[vorbis-dev] FLOAT_LOOKUP version of lsp_to_curve

[TIMMERMANS ANDRE]

It seems to me that in this version of the function using

    float p=.7071067812f;
    float q=.7071067812f;

will just leads after applying all the products and squaring
to p and q having a common factor 0.5 which can be extracted
from the formulaes.

So I propose to replace:

    float p=.7071067812f;
    float q=.7071067812f;
    float w=vorbis_coslook(wdel*k);
    float *ftmp=lsp;
    int c=m>>1;

by:

    float w=vorbis_coslook(wdel*k);
    float p=lsp[0]-w;
    float q=lsp[1]-w;
    float *ftmp=lsp + 2;
    int c=(m>>1) - 1;

and:

    vorbis_invsq2explook(qexp+m)

by:

    vorbis_invsq2explook(qexp+m-1)

André

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