I just stumbled upon the "mad" mp3 decoder that is written by Robert Leslie under the GPL. It so happens that it supports the empeg and even has a file called audio_empeg.c. The changes file notes :

* Moved the empeg-car audio output support into a separate module.

Will this be the primary mp3 decoder that replaces Xaudio is future versions? It certainly seems that this was its intention as a key feature is its use of pure integer computation.

I find it curious that Rob also hosts the empeg developer site, but makes no mention of this project on that site that I was able to find.

If this turns out to be true it may be helpful for everyone to put this through their own set of mp3s to head off any problems before v1.1.

Read more here :

http://www.mars.org/home/rob/proj/mpeg/

-Kit