Mov to mp4 won't work

[Klagar]

Hi !

I need to convert a mov to mp4 (pretty vague, I know) via FFmpeg... When I get that mp4, I can't play it with Quicktime. The thing is, someone needs the file to do something I don't really know with it, but as long as the video doesn't play in Quicktime, it's a sign it will be unuseable for its intended purpose. So long story short, I have to make this video work in Quicktime.

When I load it in quicktime, I get the error : -2002: a bad public movie atom was found in the movie.

I looked for what a movie atom is, and found some info. Apparently that's the sort of error that pops out when you're trying to play a movie that either is corrupted or has not done downloading. But since I started with a "healthy" local file and only passed it through FFmpeg, I wonder what was added to/deleted from the file that makes it readable or not.

There was a solution suggested somewhere on the web that implied modifying the id3 tags of the file, and it was supposed to work afterwards. So maybe it's got to do with certain tags ? I'd like to be able to achieve something using only FFmpeg. Cause for now, when we want to convert a mov to mp4, we first convert the mov to avi with TMPGEnc, and THEN convert the avi to mp4 ; and then it plays perfectly in Quicktime (or any other player)

Does anyone have an advice about how to arrange it, and not only curcumvent it ?

[Klagar]

I believe I found the problem, or at least part of it.
That would have been caused by the audio codec. The mov file had an AAC audio and I was converting it with a libmp3lame encoder. But by switching -acodec libmp3lame to -acodec copy in my command line, it seems to work fine.
I just need now to run some tests and make sure the audio quality is OK and that the file plays in all the major players it's expected to play in.

So I'll keep posting, for reference's sake, if I get any other issue. One might assume I circumvented the issue for the time being.