A filter with no input pads is called a "source", a filter with no
output pads is called a "sink".
+@anchor{Filtergraph syntax}
@section Filtergraph syntax
-A filtergraph can be represented using a textual representation, which
-is recognized by the @code{-vf} and @code{-af} options of the ff*
-tools, and by the @code{av_parse_graph()} function defined in
-@file{libavfilter/avfiltergraph}.
+A filtergraph can be represented using a textual representation, which is
+recognized by the @option{-filter}/@option{-vf} and @option{-filter_complex}
+options in @command{avconv} and @option{-vf} in @command{avplay}, and by the
+@code{avfilter_graph_parse()}/@code{avfilter_graph_parse2()} function defined in
+@file{libavfilter/avfiltergraph.h}.
A filterchain consists of a sequence of connected filters, each one
connected to the previous one in the sequence. A filterchain is
"=@var{arguments}".
@var{arguments} is a string which contains the parameters used to
-initialize the filter instance, and are described in the filter
-descriptions below.
+initialize the filter instance. It may have one of the two allowed forms:
+@itemize
+
+@item
+A ':'-separated list of @var{key=value} pairs.
+
+@item
+A ':'-separated list of @var{value}. In this case, the keys are assumed to be
+the option names in the order they are declared. E.g. the @code{fade} filter
+declares three options in this order -- @option{type}, @option{start_frame} and
+@option{nb_frames}. Then the parameter list @var{in:0:30} means that the value
+@var{in} is assigned to the option @option{type}, @var{0} to
+@option{start_frame} and @var{30} to @option{nb_frames}.
+
+@end itemize
+
+If the option value itself is a list of items (e.g. the @code{format} filter
+takes a list of pixel formats), the items in the list are usually separated by
+'|'.
The list of arguments can be quoted using the character "'" as initial
and ending mark, and the character '\' for escaping the characters
pads must be connected. A filtergraph is considered valid if all the
filter input and output pads of all the filterchains are connected.
+Libavfilter will automatically insert scale filters where format
+conversion is required. It is possible to specify swscale flags
+for those automatically inserted scalers by prepending
+@code{sws_flags=@var{flags};}
+to the filtergraph description.
+
Follows a BNF description for the filtergraph syntax:
@example
@var{NAME} ::= sequence of alphanumeric characters and '_'
@var{LINKLABEL} ::= "[" @var{NAME} "]"
@var{LINKLABELS} ::= @var{LINKLABEL} [@var{LINKLABELS}]
@var{FILTER_ARGUMENTS} ::= sequence of chars (eventually quoted)
-@var{FILTER} ::= [@var{LINKNAMES}] @var{NAME} ["=" @var{ARGUMENTS}] [@var{LINKNAMES}]
+@var{FILTER} ::= [@var{LINKLABELS}] @var{NAME} ["=" @var{FILTER_ARGUMENTS}] [@var{LINKLABELS}]
@var{FILTERCHAIN} ::= @var{FILTER} [,@var{FILTERCHAIN}]
-@var{FILTERGRAPH} ::= @var{FILTERCHAIN} [;@var{FILTERGRAPH}]
+@var{FILTERGRAPH} ::= [sws_flags=@var{flags};] @var{FILTERCHAIN} [;@var{FILTERGRAPH}]
@end example
@c man end FILTERGRAPH DESCRIPTION
Below is a description of the currently available audio filters.
+@section aformat
+
+Convert the input audio to one of the specified formats. The framework will
+negotiate the most appropriate format to minimize conversions.
+
+The filter accepts the following named parameters:
+@table @option
+
+@item sample_fmts
+A '|'-separated list of requested sample formats.
+
+@item sample_rates
+A '|'-separated list of requested sample rates.
+
+@item channel_layouts
+A '|'-separated list of requested channel layouts.
+
+@end table
+
+If a parameter is omitted, all values are allowed.
+
+For example to force the output to either unsigned 8-bit or signed 16-bit stereo:
+@example
+aformat=sample_fmts=u8|s16:channel_layouts=stereo
+@end example
+
+@section amix
+
+Mixes multiple audio inputs into a single output.
+
+For example
+@example
+avconv -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
+@end example
+will mix 3 input audio streams to a single output with the same duration as the
+first input and a dropout transition time of 3 seconds.
+
+The filter accepts the following named parameters:
+@table @option
+
+@item inputs
+Number of inputs. If unspecified, it defaults to 2.
