+@chapter Filtergraph description
+@c man begin FILTERGRAPH DESCRIPTION
+
+A filtergraph is a directed graph of connected filters. It can contain
+cycles, and there can be multiple links between a pair of
+filters. Each link has one input pad on one side connecting it to one
+filter from which it takes its input, and one output pad on the other
+side connecting it to the one filter accepting its output.
+
+Each filter in a filtergraph is an instance of a filter class
+registered in the application, which defines the features and the
+number of input and output pads of the filter.
+
+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 @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
+represented by a list of ","-separated filter descriptions.
+
+A filtergraph consists of a sequence of filterchains. A sequence of
+filterchains is represented by a list of ";"-separated filterchain
+descriptions.
+
+A filter is represented by a string of the form:
+[@var{in_link_1}]...[@var{in_link_N}]@var{filter_name}=@var{arguments}[@var{out_link_1}]...[@var{out_link_M}]
+
+@var{filter_name} is the name of the filter class of which the
+described filter is an instance of, and has to be the name of one of
+the filter classes registered in the program.
+The name of the filter class is optionally followed by a string
+"=@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.
+
+The list of arguments can be quoted using the character "'" as initial
+and ending mark, and the character '\' for escaping the characters
+within the quoted text; otherwise the argument string is considered
+terminated when the next special character (belonging to the set
+"[]=;,") is encountered.
+
+The name and arguments of the filter are optionally preceded and
+followed by a list of link labels.
+A link label allows to name a link and associate it to a filter output
+or input pad. The preceding labels @var{in_link_1}
+... @var{in_link_N}, are associated to the filter input pads,
+the following labels @var{out_link_1} ... @var{out_link_M}, are
+associated to the output pads.
+
+When two link labels with the same name are found in the
+filtergraph, a link between the corresponding input and output pad is
+created.
+
+If an output pad is not labelled, it is linked by default to the first
+unlabelled input pad of the next filter in the filterchain.
+For example in the filterchain:
+@example
+nullsrc, split[L1], [L2]overlay, nullsink
+@end example
+the split filter instance has two output pads, and the overlay filter
+instance two input pads. The first output pad of split is labelled
+"L1", the first input pad of overlay is labelled "L2", and the second
+output pad of split is linked to the second input pad of overlay,
+which are both unlabelled.
+
+In a complete filterchain all the unlabelled filter input and output
+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{FILTERCHAIN} ::= @var{FILTER} [,@var{FILTERCHAIN}]
+@var{FILTERGRAPH} ::= [sws_flags=@var{flags};] @var{FILTERCHAIN} [;@var{FILTERGRAPH}]
+@end example
+
+@c man end FILTERGRAPH DESCRIPTION
+
@chapter Audio Filters
@c man begin AUDIO FILTERS
-When you configure your FFmpeg build, you can disable any of the
+When you configure your Libav build, you can disable any of the
existing filters using --disable-filters.
The configure output will show the audio filters included in your
build.
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 comma-separated list of requested sample formats.
+
+@item sample_rates
+A comma-separated list of requested sample rates.
+
+@item channel_layouts
+A comma-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 correspondance between string
-and channel layout values.
+@file{libavutil/channel_layout.c} for the mapping between strings and
+channel layout values.
Follow some examples:
@example
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
+@c man begin AUDIO SINKS
+
+Below is a description of the currently available audio sinks.
+
+@section anullsink
+
+Null audio sink, do absolutely nothing with the input audio. It is
+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
@c man begin VIDEO FILTERS
-When you configure your FFmpeg build, you can disable any of the
+When you configure your Libav build, you can disable any of the
existing filters using --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 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.
+
+The filter accepts the syntax:
+@example
+blackframe[=@var{amount}:[@var{threshold}]]
+@end example
+
+@var{amount} is the percentage of the pixels that have to be below the
+threshold, and defaults to 98.
+
+@var{threshold} is the threshold below which a pixel value is
+considered black, and defaults to 32.
+
+@section boxblur
+
+Apply boxblur algorithm to the input video.
+
+This filter accepts the parameters:
+@var{luma_power}:@var{luma_radius}:@var{chroma_radius}:@var{chroma_power}:@var{alpha_radius}:@var{alpha_power}
+
+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
+boxblur=2:1
+@end example
+
+@item
+Set luma radius to 2, alpha and chroma radius to 0
+@example
+boxblur=2:1:0:0:0:0
+@end example
+
+@item
+Set luma and chroma radius to a fraction of the video dimension
+@example
+boxblur=min(h\,w)/10:1:min(cw\,ch)/10:1
+@end example
+
+@end itemize
+
+@section copy
+
+Copy the input source unchanged to the output. Mainly useful for
+testing purposes.
+
@section crop
Crop the input video to @var{out_w}:@var{out_h}:@var{x}:@var{y}.
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}
value for @var{y} is "(in_h-out_h)/2", which set the cropped area at
the center of the input image.
-The expression for @var{x} may depend on @var{y}, and the expression
-for @var{y} may depend on @var{x}.
