3d graphics

[NoiseEHC]

Hi!

I have read through the GeodeLX documentation and I noticed that its DC 
can output a video stream over the normal (1200x900) frame buffer.
Can the X11 developers create a mode with the following spec?

1. Software can request allocating two YUV (4:2:0 or 4:2:2) frame 
buffers in the Software's address space with the given dimensions (eg 
400x300).
2. Software can request displaying one of those frames in the defined 
size (as I understand the DC will upscale the video if needed).
3. Software can render in YUV to one of the frames.
4. Software can request flipping to the other frame. (If I read 
correctly the switch will happen on vsync.)
5. goto 3. (The Software can start rendering (vertex 
transformations/triangle setup/lightning) but have to wait for the vsync 
somehow...)
6. And now we have an usable display system for an OpenGL implementation.

Is it possible to implement? If so I would like to write a 3d software 
renderer since it is fun. :)

ps:
Using YUV for white lights is even better than RGB.