[pulseaudio-discuss] Stability of PulseAudio on Ubuntu 9.04?

[Jost-Philip Matysik]

Am Thu, 02 Jul 2009 16:20:37 +0100
schrieb Colin Guthrie <gmane at colin.guthr.ie>:

> 'Twas brillig, and Timothy J Massey at 02/07/09 16:30 did gyre and
> gimble:
> > Dan Chen <crimsunkg at yahoo.com> wrote on 07/02/2009 09:35:08 AM:
> > 
> >> Timothy J Massey <tmassey <at> obscorp.com> writes:
> >>> Basically, I cannot keep PA up and running under Ubuntu 9.04.
> >> The symptoms stem from Ubuntu issues _much_ more so than
> >> PulseAudio 
> > ones.
> >> Essentially, move to Karmic asap, because there's little momentum
> >> to put 2.6.31-git and PulseAudio 0.9.15 into Jaunty.
> > 
> > I did.  It has helped a fair amount (I can move sink-inputs without 
> > crashing), but it's still pretty flaky.  Crashing PulseAudio is
> > still pretty easy...
> 
> Get us some nice, ripe, juicy backtraces and we'll see what can be
> done :)
> 
> http://www.pulseaudio.org/wiki/Community#BugsPatchesTranslations
> 
> Col
> 

I use Pulseaudio in ubuntu jaunty (64bit), and I had quite some issues
with it at first, too. Here's my recipe for a rock solid system:

Mainly because of the new features and conveniance I do use the
pulseaudio-packages from the development branch of ubuntu (karmic), but
just for that! I just updated the system from the stable tree, then
changed the sources.list to point to karmic repositories, installed
pulseaudio 0.9.15, and then changed the sources.list back to jaunty.
Critics say this brakes packet management, but I haven't noticed any
side effects, yet.

As it turns out all of my problems went away when I tuned the buffering
parameters at the end of the daemon.conf for my hardware (trial and
error, start with something close to the defaults, if that doesn't work
use something way off and then work your way back) and reduced the
resampling quality!

Pulseaudios resamplers are very sophisticated, even the lower quality
ones produce reasonably good sound, and the high quailty settings are
extremely CPU-intensive and don't scale well across multiple cores!
Most of my crashes were caused by the CPU simply not keeping up with
processing the audio frames, so the streams went out of sync and the
whole thing fell apart.

Seriously, I tried the top 10 or so quality settings for upmixing
stereo to 7.1 and it simply isn't happening on my Core2Duo T9500 with
realtime priority.

I now use a lower resampling setting and Pulseaudio just works. Pretty
much the only way to crash it is to use module.combine with my 4
cheap soundcards on a lousy (=hot) day when the cards' timing crystals
are badly out of sync. It happens from time to time, but I can live with
that.

Also think about what sampling rates you really need your server to run
on. If you use cheap desktop speakers and mainly listen to mp3s ripped
from CD then there's not much point in forcing your server to resample
everything to 24bit/192KHz...

Hope that helps.

Jost