[MPlayer-users] OT(?): Matrox g400 tv-out references

[Krister Lagerstrom]

Brian J. Murrell wrote:

> On Sun, Feb 10, 2002 at 02:08:57AM -0600, Krister Lagerstrom wrote:
> 
>>Here are my settings for a G400 card, using a 4:3 ratio. I got these 
>>numbers by just fiddling around, so they can probably be improved. 
>>Please post to the list if you have any better settings. Don't blame me 
>>if your tv explodes!
>>
> 
> Any idea what the refresh rate is?  IIUC, it has to be 59.94Hz
> (assuming your video file is 29.97 frames/sec -- i.e. NTSC) if you
> want to use the vsync feature of the card for changing frames during
> the vertical refresh to have a nice smooth judder free output.


It's for a regular NTSC TV. Apparently it's close enough to whatever is 
needed to make the picture look OK. I don't think that the 768x576 
resolution is in the matroxtv script. I got my modeline to work by 
starting out with something that was close enough in resolution, and 
then tuning it with fbset to have a picture that covered the TV etc.

I discovered that a TV (at least mine) isn't really rectangular (the 
sides are a little round), so you either end up with parts at the sides 
that doesn't have a picture on them, or you gotta make the entire 
picture bigger thus covering the whole screen but losing parts of the 
movie.

I also discovered that the matroxfb driver doesn't care about some of 
the numbers given to fbset, so it takes some experimenting to get it 
right since you can't do a "regular" calculation for the fbset modeline 
(pixel clock, porches, etc). I guess I could've reverse-engineered the 
necessary data from the matroxfb driver, but hey, it worked anyway :-)

Overall, the TV-out I got is pretty good as far as I can tell. No 
flickering etc. The picture quality is pretty good too, the weak link is 
rather the WinTV board I use for capture...

I can also mention that I've hacked the mga_vid driver to accept 
adjustments to the picture size placement after mplayer has done it's 
setup. This makes it possible to do a crude letterbox (16:9) -> 
fullscreen (4:3) on-the-fly conversion.

		/ Krister