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}.
+tools, and by the @code{avfilter_graph_parse()} 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
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 three lists of formats, separated by ":", in the form:
+"@var{sample_formats}:@var{channel_layouts}:@var{packing_formats}".
+
+Elements in each list are separated by "," which has to be escaped in the
+filtergraph specification.
+
+The special parameter "all", in place of a list of elements, signifies all
+supported formats.
+
+Some examples follow:
+@example
+aformat=u8\\,s16:mono:packed
+
+aformat=s16:mono\\,stereo:all
+@end example
+
@section anull
Pass the audio source unchanged to the output.
Below is a description of the currently available audio sinks.
+@section abuffersink
+
+Buffer audio frames, and make them available to the end of filter chain.
+
+This sink is mainly intended for programmatic use, in particular
+through the interface defined in @file{libavfilter/asink_abuffer.h}.
+
+It requires a pointer to a ABufferSinkContext structure, which defines the
+incoming buffers' format, to be passed as the opaque parameter to
+@code{avfilter_init_filter} for initialization.
+
@section anullsink
Null audio sink, do absolutely nothing with the input audio. It is
@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 heigth 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 be not 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
@item ow, oh
same as @var{out_w} and @var{out_h}
+@item a
+same as @var{iw} / @var{ih}
+
+@item sar
+input sample aspect ratio
+
+@item dar
+input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
+
+@item hsub, vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
@item n
the number of input frame, starting from 0
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.
The list of the currently supported filters follows:
@table @var
@item 2xsai
-@item blackframe
-@item boxblur
-@item cropdetect
@item decimate
-@item delogo
@item denoise3d
@item detc
@item dint
@item framestep
@item fspp
@item geq
-@item gradfun
@item harddup
@item hqdn3d
@item hue
@item qp
@item rectangle
@item remove-logo
-@item rgbtest
@item rotate
@item sab
@item screenshot
@item spp
@item swapuv
@item telecine
-@item test
@item tile
@item tinterlace
@item unsharp
x and y offsets as specified by the @var{x} and @var{y}
expressions, or NAN if not yet specified
-@item dar, a
-input display aspect ratio, same as @var{iw} / @var{ih}
+@item a
+same as @var{iw} / @var{ih}
@item sar
input sample aspect ratio
+@item dar
+input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
+
@item hsub, vsub
horizontal and vertical chroma subsample values. For example for the
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
# pad the input to get a final w/h ratio of 16:9
pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
+# for anamorphic video, in order to set the output display aspect ratio,
+# it is necessary to use sar in the expression, according to the relation:
+# (ih * X / ih) * sar = output_dar
+# X = output_dar / sar
+pad="ih*16/9/sar: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"
@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 a
+same as @var{iw} / @var{ih}
@item sar
input sample aspect ratio
+@item dar
+input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
+
@item hsub, vsub
horizontal and vertical chroma subsample values. For example for the
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
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
+@item chroma_amount
Set the chroma effect strength. It can be a float number between -2.0
and 5.0, default value is 0.0.
@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
@end example
+@section mptestsrc
+
+Generate various test patterns, as generated by the MPlayer test filter.
+
+The size of the generated video is fixed, and is 256x256.
+This source is useful in particular for testing encoding features.
+
+This source accepts an optional sequence of @var{key}=@var{value} pairs,
+separated by ":". The description of the accepted options follows.
+
+@table @option
+
+@item rate, r
+Specify the frame rate of the sourced video, as the number of frames
+generated per second. It has to be a string in the format
+@var{frame_rate_num}/@var{frame_rate_den}, an integer number, a float
+number or a valid video frame rate abbreviation. The default value is
+"25".
+
+@item duration, d
+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.
+
+@item test, t
+
+Set the number or the name of the test to perform. Supported tests are:
+@table @option
+@item dc_luma
+@item dc_chroma
+@item freq_luma
+@item freq_chroma
+@item amp_luma
+@item amp_chroma
+@item cbp
+@item mv
+@item ring1
+@item ring2
+@item all
+@end table
+
+Default value is "all", which will cycle through the list of all tests.
+@end table
+
+For example the following:
+@example
+testsrc=t=dc_luma
+@end example
+
+will generate a "dc_luma" test pattern.
+
@section nullsrc
Null video source, never return images. It is mainly useful as a
frei0r_src=200x200:10:partik0l=1234 [overlay]; [in][overlay] overlay
@end example
-@section testsrc
+@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.
-Generate a test video pattern, showing a color pattern, a scrolling
-gradient and a timestamp. This is mainly intended for testing
-purposes.
+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.
-It accepts an optional sequence of @var{key}=@var{value} pairs,
+Both sources accept an optional sequence of @var{key}=@var{value} pairs,
separated by ":". The description of the accepted options follows.
@table @option
projects / ffmpeg / blobdiff