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I am interested in using SoX as part of a transcoding workflow I'm building. I need to be able to downmix stereo audio streams to mono. More specifically, I need to be able to specify which channel to write into the output file. As best as I can tell, the syntax should be as follows:

sox infile.wav -c 1 outfile.wav avg -l

However, when I issue the command, I get this error:

sox: invalid option -- l
sox: SoX v14.3.2

sox FAIL sox: invalid option

Stumped. Any ideas?

EDIT: Here's the command that does what I want.

sox infile.wav outfile.wav remix 1
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up vote 1 down vote accepted

There's no valid -l option. You could try it with the option "remix" or "oops". Both are listed in the documentation

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Gah, duh. Sorry about the RTFM question, but thanks for the answer. – whlteXbread Mar 15 '12 at 19:58

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