Ogg Vorbis Encoder/Decoder for Virtex-II Pro

Are there any good docs that explain the theory of the OGG compression ? I have read some, but they were very brief and mostly about mp3. Good docs would help in figuring out what is best in HW and SW.

I think the decoder documentation that are found at www.xiph.org/ogg/vorbis are good enough. Seems to me but I am no expert that all current lossy audio compression are similar. Just different algorithms in common blocks. Though Ogg does have some different concepts, but I am not sure if that is only to avoid patents.