p5cq

The constant Q transform method to transform a discrete Fourier transform (DFT) into a constant Q transform, where Q is the ratio of center frequency to bandwidth. This allow to have a discrete signal represented in the frequency domain by a fixed amount of bins per octave. For example setting it to 12 bins per octave each bin represents a semitone in the equally tempered musical scale, so the frequency domain representation is much more "musical" than the standard DFT. This implementation is based on the work by Judith C. Brown & Miller S. Puckette http://www.wellesley.edu/Physics/brown/pubs/effalgV92P2698-P2701.pdf and taking as starting point the matlab implementation by Benjamin Blankertz http://wwwmath1.uni-muenster.de/logik/org/staff/blankertz/constQ/constQ.html

constantQ4
constantQ4.pde
constClass.pde