----- Original Message ----- > ----- Original Message ----- > > 'Twas brillig, and Nasa at 07/08/11 21:26 did gyre and gimble: > > > Hi, > > > > > > I was hoping I could get some help troubleshooting some audio > > > quality issues I am running into. > > > Specifically, I am getting a lot of *pops/crackles* when I play > > > audio files. It shows up when I > > > move from 2-channel to 4/5 channel audio (via pauvcontrol) - I am > > > using a USB X-FI sound-card with > > > the Meego IVI. > > > > > > I have tried changing the resample method (going from ffmpeg to > > > high-quality) and setting tsched=0, > > > neither making any noticeable difference. > > > > > > The only things I saw in /var/log/messages that seemed relevant > > > was: > > > messages:Aug 6 16:59:26 localhost pulseaudio[570]: alsa-sink.c: > > > ALSA > > > woke us up to write new data to the device, but there was actually > > > nothing to write! > > > messages:Aug 6 16:59:26 localhost pulseaudio[570]: alsa-sink.c: > > > Most > > > likely this is a bug in the ALSA driver 'snd_usb_audio'. Please > > > report this issue to the ALSA developers. > > > messages:Aug 6 16:59:26 localhost pulseaudio[570]: alsa-sink.c: We > > > were woken up with POLLOUT set -- however a subsequent > > > snd_pcm_avail() returned 0 or another value < min_avail. > > > > > > And this was spout out of dmesg > > > [ 21.857184] ALSA sound/usb/mixer.c:2110: status interrupt: c0 00 > > > [ 21.897058] ALSA sound/usb/mixer.c:2110: status interrupt: c0 00 > > > [ 21.961062] ALSA sound/usb/mixer.c:2110: status interrupt: c0 00 > > > > > > I have already eliminated the speakers and the amp (played music > > > from a different source and > > > they sounded fine). > > > > > > Let me know what else I should post (I could record the sound, if > > > that would be useful). > > > > > > Thanks in advance, > > > > While this could be an issue in the alsa driver itself, can I ask if > > you're applying any volume changes to your streams or sink? > > > > There could be a problem with optimized paths for software volume > > adjustments. You can disable these optimisations via a special > > environment var: PULSE_NO_SIMD=1 > > Col, > > So I added > > export PULSE_NO_SIMD=1 > > into my .bashrc file and rebooted. From the terminal > "echo $PULSE_NO_SIMD" came back '1' -- however, that didn't > make any difference in the pops/crackles I am hearing :{ > > Nasa > > So, Is there anything else I can check, or should I place a bug report for ALSA? Nasa