On Mon, 14 Mar 2005, Lourens Veen wrote:
On Monday 14 March 2005 06:22, Daniel Phillips wrote:
Also, why does the video even have to be converted YUV->RGB and back again? Why not make the color model a property of the window and have the video controller skip the RBG->YUV conversion if the window is already in YUV?
That is interesting, but we'd need to have a YUV format that at least is packed and has the same amount of bits per pixel as the current framebuffer. Also, does the modulator for TV-out support YUV in?
Just to make it clear: all our display devices are RGB at the moment, so the conversion is needed in some place. Naturally most tv-sets do YUV->RGB conversion in the so called "colour separation matrix" which is just a bunch of analogue electronics (resistor matrix and some differential amplifiers). PAL/NTSC-modulation is plain YUV so every modulator chip should be able to take YUV (AD73xx at least). But then there are many of us who would like to take D1 video out in the the RGB-format with PAL/NTSC-timings just for the better quality. That way analogue colour-component separation is left out and 10-bit DA has its place then as YUV->RGB rounding errors do not make their way to the picture. Not to mention better signal bandwidth. Drawing some vectors to clear things out may be of some help, just in case YUV idea is not entirely clear ;)
-Vesa _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
