Ported from SoX.
+@section pan
+
+Mix channels with specific gain levels. The filter accepts the output
+channel layout followed by a set of channels definitions.
+
+The filter accepts parameters of the form:
+"@var{l}:@var{outdef}:@var{outdef}:..."
+
+@table @option
+@item l
+output channel layout or number of channels
+
+@item outdef
+output channel specification, of the form:
+"@var{out_name}=[@var{gain}*]@var{in_name}[+[@var{gain}*]@var{in_name}...]"
+
+@item out_name
+output channel to define, either a channel name (FL, FR, etc.) or a channel
+number (c0, c1, etc.)
+
+@item gain
+multiplicative coefficient for the channel, 1 leaving the volume unchanged
+
+@item in_name
+input channel to use, see out_name for details; it is not possible to mix
+named and numbered input channels
+@end table
+
+If the `=' in a channel specification is replaced by `<', then the gains for
+that specification will be renormalized so that the total is 1, thus
+avoiding clipping noise.
+
+For example, if you want to down-mix from stereo to mono, but with a bigger
+factor for the left channel:
+@example
+pan=1:c0=0.9*c0+0.1*c1
+@end example
+
+A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
+7-channels surround:
+@example
+pan=stereo: FL < FL + 0.5*FC + 0.6*BL + 0.6*SL : FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
+@end example
+
+Note that @file{ffmpeg} integrates a default down-mix (and up-mix) system
+that should be preferred (see "-ac" option) unless you have very specific
+needs.
+
@section volume
Adjust the input audio volume.
Apply fade-in/out effect to input video.
It accepts the parameters:
-@var{type}:@var{start_frame}:@var{nb_frames}
+@var{type}:@var{start_frame}:@var{nb_frames}[:@var{options}]
@var{type} specifies if the effect type, can be either "in" for
fade-in, or "out" for a fade-out effect.
will have the same intensity as the input video, at the end of the
fade-out transition the output video will be completely black.
+@var{options} is an optional sequence of @var{key}=@var{value} pairs,
+separated by ":". The description of the accepted options follows.
+
+@table @option
+
+@item type, t
+See @var{type}.
+
+@item start_frame, s
+See @var{start_frame}.
+
+@item nb_frames, n
+See @var{nb_frames}.
+
+@item alpha
+If set to 1, fade only alpha channel, if one exists on the input.
+Default value is 0.
+@end table
+
A few usage examples follow, usable too as test scenarios.
@example
# fade in first 30 frames of video
# make first 5 frames black, then fade in from frame 5-24
fade=in:5:20
+
+# fade in alpha over first 25 frames of video
+fade=in:0:25:alpha=1
@end example
@section fieldorder
For example:
@example
-./ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
+ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
@end example
@section fifo
slices.
@example
-./ffmpeg -i in.avi -vf "slicify=32" out.avi
+ffmpeg -i in.avi -vf "slicify=32" out.avi
@end example
The filter accepts the slice height as parameter. If the parameter is
unsharp=7:7:-2:7:7:-2
# Use the default values with @command{ffmpeg}
-./ffmpeg -i in.avi -vf "unsharp" out.mp4
+ffmpeg -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
+ffmpeg -i in.avi -vf "vflip" out.avi
@end example
@section yadif