Dump video coding statistics to @file{vstats_HHMMSS.log}.
@item -vstats_file @var{file}
Dump video coding statistics to @var{file}.
+@item -vstats_version @var{file}
+Specifies which version of the vstats format to use. Default is 2.
+
+version = 1 :
+
+@code{frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s}
+
+version > 1:
+
+@code{out= %2d st= %2d frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s}
@item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
top=1/bottom=0/auto=-1 field first
@item -dc @var{precision}
@section Advanced options
@table @option
-@item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
+@item -map [-]@var{input_file_id}[:@var{stream_specifier}][?][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
Designate one or more input streams as a source for the output file. Each input
stream is identified by the input file index @var{input_file_id} and
A @code{-} character before the stream identifier creates a "negative" mapping.
It disables matching streams from already created mappings.
+A trailing @code{?} after the stream index will allow the map to be
+optional: if the map matches no streams the map will be ignored instead
+of failing. Note the map will still fail if an invalid input file index
+is used; such as if the map refers to a non-existant input.
+
An alternative @var{[linklabel]} form will map outputs from complex filter
graphs (see the @option{-filter_complex} option) to the output file.
@var{linklabel} must correspond to a defined output link label in the graph.
ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
@end example
+To map the video and audio streams from the first input, and using the
+trailing @code{?}, ignore the audio mapping if no audio streams exist in
+the first input:
+@example
+ffmpeg -i INPUT -map 0:v -map 0:a? OUTPUT
+@end example
+
To pick the English audio stream:
@example
ffmpeg -i INPUT -map 0:m:language:eng OUTPUT
The mapping is particularly useful for DVD transcoding
to get the desired audio language.
-NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
+NOTE: To see the supported input formats, use @code{ffmpeg -demuxers}.
@item
You can extract images from a video, or create a video from many images: