[mythtv-users] How I got great quality TV-out on my nVidia MX4000

[Cory Papenfuss]

> Oh, me three.  I would love nothing more than to be done with all of
> this "choose the right video card for TV-Out magic" and be able to use
> any old video card that has any number of other features I may want (in
> reality any video card that can scale horizontally would suffice for
> me).
>
 	Ah... if only it were that easy.  Turned out to be a major PITA to 
find a card that would do it at the time.  One needs Xv, so it's gotta be 
fairly new (as in 5 years old or less).  Trouble is, lots of cards didn't 
do interlacing being that "new."  If it's old enough to do interlacing 
(e.g. Matrox Millenium), it doesn't do Xv.  Also, the ATI driver had a bug 
in the Xv with interlaced video for the longest time.  Dunno if that's 
been fixed.

 	NVidia seems to work OK now, although they have some modeline 
restrictions.  IIRC the modeline I'd like to use calls for 14.318MHz 
dotclock, and a total of 910 dots per line.  910 is no divisible by 8 so 
NVidia driver barfs.  I bumped it up to 912, (and the dotclock up to 
14.350MHz to compensate), and it was good.  You need to be careful though, 
since the dotclock might round/truncate what you want to something close, 
but not the same.  Doesn't sound like a big deal, but when I put in the 
frequency multiplier, it'll be using the HSYNC to generate the color 
subcarrier.  You'll want that to be pretty accurate, IMO.

 	Ah, hardware... it's what I was meant to do... :)

-Cory

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* Cory Papenfuss                                                        *
* Electrical Engineering candidate Ph.D. graduate student               *
* Virginia Polytechnic Institute and State University                   *
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