@anchor{Filtergraph syntax}
@section Filtergraph syntax
-A filtergraph has a textual representation, which is
-recognized by the @option{-filter}/@option{-vf} and @option{-filter_complex}
-options in @command{ffmpeg} and @option{-vf} in @command{ffplay}, and by the
-@code{avfilter_graph_parse()}/@code{avfilter_graph_parse2()} functions defined in
+A filtergraph has a textual representation, which is recognized by the
+@option{-filter}/@option{-vf}/@option{-af} and
+@option{-filter_complex} options in @command{ffmpeg} and
+@option{-vf}/@option{-af} in @command{ffplay}, and by the
+@code{avfilter_graph_parse_ptr()} function defined in
@file{libavfilter/avfilter.h}.
A filterchain consists of a sequence of connected filters, each one
output pad of split is linked to the second input pad of overlay,
which are both unlabelled.
+In a filter description, if the input label of the first filter is not
+specified, "in" is assumed; if the output label of the last filter is not
+specified, "out" is assumed.
+
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.
@end example
@end itemize
+@section eq
+Set brightness, contrast, saturation and approximate gamma adjustment.
+
+The filter accepts the following options:
+
+@table @option
+@item contrast
+Set the contrast value. It accepts a float value in range @code{-2.0} to
+@code{2.0}. The default value is @code{0.0}.
+
+@item brightness
+Set the brightness value. It accepts a float value in range @code{-1.0} to
+@code{1.0}. The default value is @code{0.0}.
+
+@item saturation
+Set the saturation value. It accepts a float value in range @code{0.0} to
+@code{3.0}. The default value is @code{1.0}.
+
+@item gamma
+Set the gamma value. It accepts a float value in range @code{0.1} to @code{10.0}.
+The default value is @code{1.0}.
+
+@item gamma_r
+Set the gamma value for red. It accepts a float value in range
+@code{0.1} to @code{10.0}. The default value is @code{1.0}.
+
+@item gamma_g
+Set the gamma value for green. It accepts a float value in range
+@code{0.1} to @code{10.0}. The default value is @code{1.0}.
+
+@item gamma_b
+Set the gamma value for blue. It accepts a float value in range
+@code{0.1} to @code{10.0}. The default value is @code{1.0}.
+
+@item gamma_weight
+Can be used to reduce the effect of a high gamma value on bright image areas,
+e.g. keep them from getting overamplified and just plain white. It accepts a
+float value in range @code{0.0} to @code{1.0}.A value of @code{0.0} turns the
+gamma correction all the way down while @code{1.0} leaves it at its full strength.
+Default is @code{1.0}.
+
+@end table
+
@section extractplanes
Extract color channel components from input video stream into
The list of the currently supported filters follows:
@table @var
-@item eq2
-@item eq
-@item softpulldown
@end table
The parameter syntax and behavior for the listed filters are the same
of the corresponding MPlayer filters. For detailed instructions check
the "VIDEO FILTERS" section in the MPlayer manual.
-@subsection Examples
-
-@itemize
-@item
-Adjust gamma, brightness, contrast:
-@example
-mp=eq2=1.0:2:0.5
-@end example
-@end itemize
-
See also mplayer(1), @url{http://www.mplayerhq.hu/}.
@section mpdecimate