[mythtvnz] MythFrontend freezing with audio issues

[Aaron Whitehouse]

Hello all!

Everyone was really helpful with my previous issues, so I am giving it
another go!

I have Mythbuntu Jaunty set up on an AMD 780G (Radeon 3200HD)
motherboard (with integrated sound). It has HDMI and S/PDIF sound, but I
just use the speaker-out to plug into the TV.

We have been suffering through occasional freezes during playback for
quite some time (it feels like it got a lot worse since the upgrade to
Jaunty from 8.10). Sometimes I can Ctrl+Alt right-arrow to another
screen and "killall mythfrontend.real", other times I can Ctrl+F1 and do
the same (though this sometimes takes a few minutes to come up) and
other times the system seems completely locked up and I have to hit the
reset button. We have issues about every third or so time we try to
watch a recording, so it is fairly frequent (given we watch all of our
TV, videos and DVDs through the system).

I have noticed that my mythfrontend.log files have a number of audio
issues mentioned, often just before I had to restart the machine:
2009-08-15 14:52:46.798 WriteAudio: buffer underrun
2009-08-15 14:55:36.319 WriteAudio: buffer underrun
Starting mythfrontend.real..

2009-08-16 12:37:19.928 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:19.929 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
[Above error repeats once per microsecond until here]
2009-08-16 12:37:20.464 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:20.466 Video timing method: USleep with busy wait
2009-08-16 12:37:20.467 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:20.468 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:20.468 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:20.469 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:20.469 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:20.469 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:20.470 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:20.470 NVP::AddAudioData():p1: Audio buffer overflow,
audio data lost!
2009-08-16 12:37:20.903 WriteAudio: buffer underrun
2009-08-16 12:37:22.068 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:23.669 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:25.270 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:26.871 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:28.472 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:30.073 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:31.674 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:33.275 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:34.876 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:36.477 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:38.078 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:39.680 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:41.281 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:42.882 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:44.483 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:46.084 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:47.686 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:49.287 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:50.888 NVP: Prebuffer wait timed out 10 times.
2009-08-16 12:37:52.495 NVP: Prebuffer wait timed out 10 times.
Starting mythfrontend.real..

2009-08-16 12:39:57.928 Opening ALSA audio device 'default'.
2009-08-16 12:39:57.947 ALSA, Warning: mmap not available, attempting to
fall back to slow writes.

I have quite a lot of:
2009-08-16 12:40:07.455 NVP: prebuffering pause

2009-08-16 13:18:24.291 Mixer unable to find control PCM
2009-08-16 13:22:16.202 DPMS Reactivated.
2009-08-16 13:22:16.529 WriteAudio: buffer underrun
2009-08-16 13:22:24.552 DPMS Deactivated
2009-08-16 13:22:31.491 Mixer unable to find control PCM

unknown chip id 0x9610, can't guess.

2009-08-08 13:41:39.290 Opening ALSA audio device 'default'.
I: caps.c: Limited capabilities successfully to CAP_SYS_NICE.
I: caps.c: Dropping root privileges.
I: caps.c: Limited capabilities successfully to CAP_SYS_NICE.
2009-08-08 13:41:40.758 ALSA, Warning: mmap not available, attempting to
fall back to slow writes.

2009-08-14 20:36:48.752 DPMS Reactivated.
2009-08-14 20:36:49.118 WriteAudio: buffer underrun
2009-08-14 20:38:02.879 DPMS Deactivated
2009-08-14 20:40:53.537 DPMS Reactivated.
2009-08-14 20:40:54.007 WriteAudio: buffer underrun
2009-08-14 20:41:19.720 DPMS Deactivated
Starting mythfrontend.real..

etc. etc.

I have Googled these to bits for hours and am still at a bit of a loss.
Most of the hits are people going unanswered.

I am using the -ati xorg (radeon) driver. I checked the settings
mentioned here:
http://www.mythtv.org/wiki/Prebuffering_pause#Audio_Issues
but they were all as directed.

I removed PulseAudio to get rid of a segmentation fault:
https://bugs.launchpad.net/bugs/414339
and hoped that it would fix this, but it didn't. An excerpt from my
mythfrontend.log is:
http://pastebin.com/f1c465489

Does anyone have any suggestions?

Thanks in advance for your help!

Aaron

--
FSF Associate Member