmpeg -i in.avi -vf "vflip" out.avi
+@end example
+
+@anchor{vignette}
+@section vignette
+
+Make or reverse a natural vignetting effect.
+
+The filter accepts the following options:
+
+@table @option
+@item angle, a
+Set lens angle expression as a number of radians.
+
+The value is clipped in the @code{[0,PI/2]} range.
+
+Default value: @code{"PI/5"}
+
+@item x0
+@item y0
+Set center coordinates expressions. Respectively @code{"w/2"} and @code{"h/2"}
+by default.
+
+@item mode
+Set forward/backward mode.
+
+Available modes are:
+@table @samp
+@item forward
+The larger the distance from the central point, the darker the image becomes.
+
+@item backward
+The larger the distance from the central point, the brighter the image becomes.
+This can be used to reverse a vignette effect, though there is no automatic
+detection to extract the lens @option{angle} and other settings (yet). It can
+also be used to create a burning effect.
+@end table
+
+Default value is @samp{forward}.
+
+@item eval
+Set evaluation mode for the expressions (@option{angle}, @option{x0}, @option{y0}).
+
+It accepts the following values:
+@table @samp
+@item init
+Evaluate expressions only once during the filter initialization.
+
+@item frame
+Evaluate expressions for each incoming frame. This is way slower than the
+@samp{init} mode since it requires all the scalers to be re-computed, but it
+allows advanced dynamic expressions.
+@end table
+
+Default value is @samp{init}.
+
+@item dither
+Set dithering to reduce the circular banding effects. Default is @code{1}
+(enabled).
+
+@item aspect
+Set vignette aspect. This setting allows one to adjust the shape of the vignette.
+Setting this value to the SAR of the input will make a rectangular vignetting
+following the dimensions of the video.
+
+Default is @code{1/1}.
+@end table
+
+@subsection Expressions
+
+The @option{alpha}, @option{x0} and @option{y0} expressions can contain the
+following parameters.
+
+@table @option
+@item w
+@item h
+input width and height
+
+@item n
+the number of input frame, starting from 0
+
+@item pts
+the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
+@var{TB} units, NAN if undefined
+
+@item r
+frame rate of the input video, NAN if the input frame rate is unknown
+
+@item t
+the PTS (Presentation TimeStamp) of the filtered video frame,
+expressed in seconds, NAN if undefined
+
+@item tb
+time base of the input video
+@end table
+
+
+@subsection Examples
+
+@itemize
+@item
+Apply simple strong vignetting effect:
+@example
+vignette=PI/4
+@end example
+
+@item
+Make a flickering vignetting:
+@example
+vignette='PI/4+random(1)*PI/50':eval=frame
+@end example
+
+@end itemize
+
+@section vstack
+Stack input videos vertically.
+
+All streams must be of same pixel format and of same width.
+
+Note that this filter is faster than using @ref{overlay} and @ref{pad} filter
+to create same output.
+
+The filter accept the following option:
+
+@table @option
+@item inputs
+Set number of input streams. Default is 2.
+
+@item shortest
+If set to 1, force the output to terminate when the shortest input
+terminates. Default value is 0.
+@end table
+
+@section w3fdif
+
+Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
+Deinterlacing Filter").
+
+Based on the process described by Martin Weston for BBC R&D, and
+implemented based on the de-interlace algorithm written by Jim
+Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
+uses filter coefficients calculated by BBC R&D.
+
+There are two sets of filter coefficients, so called "simple":
+and "complex". Which set of filter coefficients is used can
+be set by passing an optional parameter:
+
+@table @option
+@item filter
+Set the interlacing filter coefficients. Accepts one of the following values:
+
+@table @samp
+@item simple
+Simple filter coefficient set.
+@item complex
+More-complex filter coefficient set.
+@end table
+Default value is @samp{complex}.
+
+@item deint
+Specify which frames to deinterlace. Accept one of the following values:
+
+@table @samp
+@item all
+Deinterlace all frames,
+@item interlaced
+Only deinterlace frames marked as interlaced.
+@end table
+
+Default value is @samp{all}.
+@end table
+
+@section waveform
+Video waveform monitor.
+
+The waveform monitor plots color component intensity. By default luminance
+only. Each column of the waveform corresponds to a column of pixels in the
+source video.
+
+It accepts the following options:
+
+@table @option
+@item mode, m
+Can be either @code{row}, or @code{column}. Default is @code{column}.
+In row mode, the graph on the left side represents color component value 0 and
+the right side represents value = 255. In column mode, the top side represents
+color component value = 0 and bottom side represents value = 255.
+
+@item intensity, i
+Set intensity. Smaller values are useful to find out how many values of the same
+luminance are distributed across input rows/columns.
+Default value is @code{0.04}. Allowed range is [0, 1].
+
+@item mirror, r
+Set mirroring mode. @code{0} means unmirrored, @code{1} means mirrored.
+In mirrored mode, higher values will be represented on the left
+side for @code{row} mode and at the top for @code{column} mode. Default is
+@code{1} (mirrored).
+
+@item display, d
+Set display mode.
+It accepts the following values:
+@table @samp
+@item overlay
+Presents information identical to that in the @code{parade}, except
+that the graphs representing color components are superimposed directly
+over one another.
+
+This display mode makes it easier to spot relative differences or similarities
+in overlapping areas of the color components that are supposed to be identical,
+such as neutral whites, grays, or blacks.
+
+@item parade
+Display separate graph for the color components side by side in
+@code{row} mode or one below the other in @code{column} mode.
+
+Using this display mode makes it easy to spot color casts in the highlights
+and shadows of an image, by comparing the contours of the top and the bottom
+graphs of each waveform. Since whites, grays, and blacks are characterized
+by exactly equal amounts of red, green, and blue, neutral areas of the picture
+should display three waveforms of roughly equal width/height. If not, the
+correction is easy to perform by making level adjustments the three waveforms.
+@end table
+Default is @code{parade}.
+
+@item components, c
+Set which color components to display. Default is 1, which means only luminance
+or red color component if input is in RGB colorspace. If is set for example to
+7 it will display all 3 (if) available color components.
+
+@item envelope, e
+@table @samp
+@item none
+No envelope, this is default.
+
+@item instant
+Instant envelope, minimum and maximum values presented in graph will be easily
+visible even with small @code{step} value.
+
+@item peak
+Hold minimum and maximum values presented in graph across time. This way you
+can still spot out of range values without constantly looking at waveforms.
+
+@item peak+instant
+Peak and instant envelope combined together.
+@end table
+
+@item filter, f
+@table @samp
+@item lowpass
+No filtering, this is default.
+
+@item flat
+Luma and chroma combined together.
+
+@item aflat
+Similar as above, but shows difference between blue and red chroma.
+
+@item chroma
+Displays only chroma.
+
+@item achroma
+Similar as above, but shows difference between blue and red chroma.
+
+@item color
+Displays actual color value on waveform.
+@end table
+@end table
+
+@section xbr
+Apply the xBR high-quality magnification filter which is designed for pixel
+art. It follows a set of edge-detection rules, see
+@url{http://www.libretro.com/forums/viewtopic.php?f=6&t=134}.
