diff options
Diffstat (limited to 'doc/ffmpeg.texi')
| -rw-r--r-- | doc/ffmpeg.texi | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi index 4616a4239e..de6d3f139a 100644 --- a/doc/ffmpeg.texi +++ b/doc/ffmpeg.texi @@ -996,7 +996,7 @@ such streams is attempted. Allow input streams with unknown type to be copied instead of failing if copying such streams is attempted. -@item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}] +@item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][?][:@var{output_file_id}.@var{stream_specifier}] Map an audio channel from a given input to an output. If @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will be mapped on all the audio streams. @@ -1005,6 +1005,10 @@ Using "-1" instead of @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted channel. +A trailing @code{?} will allow the map_channel to be +optional: if the map_channel matches no channel the map_channel will be ignored instead +of failing. + For example, assuming @var{INPUT} is a stereo audio file, you can switch the two audio channels with the following command: @example @@ -1052,6 +1056,13 @@ video stream), you can use the following command: ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv @end example +To map the first two audio channels from the first input, and using the +trailing @code{?}, ignore the audio channel mapping if the first input is +mono instead of stereo: +@example +ffmpeg -i INPUT -map_channel 0.0.0 -map_channel 0.0.1? OUTPUT +@end example + @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata}) Set metadata information of the next output file from @var{infile}. Note that those are file indices (zero-based), not filenames. |