[FFmpeg-user] Handling video with four-channels of audio

[Karl E. Fitzke]

I've just started using ffmpeg.


Common here are VHS tapes with two stereo sets of audio that and we capture to 10-bit YUV and ffmpeg recognizes as four mono channels in one stream.


I'd like to store these masters as two streams of two-channel audio and generate mpeg4, prores, and msmpeg4v2 derivatives; with aac, aac, and mp3 audio for each of those respectively.


Can I do that with two streams of audio for all cases above?  Any reason I shouldn't bother doing so?


Assuming I should reformat the audio, any advice how?


I've successfully experimented with extracting the four channels of audio, reconstructing two streams of two-channel audio from that, and then replacing the video's original audio with the new audio streams.   But I wonder if there is a one command line solution?


Thanks in advance for any advice power users might provide.

Karl Fitzke
Audio/Visual Specialist
B76 Kroch Library
Ithaca, NY 14853

607-255-5521
karl.fitzke at cornell.edu