+
+It accepts the following option:
+
+@table @option
+@item n
+Set the scaling dimension: @code{2} for @code{2xBR}, @code{3} for
+@code{3xBR} and @code{4} for @code{4xBR}.
+Default is @code{3}.
+@end table
+
+@anchor{yadif}
+@section yadif
+
+Deinterlace the input video ("yadif" means "yet another deinterlacing
+filter").
+
+It accepts the following parameters:
+
+
+@table @option
+
+@item mode
+The interlacing mode to adopt. It accepts one of the following values:
+
+@table @option
+@item 0, send_frame
+Output one frame for each frame.
+@item 1, send_field
+Output one frame for each field.
+@item 2, send_frame_nospatial
+Like @code{send_frame}, but it skips the spatial interlacing check.
+@item 3, send_field_nospatial
+Like @code{send_field}, but it skips the spatial interlacing check.
+@end table
+
+The default value is @code{send_frame}.
+
+@item parity
+The picture field parity assumed for the input interlaced video. It accepts one
+of the following values:
+
+@table @option
+@item 0, tff
+Assume the top field is first.
+@item 1, bff
+Assume the bottom field is first.
+@item -1, auto
+Enable automatic detection of field parity.
+@end table
+
+The default value is @code{auto}.
+If the interlacing is unknown or the decoder does not export this information,
+top field first will be assumed.
+
+@item deint
+Specify which frames to deinterlace. Accept one of the following
+values:
+
+@table @option
+@item 0, all
+Deinterlace all frames.
+@item 1, interlaced
+Only deinterlace frames marked as interlaced.
+@end table
+
+The default value is @code{all}.
+@end table
+
+@section zoompan
+
+Apply Zoom & Pan effect.
+
+This filter accepts the following options:
+
+@table @option
+@item zoom, z
+Set the zoom expression. Default is 1.
+
+@item x
+@item y
+Set the x and y expression. Default is 0.
+
+@item d
+Set the duration expression in number of frames.
+This sets for how many number of frames effect will last for
+single input image.
+
+@item s
+Set the output image size, default is 'hd720'.
+
+@item fps
+Set the output frame rate, default is '25'.
+@end table
+
+Each expression can contain the following constants:
+
+@table @option
+@item in_w, iw
+Input width.
+
+@item in_h, ih
+Input height.
+
+@item out_w, ow
+Output width.
+
+@item out_h, oh
+Output height.
+
+@item in
+Input frame count.
+
+@item on
+Output frame count.
+
+@item x
+@item y
+Last calculated 'x' and 'y' position from 'x' and 'y' expression
+for current input frame.
+
+@item px
+@item py
+'x' and 'y' of last output frame of previous input frame or 0 when there was
+not yet such frame (first input frame).
+
+@item zoom
+Last calculated zoom from 'z' expression for current input frame.
+
+@item pzoom
+Last calculated zoom of last output frame of previous input frame.
+
+@item duration
+Number of output frames for current input frame. Calculated from 'd' expression
+for each input frame.
+
+@item pduration
+number of output frames created for previous input frame
+
+@item a
+Rational number: input width / input height
+
+@item sar
+sample aspect ratio
+
+@item dar
+display aspect ratio
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
+@example
+zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
+@end example
+
+@item
+Zoom-in up to 1.5 and pan always at center of picture:
+@example
+zoompan=z='min(zoom+0.0015,1.5)':d=700:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)'
+@end example
+@end itemize
+
+@section zscale
+Scale (resize) the input video, using the z.lib library:
+https://github.com/sekrit-twc/zimg.
+
+The zscale filter forces the output display aspect ratio to be the same
+as the input, by changing the output sample aspect ratio.
+
+If the input image format is different from the format requested by
+the next filter, the zscale filter will convert the input to the
+requested format.
+
+@subsection Options
+The filter accepts the following options.
+
+@table @option
+@item width, w
+@item height, h
+Set the output video dimension expression. Default value is the input
+dimension.
+
+If the @var{width} or @var{w} is 0, the input width is used for the output.
+If the @var{height} or @var{h} is 0, the input height is used for the output.
+
+If one of the values is -1, the zscale filter will use a value that
+maintains the aspect ratio of the input image, calculated from the
+other specified dimension. If both of them are -1, the input size is
+used
+
+If one of the values is -n with n > 1, the zscale filter will also use a value
+that maintains the aspect ratio of the input image, calculated from the other
+specified dimension. After that it will, however, make sure that the calculated
+dimension is divisible by n and adjust the value if necessary.
+
+See below for the list of accepted constants for use in the dimension
+expression.
+
+@item size, s
+Set the video size. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+
+@item dither, d
+Set the dither type.
+
+Possible values are:
+@table @var
+@item none
+@item ordered
+@item random
+@item error_diffusion
+@end table
+
+Default is none.
+
+@item filter, f
+Set the resize filter type.
+
+Possible values are:
+@table @var
+@item point
+@item bilinear
+@item bicubic
+@item spline16
+@item spline36
+@item lanczos
+@end table
+
+Default is bilinear.
+
+@item range, r
+Set the color range.
+
+Possible values are:
+@table @var
+@item input
+@item limited
+@item full
+@end table
+
+Default is same as input.
+
+@item primaries, p
+Set the color primaries.
+
+Possible values are:
+@table @var
+@item input
+@item 709
+@item unspecified
+@item 170m
+@item 240m
+@item 2020
+@end table
+
+Default is same as input.
+
+@item transfer, t
+Set the transfer characteristics.
+
+Possible values are:
+@table @var
+@item input
+@item 709
+@item unspecified
+@item 601
+@item linear
+@item 2020_10
+@item 2020_12
+@end table
+
+Default is same as input.
+
+@item matrix, m
+Set the colorspace matrix.
+
+Possible value are:
+@table @var
+@item input
+@item 709
+@item unspecified
+@item 470bg
+@item 170m
+@item 2020_ncl
+@item 2020_cl
+@end table
+
+Default is same as input.
+
+@item rangein, rin
+Set the input color range.
+
+Possible values are:
+@table @var
+@item input
+@item limited
+@item full
+@end table
+
+Default is same as input.
+
+@item primariesin, pin
+Set the input color primaries.
+
+Possible values are:
+@table @var
+@item input
+@item 709
+@item unspecified
+@item 170m
+@item 240m
+@item 2020
+@end table
+
+Default is same as input.
+
+@item transferin, tin
+Set the input transfer characteristics.
+
+Possible values are:
+@table @var
+@item input
+@item 709
+@item unspecified
+@item 601
+@item linear
+@item 2020_10
+@item 2020_12
+@end table
+
+Default is same as input.
+
+@item matrixin, min
+Set the input colorspace matrix.
+
+Possible value are:
+@table @var
+@item input
+@item 709
+@item unspecified
+@item 470bg
+@item 170m
+@item 2020_ncl
+@item 2020_cl
+@end table
+@end table
+
+The values of the @option{w} and @option{h} options are expressions
+containing the following constants:
+
+@table @var
+@item in_w
+@item in_h
+The input width and height
+
+@item iw
+@item ih
+These are the same as @var{in_w} and @var{in_h}.
