[theora] New trunk vs old trunk

Ralph Giles giles at xiph.org
Tue Dec 18 21:56:29 PST 2007


On Tue, Dec 18, 2007 at 11:14:47AM +0000, Patrick Byrne wrote:

> Can somebody please give me an brief overview of the changes between the 
> two generations of code? I see that the function names have changed, but 
> this looks mostly cosmetic. I am really concerned as to whether the 
> newer code is significantly more efficient: the old code runs like a dog 
> on the ps3 ppu.   :-(

It's a little more complicated. the theora-exp *decoder* became the 
trunk decoder. The trunk encoder is the same. There's a compatibility 
layer on top to provide both the old and new decoder APIs and, when 
someone gets around to it, the new encoder API as well.

The new decoder is much more robust and complete. It's faster on some 
architectures.

Other things you might be interested in:

http://svn.xiph.org/branches/theora-multithread/ slightly parallel 
encoder, was the start of a Cell spu port.

http://svn.xiph.org/branches/theora-thusnelda/ encoder rewrite in 
progress. Should run better, but unstable. Will be trunk in a few 
months.

And, of course, altivec optimization would help.

 -r


More information about the theora mailing list