Use fixed quality scale (VBR). The meaning of @var{q} is
codec-dependent.
+@anchor{filter_option}
@item -filter[:@var{stream_specifier}] @var{filter_graph} (@emph{output,per-stream})
+Create the filter graph specified by @var{filter_graph} and use it to
+filter the stream.
+
@var{filter_graph} is a description of the filter graph to apply to
-the stream. Use @code{-filters} to show all the available filters
-(including also sources and sinks).
+the stream, and must have a single input and a single output of the
+same type of the stream. In the filter graph, the input is associated
+to the label @code{in}, and the output to the label @code{out}. See
+the ffmpeg-filters manual for more information about the filtergraph
+syntax.
+
+See the @ref{filter_complex_option,,-filter_complex option} if you
+want to create filter graphs with multiple inputs and/or outputs.
-See also the @option{-filter_complex} option if you want to create filter graphs
-with multiple inputs and/or outputs.
@item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
Specify the preset for matching stream(s).
Set the ISO 639 language code (3 letters) of the current video stream.
@item -vf @var{filter_graph} (@emph{output})
-@var{filter_graph} is a description of the filter graph to apply to
-the input video.
-Use the option "-filters" to show all the available filters (including
-also sources and sinks). This is an alias for @code{-filter:v}.
+Create the filter graph specified by @var{filter_graph} and use it to
+filter the stream.
+This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter option}.
@end table
@section Advanced Video Options
@item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
Force key frames at the specified timestamps, more precisely at the first
frames after each specified time.
+If one of the times is "@code{chapters}[@var{delta}]", it is expanded into
+the time of the beginning of all chapters in the file, shifted by
+@var{delta}, expressed as a time in seconds.
This option can be useful to ensure that a seek point is present at a
chapter mark or any other designated place in the output file.
-The timestamps must be specified in ascending order.
+
+For example, to insert a key frame at 5 minutes, plus key frames 0.1 second
+before the beginning of every chapter:
+@example
+-force_key_frames 0:05:00,chapters-0.1
+@end example
@item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
When doing stream copy, copy also non-key frames found at the
@item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
Set the audio sample format. Use @code{-sample_fmts} to get a list
of supported sample formats.
+
@item -af @var{filter_graph} (@emph{output})
-@var{filter_graph} is a description of the filter graph to apply to
-the input audio.
-Use the option "-filters" to show all the available filters (including
-also sources and sinks). This is an alias for @code{-filter:a}.
+Create the filter graph specified by @var{filter_graph} and use it to
+filter the stream.
+
+This is an alias for @code{-filter:a}, see the @ref{filter_option,,-filter option}.
@end table
@section Advanced Audio options:
ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
@end example
+@anchor{filter_complex_option}
@item -filter_complex @var{filtergraph} (@emph{global})
Define a complex filter graph, i.e. one with arbitrary number of inputs and/or
outputs. For simple graphs -- those with one input and one output of the same
To generate 5 seconds of pure red video using lavfi @code{color} source:
@example
-ffmpeg -filter_complex 'color=red' -t 5 out.mkv
+ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
@end example
@end table