It doesn't look like the problem is in pulseaudio though. I have the very same problem (buffer underruns in alsa and the resulting stuttering / crackling), but the issue not only occurs when I use Pulseaudio.
It's a generic issue with all applications which access Alsa, although varying the size of the buffers in pulseaudio can reduce the interval of stutters. For me it's not the Wifi driver which is causing the issue, but (i think) something in the graphics driver since I get the stuttering whenever large bitmaps get drawn on screen. This seems to be highly dependent on the hardware and there appear to be multiple hardware configurations which can trigger the underruns in Alsa. I can e.g. trigger it reliably by switching the video renderer in VLC from GLX to Xvideo and back and it will start stuttering as soon as the Xserver is under load. Switching between Pulseaudio and Alsa (direct, PA suspended) as audio backend makes no difference at all, well except that the interval of the cracks is directly related to the buffer size used by the corresponding applications. What would be noteworthy, this issue is rather new for me. There appears to be some regression in the Alsa driver which makes it less tolerant towards long running, non-interruptible service routines from other drivers. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/1045771 Title: Underruns and stuttering Status in “pulseaudio” package in Ubuntu: Confirmed Bug description: When playing sound, be it in Clementine, in games via wine or in movies, I get stuttering. Attached is an example of log from clementine, running under pulseaudio -vvv Here's all the relevant info I can think of: lspci | grep Audio : 00:1b.0 Audio device: Intel Corporation Panther Point High Definition Audio Controller (rev 04) 01:00.1 Audio device: Advanced Micro Devices [AMD] nee ATI Turks HDMI Audio [Radeon HD 6000 Series] alsamixer : Chip: Realtek ALC269VC, Card: HDA Intel PCH I'm using an up-to-date Precise. Let me know if you need more info. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1045771/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
