I dont think we should make this change. Preserving the amplitude
(and thus the actual shape of the wave form) seems more important than
the energy. Also, using fabs(i^8/3 -x^2) is an unusual definition of
noise that I have never seen in any of the technical papers.
Mark
>
> >> hmm, I'm not so sure about this. The noise measure used in
> >> LAME is based *not* on the error in the energy
> >>
> >> fabs(i^8/3 - x^2)
> >>
> >> but instead on the energy of the error:
> >>
> >> ( i^4/3 -x ) ^2
> >>
> >> Since LAME picks scalefactors to try to minimize the second
> >> quantity, I think we should use a quantization consistant with
> >> this error measure?
>
> S> Ahah. I think the scalefactor picking should be consistent with
> S> the first formula instead :-)
>
> S> But seriously, what the ear hears is energy, not amplitude; so
> S> the second formula is not an accurate description of the
> S> audible error.
>
> I think this is right, Segher.
>
> with my poor listening test, I think we should take noise calculation
> >> fabs(i^8/3 - x^2)
> instead of
> >> ( i^4/3 -x ) ^2
> ---
> Takehiro TOMINAGA // may the source be with you!
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