1920x1080 x 32bits/pixel x 30 frames/sec =3D 248,832,000 bytes/sec
32 bit PCI =3D 133 MB/s
The card is supposedly going to have hardware colourspace transform,
so if you are playing video, you'll have YV12, 12 bits/pixel, which would
be approximately 89 meg/second.
Oh, yeah. That's true. You'll be able to do things like write 16-bit
YU and 16-bit YV (usually together in a 32-bit word) and have it
automatically turned into two 32-bit RGBs.
Does X11 have support for this?
Not that I'm aware of, although an extension might be possible to
support it. I know that other chips have ways to do conversion,
although OGA may be the only design that only does it on the way
in/out between the host and the graphics memory. Also, I get the
impression that some video players bypass X11 and get direct access to
the framebuffer somehow, and that won't be a problem here.
The extension is called xv (XVideo) and it does at least two things for
smooth video playback:
1) color space conversion (YUV -> RGB)
2) scaling of these data (in gpu)
(I think, that its also called overlay somewhere)
If you plan to use OGA for watching movies, you have to implement these
two features and provide access to them through xv.
And later somebody may implement HW decoding of MPEG2 and for this an
mplayer output driver will be required (if the OGA will be not
compatible with DVB cards - see mplayer manual: -vo mpegpes). That way
the PCI bus and the CPU will be totally free (I assume that 3-4MB/s of
HD stream is nothing).
Daniel
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