I was just playing with kiss fft (an LGPL fft routine that we are adding to the audio stream object) and I re-found this tutorial about fft that is very helpful:
it’s cool, because they take you through the fft in a very straightforward way – I find it useful to re-read every so often…
The following books by Curtis Roads are great material to read when learning about the FFT. Roads has a less technical and more easily readable style than most articles you’ll find.
- The Computer Music Tutorial
Books book have sections on the DFT and hence FFT.
The article Zach linked to is now available at http://www.dspdimension.com/admin/dft-a-pied/
On a related note, KISS FFT is available here http://kissfft.sourceforge.net/
I’m kind of surprised fmod was eventually used for OF’s sound spectrum stuff instead of KISS.