From: James Simmons <jsimmons@edgeglobal.com>
  To  : ggi-develop <ggi-develop@eskimo.com>
  Date: Mon, 8 Feb 1999 10:58:44 -0500 (EST)

Re: [linux-fbdev] YUV support ? (fwd)

On Mon, 8 Feb 1999, James Simmons wrote:
> Does fb have anything to do with this or will it in the future?
> 
> > > Question: what does this do for YUV support?
> > > YUV support is an area of memory that takes data in YUV format, and
> > > a chromakey in the frame buffer determines whether you see the frame
> > > buffer or the YUV buffer. It's used to speed up MPEG display (eg used
> > > by DVDs)
> > > 
> > > Will this be in a seperate YUV area -- would make sense for the Diamond
> > > DVD card for instance which takes the output of a graphics card  adds the
> > > mpeg
> > > picture into the video frame.

I'd handle this with a FB_NONSTD_* ID in var.nonstd, just like HAM
(Hold-And-Modify) on Amiga.

If the chromakey is implemented using a seperate bit in the pixel format, it
can be considered some kind of transparency and handled through var.transp.
If the chromakey is some special pixel value, we have to find something
different, perhaps an ioctl()?

Greetings,

						Geert

--
Geert Uytterhoeven                     Geert.Uytterhoeven@cs.kuleuven.ac.be
Wavelets, Linux/{m68k~Amiga,PPC~CHRP}  http://www.cs.kuleuven.ac.be/~geert/
Department of Computer Science -- Katholieke Universiteit Leuven -- Belgium