> > Why can we read in the litterature that humans got 25 CB but mp3 uses
only
> > 22?
>
> let us try to get it in order:
>
> bark scale is used by the spreading function
> Bark 0 : 0-100 Hz, Bark 24: 15.5 - 20.4 kHz
>
> masking is calculated for convolution bands
> Lame uses 64 equidistant convolution bands from 0 Hz up to Nyquist
>
> each of the 22 scalefactor bands is responsible for a group of
> subbands (the convolution bands), but we have only 21 scalefactors
> (12 scalefactors w/ short blocks)
So the highest subbands don't have any scalefactor? I know that Brandebourg
said that there is no proof that >16kHz really contribute to the hearing of
the music, and then it could be intentionnal, but could it be a "bug" or
mistake in the mp3 specs?
After all, I think that in 48kHz encoding some freq higher than 16kHz got a
scalefactor, so it could be theorically be possible to affect a scalefactor.
Is there a scalefactor for >16kHz in AAC? (Meno, are you listening?)
Also an off topic question for Robert: as you're german, is there a specific
knowledge about audio compression floating around in your university? (like
specialists, research or thesis)
Regards,
--
Gabriel Bouvigne - France
[EMAIL PROTECTED]
mobile phone: [EMAIL PROTECTED]
icq: 12138873
MP3' Tech: www.mp3-tech.org
--
MP3 ENCODER mailing list ( http://geek.rcc.se/mp3encoder/ )
