Understanding the FFT Algorithm (2013)

For anyone interested and with 30 minutes to spare, I would recommend the youtube video [1] by Reducible for an intuition on how FFT works.

[1]: https://youtu.be/h7apO7q16V0

If anyone is interested, I made a video about my favorite application of the 2D discrete Fourier transform, where it's used to erase rainbows on manga screen tones on color eink Kaleido 3 on Kobo Colour: https://youtu.be/Dw2HTJCGMhw?si=hlhwHv0qB6SoMha9

Who uses square brackets for big-O?

A bit of a stretch, but does anyone have a good way of running an FFT on a pcap?