Red Hat Bugzilla – Bug 417681
Alsa game sound is choppy when running through pulseaudio
Last modified: 2008-06-13 20:13:08 EDT
Description of problem:
Any games which provide sound through alsa end up being choppy when run through
pulseaudio. Using ppracer as an example, the sound is choppy no matter what
frequency I use, but if it's set to 8-bit (u8) rather than 16-bit (s16le) sound,
it's no longer choppy. Note that paman shows that ppracer *is* coming through
pulseaudio, so I believe alsa-plugins-pulseaudio is installed correctly.
aplay /usr/share/sounds/shutdown1.wav works perfectly and any games using esd
(i.e. bzflag) work perfectly as well.
I am running pulseaudio as a system-wide daemon with high priority.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Set up pulseaudio to run as system-wide daemon (with high priority)
2. Start ppracer (or nexuiz or any other game that uses alsa)
Beautifully rendered music to enhance the experience of shooting my friend in
the back in Nexuiz. :)
Rebuilt pulseaudio in devel for F8 today and problem still persists. I've
straced open files in both single-user and system-wide pulseaudio startups,
diffed them, and there don't seem to be any permissions differences (I
originally wondered whether pulseaudio was being blocked from accessing certain
/dev/snd files under the pulse user, but not under the regular user).
Pulseaudio still gives perfect sound under single-user, but choppy sound after a
few seconds of system-wide.
Sorry, I've just realized that both ppracer and nexuiz are SDL programs and use
ESD rather than alsa to connect to pulseaudio. Not sure if that will help in
diagnosing the problem.
And looking back at the original bug report, that means that there's something
unusual about bzflag (maybe the fact that it has no music) that keeps me from
hitting the same problem with it.
We now have native PA support in SDL, the problem should be gone.
Also, I don't really support the system mode of PA. It's available only for very
specific purposes (thin clients...)