+
+@item duration
+How to determine the end-of-stream.
+@table @option
+
+@item longest
+Duration of longest input. (default)
+
+@item shortest
+Duration of shortest input.
+
+@item first
+Duration of first input.
+
+@end table
+
+@item dropout_transition
+Transition time, in seconds, for volume renormalization when an input
+stream ends. The default value is 2 seconds.
+
+@end table
+
@section anull
Pass the audio source unchanged to the output.
+@section ashowinfo
+
+Show a line containing various information for each input audio frame.
+The input audio is not modified.
+
+The shown line contains a sequence of key/value pairs of the form
+@var{key}:@var{value}.
+
+A description of each shown parameter follows:
+
+@table @option
+@item n
+sequential number of the input frame, starting from 0
+
+@item pts
+Presentation timestamp of the input frame, in time base units; the time base
+depends on the filter input pad, and is usually 1/@var{sample_rate}.
+
+@item pts_time
+presentation timestamp of the input frame in seconds
+
+@item fmt
+sample format
+
+@item chlayout
+channel layout
+
+@item rate
+sample rate for the audio frame
+
+@item nb_samples
+number of samples (per channel) in the frame
+
+@item checksum
+Adler-32 checksum (printed in hexadecimal) of the audio data. For planar audio
+the data is treated as if all the planes were concatenated.
+
+@item plane_checksums
+A list of Adler-32 checksums for each data plane.
+@end table
+
+@section asplit
+
+Split input audio into several identical outputs.
+
+The filter accepts a single parameter which specifies the number of outputs. If
+unspecified, it defaults to 2.
+
+For example
+@example
+avconv -i INPUT -filter_complex asplit=5 OUTPUT
+@end example
+will create 5 copies of the input audio.
+
+@section asyncts
+Synchronize audio data with timestamps by squeezing/stretching it and/or
+dropping samples/adding silence when needed.
+
+The filter accepts the following named parameters:
+@table @option
+
+@item compensate
+Enable stretching/squeezing the data to make it match the timestamps. Disabled
+by default. When disabled, time gaps are covered with silence.
+
+@item min_delta
+Minimum difference between timestamps and audio data (in seconds) to trigger
+adding/dropping samples. Default value is 0.1. If you get non-perfect sync with
+this filter, try setting this parameter to 0.
+
+@item max_comp
+Maximum compensation in samples per second. Relevant only with compensate=1.
+Default value 500.
+
+@item first_pts
+Assume the first pts should be this value. The time base is 1 / sample rate.
+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
+silence if an audio stream starts after the video stream or to trim any samples
+with a negative pts due to encoder delay.
+
+@end table
+
+@section channelsplit
+Split each channel in input audio stream into a separate output stream.
+
+This filter accepts the following named parameters:
+@table @option
+@item channel_layout
+Channel layout of the input stream. Default is "stereo".
+@end table
+
+For example, assuming a stereo input MP3 file
+@example
+avconv -i in.mp3 -filter_complex channelsplit out.mkv
+@end example
+will create an output Matroska file with two audio streams, one containing only
+the left channel and the other the right channel.
+
+To split a 5.1 WAV file into per-channel files
+@example
+avconv -i in.wav -filter_complex
+'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
+-map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
+front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
+side_right.wav
+@end example
+
+@section channelmap
+Remap input channels to new locations.
+
+This filter accepts the following named parameters:
+@table @option
+@item channel_layout
+Channel layout of the output stream.
+
+@item map
+Map channels from input to output. The argument is a comma-separated list of
+mappings, each in the @code{@var{in_channel}-@var{out_channel}} or
+@var{in_channel} form. @var{in_channel} can be either the name of the input
+channel (e.g. FL for front left) or its index in the input channel layout.
+@var{out_channel} is the name of the output channel or its index in the output
+channel layout. If @var{out_channel} is not given then it is implicitly an
+index, starting with zero and increasing by one for each mapping.
+@end table
+
+If no mapping is present, the filter will implicitly map input channels to
+output channels preserving index.
+
+For example, assuming a 5.1+downmix input MOV file
+@example
+avconv -i in.mov -filter 'channelmap=map=DL-FL\,DR-FR' out.wav
+@end example
+will create an output WAV file tagged as stereo from the downmix channels of
+the input.
+
+To fix a 5.1 WAV improperly encoded in AAC's native channel order
+@example
+avconv -i in.wav -filter 'channelmap=1\,2\,0\,5\,3\,4:channel_layout=5.1' out.wav
+@end example
+
+@section join
+Join multiple input streams into one multi-channel stream.
