[mythtv-users] TV Playback Quality Problem

[Peter Darley]

Folks,

     I get consistent poor quality tv playback on my new mythtv  
frontend.  These problems are twofold.  First, the quality is just  
crummy, with horizontal lines as if it was getting poor reception off  
the air.  The second is that there are a lot of decoding glitches,  
like areas of picture not updating when they should so there is a  
distorted picture.  I can play back the same recordings on my windows  
machine, and they don't show either the general poor quality, or the  
decoding distortion, so I believe it is really a playback problem.   
Also, I can play back divx videos (such as ripped dvds) on the  
mythbox and they come out very clean and sharp.  I'm wondering where  
I should start troubleshooting this?  The video card is an on-board  
SiS that has an mpeg2 decoder.  I'm wondering if maybe it's using the  
hardware decoder which may not be the best?  If so, is there a way to  
get it to not use the onboard decoder and decode in software as it is  
with the divx?

     Any suggestions would be appreciated!

Thanks,
Peter Darley