[pulseaudio-discuss] Problems with Pulseaudio and alsa A52 plugin

[Christian Leibig]

Hey again,

First of all: way to put a typo in the header...yay me. :P

Secondly: I have to make a quick correction.

0.9.10 is actually running fine with mmap=0 and stutters with mmap=1
0.9.13 crashes with mmap=0 and stutters with mmap=1

That's all for now,
Christian

Christian Leibig wrote:
> Hello folks,
>
> I have been using Pulseaudio for a while now. Since I only run a single
> digital output to my speaker system I found the chance of using
> Pulseaudio to mix all system audio and then pipe the result through the
> alsa a52 plugin intriguing. Originally following this manual [1] I
> managed to set up pulseaudio just fine.
>
> I also learned a lot about my Problem from a thread [2] on this mailing
> list.
>
> Now I have been running Pulseaudio 0.9.10 for a while and was trying to
> upgrade to...well, basically anything _above_ 0.9.10. The problems I#ll
> be describing are the same with 0.9.11, 0.9.12 and now even 0.9.13. Keep
> in mind that my setup is working (almost) perfectly in 0.9.10.
>
>
> My Setup:
> Gentoo 64-bit with 2.6.26 (and recently 2.6.27) kernel.
> Intel Q6600 with 4GB RAM
> Intel HD Audio Controller
>
>
> Configs:
>
>   
>>>> /etc/asound.conf:
>>>>         
> pcm.!default {
>     type pulse
> }
>
> ctl.!default {
>     type pulse
> }
>
> pcm.pulseaudio a52encode
>
> ctl.pulseaudio {
>     type hw
>     card 0
> }
>
> pcm.a52encode {
>     type a52
> }
>
>   
>>>> /etc/pulse/system.pa (Disabled module auto detect stuff and added the
>>>>         
> following two lines at the end):
> load-module module-alsa-sink device=pulseaudio rate=48000 channels=6
> sink_name=alsa_surround mmap=1
> set-default-sink alsa_surround
>
>
> The Problem:
> When using anything above Pulseaudio 0.9.10 I get stuttering sound and
> using the debug log level I can see the following (repeating a hundred
> times over and over) in my system logfile:
>
> pulseaudio[13279]: module-alsa-sink.c: Starting playback.
> pulseaudio[13279]: module-alsa-sink.c: snd_pcm_avail_update: Broken pipe
> pulseaudio[13279]: module-alsa-sink.c: snd_pcm_avail_update: Buffer
> underrun!
>
> Additional logspam suggests this A52 plugin setup:
> pulseaudio[13279]: alsa-util.c: snd_pcm_dump():
> pulseaudio[13279]: alsa-util.c: A52 Output Plugin
> pulseaudio[13279]: alsa-util.c: Its setup is:
> pulseaudio[13279]: alsa-util.c:   stream       : PLAYBACK
> pulseaudio[13279]: alsa-util.c:   access       : MMAP_INTERLEAVED
> pulseaudio[13279]: alsa-util.c:   format       : S16_LE
> pulseaudio[13279]: alsa-util.c:   subformat    : STD
> pulseaudio[13279]: alsa-util.c:   channels     : 6
> pulseaudio[13279]: alsa-util.c:   rate         : 48000
> pulseaudio[13279]: alsa-util.c:   exact rate   : 48000 (48000/1)
> pulseaudio[13279]: alsa-util.c:   msbits       : 16
> pulseaudio[13279]: alsa-util.c:   buffer_size  : 3072
> pulseaudio[13279]: alsa-util.c:   period_size  : 1536
> pulseaudio[13279]: alsa-util.c:   period_time  : 32000
> pulseaudio[13279]: alsa-util.c:   tstamp_mode  : NONE
> pulseaudio[13279]: alsa-util.c:   period_step  : 1
> pulseaudio[13279]: alsa-util.c:   avail_min    : 25345
> pulseaudio[13279]: alsa-util.c:   period_event : 0
> pulseaudio[13279]: alsa-util.c:   start_threshold  : -1
> pulseaudio[13279]: alsa-util.c:   stop_threshold   : -1
> pulseaudio[13279]: alsa-util.c:   silence_threshold: 0
> pulseaudio[13279]: alsa-util.c:   silence_size : 0
> pulseaudio[13279]: alsa-util.c:   boundary     : 6917529027641081856
>
>
> Interestingly enough, even with Pulseaudio 0.9.10 I get the following in
> my log, but sound works just fine:
> Oct 11 16:40:34 lq66 pulseaudio[24693]: module-alsa-sink.c: EAGAIN         
> Oct 11 16:40:34 lq66 pulseaudio[24693]: module-alsa-sink.c: Buffer underrun!
> Oct 11 16:40:34 lq66 pulseaudio[24693]: module-alsa-sink.c: EAGAIN         
> Oct 11 16:40:34 lq66 pulseaudio[24693]: module-alsa-sink.c: Buffer underrun!
>
>
> Now I am pretty stumped. I have tried various fragment counts and sizes
> (by adding the parameters to the module-alsa-sink line) but none of
> those settings made any difference. Even worse, I can't really confirm
> that they even stuck at all because the logspam from the A52 plugin
> doesn't change a bit. The only thing I can do to make it change is to
> change the module-alsa-sink mmap parameter to "0", which will change
> MMAP_INTERLEAVED to RW_INTERLEAVED and exactly double the buffer_size.
> If I use mmap=0 with 0.9.10 I get a similar result than using mmap=1
> with 0.9.11-0.9.13.
> I I try using mmap=0 with 0.9.13 pulseaudio never loads and I have to
> kill it using the -9 switch.
>
> This may be a bit much for a single post and I suspect it is still
> lacking in some regards. I probably left out a lot of vital information
> that are necessary to debug this problem and I'll be glad to add them as
> soon as anyone tells me what's needed. :)
>
> I really hope you guys can help me with this, I don't want ot be stuck
> with 0.9.10 forever.
>
> Thanks in advance,
> Christian
>
>
> [1] http://ubuntuforums.org/showthread.php?t=714712
> [2]
> https://tango.0pointer.de/pipermail/pulseaudio-discuss/2008-February/001420.html
>
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