+
+@item out_w
+@item out_h
+The output (scaled) width and height
+
+@item ow
+@item oh
+These are the same as @var{out_w} and @var{out_h}
+
+@item a
+The same as @var{iw} / @var{ih}
+
+@item sar
+input sample aspect ratio
+
+@item dar
+The input display aspect ratio. Calculated from @code{(iw / ih) * sar}.
+
+@item hsub
+@item vsub
+horizontal and vertical input chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
+@item ohsub
+@item ovsub
+horizontal and vertical output chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+@end table
+
+@table @option
+@end table
+
+@c man end VIDEO FILTERS
+
+@chapter Video Sources
+@c man begin VIDEO SOURCES
+
+Below is a description of the currently available video sources.
+
+@section buffer
+
+Buffer video frames, and make them available to the filter chain.
+
+This source is mainly intended for a programmatic use, in particular
+through the interface defined in @file{libavfilter/vsrc_buffer.h}.
+
+It accepts the following parameters:
+
+@table @option
+
+@item video_size
+Specify the size (width and height) of the buffered video frames. For the
+syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+
+@item width
+The input video width.
+
+@item height
+The input video height.
+
+@item pix_fmt
+A string representing the pixel format of the buffered video frames.
+It may be a number corresponding to a pixel format, or a pixel format
+name.
+
+@item time_base
+Specify the timebase assumed by the timestamps of the buffered frames.
+
+@item frame_rate
+Specify the frame rate expected for the video stream.
+
+@item pixel_aspect, sar
+The sample (pixel) aspect ratio of the input video.
+
+@item sws_param
+Specify the optional parameters to be used for the scale filter which
+is automatically inserted when an input change is detected in the
+input size or format.
+
+@item hw_frames_ctx
+When using a hardware pixel format, this should be a reference to an
+AVHWFramesContext describing input frames.
+@end table
+
+For example:
+@example
+buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
+@end example
+
+will instruct the source to accept video frames with size 320x240 and
+with format "yuv410p", assuming 1/24 as the timestamps timebase and
+square pixels (1:1 sample aspect ratio).
+Since the pixel format with name "yuv410p" corresponds to the number 6
+(check the enum AVPixelFormat definition in @file{libavutil/pixfmt.h}),
+this example corresponds to:
+@example
+buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
+@end example
+
+Alternatively, the options can be specified as a flat string, but this
+syntax is deprecated:
+
+@var{width}:@var{height}:@var{pix_fmt}:@var{time_base.num}:@var{time_base.den}:@var{pixel_aspect.num}:@var{pixel_aspect.den}[:@var{sws_param}]
+
+@section cellauto
+
+Create a pattern generated by an elementary cellular automaton.
+
+The initial state of the cellular automaton can be defined through the
+@option{filename}, and @option{pattern} options. If such options are
+not specified an initial state is created randomly.
+
+At each new frame a new row in the video is filled with the result of
+the cellular automaton next generation. The behavior when the whole
+frame is filled is defined by the @option{scroll} option.
+
+This source accepts the following options:
+
+@table @option
+@item filename, f
+Read the initial cellular automaton state, i.e. the starting row, from
+the specified file.
+In the file, each non-whitespace character is considered an alive
+cell, a newline will terminate the row, and further characters in the
+file will be ignored.
+
+@item pattern, p
+Read the initial cellular automaton state, i.e. the starting row, from
+the specified string.
+
+Each non-whitespace character in the string is considered an alive
+cell, a newline will terminate the row, and further characters in the
+string will be ignored.
+
+@item rate, r
+Set the video rate, that is the number of frames generated per second.
+Default is 25.
+
+@item random_fill_ratio, ratio
+Set the random fill ratio for the initial cellular automaton row. It
+is a floating point number value ranging from 0 to 1, defaults to
+1/PHI.
+
+This option is ignored when a file or a pattern is specified.
+
+@item random_seed, seed
+Set the seed for filling randomly the initial row, must be an integer
+included between 0 and UINT32_MAX. If not specified, or if explicitly
+set to -1, the filter will try to use a good random seed on a best
+effort basis.
+
+@item rule
+Set the cellular automaton rule, it is a number ranging from 0 to 255.
+Default value is 110.
+
+@item size, s
+Set the size of the output video. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+
+If @option{filename} or @option{pattern} is specified, the size is set
+by default to the width of the specified initial state row, and the
+height is set to @var{width} * PHI.
+
+If @option{size} is set, it must contain the width of the specified
+pattern string, and the specified pattern will be centered in the
+larger row.
+
+If a filename or a pattern string is not specified, the size value
+defaults to "320x518" (used for a randomly generated initial state).
+
+@item scroll
+If set to 1, scroll the output upward when all the rows in the output
+have been already filled. If set to 0, the new generated row will be
+written over the top row just after the bottom row is filled.
+Defaults to 1.
+
+@item start_full, full
+If set to 1, completely fill the output with generated rows before
+outputting the first frame.
+This is the default behavior, for disabling set the value to 0.
+
+@item stitch
+If set to 1, stitch the left and right row edges together.
+This is the default behavior, for disabling set the value to 0.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Read the initial state from @file{pattern}, and specify an output of
+size 200x400.
+@example
+cellauto=f=pattern:s=200x400
+@end example
+
+@item
+Generate a random initial row with a width of 200 cells, with a fill
+ratio of 2/3:
+@example
+cellauto=ratio=2/3:s=200x200
+@end example
+
+@item
+Create a pattern generated by rule 18 starting by a single alive cell
+centered on an initial row with width 100:
+@example
+cellauto=p=@@:s=100x400:full=0:rule=18
+@end example
+
+@item
+Specify a more elaborated initial pattern:
+@example
+cellauto=p='@@@@ @@ @@@@':s=100x400:full=0:rule=18
+@end example
+
+@end itemize
+
+@section mandelbrot
+
+Generate a Mandelbrot set fractal, and progressively zoom towards the
+point specified with @var{start_x} and @var{start_y}.
+
+This source accepts the following options:
+
+@table @option
+
+@item end_pts
+Set the terminal pts value. Default value is 400.
+
+@item end_scale
+Set the terminal scale value.
+Must be a floating point value. Default value is 0.3.
+
+@item inner
+Set the inner coloring mode, that is the algorithm used to draw the
+Mandelbrot fractal internal region.
+
+It shall assume one of the following values:
+@table @option
+@item black
+Set black mode.
+@item convergence
+Show time until convergence.
+@item mincol
+Set color based on point closest to the origin of the iterations.
+@item period
+Set period mode.
+@end table
+
+Default value is @var{mincol}.
+
+@item bailout
+Set the bailout value. Default value is 10.0.
+
+@item maxiter
+Set the maximum of iterations performed by the rendering
+algorithm. Default value is 7189.
+
+@item outer
+Set outer coloring mode.
+It shall assume one of following values:
+@table @option
+@item iteration_count
+Set iteration cound mode.
+@item normalized_iteration_count
+set normalized iteration count mode.
+@end table
+Default value is @var{normalized_iteration_count}.
