[PD] fftw

Thomas Grill t.grill at gmx.net
Sat Oct 26 14:45:18 CEST 2002

Hi Michael,
have you had a look at the freqtweak application recently announced on the
LAD list?
It has some features you might be interested in.
Apart from that i share your opinion about FFTW, however, it's not quite
The algorithm for such a plugin is not hard to devise... you have to
decompose the input signal
stream into overlapped grains (or "windows"), do your spectral
transformation, and then recompose
the grains into a continuous stream for output. Be aware of the fact that
the due to the granular nature
of such an algorithm, the larger the spectral resolution (fft size) is, the
larger is the inherent delay of your effect!
Scoot has been working on such things as well, i guess.

best greetings,

> Hello Thomas, Scott and list,
> I would like to build an external, which is a combination of the Native
> Instruments Spectral Delay and a trigger mechanism in the analysis stage
> (depending on amplitude) for single bins. I tried to build it with the
> objects available for PD, but although limiting it to only 200 bins, it
> couldn't be anything serious to use. Since as far as I know the Spectral
> Delay is build on the FFTW-algorithm (using the full spectrum), which
> to be the fastest freely available, I would like to use it for my external
> Thanks for your help
> Michael
> Michael Iber
> http://www.iberspace.de
> mailto://mail@iber-online.de

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