[Vorbis-dev] VQ vector value decode help

[xiphmont at xiph.org]

On Sun, Apr 21, 2013 at 11:24 AM, N. Sidorova <n.sidorova at lunanite.com> wrote:
> Hello,
>
> I've been writing a decoder using the spec and it's unclear to me where
> the value [lookup_offset] comes from when performing VQ vector value
> decode (page 23 of the spec). The wording in the spec is very confusing
> to me. Someone asked this question before (
> http://lists.xiph.org/pipermail/vorbis-dev/2002-September/015282.html ),
> but it went unanswered.
>
> Could anyone help me (and anyone in the future) understand where this
> value is coming from?

I assume you're talking about section 3.2.1.

A codebook conceptually consists of a list of vectors; the
input_offset is the number of a given vector in the list.

The pseudocode is showing the decoding process for a single one of
those vectors; there's an implied higher level loop that is decoding
each vector in turn.

Monty