I’ve spent 2 days now reasearching this and all the info I’ve found doesn’t work. If I do this simple command:
ffmpeg -i test.mp3 -y -vn -c:a alac /storage/test.m4a
it copies the standard tags. The -vn is to disable copying album art, I’ve given up on that. It’s easier to just separately use AtomicParsley to handle it because some of the album art isn’t height divisble by 2.
Problem is, I have extra custom tags that I need as well. Not necessarily for this particular track, but for all the vinyl I spent 2 months archiving. I’ve tried using the -movflags use_metadata_tags option but that didn’t do anything. In fact, it completely prevented the copying of any metadata whatsoever. Here’s the command I tried:
ffmpeg -i test.mp3 -y -movflags use_metadata_tags -vn -c:a alac /storage/test.m4a
On my Windows machine, if I use Foobar2000 and convert the same file to m4a, it copies ALL metadata, 100% to the resultant m4a file. Sadly, I need to do this from a linux command line, as part of an automation process. Both commands I’ve tried show output metadata equivalent to the input (sans cover art), so I’m not sure what that’s about. In case it helps, here’s the full screen output when I use that latter command with the -movflags tag. I’m going to use a pastebin link so as to not clutter this post with the verbose output.
I’ve tried -map_metadata 0 as well, same results, but that’s to be expected as from what I’ve read that just copies the global/standard tags. This must be possible, otherwise I have no idea how foobar2000 would be able to do it. I’d love to just use that, but alas, as stated, I have to do this on Linux command line for this particular situation.