I posed this on the Mesa3D user mailing list & Brian sugested I tried the dev 
mailing list instead - so here goes (I've also CC'd in the VAAPI contact)!


-----------------------------------------------------------------------------------------

Are there any plans for adding a video acceleration API to the
Gallium3D architecture?

I'm trying to wrap my head round video acceleration, specifically how
GStreamer can fit in with the Gallium architecture. At the moment,
there is an OpenGL GStreamer sink element which accepts YUV data from
GStreamer & uses a shader to do the YUV->RGB conversion in the GPU (It
also does scaling... as you would imagine). This is (IMO) quite a
nifty use of a shader, but I think extending it's use further would
start to get painful. <edit> I'm a bit new to shaders - could they be used to 
do more of the video decoding than just colour conversion? Could a shader be 
written to decode h.264 for example? </edit>

While YUV->RGB conversion is expensive & good to off-load to the GPU,
there's lots more which can be achieved by the GPU. Full h.264
decoding for example. I'm aware of Freedesktop's VAAPI - which looks
exactly what I'm thinking about - my question is weather this is going
to be implemented/ported to the Gallium3D architecture? Also, are
there any plans to implement GStreamer sink elements for this API?

If there's no hardware suport for e.g. h.264, what happens? Does
GStreamer fall back to other (software) decode elements, or will
Gallium's software fallbacks be used instead (which presumably would
be slower)?

Also, there doesn't seem to be a way of using the VAAPI to accelerate
other unsupported codecs (I.e. a way to pass in raw YUV data). <edit> I've 
looked a bit closer at the VAAPI spec and now think there may be a way to 
pass in YUV data buffers </edit>.


Any help understanding this would be greatly welcomed. :-)


Cheers,

Tom


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