+
+The filter accepts the following named parameters:
+@table @option
+
+@item inputs
+Number of input streams. Defaults to 2.
+
+@item channel_layout
+Desired output channel layout. Defaults to stereo.
+
+@item map
+Map channels from inputs to output. The argument is a comma-separated list of
+mappings, each in the @code{@var{input_idx}.@var{in_channel}-@var{out_channel}}
+form. @var{input_idx} is the 0-based index of the input stream. @var{in_channel}
+can be either the name of the input channel (e.g. FL for front left) or its
+index in the specified input stream. @var{out_channel} is the name of the output
+channel.
+@end table
+
+The filter will attempt to guess the mappings when those are not specified
+explicitly. It does so by first trying to find an unused matching input channel
+and if that fails it picks the first unused input channel.
+
+E.g. to join 3 inputs (with properly set channel layouts)
+@example
+avconv -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
+@end example
+
+To build a 5.1 output from 6 single-channel streams:
+@example
+avconv -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
+'join=inputs=6:channel_layout=5.1:map=0.0-FL\,1.0-FR\,2.0-FC\,3.0-SL\,4.0-SR\,5.0-LFE'
+out
+@end example
+
+@section resample
+Convert the audio sample format, sample rate and channel layout. This filter is
+not meant to be used directly, it is inserted automatically by libavfilter
+whenever conversion is needed. Use the @var{aformat} filter to force a specific
+conversion.
+
+@section volume
+
+Adjust the input audio volume.
+
+The filter accepts the following named parameters:
+@table @option
+
+@item volume
+Expresses how the audio volume will be increased or decreased.
+
+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
+
+Default value for @var{volume} is 1.0.
+
+@item precision
+Mathematical precision.
+
+This determines which input sample formats will be allowed, which affects the
+precision of the volume scaling.
+
+@table @option
+@item fixed
+8-bit fixed-point; limits input sample format to U8, S16, and S32.
+@item float
+32-bit floating-point; limits input sample format to FLT. (default)
+@item double
+64-bit floating-point; limits input sample format to DBL.
+@end table
+@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
+
+@item
+Increase input audio power by 6 decibels using fixed-point precision:
+@example
+volume=volume=6dB:precision=fixed
+@end example
+@end itemize
+
@c man end AUDIO FILTERS
@chapter Audio Sources
of @var{channel_layout} is 3, which corresponds to CH_LAYOUT_STEREO.
Check the channel_layout_map definition in
-@file{libavcodec/audioconvert.c} for the mapping between strings and
+@file{libavutil/channel_layout.c} for the mapping between strings and
channel layout values.
Follow some examples:
anullsrc=48000:mono
@end example
+@section abuffer
+Buffer audio frames, and make them available to the filter chain.
+
+This source is not intended to be part of user-supplied graph descriptions but
+for insertion by calling programs through the interface defined in
+@file{libavfilter/buffersrc.h}.
+
+It accepts the following named parameters:
+@table @option
+
+@item time_base
+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
+Audio sample rate.
+
+@item sample_fmt
+Name of the sample format, as returned by @code{av_get_sample_fmt_name()}.
+
+@item channel_layout
+Channel layout of the audio data, in the form that can be accepted by
+@code{av_get_channel_layout()}.
+@end table
+
+All the parameters need to be explicitly defined.
+
@c man end AUDIO SOURCES
@chapter Audio Sinks
mainly useful as a template and to be employed in analysis / debugging
tools.
+@section abuffersink
+This sink is intended for programmatic use. Frames that arrive on this sink can
+be retrieved by the calling program using the interface defined in
+@file{libavfilter/buffersink.h}.
+
+This filter accepts no parameters.
+
@c man end AUDIO SINKS
@chapter Video Filters
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 syntax:
+The filter accepts the following options:
+
+@table @option
+
+@item amount
+The percentage of the pixels that have to be below the threshold, defaults to
+98.
+
+@item threshold
+Threshold below which a pixel value is considered black, defaults to 32.
+
+@end table
+
+@section boxblur
+
+Apply boxblur algorithm to the input video.
+
+This filter accepts the following options:
+
+@table @option
+
+@item luma_radius
+@item luma_power
+@item chroma_radius
+@item chroma_power
+@item alpha_radius
+@item alpha_power
+
+@end table
+
+Chroma and alpha parameters are optional, if not specified they default
+to the corresponding values set for @var{luma_radius} and
+@var{luma_power}.
