[theora-dev] Using i915/i945 XvMc in Theora

[Timothy B. Terriberry]

Zoran Tomicic wrote:
> Hi,
> 
> Intel has recently open sourced  otion compensation code (XvMC) for
> their i915/i945 integrated graphics chips.
> 
> See:
> http://gitweb.freedesktop.org/?p=xorg/driver/xf86-video-intel.git;a=blob;hb=xvmc-i915;f=src/xvmc/I915XvMC.c
> 
> 
> XvMC API was intended for MPEG{2,4} class of codecs - so it can not be
> used for Theora as-is. However, could at least some parts of it such as
> hardware accelerated YUV->RGB conversion be utilized, by exposing them
> through custom interface?

Well, the RGB->YUV conversion is not part of libtheora in the first
place precisely because one usually wants to take advantage of some form
of hardware acceleration, and the means of achieving this vary
drastically from platform to platform. This is not a codec-specific
problem, and is generally handled at a higher layer (e.g., in a media
framework like gstreamer).

I don't know enough about the XvMC API to say what other parts would be
useful to Theora, if any.