NTSC nVidia TV Out Image Unstable

[cwaltrs]

I've been working for weeks to get my tv-out

to work correctly. The Linux TV image is

very unstable in both desktop and full screen (DVD). The image

'rolls' about a third of the way down the screen so there's a 3 inch

black horizontal line on the screen and the bottom of the image is on

the top of the screen. It will occasionally roll back to normal and

then it goes awry again. It seems worse in full screen. Once in a

while, the whole screen will 'flail' around so I can't even locate

the mouse. Opening a terminal window usually stabilizes the image.

 

I'm running Mandriva 2006 with the latest nVidia driver. I've

attached my xorg.conf and my Xorg.0.log (verbose).

 

Here's a brief history of what I've tried...

 

I originally used a minimum of options when configuring xorg.conf:

Option "TVStandard" "NTSC-M"

Option "ConnectedMonitor" "TV"

Option "TVOutFormat" "COMPOSITE"

 

I figured the NTSC designation should be sufficient to properly

specify the TV output (sync, refresh, etc.) because it's built into

the ntsc standard. Unfortunately, the default specs xorg generated

were really for a monitor (30 KHZ horz sync), not a TV. The TV image

was unstable and jumpy and rolled down the screen. Plus the maximum

detected virtual screen 640x480 which was almost unusable for many

Linux apps.

 

So I did some research and manually set all the proper NTSC settings

in the xorg.conf. The logfile now looks perfect based on the NTSC

spec. The TV image still looks about the same... it 'rolls' about a

third of the way down the screen. It will occasionally roll back to

normal and then it goes awry again. It's worse in full screen DVD.

 

I guess I have two questions:

1. Based on my image problems, what parameters should I try to adjust? Is there a sane way to tweak the parameters without risking damage to the TV?

2. How can the sample xorg.conf files TV-out I've found specify a horz sync of 30-60KHz when this is clearly out of line with NTSC which are around FH = 15.734 KHz, FV = 59.940 Hz. Someone suggested I purchase a 100 ?Hz TV, and I don't understand how the TV specs can disagree with the NTSC broadcast spec.

 

Can someone please set me straight?

Thanks,

Charlie

 

 

Thanks,

Charlie

Xorg_1__1_.0.ntsc.txt

xorg_1__1_.conf.ntsc.txt