[Vorbis] quantization of floor/residue

[don_homer at gmx.net]

hello,

i am new to vorbis and try to figure out how and where the quantization process of the floor and residue data takes place.
my first question is at all, whether the codebooks for the vq-quantization are static in the sourcecode or whether they are generated dynamically upon the data. there are a lot of codebooks in the sourcecode, e.g. res_books_stereo.h. 

i found the function "_01forward" in res0.c. am i right that this function is preparing the codebooks and the function "encode" which is given via the parameters is doing the quantization stuff on the data? 
"_encodepart" is a possible function for this and finally "local_book_besterror" is quantizing the data?
i had more problems finding something similiar for the floor data.  for floor1, e.g. i think "floor1_encode" is doing this stuff, but i am not quite sure. 
last but not least, channel coupling. is this only done on the floor data, or both?
i appreciate all help on this topic.
thanks, 
gerald