+The expression for @var{x} may depend on @var{y}, and the expression
+for @var{y} may depend on @var{x}.
+
+Follow some examples:
+@example
+# crop the central input area with size 100x100
+crop=100:100
+
+# crop the central input area with size 2/3 of the input video
+"crop=2/3*in_w:2/3*in_h"
+
+# crop the input video central square
+crop=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 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"
+
+# keep only the bottom right quarter of the input image
+"crop=in_w/2:in_h/2:in_w/2:in_h/2"
+
+# crop height for getting Greek harmony
+"crop=in_w: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)"
+
+# set x depending on the value of y
+"crop=in_w/2:in_h/2:y:10+10*sin(n/10)"
+@end example
+
+@section cropdetect
+
+Auto-detect crop size.
+
+Calculate necessary cropping parameters and prints the recommended
+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
+
+@table @option
+
+@item limit
+Threshold, which can be optionally specified from nothing (0) to
+everything (255), defaults to 24.
+
+@item round
+Value which the width/height should be divisible by, 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
+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. Defaults to 0.
+
+This can be useful when channel logos distort the video area. 0
+indicates never reset and return the largest area encountered during
+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.
+
+It accepts the syntax:
+@example
+drawbox=@var{x}:@var{y}:@var{width}:@var{height}:@var{color}
+@end example
+
+@table @option
+
+@item x, y
+Specify the top left corner coordinates of the box. Default to 0.
+
+@item width, height
+Specify the width and height of the box, if 0 they are interpreted as
+the input width and height. Default to 0.
+
+@item color
+Specify the color of the box to write, it can be the name of a color
+(case insensitive match) or a 0xRRGGBB[AA] sequence.
+@end table
+
+Follow some examples:
+@example
+# draw a black box around the edge of the input image
+drawbox
+
+# draw a box with color red and an opacity of 50%
+drawbox=10:20:200:60:red@@0.5"
+@end example
+
+@section drawtext
+
+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 Libav with
+@code{--enable-libfreetype}.
+
+The filter also recognizes strftime() sequences in the provided text
+and expands them accordingly. Check the documentation of strftime().
+
+The filter accepts parameters as a list of @var{key}=@var{value} pairs,
+separated by ":".
+
+The description of the accepted parameters follows.
+
+@table @option
+
+@item fontfile
+The font file to be used for drawing text. Path must be included.
+This parameter is mandatory.
+
+@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 text and textfile are specified, an error is thrown.
+
+@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 fontsize
+The font size to be used for drawing text.
+The default value of @var{fontsize} is 16.
+
+@item fontcolor
+The color to be used for drawing fonts.
+Either a string (e.g. "red") or in 0xRRGGBB[AA] format
+(e.g. "0xff000033"), possibly followed by an alpha specifier.
+The default value of @var{fontcolor} is "black".
+
+@item boxcolor
+The color to be used for drawing box around text.
+Either a string (e.g. "yellow") or in 0xRRGGBB[AA] format
+(e.g. "0xff00ff"), possibly followed by an alpha specifier.
+The default value of @var{boxcolor} is "white".
+
+@item box
+Used to draw a box around text using background color.
+Value should be either 1 (enable) or 0 (disable).
+The default value of @var{box} is 0.
+
+@item shadowx, 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. Default value for both is "0".
+
+@item shadowcolor
+The color to be used for drawing a shadow behind the drawn text. It
+can be a color name (e.g. "yellow") or a string in the 0xRRGGBB[AA]
+form (e.g. "0xff00ff"), possibly followed by an alpha specifier.
+The default value of @var{shadowcolor} is "black".
+
+@item ft_load_flags
+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
+@item end table
+@end table
+
+Default value is "render".
+
+For more information consult the documentation for the FT_LOAD_*
+libfreetype flags.
+
+@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:
+@example
+drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text'"
+@end example
+
+will draw "Test Text" with font FreeSerif, using the default values
+for the optional parameters.
+
+The command:
+@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
+
+will 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%.
+
+Note that the double quotes are not necessary if spaces are not used
+within the parameter list.
+
+For more information about libfreetype, check:
+@url{http://www.freetype.org/}.
+
+@section fade
+
+Apply fade-in/out effect to input video.
+
+It accepts the parameters:
+@var{type}:@var{start_frame}:@var{nb_frames}
+
+@var{type} specifies if the effect type, can be either "in" for
+fade-in, or "out" for a fade-out effect.
+
+@var{start_frame} specifies the number of the start frame for starting
+to apply the fade effect.
+
+@var{nb_frames} specifies the number of frames 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 completely black.
+
+A few usage examples follow, usable too as test scenarios.
+@example
+# fade in first 30 frames of video
+fade=in:0:30
+
+# fade out last 45 frames of a 200-frame video
+fade=out:155:45
+
+# fade in first 25 frames and fade out last 25 frames of a 1000-frame video
+fade=in:0:25, fade=out:975:25
+
+# make first 5 frames black, then fade in from frame 5-24
+fade=in:5:20
+@end example
+
+@section fieldorder
+
+Transform the field order of the input video.
