[FFmpeg-user] map_channel without re-encoding

[Carl Eugen Hoyos]

2019-04-04 1:35 GMT+02:00, Elliott Balsley <elliottbalsley at gmail.com>:
> Is this possible?  I have a WAV file with a single track containing 8
> channels.  I want to convert it to an MOV with a 5.1 track and a stereo
> track.  The below command works, but if I use -c:a copy then it makes both
> output tracks 7.1.
>
> ffmpeg -I input.wav -vn -c:a pcm_s24le -map 0:0 -map 0:0 -map_channel
> 0.0.0:0.0.0 -map_channel 0.0.1:0.0.1 -map_channel 0.0.2:0.0.2 -map_channel
> 0.0.3:0.0.3 -map_channel 0.0.4:0.0.4 -map_channel 0.0.5:0.0.5 -map_channel
> 0.0.6:0.1.0 -map_channel 0.0.7:0.1.1 -y output.mov

I don't see how -map_channel could work without re-encoding
(theoretically) but note that for wav input and pcm output,
"re-encoding" and "remuxing" are mostly the same, both
effect- and performance-wise.

Carl Eugen