[mythtv-users] playback quality problems on Nvidia 7NIF2

[mythtv-users.mythtv.org at tgice.com]

I've been using MythTV for a little over two years now and love it 
(except when I'm try to upgrade things on my Gentoo box -- things 
generally get a bit hairy).

I just did this recently to bring my 7NIF2 system up to the most recent 
software all around.  This included:

kernel 2.6.18
x11-drivers/nvidia-drivers-1.0.8776
media-tv/ivtv-0.8.2 (stable ivtv 0.8.0 gave me oddly crappy quality, 
0.8.2 seems fine)
x11-base/xorg-server-1.1.1-r1 (I think this is part of X.org 7.1)
MythTV 0.20 (or 0.20a, w/e the latest stable release is)

All but the MythTV install I have installed from Gentoo's portage. 
MythTV I compiled on my own.

My main problem (after plowing through a bunch of other more minor ones) 
is that video playback will get pretty crappy at times.  I'm virtually 
positive that it has nothing to do with IVTV now.  I also think (after 
playing some videos w/ mplayer in non-full screen mode) that the effect 
only happens when playing full screen video.

I get these little tearing lines on some of the lines of resolution 
where I can clearly see that some pixels that should be to the left are 
offset about 10 - 20% of the screen to the right.  Sometimes the effect 
is very small, and I think it gets worse with more activity on the 
system (last night I was compiling Myth plugins and it got really bad, 
e.g.).

I suspect it has something to do with the new nvidia driver I installed 
and/or some combination of that with XvMC, OpenGL or something along 
those lines, but have found now direct references to it the few places I 
checked out.

The only reason I think I may've enabled XvMC in a few places (MythTV 
compile and possible in my X.org config) is b/c I just got a pcHDTV card 
that I'm going to be playing with and I've heard that I may need that 
Nvidia acceleration to successfully play back HD content (I have an 
Athlon XP 2400+ w/ 512 MB of RAM (32MB currently shared to the onboard 
Nvidia).

Any suggestions to solve this?  I apologize if this is something that's 
well known and I missed it.  If there's a good FAQ somewhere on it, just 
point me in that direction.

Thanks,

jl