[MEncoder-users] ac3 mistaken for mp3 in recent versions of MEncoder

[Reimar Döffinger]

On Thu, Apr 29, 2010 at 04:50:19PM -0500, Laine Lee wrote:
> On 4/29/10 2:55 PM, "Reimar Döffinger" <Reimar.Doeffinger at gmx.de> wrote:
> 
> > You are making a insurmountable mountain out of a rather trivial problem.
> 
> It's just a matter of accomplishment vs. aptitude (not *that* aptitude, my
> own). :) 

Actually it is a matter of assuming that we need something very specific.
Yes, sometimes we need that to reproduce a bug, however in that case just
"any file like that" would have been enough.
Unfortunately, your exporting app produced a completely different AC3 file
when you tried to make a short extract.

> Here are cut.mp4 and cut.ac3,
> obtained as you specified. The cut mp4 is useless as you noted. Thanks
> again.

The cut.ac3 is enough to reproduce, MPlayer can't even play it (that kind
of thing is a really good idea to test btw., it makes the description
much simpler and we can analyze the issue faster).
It seems FFmpeg does not recognize the file as a valid AC3 file (or
actually it misdetects it as MP3 - which I guess could be the fault
of how MPlayer uses it currently).
As a workaround you can just add
-audio-demuxer rawaudio -rawaudio format=0x2000
to your commandline.