>> How can I tell (from a script) if some *.m4a file is using the AAC codec
>> or the ALAC codec?
> One possibility is to use ffmpeg -i filename and then parse the
> output. (Grepping for the strings used in each codec should give
> the answer.)
Indeed, that did the trick: the stderr either include "Audio: alac" or
"Audio: aac".
Thank you,
Stefan