+
+@item rate, r
+Set frame rate, expressed as number of frames per second. Default
+value is "25".
+
+@item size, s
+Set frame size. For the syntax of this option, check the "Video
+size" section in the ffmpeg-utils manual. Default value is "640x480".
+
+@item start_scale
+Set the initial scale value. Default value is 3.0.
+
+@item start_x
+Set the initial x position. Must be a floating point value between
+-100 and 100. Default value is -0.743643887037158704752191506114774.
+
+@item start_y
+Set the initial y position. Must be a floating point value between
+-100 and 100. Default value is -0.131825904205311970493132056385139.
+@end table
+
+@section mptestsrc
+
+Generate various test patterns, as generated by the MPlayer test filter.
+
+The size of the generated video is fixed, and is 256x256.
+This source is useful in particular for testing encoding features.
+
+This source accepts the following options:
+
+@table @option
+
+@item rate, r
+Specify the frame rate of the sourced video, as the number of frames
+generated per second. It has to be a string in the format
+@var{frame_rate_num}/@var{frame_rate_den}, an integer number, a floating point
+number or a valid video frame rate abbreviation. The default value is
+"25".
+
+@item duration, d
+Set the duration of the sourced video. See
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
+
+If not specified, or the expressed duration is negative, the video is
+supposed to be generated forever.
+
+@item test, t
+
+Set the number or the name of the test to perform. Supported tests are:
+@table @option
+@item dc_luma
+@item dc_chroma
+@item freq_luma
+@item freq_chroma
+@item amp_luma
+@item amp_chroma
+@item cbp
+@item mv
+@item ring1
+@item ring2
+@item all
+
+@end table
+
+Default value is "all", which will cycle through the list of all tests.
+@end table
+
+Some examples:
+@example
+mptestsrc=t=dc_luma
+@end example
+
+will generate a "dc_luma" test pattern.
+
+@section frei0r_src
+
+Provide a frei0r source.
+
+To enable compilation of this filter you need to install the frei0r
+header and configure FFmpeg with @code{--enable-frei0r}.
+
+This source accepts the following parameters:
+
+@table @option
+
+@item size
+The size of the video to generate. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+
+@item framerate
+The framerate of the generated video. It may be a string of the form
+@var{num}/@var{den} or a frame rate abbreviation.
+
+@item filter_name
+The name to the frei0r source to load. For more information regarding frei0r and
+how to set the parameters, read the @ref{frei0r} section in the video filters
+documentation.
+
+@item filter_params
+A '|'-separated list of parameters to pass to the frei0r source.
+
+@end table
+
+For example, to generate a frei0r partik0l source with size 200x200
+and frame rate 10 which is overlaid on the overlay filter main input:
+@example
+frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
+@end example
+
+@section life
+
+Generate a life pattern.
+
+This source is based on a generalization of John Conway's life game.
+
+The sourced input represents a life grid, each pixel represents a cell
+which can be in one of two possible states, alive or dead. Every cell
+interacts with its eight neighbours, which are the cells that are
+horizontally, vertically, or diagonally adjacent.
+
+At each interaction the grid evolves according to the adopted rule,
+which specifies the number of neighbor alive cells which will make a
+cell stay alive or born. The @option{rule} option allows one to specify
+the rule to adopt.
+
+This source accepts the following options:
+
+@table @option
+@item filename, f
+Set the file from which to read the initial grid state. In the file,
+each non-whitespace character is considered an alive cell, and newline
+is used to delimit the end of each row.
+
+If this option is not specified, the initial grid is generated
+randomly.
+
+@item rate, r
+Set the video rate, that is the number of frames generated per second.
+Default is 25.
+
+@item random_fill_ratio, ratio
+Set the random fill ratio for the initial random grid. It is a
+floating point number value ranging from 0 to 1, defaults to 1/PHI.
+It is ignored when a file is specified.
+
+@item random_seed, seed
+Set the seed for filling the initial random grid, must be an integer
+included between 0 and UINT32_MAX. If not specified, or if explicitly
+set to -1, the filter will try to use a good random seed on a best
+effort basis.
+
+@item rule
+Set the life rule.
+
+A rule can be specified with a code of the kind "S@var{NS}/B@var{NB}",
+where @var{NS} and @var{NB} are sequences of numbers in the range 0-8,
+@var{NS} specifies the number of alive neighbor cells which make a
+live cell stay alive, and @var{NB} the number of alive neighbor cells
+which make a dead cell to become alive (i.e. to "born").
+"s" and "b" can be used in place of "S" and "B", respectively.
+
+Alternatively a rule can be specified by an 18-bits integer. The 9
+high order bits are used to encode the next cell state if it is alive
+for each number of neighbor alive cells, the low order bits specify
+the rule for "borning" new cells. Higher order bits encode for an
+higher number of neighbor cells.
+For example the number 6153 = @code{(12<<9)+9} specifies a stay alive
+rule of 12 and a born rule of 9, which corresponds to "S23/B03".
+
+Default value is "S23/B3", which is the original Conway's game of life
+rule, and will keep a cell alive if it has 2 or 3 neighbor alive
+cells, and will born a new cell if there are three alive cells around
+a dead cell.
+
+@item size, s
+Set the size of the output video. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+
+If @option{filename} is specified, the size is set by default to the
+same size of the input file. If @option{size} is set, it must contain
+the size specified in the input file, and the initial grid defined in
+that file is centered in the larger resulting area.
+
+If a filename is not specified, the size value defaults to "320x240"
+(used for a randomly generated initial grid).
+
+@item stitch
+If set to 1, stitch the left and right grid edges together, and the
+top and bottom edges also. Defaults to 1.
+
+@item mold
+Set cell mold speed. If set, a dead cell will go from @option{death_color} to
+@option{mold_color} with a step of @option{mold}. @option{mold} can have a
+value from 0 to 255.
+
+@item life_color
+Set the color of living (or new born) cells.
+
+@item death_color
+Set the color of dead cells. If @option{mold} is set, this is the first color
+used to represent a dead cell.
+
+@item mold_color
+Set mold color, for definitely dead and moldy cells.
+
+For the syntax of these 3 color options, check the "Color" section in the
+ffmpeg-utils manual.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Read a grid from @file{pattern}, and center it on a grid of size
+300x300 pixels:
+@example
+life=f=pattern:s=300x300
+@end example
+
+@item
+Generate a random grid of size 200x200, with a fill ratio of 2/3:
+@example
+life=ratio=2/3:s=200x200
+@end example
+
+@item
+Specify a custom rule for evolving a randomly generated grid:
+@example
+life=rule=S14/B34
+@end example
+
+@item
+Full example with slow death effect (mold) using @command{ffplay}:
+@example
+ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
+@end example
+@end itemize
+
+@anchor{allrgb}
+@anchor{allyuv}
+@anchor{color}
+@anchor{haldclutsrc}
+@anchor{nullsrc}
+@anchor{rgbtestsrc}
+@anchor{smptebars}
+@anchor{smptehdbars}
+@anchor{testsrc}
+@section allrgb, allyuv, color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc
+
+The @code{allrgb} source returns frames of size 4096x4096 of all rgb colors.
