X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=doc%2Ffilters.texi;h=0654531858245d0e7a25be9e506606182fea7208;hb=db4234c5002fc0ac7ecae323874b97a4547ae0c3;hp=dbcd3911ae8ecc6cb7a13b659e1e5c3ad551fd67;hpb=e46a7fdc8748c286e391c1e7f2921d98a4486681;p=ffmpeg

diff --git a/doc/filters.texi b/doc/filters.texi
index dbcd3911ae8..06545318582 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -4366,40 +4366,72 @@ 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}.
+Set the contrast expression. The value must be a float value in range
+@code{-2.0} to @code{2.0}. The default value is "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}.
+Set the brightness expression. The value must be a float value in
+range @code{-1.0} to @code{1.0}. The default value is "0".
 
 @item saturation
-Set the saturation value. It accepts a float value in range @code{0.0} to
-@code{3.0}. The default value is @code{1.0}.
+Set the saturation expression. The value must be a float in
+range @code{0.0} to @code{3.0}. The default value is "1".
 
 @item gamma
-Set the gamma value. It accepts a float value in range @code{0.1} to @code{10.0}.
-The default value is @code{1.0}.
+Set the gamma expression. The value must be a float in range
+@code{0.1} to @code{10.0}.  The default value is "1".
 
 @item gamma_r
-Set the gamma value for red. It accepts a float value in range
-@code{0.1} to @code{10.0}. The default value is @code{1.0}.
+Set the gamma expression for red. The value must be a float in
+range @code{0.1} to @code{10.0}. The default value is "1".
 
 @item gamma_g
-Set the gamma value for green. It accepts a float value in range
-@code{0.1} to @code{10.0}. The default value is @code{1.0}.
+Set the gamma expression for green. The value must be a float in range
+@code{0.1} to @code{10.0}. The default value is "1".
 
 @item gamma_b
-Set the gamma value for blue. It accepts a float value in range
-@code{0.1} to @code{10.0}. The default value is @code{1.0}.
+Set the gamma expression for blue. The value must be a float in range
+@code{0.1} to @code{10.0}. The default value is "1".
 
 @item gamma_weight
-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}.
+Set the gamma weight expression. It can be used to reduce the effect
+of a high gamma value on bright image areas, e.g. keep them from
+getting overamplified and just plain white. The value must be a float
+in range @code{0.0} to @code{1.0}. A value of @code{0.0} turns the
+gamma correction all the way down while @code{1.0} leaves it at its
+full strength. Default is "1".
 
+@item eval
+Set when the expressions for brightness, contrast, saturation and
+gamma expressions are evaluated.
+
+It accepts the following values:
+@table @samp
+@item init
+only evaluate expressions once during the filter initialization or
+when a command is processed
+
+@item frame
+evaluate expressions for each incoming frame
+@end table
+
+Default value is @samp{init}.
+@end table
+
+The expressions accept the following parameters:
+@table @option
+@item n
+frame count of the input frame starting from 0
+
+@item pos
+byte position of the corresponding packet in the input file, NAN if
+unspecified
+
+@item r
+frame rate of the input video, NAN if the input frame rate is unknown
+
+@item t
+timestamp expressed in seconds, NAN if the input timestamp is unknown
 @end table
 
 @subsection Commands
@@ -11741,6 +11773,33 @@ aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=
 @end example
 @end itemize
 
+@section showwavespic
+
+Convert input audio to a single video frame, representing the samples waves.
+
+The filter accepts the following options:
+
+@table @option
+@item size, s
+Specify the video size for the output. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+Default value is @code{600x240}.
+
+@item split_channels
+Set if channels should be drawn separately or overlap. Default value is 0.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Extract a channel split representation of the wave form of a whole audio track
+in a 1024x800 picture using @command{ffmpeg}:
+@example
+ffmpeg -i audio.flac -lavfi showwavespic=split_channels=1:s=1024x800 waveform.png
+@end example
+@end itemize
+
 @section split, asplit
 
 Split input into several identical outputs.