the corresponding numeric value defined in @file{libavutil/samplefmt.h}.
@var{channel_layout} specifies the channel layout, and can be a string
-or the corresponding number value defined in @file{libavutil/chlayout.h}.
+or the corresponding number value defined in @file{libavutil/audioconvert.h}.
@var{packing_format} specifies the type of packing in output, can be one
of "planar" or "packed", or the corresponding numeric values "0" or "1".
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}.
+
+@end table
+
A few usage examples follow, usable too as test scenarios.
@example
# fade in first 30 frames of video