[MPlayer-dev-eng] twos audio in mov files

Roberto Togni r_togni at tiscali.it
Sun Dec 28 18:45:24 CET 2003

Hi all!

I'm working on some bugreports about twos audio in mov files that plays  
at double speed. The problem is caused by my patch to ad_pcm.c that  
adds these two lines:

 sh_audio->ds->ss_div= sh_audio->samplesize;
 sh_audio->ds->ss_mul= sh_audio->samplesize * sh_audio->channels;

I added them to fix another buggy file reported on -users (sgi.mov),  
and other samples i have (uploaded in directory twos on ftp, along with  
other files referred in this message, except qt_fast_audio.mov that is  
already in incoming).

One user (Alex F) uploaded qt_fast_audio.mov, that work without my  
patch and have double speed audio with it.

All the files have the same parameters: 2ch, 16 bit, twos audio; they  
have different rates (32000Hz for qt_fast..., 44100Hz for pet... and  
48000Hz  for sgi), but that sould not matter.
For every file ss_div and ss_mul are both 0 when init in ad_pcm is  

So i can't find any way to tell the difference among them at ad_pcm.
I think that the problem have to be solved at demuxer level, but i  
don't know  lot about mov demuxing.

xine plays them correctly, and they don't seem to do any trick in pcm  
decoder (qt_fast... tested audio only, my copy of xine does not have dv  

Any clue about it? Do you have other broken files?
If my patch breaks more files than it fixes, it could be wise to revert  
it until we fing a good solution.


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