+
+The @code{allyuv} source returns frames of size 4096x4096 of all yuv colors.
+
+The @code{color} source provides an uniformly colored input.
+
+The @code{haldclutsrc} source provides an identity Hald CLUT. See also
+@ref{haldclut} filter.
+
+The @code{nullsrc} source returns unprocessed video frames. It is
+mainly useful to be employed in analysis / debugging tools, or as the
+source for filters which ignore the input data.
+
+The @code{rgbtestsrc} source generates an RGB test pattern useful for
+detecting RGB vs BGR issues. You should see a red, green and blue
+stripe from top to bottom.
+
+The @code{smptebars} source generates a color bars pattern, based on
+the SMPTE Engineering Guideline EG 1-1990.
+
+The @code{smptehdbars} source generates a color bars pattern, based on
+the SMPTE RP 219-2002.
+
+The @code{testsrc} source generates a test video pattern, showing a
+color pattern, a scrolling gradient and a timestamp. This is mainly
+intended for testing purposes.
+
+The sources accept the following parameters:
+
+@table @option
+
+@item color, c
+Specify the color of the source, only available in the @code{color}
+source. For the syntax of this option, check the "Color" section in the
+ffmpeg-utils manual.
+
+@item level
+Specify the level of the Hald CLUT, only available in the @code{haldclutsrc}
+source. A level of @code{N} generates a picture of @code{N*N*N} by @code{N*N*N}
+pixels to be used as identity matrix for 3D lookup tables. Each component is
+coded on a @code{1/(N*N)} scale.
+
+@item size, s
+Specify the size of the sourced video. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+The default value is @code{320x240}.
+
+This option is not available with the @code{haldclutsrc} filter.
+
+@item rate, r
+Specify the frame rate of the sourced video, as the number of frames
+generated per second. It has to be a string in the format
+@var{frame_rate_num}/@var{frame_rate_den}, an integer number, a floating point
+number or a valid video frame rate abbreviation. The default value is
+"25".
+
+@item sar
+Set the sample aspect ratio of the sourced video.
+
+@item duration, d
+Set the duration of the sourced video. See
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
+
+If not specified, or the expressed duration is negative, the video is
+supposed to be generated forever.
+
+@item decimals, n
+Set the number of decimals to show in the timestamp, only available in the
+@code{testsrc} source.
+
+The displayed timestamp value will correspond to the original
+timestamp value multiplied by the power of 10 of the specified
+value. Default value is 0.
+@end table
+
+For example the following:
+@example
+testsrc=duration=5.3:size=qcif:rate=10
+@end example
+
+will generate a video with a duration of 5.3 seconds, with size
+176x144 and a frame rate of 10 frames per second.
+
+The following graph description will generate a red source
+with an opacity of 0.2, with size "qcif" and a frame rate of 10
+frames per second.
+@example
+color=c=red@@0.2:s=qcif:r=10
+@end example
+
+If the input content is to be ignored, @code{nullsrc} can be used. The
+following command generates noise in the luminance plane by employing
+the @code{geq} filter:
+@example
+nullsrc=s=256x256, geq=random(1)*255:128:128
+@end example
+
+@subsection Commands
+
+The @code{color} source supports the following commands:
+
+@table @option
+@item c, color
+Set the color of the created image. Accepts the same syntax of the
+corresponding @option{color} option.
+@end table
+
+@c man end VIDEO SOURCES
+
+@chapter Video Sinks
+@c man begin VIDEO SINKS
+
+Below is a description of the currently available video sinks.
+
+@section buffersink
+
+Buffer video frames, and make them available to the end of the filter
+graph.
+
+This sink is mainly intended for programmatic use, in particular
+through the interface defined in @file{libavfilter/buffersink.h}
+or the options system.
+
+It accepts a pointer to an AVBufferSinkContext structure, which
+defines the incoming buffers' formats, to be passed as the opaque
+parameter to @code{avfilter_init_filter} for initialization.
+
+@section nullsink
+
+Null video sink: do absolutely nothing with the input video. It is
+mainly useful as a template and for use in analysis / debugging
+tools.
+
+@c man end VIDEO SINKS
+
+@chapter Multimedia Filters
+@c man begin MULTIMEDIA FILTERS
+
+Below is a description of the currently available multimedia filters.
+
+@section ahistogram
+
+Convert input audio to a video output, displaying the volume histogram.
+
+The filter accepts the following options:
+
+@table @option
+@item dmode
+Specify how histogram is calculated.
+
+It accepts the following values:
+@table @samp
+@item single
+Use single histogram for all channels.
+@item separate
+Use separate histogram for each channel.
+@end table
+Default is @code{single}.
+
+@item rate, r
+Set frame rate, expressed as number of frames per second. Default
+value is "25".
+
+@item size, s
+Specify the video size for the output. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+Default value is @code{hd720}.
+
+@item scale
+Set display scale.
+
+It accepts the following values:
+@table @samp
+@item log
+logarithmic
+@item sqrt
+square root
+@item cbrt
+cubic root
+@item lin
+linear
+@item rlog
+reverse logarithmic
+@end table
+Default is @code{log}.
+
+@item ascale
+Set amplitude scale.
+
+It accepts the following values:
+@table @samp
+@item log
+logarithmic
+@item lin
+linear
+@end table
+Default is @code{log}.
+
+@item acount
+Set how much frames to accumulate in histogram.
+Defauls is 1. Setting this to -1 accumulates all frames.
+
+@item rheight
+Set histogram ratio of window height.
+
+@item slide
+Set sonogram sliding.
+
+It accepts the following values:
+@table @samp
+@item replace
+replace old rows with new ones.
+@item scroll
+scroll from top to bottom.
+@end table
+Default is @code{replace}.
+@end table
+
+@section aphasemeter
+
+Convert input audio to a video output, displaying the audio phase.
+
+The filter accepts the following options:
+
+@table @option
+@item rate, r
+Set the output frame rate. Default value is @code{25}.
+
+@item size, s
+Set the video size for the output. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+Default value is @code{800x400}.
+
+@item rc
+@item gc
+@item bc
+Specify the red, green, blue contrast. Default values are @code{2},
+@code{7} and @code{1}.
+Allowed range is @code{[0, 255]}.
+
+@item mpc
+Set color which will be used for drawing median phase. If color is
+@code{none} which is default, no median phase value will be drawn.
+@end table
+
+The filter also exports the frame metadata @code{lavfi.aphasemeter.phase} which
+represents mean phase of current audio frame. Value is in range @code{[-1, 1]}.
+The @code{-1} means left and right channels are completely out of phase and
+@code{1} means channels are in phase.
+
+@section avectorscope
+
+Convert input audio to a video output, representing the audio vector
+scope.
+
+The filter is used to measure the difference between channels of stereo
+audio stream. A monoaural signal, consisting of identical left and right
+signal, results in straight vertical line. Any stereo separation is visible
+as a deviation from this line, creating a Lissajous figure.
+If the straight (or deviation from it) but horizontal line appears this
+indicates that the left and right channels are out of phase.
+
+The filter accepts the following options:
+
+@table @option
+@item mode, m
+Set the vectorscope mode.
