Here's my situation. . . I currently have a MythTV box (KnoppMyth R5B7) with a PVR350 card installed with TVout working - it does freeze at times, though. I am getting a new settop case and I'm thinking about rebuilding with some different components. I have an Asus AGP card with SVideo out laying around. I'm wondering if I can use this TVout rather than my PVR350's TVout?; being that MythTV freezes, which seems to be attributed to the ivtv driver. Will MythTV see my SVideo for the TVout functionality? I'm curious how this could work? I've read a lot about getting NVidia card's TVout working, but I'm curious if any graphics card will work for TVout (and how)? Thanks.

Yes it will, though you will have to edit your XF86Conf-4 file to reflect that Myth is supposed to be using the S-Video out, you are going to a CRT (or whatever screen), what your TV standard is, and your modeline.
As you have had to tweak it for your PVR350, I guess you know what to do. Though read the stuff on the wiki about setting it up if unsure.

Oh, it also depends on what type of graphics card you have. The older AGP cards such as MX400 don't do wide screen easily, whereas newer ones do. As long is it's not right at the bleeding edge u should be fine.

I put up a howto on recompiling your kernel.. I had problems with freezes with the pvr350
but after a recompile to turn off SMP it cleared up the problem. BTW -- its does not matter
if your machine is just a single cpu, the SMP kernel code seems to cause problems with
certian MB's that seem to manifest as IvTV problems..

http://mysettopbox.tv/phpBB2/viewtopic.php?t=9218

It might be something to try..