[mythtv-users] A/V sync issue DVB

[Haakon Innerdal]

Hi, 

I've tried to investigate this for a bit, but I'm stuck, if someone has 
some advise, I'll be very grateful.

Problem: In MythTV, Audio/Video from DVB tuner (Live/Recordings) are 
shifting over time. A/V sync from Analog tuners are perfect.

Setup:

Analog tuners: Hauppauge pvr 350 + Hauppauge pvr 150, ivtv driver
DVB-C Tuner: Terratec Synergy DVB-C (Philips CU1216 DVB-C, TDA10023 
frontend), latest mantis driver http://jusst.de/hg/mantis/rev/620b21a72884

gentoo linux running mythtv-0.21_p16867, xvmc, 1280x720 on a GeForce FX 5700LE
Abit KD7A, AMD Athlon XP 2500+, 1G mem

a source of the problem may be the system beeing to slow, or signal may 
not good enough, (average 90% signal reported in mythtv on dvb), or some 
problems with the mantis driver, because I get artifacts in the sound 
and video stream from the DVB card now and then. (also from the analog 
tuners)

Playing back a DVB sourced from the Terratec, directly, or indirect with 
mplayer, the A/V sync is good, but playing it in mythtv, the sound and 
video get badly out of sync over time. However, when skipping the video 
back or forth, it gets in sync again. This doesnt happen with streams from 
the analog tuners.

It seems that since mplayer is keeping up with sync, I suspect MythTV has 
trouble with keyframes from my DVB-source, or that the Terratec (or 
driver) is producing a bad stream that only mplayer can cope with. 

Any suggestions on how to work this out?

Kind Regards,
Haakon Innerdal