I have a BD Rip in an MKV which I am trying to remux with ffmpeg into a MOV container. So far am having some good success, but I am trying to enhance the process a little by including a 2 channel AAC mixdown into the output streams.

To achieve the conversion I am using:

ffmpeg.exe -i %1 -map 0:0 -map 0:1 -map 0:1 -c:v copy -c:a:0 ac3 -c:a:1 libfaac -b:a:1 192k -ac 2 %2

Problem with this version of the commandline is that the -ac 2 command drops the channel count of BOTH output audio streams down to 2.

What I am looking for is that audio stream 0 will be 6-channel ac3 and audio stream 1 will be 2-channel aac. Can I use a "stream definition" command to only change the number of output channels on stream 1 - rather than having it change both output streams?

Have looked in the doc and have not been able to locate a reference which refers to this.



  • Well, you seem to broadly know what you're doing with ffmpeg (so +1), so why not just try it out? -ac:a:0 6 -ac:a:1 2. Don't know if it will work, but there's only one way to find out. If you add -t 60 before the output, you can generate a 60-second clip just for testing purposes. – evilsoup Apr 1 '13 at 14:08

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