+
+@var{luma_radius}, @var{chroma_radius}, and @var{alpha_radius} represent
+the radius in pixels of the box used for blurring the corresponding
+input plane. They are expressions, and can contain the following
+constants:
+@table @option
+@item w, h
+the input width and height in pixels
+
+@item cw, ch
+the input chroma image width and height in pixels
+
+@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
+
+The radius 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.
+
+@var{luma_power}, @var{chroma_power}, and @var{alpha_power} represent
+how many times the boxblur filter is applied to the corresponding
+plane.
+
+Some examples follow:
+
+@itemize
+
+@item
+Apply a boxblur filter with luma, chroma, and alpha radius
+set to 2:
@example
-blackframe[=@var{amount}:[@var{threshold}]]
+boxblur=luma_radius=2:luma_power=1
@end example
-@var{amount} is the percentage of the pixels that have to be below the
-threshold, and defaults to 98.
+@item
+Set luma radius to 2, alpha and chroma radius to 0
+@example
+boxblur=2:1:0:0:0:0
+@end example
-@var{threshold} is the threshold below which a pixel value is
-considered black, and defaults to 32.
+@item
+Set luma and chroma radius 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 copy
@section crop
-Crop the input video to @var{out_w}:@var{out_h}:@var{x}:@var{y}.
+Crop the input video to given dimensions.
+
+This filter accepts the following options:
+
+@table @option
+
+@item out_w
+Width of the output video.
+
+@item out_h
+Height of the output video.
+
+@item x
+Horizontal position, in the input video, of the left edge of the output video.
+
+@item y
+Vertical position, in the input video, of the top edge of the output video.
+
+@end table
The parameters are expressions containing the following constants:
each new frame.
@item in_w, in_h
-the input width and heigth
+the input width and height
@item iw, ih
same as @var{in_w} and @var{in_h}
@item out_w, out_h
-the output (cropped) width and heigth
+the output (cropped) width and height
@item ow, oh
same as @var{out_w} and @var{out_h}
@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
timestamp expressed in seconds, NAN if the input timestamp is unknown
Follow some examples:
@example
# crop the central input area with size 100x100
-crop=100:100
+crop=out_w=100:out_h=100
# crop the central input area with size 2/3 of the input video
-"crop=2/3*in_w:2/3*in_h"
+"crop=out_w=2/3*in_w:out_h=2/3*in_h"
# crop the input video central square
-crop=in_h
+crop=out_w=in_h
# 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.
-crop=in_w-100:in_h-100:100:100
+crop=out_w=in_w-100:out_h=in_h-100:x=100:y=100
# crop 10 pixels from the left and right borders, and 20 pixels from
# the top and bottom borders
-"crop=in_w-2*10:in_h-2*20"
+"crop=out_w=in_w-2*10:out_h=in_h-2*20"
# keep only the bottom right quarter of the input image
-"crop=in_w/2:in_h/2:in_w/2:in_h/2"
+"crop=out_w=in_w/2:out_h=in_h/2:x=in_w/2:y=in_h/2"
# crop height for getting Greek harmony
-"crop=in_w:1/PHI*in_w"
+"crop=out_w=in_w:out_h=1/PHI*in_w"
# trembling effect
"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)"
# erratic camera effect depending on timestamp
-"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)"
+"crop=out_w=in_w/2:out_h=in_h/2:x=(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):y=(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)"
# set x depending on the value of y
"crop=in_w/2:in_h/2:y:10+10*sin(n/10)"
parameters through the logging system. The detected dimensions
correspond to the non-black area of the input video.
-It accepts the syntax:
-@example
-cropdetect[=@var{limit}[:@var{round}[:@var{reset}]]]
-@end example
+This filter accepts the following options:
@table @option
playback.
@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).
+
+The filter accepts parameters as a string of the form
+"@var{x}:@var{y}:@var{w}:@var{h}:@var{band}", or as a list of
+@var{key}=@var{value} pairs, separated by ":".
+
+The description of the accepted parameters follows.
+
+@table @option
+
+@item x, y
+Specify the top left corner coordinates of the logo. They must be
+specified.
+
+@item w, 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 4.
+
+@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}, @var{h} parameters, and
+@var{band} is set to 4. The default value is 0.
