most likely, it's based on a gzip like format, tuned for audio. (like bzi p is tuned for text) I've looked into some more open-standard non-loss compression types.. and there has been talk about adding the formats to the empeg.
floating point isn't really necessary, most of the operations are bitwise, so they don't loose data.. floating point operations loose data. (famous bug note.. pentium FDIV bug was 10th decimal error, enough of a loss to make it a problem)
and like the empeg guys have proved.. anything you can do in FPU, you can do in INT..
remember, doom2 was all INT, no FPU (and wow, what a game :)
12gig green mk2 -- 080000125
_________________________
80gig red mk2 -- 080000125
(No, I don't actually hate Alan Cox)