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.

** Attachment added: "PulseAudioLog_VLC.txt"
   
https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1087916/+attachment/3454560/+files/PulseAudioLog_VLC.txt

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1087916

Title:
  [GA-MA770T-UD3P, Realtek ALC888] Distorted crackling noise when using
  FluidSynth

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1087916/+subscriptions

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to