+
+It accepts one parameter which specifies the required field order that
+the input interlaced video will be transformed to. The parameter can
+assume one of the following values:
+
+@table @option
+@item 0 or bff
+output bottom field first
+@item 1 or tff
+output top field first
+@end table
+
+Default value is "tff".
+
+Transformation is achieved 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.
+
+This filter is very useful when converting to or from PAL DV material,
+which is bottom field first.
+
+For example:
+@example
+./avconv -i in.vob -vf "fieldorder=bff" out.dv
+@end example
+
+@section fifo
+
+Buffer input images and send them when they are requested.
+
+This filter is mainly useful when auto-inserted by the libavfilter
+framework.
+
+The filter does not take parameters.
+
+@section format
+
+Convert the input video to one of the specified pixel formats.
+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".
+
+Some examples follow:
+@example
+# convert the input video to the format "yuv420p"
+format=yuv420p
+
+# convert the input video to any of the formats in the list
+format=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
+
+Apply a frei0r effect to the input video.
+
+To enable compilation of this filter you need to install the frei0r
+header and configure Libav with --enable-frei0r.
+
+The filter supports the syntax:
+@example
+@var{filter_name}[@{:|=@}@var{param1}:@var{param2}:...:@var{paramN}]
+@end example
+
+@var{filter_name} is the name to the frei0r effect to load. If the
+environment variable @env{FREI0R_PATH} is defined, the frei0r effect
+is searched in each one of the directories specified by the colon
+separated list in @env{FREIOR_PATH}, otherwise in the standard frei0r
+paths, which are in this order: @file{HOME/.frei0r-1/lib/},
+@file{/usr/local/lib/frei0r-1/}, @file{/usr/lib/frei0r-1/}.
+
+@var{param1}, @var{param2}, ... , @var{paramN} specify the parameters
+for the frei0r effect.
+
+A frei0r effect parameter can be a boolean (whose values are specified
+with "y" and "n"), a double, a color (specified by the syntax
+@var{R}/@var{G}/@var{B}, @var{R}, @var{G}, and @var{B} being float
+numbers from 0.0 to 1.0) or by an @code{av_parse_color()} color
+description), a position (specified by the syntax @var{X}/@var{Y},
+@var{X} and @var{Y} being float numbers) and a string.
+
+The number and kind of parameters depend on the loaded effect. If an
+effect parameter is not specified the default value is set.
+
+Some examples follow:
+@example
+# apply the distort0r effect, set the first two double parameters
+frei0r=distort0r:0.5:0.01
+
+# apply the colordistance effect, takes a color as first parameter
+frei0r=colordistance:0.2/0.3/0.4
+frei0r=colordistance:violet
+frei0r=colordistance:0x112233
+
+# apply the perspective effect, specify the top left and top right
+# image positions
+frei0r=perspective:0.2/0.2:0.8/0.2
+@end example
+
+For more information see:
+@url{http://piksel.org/frei0r}
+
+@section gradfun
+
+Fix the banding artifacts that are sometimes introduced into nearly flat
+regions by truncation to 8bit colordepth.
+Interpolate the gradients that should go where the bands are, and
+dither them.
+
+This filter 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.
+
+The filter takes two optional parameters, separated by ':':
+@var{strength}:@var{radius}
+
+@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
+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
+radius makes for smoother gradients, but also prevents the filter from
+modifying the pixels near detailed regions. Acceptable values are
+8-32, default value is 16, out-of-range values will be clipped to the
+valid range.
+
+@example
+# default parameters
+gradfun=1.2:16
+
+# omitting radius
+gradfun=1.2
+@end example
+
+@section hflip
+
+Flip the input video horizontally.
+
+For example to horizontally flip the input video with @command{avconv}:
+@example
+avconv -i in.avi -vf "hflip" out.avi
+@end example
+
+@section hqdn3d
+
+High precision/quality 3d denoise filter. This filter aims to reduce
+image noise producing smooth images and making still images really
+still. It should enhance compressibility.
+
+It accepts the following optional parameters:
+@var{luma_spatial}:@var{chroma_spatial}:@var{luma_tmp}:@var{chroma_tmp}
+
+@table @option
+@item luma_spatial
+a non-negative float number which specifies spatial luma strength,
+defaults to 4.0
+
+@item chroma_spatial
+a non-negative float number which specifies spatial chroma strength,
+defaults to 3.0*@var{luma_spatial}/4.0
+
+@item luma_tmp
+a float number which specifies luma temporal strength, defaults to
+6.0*@var{luma_spatial}/4.0
+
+@item chroma_tmp
+a float number which specifies chroma temporal strength, defaults to
+@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.
+
+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".
+
+Some examples follow:
+@example
+# force libavfilter to use a format different from "yuv420p" for the
+# input to the vflip filter
+noformat=yuv420p,vflip
+
+# convert the input video to any of the formats not contained in the list
+noformat=yuv420p:yuv444p:yuv410p
+@end example
+
+@section null
+
+Pass the video source unchanged to the output.
