A UGen to measure the spectral centroid. Given an FFT chain, this measures the
spectral centroid, which is the weighted mean frequency, or the "centre of mass"
of the spectrum. (DC is ignored.) This can be a useful indicator of the
perceptual brightness of a signal.
Note that the output frequency is pretty close to the correct value when
feeding in a sine signal, but the estimate is usually too high when using for
example filtered noise. In that case, you will get better results using
SpecPcile at 50%.
Note that despite running at control-rate, the output remains constant for each
FFT frame. E.g. with an FFT size of 1024 and 50% overlap, a new measure is
generated every 512 audio frames, or (at control block size 64) every 8 control
the fft signal (buffer) to analyze