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author | Lou Logan <lou@lrcd.com> | 2017-02-13 15:26:43 -0900 |
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committer | Lou Logan <lou@lrcd.com> | 2017-02-13 15:26:43 -0900 |
commit | 1c049d5ffe08b3af36844cdbe7a5950879122b8b (patch) | |
tree | 90c7f2c97fb604c46c92a64162674a51288f8a86 /doc | |
parent | c1a5fca06f75cc0e7b9b2808fecaa0c1b424da50 (diff) | |
download | ffmpeg-streaming-1c049d5ffe08b3af36844cdbe7a5950879122b8b.zip ffmpeg-streaming-1c049d5ffe08b3af36844cdbe7a5950879122b8b.tar.gz |
doc/ffmpeg: document trailing "?" in map option
This feature was added in 2375a85c36c4941042e6ee58a31d6560bde91d37.
Signed-off-by: Lou Logan <lou@lrcd.com>
Diffstat (limited to 'doc')
-rw-r--r-- | doc/ffmpeg.texi | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi index 11b527d..8b08e22 100644 --- a/doc/ffmpeg.texi +++ b/doc/ffmpeg.texi @@ -871,7 +871,7 @@ Set the size of the canvas used to render subtitles. @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 @@ -887,6 +887,11 @@ the source for output stream 1, etc. 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. @@ -924,6 +929,13 @@ To map all the streams except the second audio, use negative mappings 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 |