Re : [MP3 ENCODER] spreading function buggy?

[Lionel Bonnet]

Title: Re : [MP3 ENCODER] spreading function buggy?

> I would suggest: > >    if (j>=i) tempy = (bval_l[j] - bval_l[i])*(-10); >    else    tempy = (bval_l[j] - bval_l[i])*25; > >    if (tempy <= -60.0) s3_l[i][j] = 0.0; >    else                s3_l[i][j] = exp( tempy*LN_TO_LOG10 ); > > but this will need a lot of testing. > > One additional confusion: in the ISO doc, the meaning of i and j > seem to be reversed from the ISO code. > > Mark It 's not true. The slope is for the spreading function s3_l, not for tempy or tempx. You must test the slope on s3_l = 15.81 + 7.5 � and see that it is 25db and -10db. Ther is another way to see it : you can calculate the norm_l coefficient by norm_l[i] = 1/(sum of s3_l[i][j]). With the current version(don't change anything), you will find the normalisation coefficient of table C.7. The formula is correct with the tables given in the ISO doc and with the Painter article. Lionel