[alsa-devel] xine AC3 dropout problem - Please help!

VDR User user.vdr at gmail.com
Fri Aug 27 18:24:19 CEST 2010


Hi.  Xine seems to have a problem with ac3 audio dropping out
frequently, which ruins the ability to watch hdtv for example.  I have
made a sample which exhibits this problem, which plays just fine in
mplayer so I assume that means root causes such as a buggy system
scheduler can be ruled out.  The sample also plays fine on my main
Windows desktop as well.  Adjusting things such as
engine.buffers.audio_num_buffers in xine's config has no affect.  It
has been suggested that the problem may be xine not properly handling
a stream error.

If anyone can and is willing to take a look at this and hopefully
resolve the problem once and for all, that would be great.  The sample
is 20MB so it can't be attached to this post.  Until I can find a
better place to host the sample, I've temporarily uploaded it to:
http://rapidshare.com/files/415479559/xine_ac3_dropout_bug.tar.bz2

System details are:

debian testing
stable kernel 2.6.35.3 (quiet notsc clocksource=hpet)
gcc 4.4.4-8
alsa-base 1.0.23+dfsg-1
alsa-utils 1.0.23-2
xine-lib-1.2 hg r11577
xine-ui hg r3054
VDR-1.7.15
mplayer-nogui 2:1.0~rc3++svn20100804-0.0

I recently tried the notsc and clocksource=hpet kernel options, which
also had no affect.  I want to reiterate that the dropout problem only
occurs in xine.  The error I see in the xine log when the dropout
occurs is: pcm_hw.c: snd_pcm_hw_delay() SNDRV_PCM_IOCTL_DELAY failed
(-32).

Best regards,
Derek


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