[mythtv-users] Audio/Video Stutter on one particular HD channel.

[Josh]

Affected system is:
Motherboard: Asus P5N7A-VM
Onboard Video: Geforce 9300
CPU: Core2Quad Q6600
Sound: SB Audigy4 Value
1GB DDR2
40GB sata HD.

Running Gentoo Linux,
mythtv ~ # uname -a
Linux mythtv 2.6.27-gentoo-r7 #6 SMP PREEMPT Tue Feb 10 11:10:31 CST 2009
i686 Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz GenuineIntel GNU/Linux
Mythtv version 0.21-fixes
media-tv/mythtv-0.21_p19046  USE="aac alsa dvb dvd ieee1394 lirc mmx opengl
perl python xvmc (-altivec) -autostart -debug -directv -fftw -jack -lcd"
VIDEO_CARDS="nvidia" 0 kB

Audio is handled by Audigy4 value, through coaxial/spdif
It's a standalone frontend, backend is on another machine.

Apparently only one channel is affected, with the audio buffer underruns and
dropping video frames to resync with audio.
I have disabled audio by setting the audio device in mythfrontend to 'NULL',
video playback is silky smooth, no dropped frames at all.
Mabye it was a hardware issue, so I removed the Audigy4 and tried using
onboard audio analog to my TV speakers. That resulted in worse performance,
with nearly all channels stuttering occaisionally.

I've checked for conflicting IRQ's, my Audigy sound card is using IRQ 18 and
is not shared. Unsure about onboard, have not tested, it is disabled when
the Audigy is installed.
My 'mythfrontend -v playback' is located here:
http://rafb.net/p/mkLEhL42.html
I was playing back a recording from the affected channel while dumping the
logfile, so all the errors at the end are related.

A clip from the HD stream is hosted here:
http://www.megaupload.com/?d=WX0KIIFC - Keep in mind that after about 1-2
seconds, playback would stutter

Although I have virtually no proof to back this theory up, I belive the
issue is related to audio moreso than video.
I'm not sure what else to try.

ANY help is appreciated!
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