+
+@section ocv
+
+Apply video transform using libopencv.
+
+To enable this filter install libopencv library and headers and
+configure Libav with --enable-libopencv.
+
+The filter takes the parameters: @var{filter_name}@{:=@}@var{filter_params}.
+
+@var{filter_name} is the name of the libopencv filter to apply.
+
+@var{filter_params} specifies the parameters to pass to the libopencv
+filter. If not specified the default values are assumed.
+
+Refer to the official libopencv documentation for more precise
+information:
+@url{http://opencv.willowgarage.com/documentation/c/image_filtering.html}
+
+Follows the list of supported libopencv filters.
+
+@anchor{dilate}
+@subsection dilate
+
+Dilate an image by using a specific structuring element.
+This filter 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, and
+can be one of the values "rect", "cross", "ellipse", "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.
+
+Follow some example:
+@example
+# use the default values
+ocv=dilate
+
+# dilate using a structuring element with a 5x5 cross, iterate two times
+ocv=dilate=5x5+2x2/cross:2
+
+# read the shape from the file diamond.shape, iterate two times
+# the file diamond.shape may contain a pattern of characters like this:
+# *
+# ***
+# *****
+# ***
+# *
+# the specified cols and rows are ignored (but not the anchor point coordinates)
+ocv=0x0+2x2/custom=diamond.shape:2
+@end example
+
+@subsection erode
+
+Erode an image by using a specific structuring element.
+This filter corresponds to the libopencv function @code{cvErode}.
+
+The filter 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 can be one of
+the following values: "blur", "blur_no_scale", "median", "gaussian",
+"bilateral". The default value is "gaussian".
+
+@var{param1}, @var{param2}, @var{param3}, and @var{param4} are
+parameters whose meanings depend on smooth type. @var{param1} and
+@var{param2} accept integer positive values or 0, @var{param3} and
+@var{param4} accept float 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 one output, the first input is the "main"
+video on which the second input is overlayed.
+
+It accepts the parameters: @var{x}:@var{y}.
+
+@var{x} is the x coordinate of the overlayed video on the main video,
+@var{y} is the y coordinate. The parameters are expressions containing
+the following parameters:
+
+@table @option
+@item main_w, main_h
+main input width and height
+
+@item W, H
+same as @var{main_w} and @var{main_h}
+
+@item overlay_w, overlay_h
+overlay input width and height
+
+@item w, h
+same as @var{overlay_w} and @var{overlay_h}
+@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 it does the example for
+the @var{movie} filter.
+
+Follow some examples:
+@example
+# draw the overlay at 10 pixels from the bottom right
+# corner of the main video.
+overlay=main_w-overlay_w-10:main_h-overlay_h-10
+
+# insert a transparent PNG logo in the bottom left corner of the input
+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):
+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 together more overlays but the efficiency of such
+approach is yet to be tested.
+
+@section pad
+
+Add paddings to the input image, and places the original input at the
+given coordinates @var{x}, @var{y}.
+
+It accepts the following parameters:
+@var{width}:@var{height}:@var{x}:@var{y}:@var{color}.
+
+The parameters @var{width}, @var{height}, @var{x}, and @var{y} are
+expressions containing the following constants:
+
+@table @option
+@item E, PI, PHI
+the corresponding mathematical approximated values for e
+(euler number), pi (greek PI), phi (golden ratio)
+
+@item in_w, in_h
+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 height, that is the size of the padded area as
+specified by the @var{width} and @var{height} expressions
+
+@item ow, oh
+same as @var{out_w} and @var{out_h}
+
+@item x, y
+x and y offsets as specified by the @var{x} and @var{y}
+expressions, or NAN if not yet specified
+
+@item a
+input display aspect ratio, same as @var{iw} / @var{ih}
+
+@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
+
+Follows the description of the accepted parameters.
+
+@table @option
+@item width, height
+
+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.
+
+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, y
+
+Specify the offsets where to place the input image in 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, it can be the name of a color
+(case insensitive match) or a 0xRRGGBB[AA] sequence.
+
+The default value of @var{color} is "black".
+
+@end table
+
+Some examples follow:
+
+@example
+# Add paddings with color "violet" to the input video. Output video
+# size is 640x480, the top-left corner of the input video is placed at
+# column 0, row 40.
+pad=640:480:0:40:violet
+
+# pad the input to get an output with dimensions increased bt 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"
+
+# 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"
+
+# pad the input to get a final w/h ratio of 16:9
+pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
+
+# double 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
+
+@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 scale
+
+Scale the input video to @var{width}:@var{height} and/or convert the image format.
+
+The parameters @var{width} and @var{height} are expressions containing
+the following constants:
+
+@table @option
+@item E, PI, PHI
+the corresponding mathematical approximated values for e
+(euler number), pi (greek PI), phi (golden ratio)
+
+@item in_w, in_h
+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 height
+
+@item ow, oh
+same as @var{out_w} and @var{out_h}
+
+@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.
+@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.
