[PD-dev] Re: [PD] Re: YUV textures
daniel at bogusfront.org
Wed Dec 4 00:42:43 CET 2002
i've moved this one to PD-dev.
chris clepper writes:
> >AFAIK, YUV textures are only available using Direct3D under windows... I
> >think Apple is the only OpenGL vendor to include general support for YUV
> >textures. Can anyone confirm/deny this?
> that may indeed be the case at this point in time.
hmmm... a pity. it wouldn't seem like much work on the part of the vendors
to add this support to openGL.
> >Is it possible to do HW assisted YUV->RGB(A) conversion using texture
> >transfer options and a colour matrix in OpenGL?
> all the cards seem to have that feature listed in their specs, but i
> have no idea how to tap into that using a common api/lib other than
> opengl. i attempted to write a yuv->pix object but didn't have much
> success. not sure what sort of performance hit that will be doing
> the conversion in software. it could wipe out any speed gains of yuv
which YUV format is being used? UYVY packed into 32bits? that could be
done using a openGL 1.2 color matrix if the double Y resolution is
sacrificed. might be possible to do something clever to achieve full
resolution Y but can't quite see how to do it off the top of my head... i
don't know how fast non-standard pixel transfer is anyway, for that
if the effects are convenient/efficient in yuv and there's any significant
amount of buffer copying going on in the processing chain then i'd guess
that YUV should still come out ahead even with a last step sw or hw
this all begs for some code and experimentation. i'll get around to it
eventually if nobody gets there first!
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