Vorbis - Nov 2004 - quantization of floor/residue

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

On Mon, Nov 22, 2004 at 12:04:23PM +0100, don_homer@gmx.net wrote:
> 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.
Our encoder includes a large array of codebooks, and chooses a subset
from them based on the desired coding parameters.  These codebooks are
packed into the stream header.
> 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?
No, the codebooks are prepared, packed and unpacked in sharedbook.c
and codebook.c.  res0.c encodes/decodes residue vectors using
already-prepared codebooks.
> last but not least, channel coupling. is this only done on the floor
> data, or both?
This is done only on residue data; see mapping0.c and psy.c

Monty