+
+If the value for @var{width} or @var{height} is 0, the respective input
+size is used for the output.
+
+If the value for @var{width} or @var{height} is -1, the scale filter will
+use, for the respective output size, a value that maintains the aspect
+ratio of the input image.
+
+The default value of @var{width} and @var{height} is 0.
+
+Some examples follow:
+@example
+# scale the input video to a size of 200x100.
+scale=200:100
+
+# scale the input to 2x
+scale=2*iw:2*ih
+# the above is the same as
+scale=2*in_w:2*in_h
+
+# scale the input to half size
+scale=iw/2:ih/2
+
+# increase the width, and set the height to the same size
+scale=3/2*iw:ow
+
+# seek for Greek harmony
+scale=iw:1/PHI*iw
+scale=ih*PHI:ih
+
+# increase the height, and set the width to 3/2 of the height
+scale=3/2*oh:3/5*ih
+
+# increase the size, but make the size a multiple of the chroma
+scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
+
+# increase the width to a maximum of 500 pixels, keep the same input aspect ratio
+scale='min(500\, iw*3/2):-1'
+@end example
+
+@section select
+Select frames to pass in output.
+
+It accepts in input an expression, which is evaluated for each input
+frame. If the expression is evaluated to a non-zero value, the frame
+is selected and passed to the output, otherwise it is discarded.
+
+The expression can contain the following constants:
+
+@table @option
+@item PI
+Greek PI
+
+@item PHI
+golden ratio
+
+@item E
+Euler number
+
+@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, NAN if undefined
+
+@item TB
+timebase of the input timestamps
+
+@item pts
+the PTS (Presentation TimeStamp) of the filtered video frame,
+expressed in @var{TB} units, NAN if undefined
+
+@item t
+the PTS (Presentation TimeStamp) of the filtered video frame,
+expressed in seconds, NAN if undefined
+
+@item prev_pts
+the PTS of the previously filtered video frame, NAN if undefined
+
+@item prev_selected_pts
+the PTS of the last previously filtered video frame, NAN if undefined
+
+@item prev_selected_t
+the PTS of the last previously selected video frame, NAN if undefined
+
+@item start_pts
+the PTS of the first video frame in the video, NAN if undefined
+
+@item start_t
+the time of the first video frame in the video, NAN if undefined
+
+@item pict_type
+the type of the filtered frame, 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
-Follow some examples:
-@example
-# crop the central input area with size 100x100
-crop=100:100
+@item interlace_type
+the frame interlace type, 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
-# crop the central input area with size 2/3 of the input video
-"crop=2/3*in_w:2/3*in_h"
+@item key
+1 if the filtered frame is a key-frame, 0 otherwise
-# crop the input video central square
-crop=in_h
+@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
-# 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
+The default value of the select expression is "1".
-# crop 10 pixels from the lefth and right borders, and 20 pixels from
-# the top and bottom borders
-"crop=in_w-2*10:in_h-2*20"
+Some examples follow:
-# keep only the bottom right quarter of the input image
-"crop=in_w/2:in_h/2:in_w/2:in_h/2"
+@example
+# select all frames in input
+select
-# crop height for getting Greek harmony
-"crop=in_w:1/PHI*in_w"
+# the above is the same as:
+select=1
-# 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)"
+# skip all frames:
+select=0
-# erratic camera effect depending on timestamp and position
-"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)"
+# select only I-frames
+select='eq(pict_type\,I)'
-# set x depending on the value of y
-"crop=in_w/2:in_h/2:y:10+10*sin(n/10)"
-@end example
+# select one frame every 100
+select='not(mod(n\,100))'
-@section fifo
+# select only frames contained in the 10-20 time interval
+select='gte(t\,10)*lte(t\,20)'
-Buffer input images and send them when they are requested.
+# select only I frames contained in the 10-20 time interval
+select='gte(t\,10)*lte(t\,20)*eq(pict_type\,I)'
-This filter is mainly useful when auto-inserted by the libavfilter
-framework.
+# select frames with a minimum distance of 10 seconds
+select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
+@end example
-The filter does not take parameters.
+@anchor{setdar}
+@section setdar
-@section format
+Set the Display Aspect Ratio for the filter output video.
-Convert the input video to one of the specified pixel formats.
-Libavfilter will try to pick one that is supported for the input to
-the next filter.
+This is done by changing the specified Sample (aka Pixel) Aspect
+Ratio, according to the following equation:
+@math{DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR}
-The filter accepts a list of pixel format names, separated by ":",
-for example "yuv420p:monow:rgb24".
+Keep in mind that this 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 following command:
+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".
+For example to change the display aspect ratio to 16:9, specify:
@example
-./ffmpeg -i in.avi -vf "format=yuv420p" out.avi
+setdar=16:9
+# the above is equivalent to
+setdar=1.77777
@end example
-will convert the input video to the format "yuv420p".
+See also the @ref{setsar} filter documentation.
-@section frei0r
+@section setpts
-Apply a frei0r effect to the input video.
