[mythtv-users] How do I center the image on the TV screen?

Mark Goldberg marklgoldberg at gmail.com
Thu Sep 20 19:05:44 UTC 2007

Craig wrote:

>Thanks all, for the advice, however...
>xvidtune *always* reported that the mode was unsupported, even the
>functioning mode.

I have the same motherboard, and the almost latest Nvidia Driver. and
can confirm this. Even if you can get an explicit modeline working
(which I could not using the built in Nvidia TV encoder to drive S
Video or Component Out) you get the same error. You can, however, see
what xvidtune would do and go back and edit the modeline, restart X
and see how it works. Using the TV out, I think it only will use an
internal set of modes compatible with the TV encoder.

>Worse, it seems that the modelines I've tried from the wiki don't get
>recognized. I had to read between the lines and guess that the first
>parameter in the modeline is a "label" that is used in the mode statement to
>add the settings to the list of supported modes. Also, suggested modes like
>"720x480_60" were silently ignored while "720x480" would be supported. With
>*no* mode record, I got modes from 640x480 and down to something like
>320x240. The TV will work with settings up to at least 1024x768, but text
>is nigh unreadable.

I can confirm this also. 720x480 worked the best for me. You have to
tell it the size of the screen explicitly in xorg.conf or the fonts
are too small and the aspect ratios are not right.

>In any case, the display is offset to the right and down on the screen.
>Still. I can use nvidia-settings to overscan, but then part of the picture
>would be off the right-hand side of the screen.
>I haven't had time to investigate and I'm getting tired of messing with it,
>but I seem to recall seeing something about the xorg.conf settings and
>TV-out to the effect that having setting(s) that specify TV-out cause modes
>and/or modelines (and maybe more) to be ignored.

Yep, seems to be true, although you could try the list of
ModeValidation options.
I set it up with a 50 inch 1080p plasma using explicit modelines and a
DVI to HDMI cable and had to use them because this motherboard
apparently does not get the EDID info correctly, Then it works very
well, as long as you use one mode for everything.

In short, with a TV out, I lived with a black bar to the right and
vertical interval pulses at the top.

Nvidia has a new driver just out. You might try it. It says it fixes
lots of stuff.


More information about the mythtv-users mailing list