Converting files for iTunes

[dinkypumpkin]

On 24/07/2011 18:04, Arthur Dent wrote:
> I saw a posting from Jon Davies with a script "fixupm4a.sh" which seemed
> to be just what I am looking for. Unfortunately it seems to rely on
> mp4tags (which I have found comes with libmp4v2 on Fedora) and
> mp4creator which is just not available (that I can find) on Fedora.

That script doesn't do the actual conversion of AAC files.  It was 
written to deal with hardware that couldn't play the M4A files written 
by ffmpeg available at the time.  The script works around the problem by 
forcing a re-optimisation of the file. See Jon's explanation in the 
message to which the script is attached. I think the problem may have 
been corrected in ffmpeg shortly after.

The basic ffmpeg command to convert a file is:

ffmpeg -i x.aac -vn -acodec copy -absf aac_adtstoasc -y x.m4a

I believe we established that ffmpeg from the 0.6 branch produces files 
that don't work with iTunes.  If that's what you have, you'll probably 
need to find a more recent version.  The latest release version (0.8) 
works OK.

BTW, if it should prove necessary, the mp4file utility that is part of 
the mp4v2 distribution can replace mp4creator, at least for optimisation 
purposes.  I'm not a Fedoran, so I'm not sure which RPM you would find 
it lurking in.