[MPlayer-dev-eng] liba52 resample_altivec.c broken (severe glitches in audio) on ppc mac-mini

[Bas Hulsken]

Not sure if this is a known problem, I did a quick search but couldn't
find anything.

this is the problem:
I run mplayer (svn, current) on a mac mini g4 with fedora core 5 (also
tried 4). All is well, but playing a movie with an ac3 soundtrack causes
severe glitches in the sound if played back over alsa. On oss
(emulation) there are no glitches, but then the sound quality is
horrible (sounds like poor quality resampling).

all other sound is ok. The problem is in the altivec resampling routine of 
liba52. this file: resample_altivec.c. Disabling the use of this routine 
(with --disable-altivec, or with the patch I've attached) solves the 
problem, sound is perfectly smooth again.

The patch of course is not a real fix, it just uses much slower 
(resample_c.c) code. I couldn't find any obvious errors in 
resample_altivec.c, and my altivec knowledge is zero, so I'm afraid I wont 
be able to fix this.

Do other ppc users experience the same problem? Is it mac-mini specific? Can 
anybody with altivec understanding take a look at this piece of code (it 
looks simple enough, and it's only a few lines)?

if you need any more information, I can give it.

Thanks for any help,

best regards,
Bas

-------------- next part --------------
A non-text attachment was scrubbed...
Name: disableliba52altivecresampler.diff
Type: text/x-patch
Size: 693 bytes
Desc: not available
URL: <http://lists.mplayerhq.hu/pipermail/mplayer-dev-eng/attachments/20060715/ad88e90b/attachment.bin>