[mythtv-users] Horizontal line flicker effect

[Roger Fleig]

I have a shuttle SN41G2:
Athlon 2500+
nForce2
VGA : Geforce4 MX, 128 MB VGA share memory
Audio : Realtek ALC650 6 Ch, Support Digital SPDIF Output
IDE interface : ATA-133
Hauppage PVR 250
WD 120G HD w/8 Meg Buffer
TV out is SVIDEO

I have myth up and running but there is a very noticeable flickering affect 
whenever there is a lot of motion on the screen.  It is usually localized to 
the moving object (person, car, etc...)  I don't have the vocabulary for 
what this is called in vid-speak (moire maybe?)  It's not on the entire 
picture, just the object that is moving.  It is bad enough to prevent me 
from using Myth currently.  I don't believe it has anything to do with myth 
per se, but rather linux, but I figure someone on this list may have more 
ideas on how to troubleshoot this.

I have a dual-boot winxp system and when I use the software that came with 
my pvr250 on windows (wintv2000 or something) I don't see these weird 
effects on moving objects.  This makes me think that the problem is 
software, probably my configuration, hopefully not the drivers.

I have tried running X at 800x600 and 640x480, and recording tv in myth at 
720x480 down to 480x480.  But the problem remains and frankly I don't 
understand the relationships between the X server resolution and the capture 
resolution and the conversion from vga to svideo.  In fact, I believe that I 
can still see this "horizontal-flicker-effect" even when watching video on 
my VGA monitor (but it is more difficult to observe and it might be my eyes 
after debugging this for two days.)

One thing to note is that I ripped a dvd and when I play it in myth I do not 
observe these effects.  It's played with gmplayer.  Same with straight dvd 
playback.  I don't see the flicker-effect on the tv with these either.  This 
plus the high quality of video playback on windows makes me think I can 
config my way around it.

Any ideas of where I can troubleshoot this is much appreciated.