[alsa-devel] xine AC3 dropout problem - Please help!
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
On Fri, 27 Aug 2010, VDR User wrote:
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).
-32 means -EPIPE - underrun has occured. It means that xine does not deliver samples in time to the driver for some reason. Because mplayer works, it does not seem like a general ALSA issue. I would ask xine developers for further debugging of this issue (compare the audio write calls with the realtime clock).
Jaroslav
----- Jaroslav Kysela perex@perex.cz Linux Kernel Sound Maintainer ALSA Project, Red Hat, Inc.
On Fri, Aug 27, 2010 at 10:33 AM, Jaroslav Kysela perex@perex.cz wrote:
On Fri, 27 Aug 2010, VDR User wrote:
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).
-32 means -EPIPE - underrun has occured. It means that xine does not deliver samples in time to the driver for some reason. Because mplayer works, it does not seem like a general ALSA issue. I would ask xine developers for further debugging of this issue (compare the audio write calls with the realtime clock).
Jaroslav
Hi Jaroslav. Thanks for your reply. It seems I mistakeningly sent this to the alsa-dev mailing list instead of xine-dev for which it was intended. Sorry about that, but thanks for the comments!
Best regards, Derek
participants (2)
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Jaroslav Kysela
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VDR User