+
+@end table
+
+Some examples follow.
+
+@itemize
+
+@item
+Set a rectangle covering the area with top left corner coordinates 0,0
+and size 100x77, setting a band of size 10:
+@example
+delogo=0:0:100:77:10
+@end example
+
+@item
+As the previous example, but use named options:
+@example
+delogo=x=0:y=0:w=100:h=77:band=10
+@end example
+
+@end itemize
+
@section drawbox
Draw a colored box on the input image.
Draw text string or text from specified file on top of video using the
libfreetype library.
-To enable compilation of this filter you need to configure FFmpeg with
+To enable compilation of this filter you need to configure Libav with
@code{--enable-libfreetype}.
The filter also recognizes strftime() sequences in the provided text
@item x, y
The offsets where text will be drawn within the video frame.
Relative to the top/left border of the output image.
+They accept expressions similar to the @ref{overlay} filter:
+@table @option
+
+@item x, y
+the computed values for @var{x} and @var{y}. They are evaluated for
+each new frame.
+
+@item main_w, main_h
+main input width and height
+
+@item W, H
+same as @var{main_w} and @var{main_h}
+
+@item text_w, text_h
+rendered text width and height
+
+@item w, h
+same as @var{text_w} and @var{text_h}
+
+@item n
+the number of frames processed, starting from 0
+
+@item t
+timestamp expressed in seconds, NAN if the input timestamp is unknown
+
+@end table
The default value of @var{x} and @var{y} is 0.
@item tabsize
The size in number of spaces to use for rendering the tab.
Default value is 4.
+
+@item fix_bounds
+If true, check and fix text coords to avoid clipping.
@end table
For example the command:
For example:
@example
-./ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
+./avconv -i in.vob -vf "fieldorder=bff" out.dv
@end example
@section fifo
Libavfilter will try to pick one that is supported for the input to
the next filter.
-The filter accepts a list of pixel format names, separated by ":",
-for example "yuv420p:monow:rgb24".
+This filter accepts the following parameters:
+@table @option
+
+@item pix_fmts
+A '|'-separated list of pixel format names, for example
+"pix_fmts=yuv420p|monow|rgb24".
+
+@end table
Some examples follow:
@example
# convert the input video to the format "yuv420p"
-format=yuv420p
+format=pix_fmts=yuv420p
# convert the input video to any of the formats in the list
-format=yuv420p:yuv444p:yuv410p
+format=pix_fmts=yuv420p|yuv444p|yuv410p
@end example
+@section fps
+
+Convert the video to specified constant framerate by duplicating or dropping
+frames as necessary.
+
+This filter accepts the following named parameters:
+@table @option
+
+@item fps
+Desired output framerate.
+
+@end table
+
@anchor{frei0r}
@section frei0r
@var{strength} is the maximum amount by which the filter will change
any one pixel. Also the threshold for detecting nearly flat
-regions. Acceptable values range from .51 to 255, default value is
+regions. Acceptable values range from .51 to 64, default value is
1.2, out-of-range values will be clipped to the valid range.
@var{radius} is the neighborhood to fit the gradient to. A larger
Flip the input video horizontally.
-For example to horizontally flip the video in input with
-@file{ffmpeg}:
+For example to horizontally flip the input video with @command{avconv}:
@example
-ffmpeg -i in.avi -vf "hflip" out.avi
+avconv -i in.avi -vf "hflip" out.avi
@end example
@section hqdn3d
@var{luma_tmp}*@var{chroma_spatial}/@var{luma_spatial}
@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 input video.
+
+@var{lutyuv} applies a lookup table to a YUV input video, @var{lutrgb}
+to an RGB input video.
+
+These filters accept in input a ":"-separated list of options, which
+specify the expressions used for computing the lookup table for the
+corresponding pixel component values.
+
+The @var{lut} filter requires either YUV or RGB pixel formats in
+input, and accepts the options:
+@table @option
+@item @var{c0} (first pixel component)
+@item @var{c1} (second pixel component)
+@item @var{c2} (third pixel component)
+@item @var{c3} (fourth pixel component, corresponds to the alpha component)
+@end table
+
+The exact component associated to each option depends on the format in
+input.
