Why is D unpopular?

[Ola Fosheim Grøstad]

On Monday, 2 May 2022 at 08:57:21 UTC, user1234 wrote:
> The concept of "windowing" + "overlapp add" to reduce artifacts 
> is quite old, e.g the Harris Window is [1978]. Dont known for 
> better ones (typically Hanning).
> This doubles the amount of FFT required for a frame but you 
> seem to say this was technically possible.

Yes, I assume anyone who knows about FFT also knows the theory 
for windowing? The theoretically "optimal" one for analysis is 
DPSS, although Kaiser is basicially the same, but I never use 
those.

I use 4x not 2x and Hann^2 (cos*cos) as the window function for 
simplicity. The reason for this is that when you heavily modify 
the frequency content you need to window it again. So you 
multiply with cos(t) twice, but when you add them together the 
sum = 1. Probably not optimal, but easy to deal with for 
experiments.

I also believe it is possible to use Hann-Poisson for analysis. 
It has excessive spectral leakage, but supposedly allows you to 
accurately find the peaks as the flanks for the spectral leakage 
are monotone (smooth slope) so you can use hill climbing. But I 
doubt you can use this for resynthesis.

What you could do is use Hann-Poisson for detecting peaks and 
then use another window function for resynthesis. I will try this 
some day :-).