Comment 3 for bug 1087916

Raymond: Yes, I do suspect this is a problem with "glitch-free" PulseAudio output when applications ask for low latency, and it definitely happened with both FluidSynth and VLC on both 12.04 and 12.10.

On 12.10, I can only reproduce the problem in VLC using its PulseAudio output module, through which it requests "0.00 ms" latency - NOT using its ALSA output module set to "Playback/recording through the PulseAudio sound server". VLC was not misbehaving at the time Symptom_PulseAudioLog.txt was captured, because I had already switched it to the ALSA setting when I was running 12.04.

Here is a PulseAudio "-vvvv" log of this. The crackling noise stopped at about the time "alsa-sink.c: Underrun!" appeared following all the "memblock.c: Pool full" and "flist.c: pulsecore/memblockq.c: list_items flist is full (don't worry)" lines. This was about a minute after I started a video playing. (Unfortunately, this particular log file does not have timestamps, although the problem is easy to reproduce if necessary.)

Recording might have only been an issue in 12.04, which did not even seem to detect my input jacks correctly. Aside from the usual noise, I seem to have no problem with my mic input right now. So we should probably focus on the playback issue.