Gabriel Bouvigne schrieb am Son, 17 Sep 2000:
> Normally the ATH is used as the masking value for the latest sfb. But
> if --noath is used, how is this sfb processed?
>
> Regards,
>
> --
>
> Gabriel Bouvigne - France
> [EMAIL PROTECTED]
> icq: 12138873
>
> MP3' Tech: www.mp3-tech.org
Well, CBR doesn't care about sfb21 distortions, VBR does
for MPEG-1. When using --noath the sfb21 still gets its
ATH value.
look in quantize_pvt.c, compute_ath():
/* in no ATH mode leave ATH for the last scalefactor band in
* because VBR mode needs it
*/
if (gfp->noATH) {
for ( sfb = 0; sfb < SBMAX_l-1; sfb++ ) {
ATH_l[sfb]=1E-20;
}
for ( sfb = 0; sfb < SBMAX_s-1; sfb++ ) {
ATH_s[sfb]=1E-20;
}
}
As you can see, in --noath mode the ATH is turned off for all
scalefactor bands but sfb21.
Ciao Robert
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