+
+The @var{lutrgb} filter requires RGB pixel formats in input, and
+accepts the options:
+@table @option
+@item @var{r} (red component)
+@item @var{g} (green component)
+@item @var{b} (blue component)
+@item @var{a} (alpha component)
+@end table
+
+The @var{lutyuv} filter requires YUV pixel formats in input, and
+accepts the options:
+@table @option
+@item @var{y} (Y/luminance component)
+@item @var{u} (U/Cb component)
+@item @var{v} (V/Cr component)
+@item @var{a} (alpha component)
+@end table
+
+The expressions can contain the following constants and functions:
+
+@table @option
+@item E, PI, PHI
+the corresponding mathematical approximated values for e
+(euler number), pi (greek PI), PHI (golden ratio)
+
+@item w, h
+the input width and height
+
+@item val
+input value for the pixel component
+
+@item clipval
+the input value clipped in the @var{minval}-@var{maxval} range
+
+@item maxval
+maximum value for the pixel component
+
+@item minval
+minimum value for the pixel component
+
+@item negval
+the negated value for the pixel component value clipped in the
+@var{minval}-@var{maxval} range , it corresponds to the expression
+"maxval-clipval+minval"
+
+@item clip(val)
+the computed value in @var{val} clipped in the
+@var{minval}-@var{maxval} range
+
+@item gammaval(gamma)
+the computed gamma correction value of the pixel component value
+clipped in the @var{minval}-@var{maxval} range, corresponds to the
+expression
+"pow((clipval-minval)/(maxval-minval)\,@var{gamma})*(maxval-minval)+minval"
+
+@end table
+
+All expressions default to "val".
+
+Some examples follow:
+@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"
+
+# the above is the same as
+lutrgb="r=negval:g=negval:b=negval"
+lutyuv="y=negval:u=negval:v=negval"
+
+# negate luminance
+lutyuv=negval
+
+# remove chroma components, turns the video into a graytone image
+lutyuv="u=128:v=128"
+
+# apply a luma burning effect
+lutyuv="y=2*val"
+
+# remove green and blue components
+lutrgb="g=0:b=0"
+
+# set a constant alpha channel value on input
+format=rgba,lutrgb=a="maxval-minval/2"
+
+# correct luminance gamma by a 0.5 factor
+lutyuv=y=gammaval(0.5)
+@end example
+
+@section negate
+
+Negate input video.
+
+This filter accepts an integer in input, if non-zero it negates the
+alpha component (if available). The default value in input is 0.
+
@section noformat
Force libavfilter not to use any of the specified pixel formats for the
input to the next filter.
-The filter accepts a list of pixel format names, separated by ":",
-for example "yuv420p:monow:rgb24".
+This filter accepts the following parameters:
+@table @option
+
+@item pix_fmts
+A '|'-separated list of pixel format names, for example
+"pix_fmts=yuv420p|monow|rgb24".
+
+@end table
Some examples follow:
@example
# force libavfilter to use a format different from "yuv420p" for the
# input to the vflip filter
-noformat=yuv420p,vflip
+noformat=pix_fmts=yuv420p,vflip
# convert the input video to any of the formats not contained in the list
-noformat=yuv420p:yuv444p:yuv410p
+noformat=yuv420p|yuv444p|yuv410p
@end example
@section null
filter. If not specified the default values are assumed.
Refer to the official libopencv documentation for more precise
-informations:
+information:
@url{http://opencv.willowgarage.com/documentation/c/image_filtering.html}
Follows the list of supported libopencv filters.
@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 colums and rows of
+@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, and
can be one of the values "rect", "cross", "ellipse", "custom".
These parameters correspond to the parameters assigned to the
libopencv function @code{cvSmooth}.
+@anchor{overlay}
@section overlay
Overlay one video on top of another.
overlay=main_w-overlay_w-10:main_h-overlay_h-10
# insert a transparent PNG logo in the bottom left corner of the input
-movie=logo.png [logo];
-[in][logo] overlay=10:main_h-overlay_h-10 [out]
+avconv -i input -i logo -filter_complex 'overlay=10:main_h-overlay_h-10' output
# insert 2 different transparent PNG logos (second logo on bottom
# right corner):
-movie=logo1.png [logo1];
-movie=logo2.png [logo2];
-[in][logo1] overlay=10:H-h-10 [in+logo1];
-[in+logo1][logo2] overlay=W-w-10:H-h-10 [out]
+avconv -i input -i logo1 -i logo2 -filter_complex
+'overlay=10:H-h-10,overlay=W-w-10:H-h-10' output
# 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]
@end example
-You can chain togheter more overlays but the efficiency of such
+You can chain together more overlays but the efficiency of such
approach is yet to be tested.
