[mythtv-users] TV Playback Quality Problem

[MythTV]

<SNIP>

     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?

</SNIP>

Are the horizontal lines a result of not deinterlacing the playback?  If you
haven't already, walk through the setup menu to TV to playback (I can't
remember the menu path).  One the 1st screen you can set deinterlacing on
and select the algorithm.  

Good luck,
Todd