[MPlayer-users] Re: Display card recommendations

[D Richard Felker III]

On Tue, Sep 17, 2002 at 03:07:38AM +0200, Arpi wrote:
> anyway the tvout chip on the Gx50 cards is crap compared to g400,
> someone (the matroxfb author?) said it's like software modem (winmodem)
> compared to hw modem.

Yeah, I'd heard bad things like that too, but I didn't want to say
something that might be just a rumor since I was flaming that guy for
not knowing what he was talking about when it comes to nvidia. :))

> matrox - to push price down - left the Maven chip out, and somehow emulates
> the tv encoder using normal DAC and some electrical hacks.
> probably something like the external vga-to-tv circuits which depend a lot
> on the lowlevel programming of the dac to the right h/v/p freqs.

Hmm, my external vga-to-tv works rather well. I *did* spend a lot of
time tweaking with fbset to get it working though...and it doesn't
help that matroxfb rounds the values you give it without telling you
how it rounded them...

> even if it was false info, there is big difference between g400 and gx50
> tvout behaviour and programming.
> the Gx50 does hw scaling from any size on tvout, at 512..1024 width.
> the output image has always the same size.
> for g400, the resolution was actually displayed on teh tv, with no hw
> scaling, so if you set up too high or low res compared to pal/ntsc res,
> the picture was broken (depending on your tv).

Ah, G400 is much better then. I was actually wondering about that --
one of the most appealing things to me about building my own circuit
for tvout was avoiding nonsense scaling and scan conversion stuff that
would ruin the image quality.

Actually for maximum quality, i'm considering making a custom tvout
circuit without conversion from RGB, and hacking mplayer to store
packed YUV 4:4:4 in the RGB framebuffer. I'm still not familiar enough
with NTSC video to figure out how to put it all together, though, so
that'll have to wait for a while... :)

Rich