@section pad
(euler number), pi (greek PI), phi (golden ratio)
@item in_w, in_h
-the input video width and heigth
+the input video width and height
@item iw, ih
same as @var{in_w} and @var{in_h}
@item out_w, out_h
-the output width and heigth, that is the size of the padded area as
+the output width and height, that is the size of the padded area as
specified by the @var{width} and @var{height} expressions
@item ow, oh
is used for the output.
The @var{width} expression can reference the value set by the
-@var{height} expression, and viceversa.
+@var{height} expression, and vice versa.
The default value of @var{width} and @var{height} is 0.
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 viceversa.
+expression, and vice versa.
The default value of @var{x} and @var{y} is 0.
(euler number), pi (greek PI), phi (golden ratio)
@item in_w, in_h
-the input width and heigth
+the input width and height
@item iw, ih
same as @var{in_w} and @var{in_h}
@item out_w, out_h
-the output (cropped) width and heigth
+the output (cropped) width and height
@item ow, oh
same as @var{out_w} and @var{out_h}
-@item a
+@item dar, a
input display aspect ratio, same as @var{iw} / @var{ih}
+@item sar
+input sample aspect ratio
+
@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.
@item key
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)
@end table
The default value of the select expression is "1".
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 filter accepts a parameter string which represents the wanted
-display aspect ratio.
-The parameter can be a floating point number string, or an expression
-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 "0:1".
+This filter accepts the following options:
+
+@table @option
+
+@item dar
+Output display aspect ratio, as a rational or a decimal number.
+
+@end table
For example to change the display aspect ratio to 16:9, specify:
@example
-setdar=16:9
+setdar=dar=16/9
# the above is equivalent to
-setdar=1.77777
+setdar=dar=1.77777
@end example
See also the @ref{setsar} filter documentation.
@item INTERLACED
tell if the current frame is interlaced
-@item POS
-original position in the file of the frame, or undefined if undefined
-for the current frame
-
@item PREV_INPTS
previous input PTS
@item PREV_OUTPTS
previous output PTS
+@item RTCTIME
+wallclock (RTC) time in microseconds
+
+@item RTCSTART
+wallclock (RTC) time at the start of the movie in microseconds
+
@end table
Some examples follow:
# fixed rate 25 fps with some jitter
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
+
+# generate timestamps from a "live source" and rebase onto the current timebase
+setpts='(RTCTIME - RTCSTART) / (TB * 1000000)"
@end example
@anchor{setsar}
changed by later filters in the filterchain, e.g. if another "setsar"
or a "setdar" filter is applied.
-The filter accepts a parameter string which represents the wanted
-sample aspect ratio.
-The parameter can be a floating point number string, or an expression
-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 "0:1".
+This filter accepts the following options:
+
+@table @option
+
+@item sar
+Output sample aspect ratio, as a rational or decimal number.
+
+@end table
For example to change the sample aspect ratio to 10:11, specify:
@example
-setsar=10:11
+setsar=sar=10/11
@end example
@section settb
@item pos
position of the frame in the input stream, -1 if this information in
-unavailable and/or meanigless (for example in case of synthetic video)
+unavailable and/or meaningless (for example in case of synthetic video)
@item fmt
pixel format name
"[@var{c0} @var{c1} @var{c2} @var{c3}]"
@end table
-@section slicify
+@section split
+
+Split input video into several identical outputs.
-Pass the images of input video on to next video filter as multiple
-slices.
+The filter accepts a single parameter which specifies the number of outputs. If
+unspecified, it defaults to 2.
+For example
@example
-./ffmpeg -i in.avi -vf "slicify=32" out.avi
+avconv -i INPUT -filter_complex split=5 OUTPUT
@end example
-
-The filter accepts the slice height as parameter. If the parameter is
-not specified it will use the default value of 16.
-
-Adding this in the beginning of filter chains should make filtering
-faster due to better use of the memory cache.
+will create 5 copies of the input video.
@section transpose
Negative values for the amount will blur the input video, while positive
values will sharpen. All parameters are optional and default to the
-equivalent of the string '5:5:1.0:0:0:0.0'.
+equivalent of the string '5:5:1.0:5:5:0.0'.
@table @option
@item chroma_msize_x
Set the chroma matrix horizontal size. It can be an integer between 3
-and 13, default value is 0.
+and 13, default value is 5.
