[MPlayer-users] Problem with Windows Media audio

[Vladimir Mosgalin]

Hi Rich Felker!

 On 2005.06.15 at 19:51:11 -0400, Rich Felker wrote next:

> > >   Thanks a lot, I tried -afm dmo, works perfectly! I don't think I'd run
> > >   across that one yet. :)
> > 
> > Well, next times you experience problems with wmv1/2 codecs, try
> > -vfm dmo ;) It helps even more often than with wma. You'll lose nice
> > postprocessing, though, but that's much better than watching as your
> > video is falling apart (and what the hell are those j-frames, does
> > anyone know?).
> > 
> > But afm = dmo has no drawbacks, that's why I suggested to append it to
> > config file and forget about this problem.
> 
> No drawbacks?? Won't it cause windows dll crap to get loaded for many
> formats that are playable with free decoders, resulting in worse
> performance if nothing else..?

Worse performance for audio decoding? No, not really. Besides, (AFAIR it
I heard it on this list), dmo codecs are heavily optimized and they
quite fast. I checked it now, ffmpeg audio decoder uses 0.3-0.4% cpu on
wma2 files I tested. acm decoder uses 0.4-0.5% cpu. dmo one - 0.5-0.6%.

More real tests showed that dmo is actually faster than acm: decoding
with "-ao pcm -quiet" took 1:15-1:16 for ffmpeg, 1:50-1:55 for acm and
1.20-1.24 for dmo. So I'd say dmo has exactly the same speed as ffmpeg,
and no problems with audio files whatsoever.

And when I turn on 44k->48k resampling, overall decoding time jumps to
11.83.. so even not so optimized acm codec gives exactly the same speed
in that case.

I checked only wma2, don't have audio-only wma1 files on my system.


I understand that there is reason behind selecting ffmpeg codecs by
default, so users would test it and report errors so they could be
fixed, but in this case, problem with some wma files hasn't been fixed
for year or maybe two. wmv decoder is even worse and breaks on quite an
amount of files (again, exactly the same problems as a long time ago,
though it started to work a little better several months ago), so I
suggest all my friends not to use ffmpeg for decoding wma and wmv and
don't feel guilty about this...

-- 

Vladimir