[vorbis-dev] New LSP code committed

Segher Boessenkool segher at eastsite.nl
Tue Aug 29 13:59:59 PDT 2000



> Not as useful, unfortunately (tell me if I've missed it).  The only point where
> we need fromdB is the ugly foo=amp/sqrt(p*p*(1.+w)+q*q*(1.-w)) computation in
> lsp_to_curve (and then outside the function, those values are immediately taken
> to linear amplitude with fromdB and an offset).  

After applying my patch, fromdB() still takes more time than
vorbis_lsp_to_curve(), not counting the sqrt() (it's about one third
of that time).

We could try a lookup table for fromdB(amp/sqrt(x)). You'll here from me
tomorrow or something like that.

Ciao,

Segher

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