>
> > You have to do some work to decifer it: look up the MDCT coefficients
> > which belong in each band. Knowing the sampling rate and MDCIT
> coefficient
> > index you can compute the frequency.
>
> I'd like to, but I don't have the mathematical background to do it.
>
>
It is actually not so bad. The filter banks create some leakage,
so the i'th coefficient is not a perfect cosine wave, but it
is more or less like this:
576 coefficients representing 576 samples.
0th coefficient is the constant mode (frequency = 0)
575 coefficient is the highest frequency. At 44.1kHz, this is 22.05kHz.
So the frequency of the i'th coefficient is:
(sampling_rate/2)*(i/575)
For example, 44.1kHz scalefactor 1 contains MDCT coefficients 0,1,2,3,
which is 0-115Hz. For short blocks, change 575 to 191.
Mark
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