HydrogenAudio

Lossy Audio Compression => AAC => AAC - Tech => Topic started by: wkw on 2002-08-02 10:28:19

Title: Something wrong with ISO Psy model II\'s bark-scale tables?
Post by: wkw on 2002-08-02 10:28:19
Hi,

I notice in the MPEG4 ISO specs that the psychoacoustic model's bark-scale table for
44100 kHz long block is giving me poor audio quality especially for the lower frequencies. I wonder if the values are not accurate?

wkw
Title: Something wrong with ISO Psy model II\'s bark-scale tables?
Post by: Ivan Dimkovic on 2002-08-02 11:21:30
No !

Don't use bark tables from ISO docs!!! In fact, don't use ANY tables for psychoacostics!!! There are lot of good approximation formulaes, and you can compute your own values.

Also, the ATH (QTHR) is a complete mess, and it is normalized to some level unknown to me!  You also need to calculate that properly!

Take a look at LAME or FAAC code.