Merge M4A files in Terminal
I have a couple of M4A (sound) files on a Mac that I want to combine into a single sound file. Can this be done with a Terminal command? Is there such a thing?
Answer
Yeah, ffmpeg doesn't work, contrary to what the internet echo chamber will tell you. At least not that way. It's incredible how many have to drool their wisdumb and waste everyone's time.
Here. Prove me wrong with a link, but this is what you want and this is the only place you'll see it. Tres simple.
ffmpeg -i file1.m4a -acodec copy file1.aac
ffmpeg -i file2.m4a -acodec copy file2.aac
cat file1.aac file2.aac >>filenew.aac
ffmpeg -i filenew.aac -acodec copy -bsf:a aac_adtstoasc filenew.m4a
I compiled my own ffmpeg for the extra libs, so I hope that that is one of the default ones. If not, it's definitely worth the hassle. I haven't been able to validate the above on a second system, but on my old Hardy Heron Ubuntu grunt system the joined file has all the right m4a meta data and tags and there is no change in audio quality.