[dspig]

> One way to get around this would be to decrease bucket size by increasing the FFT size.

A better way is parabolic interpolation, which is in the source code but not mentioned in the article - and that works for finding the fractional position of peaks in the FFT or in the autocorrelation.

An even better way is by comparing the phase of the peak in two successive FFTs: If the signal phase has changed by X degrees after T seconds, what's the nearest frequency to the bin centre that can be true for? (this is the main thing a "phase vocoder" does)