+
+Available values are:
+@table @samp
+@item lissajous
+Lissajous rotated by 45 degrees.
+
+@item lissajous_xy
+Same as above but not rotated.
+
+@item polar
+Shape resembling half of circle.
+@end table
+
+Default value is @samp{lissajous}.
+
+@item size, s
+Set the video size for the output. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+Default value is @code{400x400}.
+
+@item rate, r
+Set the output frame rate. Default value is @code{25}.
+
+@item rc
+@item gc
+@item bc
+@item ac
+Specify the red, green, blue and alpha contrast. Default values are @code{40},
+@code{160}, @code{80} and @code{255}.
+Allowed range is @code{[0, 255]}.
+
+@item rf
+@item gf
+@item bf
+@item af
+Specify the red, green, blue and alpha fade. Default values are @code{15},
+@code{10}, @code{5} and @code{5}.
+Allowed range is @code{[0, 255]}.
+
+@item zoom
+Set the zoom factor. Default value is @code{1}. Allowed range is @code{[1, 10]}.
+
+@item draw
+Set the vectorscope drawing mode.
+
+Available values are:
+@table @samp
+@item dot
+Draw dot for each sample.
+
+@item line
+Draw line between previous and current sample.
+@end table
+
+Default value is @samp{dot}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Complete example using @command{ffplay}:
+@example
+ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
+ [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
+@end example
+@end itemize
+
+@section concat
+
+Concatenate audio and video streams, joining them together one after the
+other.
+
+The filter works on segments of synchronized video and audio streams. All
+segments must have the same number of streams of each type, and that will
+also be the number of streams at output.
+
+The filter accepts the following options:
+
+@table @option
+
+@item n
+Set the number of segments. Default is 2.
+
+@item v
+Set the number of output video streams, that is also the number of video
+streams in each segment. Default is 1.
+
+@item a
+Set the number of output audio streams, that is also the number of audio
+streams in each segment. Default is 0.
+
+@item unsafe
+Activate unsafe mode: do not fail if segments have a different format.
+
+@end table
+
+The filter has @var{v}+@var{a} outputs: first @var{v} video outputs, then
+@var{a} audio outputs.
+
+There are @var{n}x(@var{v}+@var{a}) inputs: first the inputs for the first
+segment, in the same order as the outputs, then the inputs for the second
+segment, etc.
+
+Related streams do not always have exactly the same duration, for various
+reasons including codec frame size or sloppy authoring. For that reason,
+related synchronized streams (e.g. a video and its audio track) should be
+concatenated at once. The concat filter will use the duration of the longest
+stream in each segment (except the last one), and if necessary pad shorter
+audio streams with silence.
+
+For this filter to work correctly, all segments must start at timestamp 0.
+
+All corresponding streams must have the same parameters in all segments; the
+filtering system will automatically select a common pixel format for video
+streams, and a common sample format, sample rate and channel layout for
+audio streams, but other settings, such as resolution, must be converted
+explicitly by the user.
+
+Different frame rates are acceptable but will result in variable frame rate
+at output; be sure to configure the output file to handle it.
+
+@subsection Examples
+
+@itemize
+@item
+Concatenate an opening, an episode and an ending, all in bilingual version
+(video in stream 0, audio in streams 1 and 2):
+@example
+ffmpeg -i opening.mkv -i episode.mkv -i ending.mkv -filter_complex \
+ '[0:0] [0:1] [0:2] [1:0] [1:1] [1:2] [2:0] [2:1] [2:2]
+ concat=n=3:v=1:a=2 [v] [a1] [a2]' \
+ -map '[v]' -map '[a1]' -map '[a2]' output.mkv
+@end example
+
+@item
+Concatenate two parts, handling audio and video separately, using the
+(a)movie sources, and adjusting the resolution:
+@example
+movie=part1.mp4, scale=512:288 [v1] ; amovie=part1.mp4 [a1] ;
+movie=part2.mp4, scale=512:288 [v2] ; amovie=part2.mp4 [a2] ;
+[v1] [v2] concat [outv] ; [a1] [a2] concat=v=0:a=1 [outa]
+@end example
+Note that a desync will happen at the stitch if the audio and video streams
+do not have exactly the same duration in the first file.
+
+@end itemize
+
+@anchor{ebur128}
+@section ebur128
+
+EBU R128 scanner filter. This filter takes an audio stream as input and outputs
+it unchanged. By default, it logs a message at a frequency of 10Hz with the
+Momentary loudness (identified by @code{M}), Short-term loudness (@code{S}),
+Integrated loudness (@code{I}) and Loudness Range (@code{LRA}).
+
+The filter also has a video output (see the @var{video} option) with a real
+time graph to observe the loudness evolution. The graphic contains the logged
+message mentioned above, so it is not printed anymore when this option is set,
+unless the verbose logging is set. The main graphing area contains the
+short-term loudness (3 seconds of analysis), and the gauge on the right is for
+the momentary loudness (400 milliseconds).
+
+More information about the Loudness Recommendation EBU R128 on
+@url{http://tech.ebu.ch/loudness}.
+
+The filter accepts the following options:
+
+@table @option
+
+@item video
+Activate the video output. The audio stream is passed unchanged whether this
+option is set or no. The video stream will be the first output stream if
+activated. Default is @code{0}.
+
+@item size
+Set the video size. This option is for video only. For the syntax of this
+option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+Default and minimum resolution is @code{640x480}.
+
+@item meter
+Set the EBU scale meter. Default is @code{9}. Common values are @code{9} and
+@code{18}, respectively for EBU scale meter +9 and EBU scale meter +18. Any
+other integer value between this range is allowed.
+
+@item metadata
+Set metadata injection. If set to @code{1}, the audio input will be segmented
+into 100ms output frames, each of them containing various loudness information
+in metadata. All the metadata keys are prefixed with @code{lavfi.r128.}.
+
+Default is @code{0}.
+
+@item framelog
+Force the frame logging level.
+
+Available values are:
+@table @samp
+@item info
+information logging level
+@item verbose
+verbose logging level
+@end table
+
+By default, the logging level is set to @var{info}. If the @option{video} or
+the @option{metadata} options are set, it switches to @var{verbose}.
+
+@item peak
+Set peak mode(s).
+
+Available modes can be cumulated (the option is a @code{flag} type). Possible
+values are:
+@table @samp
+@item none
+Disable any peak mode (default).
+@item sample
+Enable sample-peak mode.
+
+Simple peak mode looking for the higher sample value. It logs a message
+for sample-peak (identified by @code{SPK}).
+@item true
+Enable true-peak mode.
+
+If enabled, the peak lookup is done on an over-sampled version of the input
+stream for better peak accuracy. It logs a message for true-peak.
+(identified by @code{TPK}) and true-peak per frame (identified by @code{FTPK}).
+This mode requires a build with @code{libswresample}.
+@end table
+
+@item dualmono
+Treat mono input files as "dual mono". If a mono file is intended for playback
+on a stereo system, its EBU R128 measurement will be perceptually incorrect.
+If set to @code{true}, this option will compensate for this effect.
