'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 It's worth checking this to see if it's that area that's at fault. Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mageia Contributor [http://www.mageia.org/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/] ------------------------------------------------------------------------------ BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA The must-attend event for mobile developers. Connect with experts. Get tools for creating Super Apps. See the latest technologies. Sessions, hands-on labs, demos & much more. Register early & save! http://p.sf.net/sfu/rim-blackberry-1 _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