+Change the PTS (presentation timestamp) of the input video frames.
-To enable compilation of this filter you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
+Accept in input an expression evaluated through the eval API, which
+can contain the following constants:
-The filter supports the syntax:
-@example
-@var{filter_name}:@var{param1}:@var{param2}:...:@var{paramN}
-@end example
+@table @option
+@item PTS
+the presentation timestamp in input
-@var{filter_name} is the name to the frei0r effect to load. If the
-environment variable @env{FREI0R_PATH} is defined, the frei0r effect
-is searched in each one of the directories specified by the colon
-separated list in @env{FREIOR_PATH}, otherwise in the standard frei0r
-paths, which are in this order: @file{HOME/.frei0r-1/lib/},
-@file{/usr/local/lib/frei0r-1/}, @file{/usr/lib/frei0r-1/}.
+@item PI
+Greek PI
-@var{param1}, @var{param2}, ... , @var{paramN} specify the parameters
-for the frei0r effect.
+@item PHI
+golden ratio
-A frei0r effect parameter can be a boolean (whose values are specified
-with "y" and "n"), a double, a color (specified by the syntax
-@var{R}/@var{G}/@var{B}, @var{R}, @var{G}, and @var{B} being float
-numbers from 0.0 to 1.0) or by an @code{av_parse_color()} color
-description), a position (specified by the syntax @var{X}/@var{Y},
-@var{X} and @var{Y} being float numbers) and a string.
+@item E
+Euler number
-The number and kind of parameters depend on the loaded effect. If an
-effect parameter is not specified the default value is set.
+@item N
+the count of the input frame, starting from 0.
-Some examples follow:
-@example
-# apply the distort0r effect, set the first two double parameters
-frei0r=distort0r:0.5:0.01
+@item STARTPTS
+the PTS of the first video frame
-# apply the colordistance effect, takes a color as first parameter
-frei0r=colordistance:0.2/0.3/0.4
-frei0r=colordistance:violet
-frei0r=colordistance:0x112233
+@item INTERLACED
+tell if the current frame is interlaced
-# apply the perspective effect, specify the top left and top right
-# image positions
-frei0r=perspective:0.2/0.2:0.8/0.2
-@end example
+@item POS
+original position in the file of the frame, or undefined if undefined
+for the current frame
-For more information see:
-@url{http://piksel.org/frei0r}
+@item PREV_INPTS
+previous input PTS
-@section hflip
+@item PREV_OUTPTS
+previous output PTS
-Flip the input video horizontally.
+@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:
-For example to horizontally flip the video in input with
-@file{ffmpeg}:
@example
-ffmpeg -i in.avi -vf "hflip" out.avi
-@end example
+# start counting PTS from zero
+setpts=PTS-STARTPTS
-@section noformat
+# fast motion
+setpts=0.5*PTS
-Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
+# slow motion
+setpts=2.0*PTS
-The filter accepts a list of pixel format names, separated by ":",
-for example "yuv420p:monow:rgb24".
+# fixed rate 25 fps
+setpts=N/(25*TB)
-The following command:
+# fixed rate 25 fps with some jitter
+setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
-@example
-./ffmpeg -i in.avi -vf "noformat=yuv420p, vflip" out.avi
+# generate timestamps from a "live source" and rebase onto the current timebase
+setpts='(RTCTIME - RTCSTART) / (TB * 1000000)"
@end example
-will make libavfilter use a format different from "yuv420p" for the
-input to the vflip filter.
+@anchor{setsar}
+@section setsar
-@section null
+Set the Sample (aka Pixel) Aspect Ratio for the filter output video.
-Pass the video source unchanged to the output.
+Note that as a consequence of the application of this filter, the
+output display aspect ratio will change according to the following
+equation:
+@math{DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR}
-@section ocv_smooth
+Keep in mind that the sample aspect ratio set by this filter may be
+changed by later filters in the filterchain, e.g. if another "setsar"
+or a "setdar" filter is applied.
-Apply smooth transform using libopencv.
+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".
-To enable this filter install libopencv library and headers and
-configure FFmpeg with --enable-libopencv.
+For example to change the sample aspect ratio to 10:11, specify:
+@example
+setsar=10:11
+@end example
-The filter accepts the following parameters:
-@var{type}:@var{param1}:@var{param2}:@var{param3}:@var{param4}.
+@section settb
-@var{type} is the type of smooth filter to apply, and can be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-"bilateral". The default value is "gaussian".
+Set the timebase to use for the output frames timestamps.
+It is mainly useful for testing timebase configuration.
-@var{param1}, @var{param2}, @var{param3}, and @var{param4} are
-parameters whose meanings depend on smooth type. @var{param1} and
-@var{param2} accept integer positive values or 0, @var{param3} and
-@var{param4} accept float values.
+It accepts in input an arithmetic expression representing a rational.
+The expression can contain the constants "PI", "E", "PHI", "AVTB" (the
+default timebase), and "intb" (the input timebase).
-The default value for @var{param1} is 3, the default value for the
-other parameters is 0.