+Multi-channel input files are not affected by this option.
+
+@item panlaw
+Set a specific pan law to be used for the measurement of dual mono files.
+This parameter is optional, and has a default value of -3.01dB.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Real-time graph using @command{ffplay}, with a EBU scale meter +18:
+@example
+ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
+@end example
+
+@item
+Run an analysis with @command{ffmpeg}:
+@example
+ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
+@end example
+@end itemize
+
+@section interleave, ainterleave
+
+Temporally interleave frames from several inputs.
+
+@code{interleave} works with video inputs, @code{ainterleave} with audio.
+
+These filters read frames from several inputs and send the oldest
+queued frame to the output.
+
+Input streams must have a well defined, monotonically increasing frame
+timestamp values.
+
+In order to submit one frame to output, these filters need to enqueue
+at least one frame for each input, so they cannot work in case one
+input is not yet terminated and will not receive incoming frames.
+
+For example consider the case when one input is a @code{select} filter
+which always drop input frames. The @code{interleave} filter will keep
+reading from that input, but it will never be able to send new frames
+to output until the input will send an end-of-stream signal.
+
+Also, depending on inputs synchronization, the filters will drop
+frames in case one input receives more frames than the other ones, and
+the queue is already filled.
+
+These filters accept the following options:
+
+@table @option
+@item nb_inputs, n
+Set the number of different inputs, it is 2 by default.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Interleave frames belonging to different streams using @command{ffmpeg}:
+@example
+ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
+@end example
+
+@item
+Add flickering blur effect:
+@example
+select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
+@end example
+@end itemize
+
+@section perms, aperms
+
+Set read/write permissions for the output frames.
+
+These filters are mainly aimed at developers to test direct path in the
+following filter in the filtergraph.
+
+The filters accept the following options:
+
+@table @option
+@item mode
+Select the permissions mode.
+
+It accepts the following values:
+@table @samp
+@item none
+Do nothing. This is the default.
+@item ro
+Set all the output frames read-only.
+@item rw
+Set all the output frames directly writable.
+@item toggle
+Make the frame read-only if writable, and writable if read-only.
+@item random
+Set each output frame read-only or writable randomly.
+@end table
+
+@item seed
+Set the seed for the @var{random} mode, must be an integer included between
+@code{0} and @code{UINT32_MAX}. If not specified, or if explicitly set to
+@code{-1}, the filter will try to use a good random seed on a best effort
+basis.
+@end table
+
+Note: in case of auto-inserted filter between the permission filter and the
+following one, the permission might not be received as expected in that
+following filter. Inserting a @ref{format} or @ref{aformat} filter before the
+perms/aperms filter can avoid this problem.
+
+@section realtime, arealtime
+
+Slow down filtering to match real time approximatively.
+
+These filters will pause the filtering for a variable amount of time to
+match the output rate with the input timestamps.
+They are similar to the @option{re} option to @code{ffmpeg}.
+
+They accept the following options:
+
+@table @option
+@item limit
+Time limit for the pauses. Any pause longer than that will be considered
+a timestamp discontinuity and reset the timer. Default is 2 seconds.
+@end table
+
+@section select, aselect
+
+Select frames to pass in output.
+
+This filter accepts the following options:
+
+@table @option
+
+@item expr, e
+Set expression, which is evaluated for each input frame.
+
+If the expression is evaluated to zero, the frame is discarded.
+
+If the evaluation result is negative or NaN, the frame is sent to the
+first output; otherwise it is sent to the output with index
+@code{ceil(val)-1}, assuming that the input index starts from 0.
+
+For example a value of @code{1.2} corresponds to the output with index
+@code{ceil(1.2)-1 = 2-1 = 1}, that is the second output.
+
+@item outputs, n
+Set the number of outputs. The output to which to send the selected
+frame is based on the result of the evaluation. Default value is 1.
+@end table
+
+The expression can contain the following constants:
+
+@table @option
+@item n
+The (sequential) number of the filtered frame, starting from 0.
+
+@item selected_n
+The (sequential) number of the selected frame, starting from 0.
+
+@item prev_selected_n
+The sequential number of the last selected frame. It's NAN if undefined.
+
+@item TB
+The timebase of the input timestamps.
+
+@item pts
+The PTS (Presentation TimeStamp) of the filtered video frame,
+expressed in @var{TB} units. It's NAN if undefined.
+
+@item t
+The PTS of the filtered video frame,
+expressed in seconds. It's NAN if undefined.
+
+@item prev_pts
+The PTS of the previously filtered video frame. It's NAN if undefined.
+
+@item prev_selected_pts
+The PTS of the last previously filtered video frame. It's NAN if undefined.
+
+@item prev_selected_t
+The PTS of the last previously selected video frame. It's NAN if undefined.
+
+@item start_pts
+The PTS of the first video frame in the video. It's NAN if undefined.
+
+@item start_t
+The time of the first video frame in the video. It's NAN if undefined.
+
+@item pict_type @emph{(video only)}
+The type of the filtered frame. It can assume one of the following
+values:
+@table @option
+@item I
+@item P
+@item B
+@item S
+@item SI
+@item SP
+@item BI
+@end table
+
+@item interlace_type @emph{(video only)}
+The frame interlace type. It can assume one of the following values:
+@table @option
+@item PROGRESSIVE
+The frame is progressive (not interlaced).
+@item TOPFIRST
+The frame is top-field-first.
+@item BOTTOMFIRST
+The frame is bottom-field-first.
+@end table
+
+@item consumed_sample_n @emph{(audio only)}
+the number of selected samples before the current frame
+
+@item samples_n @emph{(audio only)}
+the number of samples in the current frame
+
+@item sample_rate @emph{(audio only)}
+the input sample rate
+
+@item key
+This is 1 if the filtered frame is a key-frame, 0 otherwise.
+
+@item pos
+the position in the file of the filtered frame, -1 if the information
+is not available (e.g. for synthetic video)
+
+@item scene @emph{(video only)}
+value between 0 and 1 to indicate a new scene; a low value reflects a low
+probability for the current frame to introduce a new scene, while a higher
+value means the current frame is more likely to be one (see the example below)
+
+@item concatdec_select
+The concat demuxer can select only part of a concat input file by setting an
+inpoint and an outpoint, but the output packets may not be entirely contained
+in the selected interval. By using this variable, it is possible to skip frames
+generated by the concat demuxer which are not exactly contained in the selected
+interval.
+
+This works by comparing the frame pts against the @var{lavf.concat.start_time}
+and the @var{lavf.concat.duration} packet metadata values which are also
+present in the decoded frames.
+
+The @var{concatdec_select} variable is -1 if the frame pts is at least
+start_time and either the duration metadata is missing or the frame pts is less
+than start_time + duration, 0 otherwise, and NaN if the start_time metadata is
+missing.
+
+That basically means that an input frame is selected if its pts is within the
+interval set by the concat demuxer.
+
+@end table
+
+The default value of the select expression is "1".
