[mythtv-users] Configuring XFree86 for TV out

[Jay R. Ashworth]

On Sat, Aug 14, 2004 at 04:01:45PM -0700, Shaun Jackman wrote:
> I have a Matrox G550 I'm attempting to configure for TV out. So, a
> couple questions...
> 
> 1. What's the the best display mode for NTSC output?
> 
> How many vertical lines does NTSC really have anyways? Can I set up a
> display mode for the NTSC television's actual native resolution?

Ah, a question without an answer.  :-)

Well, maybe not a useful answer.

There are 486 active scan lines in an NTSC picture, plus or minus.

The common size for pixels per scanline is 720, stolen from D-1 by DVD;
that gives you, IIRC, a .9 pixel aspect ratio.

As everyone keeps pointing out on this list and others, of course, the
pixel counts do *not* specify the image aspect ratio in video
production, because you cannot assume that the pixels are square --
MPEG gets this right (by including an image aspect ratio parameter in
the file) and AVI, of course, does not.

Ok, I was lying; your question really does have an answer: you should
get as close to 480/486 scanlines as you can.  In the other direction,
well... depends on what you play most, and how much scaling a) your
video card will do and b) you want your processor to do.

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra at baylink.com
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	"You know: I'm a fan of photosynthesis as much as the next guy,
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