[theora-dev] Re: YUV to RGB

[Ralph Giles]

On Mon, Jan 14, 2008 at 10:59:39PM -0800, wesley kiriinya wrote:

>  I'm trying to write an OpenGL application that plays theora frames. SDL is not an option. Is there a function/routine that can do this for me efficiently or do I have to write my own with a bit of SSE so that the YUV to RGB conversion is fast enough. Also wouldn't it be OK if a Theora stream could be encoded in RGB instead of YUV or is there already something like this? I'm writing a decoder not an encoder.

If you're doing OpenGL, the best thing is to write a fragment shader to 
do the conversion. In most applications the GPU can more easily spare 
the cycles.

For one implementation on the host side, see:

  http://svn.annodex.net/liboggplay/trunk/src/liboggplay/oggplay_yuv2rgb.c

There are many others, of various speed and quality.

I'd eventually like to add to-from RGB routines to the reference 
implementation, but that's post-1.0.

HTH,
 -r