>
> > You want to use table B.8: It lists the MDCT coefficients in
> > scalefactor bands 0-20. The missing MDCT coefficients (418-575) are
> > in scalefactor band 21 (16->22kHz). I've never understood this, but
> > the standard ignores band 21. No masking thresholds, no distortion
> > and no scalefactors are used in band 21.
>
> The standard claims that there are 21 bands. In the doc, there are 21, from
> 0 to 20, but they stop at 16kHz. So how many bands are used in mp3? 21 or
> 22?
> The iso doc seems to be quite obscure sometimes.
>
>
My interpretation: There are 22 bands, 0..21. Band 21 contains the
MDCT coefficients above 16kHz. Band 21 coefficients are correctly
encoded and decoded, (although LAME and FhG remove them at 128kbs and
less).
But the standard does not allow a scalefactors for band 21, and
thus there is no reason to compute masking thresholds or the
distortion in band 21.
Mark
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