@item chroma_msize_y
Set the chroma matrix vertical size. It can be an integer between 3
-and 13, default value is 0.
+and 13, default value is 5.
@item luma_amount
Set the chroma effect strength. It can be a float number between -2.0
# Strong blur of both luma and chroma parameters
unsharp=7:7:-2:7:7:-2
-# Use the default values with @command{ffmpeg}
-./ffmpeg -i in.avi -vf "unsharp" out.mp4
+# Use the default values with @command{avconv}
+./avconv -i in.avi -vf "unsharp" out.mp4
@end example
@section vflip
Flip the input video vertically.
@example
-./ffmpeg -i in.avi -vf "vflip" out.avi
+./avconv -i in.avi -vf "vflip" out.avi
@end example
@section yadif
@table @option
@item 0
-assume bottom field first
-@item 1
assume top field first
+@item 1
+assume bottom field first
@item -1
enable automatic detection
@end table
If interlacing is unknown or decoder does not export this information,
top field first will be assumed.
-@var{auto] specifies if deinterlacer should trust the interlaced flag
+@var{auto} specifies if deinterlacer should trust the interlaced flag
and only deinterlace frames marked as interlaced
@table @option
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:
-@var{width}:@var{height}:@var{pix_fmt_string}:@var{timebase_num}:@var{timebase_den}:@var{sample_aspect_ratio_num}:@var{sample_aspect_ratio.den}
+This filter accepts the following parameters:
-All the parameters need to be explicitely defined.
+@table @option
-Follows the list of the accepted parameters.
+@item width
+Input video width.
-@table @option
+@item height
+Input video height.
-@item width, height
-Specify the width and height of the buffered video frames.
+@item pix_fmt
+Name of the input video pixel format.
-@item pix_fmt_string
-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
+The time base used for input timestamps.
-@item timebase_num, timebase_den
-Specify numerator and denomitor of the timebase assumed by the
-timestamps of the buffered frames.
+@item sar
+Sample (pixel) aspect ratio of the input video.
-@item sample_aspect_ratio.num, sample_aspect_ratio.den
-Specify numerator and denominator of the sample aspect ratio assumed
-by the video frames.
@end table
For example:
@example
-buffer=320:240:yuv410p:1:24:1:1
+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 PixelFormat definition in @file{libavutil/pixfmt.h}),
-this example corresponds to:
-@example
-buffer=320:240:6:1:24
-@end example
@section color
@item frame_size
Specify the size of the sourced video, it may be a string of the form
-@var{width}x@var{heigth}, or the name of a size abbreviation. The
+@var{width}x@var{height}, or the name of a size abbreviation. The
default value is "320x240".
@item frame_rate
Read a video stream from a movie container.
+Note that this source is a hack that bypasses the standard input path. It can be
+useful in applications that do not support arbitrary filter graphs, but its use
+is discouraged in those that do. Specifically in @command{avconv} this filter
+should never be used, the @option{-filter_complex} option fully replaces it.
+
It accepts the syntax: @var{movie_name}[:@var{options}] where
@var{movie_name} is the name of the resource to read (not necessarily
a file but also a device or a stream accessed through some protocol),
frei0r_src=200x200:10:partik0l=1234 [overlay]; [in][overlay] overlay
@end example
+@section rgbtestsrc, testsrc
+
+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{testsrc} source generates a test video pattern, showing a
+color pattern, a scrolling gradient and a timestamp. This is mainly
+intended for testing purposes.
+
+Both sources accept an optional sequence of @var{key}=@var{value} pairs,
+separated by ":". The description of the accepted options follows.
+
+@table @option
+
+@item size, s
+Specify the size of the sourced video, it may be a string of the form
+@var{width}x@var{height}, or the name of a size abbreviation. The
+default value is "320x240".
+
+@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 float
+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
+Set the video duration of the sourced video. The accepted syntax is:
+@example
+[-]HH[:MM[:SS[.m...]]]
+[-]S+[.m...]
+@end example
+See also the function @code{av_parse_time()}.
+
+If not specified, or the expressed duration is negative, the video is
+supposed to be generated forever.
+@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 framerate of 10 frames per second.
+
@c man end VIDEO SOURCES
@chapter 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 intended for a programmatic use through the interface defined in
+@file{libavfilter/buffersink.h}.
+
@section nullsink
Null video sink, do absolutely nothing with the input video. It is
tools.
@c man end VIDEO SINKS
-
projects / ffmpeg / blobdiff