+The default value for the input is "intb".
-These parameters correspond to the parameters assigned to the
-libopencv function @code{cvSmooth}. Refer to the official libopencv
-documentation for the exact meaning of the parameters:
-@url{http://opencv.willowgarage.com/documentation/c/image_filtering.html}
+Follow some examples.
-@section pad
+@example
+# set the timebase to 1/25
+settb=1/25
-Add paddings to the input image, and places the original input at the
-given coordinates @var{x}, @var{y}.
+# set the timebase to 1/10
+settb=0.1
-It accepts the following parameters:
-@var{width}:@var{height}:@var{x}:@var{y}:@var{color}.
+#set the timebase to 1001/1000
+settb=1+0.001
-Follows the description of the accepted parameters.
+#set the timebase to 2*intb
+settb=2*intb
-@table @option
-@item width, height
+#set the default timebase value
+settb=AVTB
+@end example
-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.
+@section showinfo
-The default value of @var{width} and @var{height} is 0.
+Show a line containing various information for each input video frame.
+The input video is not modified.
-@item x, y
+The shown line contains a sequence of key/value pairs of the form
+@var{key}:@var{value}.
-Specify the offsets where to place the input image in the padded area
-with respect to the top/left border of the output image.
+A description of each shown parameter follows:
-The default value of @var{x} and @var{y} is 0.
+@table @option
+@item n
+sequential number of the input frame, starting from 0
-@item color
+@item pts
+Presentation TimeStamp of the input frame, expressed as a number of
+time base units. The time base unit depends on the filter input pad.
-Specify the color of the padded area, it can be the name of a color
-(case insensitive match) or a 0xRRGGBB[AA] sequence.
+@item pts_time
+Presentation TimeStamp of the input frame, expressed as a number of
+seconds
-The default value of @var{color} is "black".
+@item pos
+position of the frame in the input stream, -1 if this information in
+unavailable and/or meaningless (for example in case of synthetic video)
-@end table
+@item fmt
+pixel format name
-@section pixdesctest
+@item sar
+sample aspect ratio of the input frame, expressed in the form
+@var{num}/@var{den}
-Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
+@item s
+size of the input frame, expressed in the form
+@var{width}x@var{height}
-For example:
-@example
-format=monow, pixdesctest
-@end example
+@item i
+interlaced mode ("P" for "progressive", "T" for top field first, "B"
+for bottom field first)
-can be used to test the monowhite pixel format descriptor definition.
+@item iskey
+1 if the frame is a key frame, 0 otherwise
-@section scale
+@item type
+picture type of the input frame ("I" for an I-frame, "P" for a
+P-frame, "B" for a B-frame, "?" for unknown type).
+Check also the documentation of the @code{AVPictureType} enum and of
+the @code{av_get_picture_type_char} function defined in
+@file{libavutil/avutil.h}.
-Scale the input video to @var{width}:@var{height} and/or convert the image format.
+@item checksum
+Adler-32 checksum of all the planes of the input frame
-For example the command:
+@item plane_checksum
+Adler-32 checksum of each plane of the input frame, expressed in the form
+"[@var{c0} @var{c1} @var{c2} @var{c3}]"
+@end table
-@example
-./ffmpeg -i in.avi -vf "scale=200:100" out.avi
-@end example
+@section split
-will scale the input video to a size of 200x100.
+Split input video into several identical outputs.
-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.
+The filter accepts a single parameter which specifies the number of outputs. If
+unspecified, it defaults to 2.
-If the value for @var{width} or @var{height} is 0, the respective input
-size is used for the output.
+For example
+@example
+avconv -i INPUT -filter_complex split=5 OUTPUT
+@end example
+will create 5 copies of the input video.
-If the value for @var{width} or @var{height} is -1, the scale filter will
-use, for the respective output size, a value that maintains the aspect
-ratio of the input image.
+@section transpose
-The default value of @var{width} and @var{height} is 0.
+Transpose rows with columns in the input video and optionally flip it.
-@section slicify
+It accepts a parameter representing an integer, which can assume the
+values:
-Pass the images of input video on to next video filter as multiple
-slices.
+@table @samp
+@item 0
+Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
+@example
+L.R L.l
+. . -> . .
+l.r R.r
+@end example
+@item 1
+Rotate by 90 degrees clockwise, that is:
@example
-./ffmpeg -i in.avi -vf "slicify=32" out.avi
+L.R l.L
+. . -> . .
+l.r r.R
@end example
-The filter accepts the slice height as parameter. If the parameter is
-not specified it will use the default value of 16.
+@item 2
+Rotate by 90 degrees counterclockwise, that is:
+@example
+L.R R.r
+. . -> . .
+l.r L.l
+@end example
-Adding this in the beginning of filter chains should make filtering
-faster due to better use of the memory cache.
+@item 3
+Rotate by 90 degrees clockwise and vertically flip, that is:
+@example
+L.R r.R
+. . -> . .
+l.r l.L
+@end example
+@end table
@section unsharp
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
+
+Deinterlace the input video ("yadif" means "yet another deinterlacing
+filter").