+
+@subsection Examples
+
+@itemize
+@item
+Select all frames in input:
+@example
+select
+@end example
+
+The example above is the same as:
+@example
+select=1
+@end example
+
+@item
+Skip all frames:
+@example
+select=0
+@end example
+
+@item
+Select only I-frames:
+@example
+select='eq(pict_type\,I)'
+@end example
+
+@item
+Select one frame every 100:
+@example
+select='not(mod(n\,100))'
+@end example
+
+@item
+Select only frames contained in the 10-20 time interval:
+@example
+select=between(t\,10\,20)
+@end example
+
+@item
+Select only I frames contained in the 10-20 time interval:
+@example
+select=between(t\,10\,20)*eq(pict_type\,I)
+@end example
+
+@item
+Select frames with a minimum distance of 10 seconds:
+@example
+select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
+@end example
+
+@item
+Use aselect to select only audio frames with samples number > 100:
+@example
+aselect='gt(samples_n\,100)'
+@end example
+
+@item
+Create a mosaic of the first scenes:
+@example
+ffmpeg -i video.avi -vf select='gt(scene\,0.4)',scale=160:120,tile -frames:v 1 preview.png
+@end example
+
+Comparing @var{scene} against a value between 0.3 and 0.5 is generally a sane
+choice.
+
+@item
+Send even and odd frames to separate outputs, and compose them:
+@example
+select=n=2:e='mod(n, 2)+1' [odd][even]; [odd] pad=h=2*ih [tmp]; [tmp][even] overlay=y=h
+@end example
+
+@item
+Select useful frames from an ffconcat file which is using inpoints and
+outpoints but where the source files are not intra frame only.
+@example
+ffmpeg -copyts -vsync 0 -segment_time_metadata 1 -i input.ffconcat -vf select=concatdec_select -af aselect=concatdec_select output.avi
+@end example
+@end itemize
+
+@section sendcmd, asendcmd
+
+Send commands to filters in the filtergraph.
+
+These filters read commands to be sent to other filters in the
+filtergraph.
+
+@code{sendcmd} must be inserted between two video filters,
+@code{asendcmd} must be inserted between two audio filters, but apart
+from that they act the same way.
+
+The specification of commands can be provided in the filter arguments
+with the @var{commands} option, or in a file specified by the
+@var{filename} option.
+
+These filters accept the following options:
+@table @option
+@item commands, c
+Set the commands to be read and sent to the other filters.
+@item filename, f
+Set the filename of the commands to be read and sent to the other
+filters.
+@end table
+
+@subsection Commands syntax
+
+A commands description consists of a sequence of interval
+specifications, comprising a list of commands to be executed when a
+particular event related to that interval occurs. The occurring event
+is typically the current frame time entering or leaving a given time
+interval.
+
+An interval is specified by the following syntax:
+@example
+@var{START}[-@var{END}] @var{COMMANDS};
+@end example
+
+The time interval is specified by the @var{START} and @var{END} times.
+@var{END} is optional and defaults to the maximum time.
+
+The current frame time is considered within the specified interval if
+it is included in the interval [@var{START}, @var{END}), that is when
+the time is greater or equal to @var{START} and is lesser than
+@var{END}.
+
+@var{COMMANDS} consists of a sequence of one or more command
+specifications, separated by ",", relating to that interval. The
+syntax of a command specification is given by:
+@example
+[@var{FLAGS}] @var{TARGET} @var{COMMAND} @var{ARG}
+@end example
+
+@var{FLAGS} is optional and specifies the type of events relating to
+the time interval which enable sending the specified command, and must
+be a non-null sequence of identifier flags separated by "+" or "|" and
+enclosed between "[" and "]".
+
+The following flags are recognized:
+@table @option
+@item enter
+The command is sent when the current frame timestamp enters the
+specified interval. In other words, the command is sent when the
+previous frame timestamp was not in the given interval, and the
+current is.
+
+@item leave
+The command is sent when the current frame timestamp leaves the
+specified interval. In other words, the command is sent when the
+previous frame timestamp was in the given interval, and the
+current is not.
+@end table
+
+If @var{FLAGS} is not specified, a default value of @code{[enter]} is
+assumed.
-Some examples:
-@example
-# Scale the input video to a size of 200x100
-scale=w=200:h=100
+@var{TARGET} specifies the target of the command, usually the name of
+the filter class or a specific filter instance name.
-# Scale the input to 2x
-scale=w=2*iw:h=2*ih
-# The above is the same as
-scale=2*in_w:2*in_h
+@var{COMMAND} specifies the name of the command for the target filter.
-# Scale the input to half the original size
-scale=w=iw/2:h=ih/2
+@var{ARG} is optional and specifies the optional list of argument for
+the given @var{COMMAND}.
-# Increase the width, and set the height to the same size
-scale=3/2*iw:ow
+Between one interval specification and another, whitespaces, or
+sequences of characters starting with @code{#} until the end of line,
+are ignored and can be used to annotate comments.
-# Seek Greek harmony
-scale=iw:1/PHI*iw
-scale=ih*PHI:ih
+A simplified BNF description of the commands specification syntax
+follows:
+@example
+@var{COMMAND_FLAG} ::= "enter" | "leave"
+@var{COMMAND_FLAGS} ::= @var{COMMAND_FLAG} [(+|"|")@var{COMMAND_FLAG}]
+@var{COMMAND} ::= ["[" @var{COMMAND_FLAGS} "]"] @var{TARGET} @var{COMMAND} [@var{ARG}]
+@var{COMMANDS} ::= @var{COMMAND} [,@var{COMMANDS}]
+@var{INTERVAL} ::= @var{START}[-@var{END}] @var{COMMANDS}
+@var{INTERVALS} ::= @var{INTERVAL}[;@var{INTERVALS}]
+@end example
-# Increase the height, and set the width to 3/2 of the height
-scale=w=3/2*oh:h=3/5*ih
+@subsection Examples
-# Increase the size, making the size a multiple of the chroma
-scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
+@itemize
+@item
+Specify audio tempo change at second 4:
+@example
+asendcmd=c='4.0 atempo tempo 1.5',atempo
+@end example
-# Increase the width to a maximum of 500 pixels,
-# keeping the same aspect ratio as the input
-scale=w='min(500\, iw*3/2):h=-1'
+@item
+Specify a list of drawtext and hue commands in a file.
+@example
+# show text in the interval 5-10
+5.0-10.0 [enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=hello world',
+ [leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=';
+
+# desaturate the image in the interval 15-20
+15.0-20.0 [enter] hue s 0,
+ [enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=nocolor',
+ [leave] hue s 1,
+ [leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=color';
+
+# apply an exponential saturation fade-out effect, starting from time 25
+25 [enter] hue s exp(25-t)
@end example
-@section select
-Select frames to pass in output.
+A filtergraph allowing to read and process the above command list
+stored in a file @file{test.cmd}, can be specified with:
+@example
+sendcmd=f=test.cmd,drawtext=fontfile=FreeSerif.ttf:text='',hue
+@end example
+@end itemize
-It accepts the following parameters:
+@anchor{setpts}
+@section setpts, asetpts
+
+Change the PTS (presentation timestamp) of the input frames.
+
+@code{setpts} works on video frames, @code{asetpts} on audio frames.
+
+This filter accepts the following options:
@table @option
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