[vorbis] Vorbis Codebooks

[Michael Smith]

On Sunday 04 May 2003 16:31, stoffke at directbox.com wrote:
> Hello,
>
> Vorbis uses codebooks,  for example to do vectorquantization and
> huffman-encoding.
>
> My question is - are all these codebook dynamicly generated ("trained")
>

Sort of. The codebooks are trained 'offline'. For a given libvorbis release, 
they're effectively static - but because the format doesn't specify a set of 
static codebooks, the books used by the encoder are efficiently packed into 
one of the vorbis header packets. An encoder is free to use any codebooks it 
wants to - it can, if it so chooses, do fully-dynamic training of the books 
(though that obviously doesn't work with single-pass encoding, and the 
overhead isn't all that likely to be worth it).

Mike

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