+
+It accepts the optional parameters: @var{mode}:@var{parity}:@var{auto}.
+
+@var{mode} specifies the interlacing mode to adopt, accepts one of the
+following values:
+
+@table @option
+@item 0
+output 1 frame for each frame
+@item 1
+output 1 frame for each field
+@item 2
+like 0 but skips spatial interlacing check
+@item 3
+like 1 but skips spatial interlacing check
+@end table
+
+Default value is 0.
+
+@var{parity} specifies the picture field parity assumed for the input
+interlaced video, accepts one of the following values:
+
+@table @option
+@item 0
+assume top field first
+@item 1
+assume bottom field first
+@item -1
+enable automatic detection
+@end table
+
+Default value is -1.
+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
+and only deinterlace frames marked as interlaced
+
+@table @option
+@item 0
+deinterlace all frames
+@item 1
+only deinterlace frames marked as interlaced
+@end table
+
+Default value is 0.
+
@c man end VIDEO FILTERS
@chapter Video Sources
through the interface defined in @file{libavfilter/vsrc_buffer.h}.
It accepts the following parameters:
-@var{width}:@var{height}:@var{pix_fmt_string}
+@var{width}:@var{height}:@var{pix_fmt_string}:@var{timebase_num}:@var{timebase_den}:@var{sample_aspect_ratio_num}:@var{sample_aspect_ratio.den}
-All the parameters need to be explicitely defined.
+All the parameters need to be explicitly defined.
Follows the list of the accepted parameters.
Specify the width and height of the buffered video frames.
@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 timebase_num, timebase_den
+Specify numerator and denomitor of the timebase assumed by the
+timestamps of the buffered frames.
+
+@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
+buffer=320:240:yuv410p:1:24:1:1
@end example
will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p". 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:
+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=320:240:6
+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
"color=red@@0.2:qcif:10 [color]; [in][color] overlay [out]"
@end example
+@section movie
+
+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),
+and @var{options} is an optional sequence of @var{key}=@var{value}
+pairs, separated by ":".
+
+The description of the accepted options follows.
+
+@table @option
+
+@item format_name, f
+Specifies the format assumed for the movie to read, and can be either
+the name of a container or an input device. If not specified the
+format is guessed from @var{movie_name} or by probing.
+
+@item seek_point, sp
+Specifies the seek point in seconds, the frames will be output
+starting from this seek point, the parameter is evaluated with
+@code{av_strtod} so the numerical value may be suffixed by an IS
+postfix. Default value is "0".
+
+@item stream_index, si
+Specifies the index of the video stream to read. If the value is -1,
+the best suited video stream will be automatically selected. Default
+value is "-1".
+
+@end table
+
+This filter allows to overlay a second video on top of main input of
+a filtergraph as shown in this graph:
+@example
+input -----------> deltapts0 --> overlay --> output
+ ^
+ |
+movie --> scale--> deltapts1 -------+
+@end example
+
+Some examples follow:
+@example
+# skip 3.2 seconds from the start of the avi file in.avi, and overlay it
+# on top of the input labelled as "in".
+movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [movie];
+[in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
+
+# read from a video4linux2 device, and overlay it on top of the input
+# labelled as "in"
+movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [movie];
+[in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
+
+@end example
+
@section nullsrc
Null video source, never return images. It is mainly useful as a
template and to be employed in analysis / debugging tools.
It accepts as optional parameter a string of the form
-@var{width}:@var{height}, where @var{width} and @var{height} specify the size of
-the configured source.
+@var{width}:@var{height}:@var{timebase}.
+
+@var{width} and @var{height} specify the size of the configured
+source. The default values of @var{width} and @var{height} are
+respectively 352 and 288 (corresponding to the CIF size format).
+
+@var{timebase} specifies an arithmetic expression representing a
+timebase. The expression can contain the constants "PI", "E", "PHI",
+"AVTB" (the default timebase), and defaults to the value "AVTB".
+
+@section frei0r_src
+
+Provide a frei0r source.
+
+To enable compilation of this filter you need to install the frei0r
+header and configure Libav with --enable-frei0r.
+
+The source supports the syntax:
+@example
+@var{size}:@var{rate}:@var{src_name}[@{=|:@}@var{param1}:@var{param2}:...:@var{paramN}]
+@end example
+
+@var{size} is the size of the video to generate, may be a string of the
+form @var{width}x@var{height} or a frame size abbreviation.
+@var{rate} is the rate of the video to generate, may be a string of
+the form @var{num}/@var{den} or a frame rate abbreviation.
+@var{src_name} is the name to the frei0r source to load. For more
+information regarding frei0r and how to set the parameters read the
+section @ref{frei0r} in the description of the video filters.
-The default values of @var{width} and @var{height} are respectively 352
-and 288 (corresponding to the CIF size format).
+Some examples follow:
+@example
+# generate a frei0r partik0l source with size 200x200 and framerate 10
+# which is overlayed on the overlay filter main input
+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
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