@audio/spectral-centroid

@audio/spectral-centroid

Spectral centroid — magnitude-weighted mean frequency (Hz). Peeters 2004 §6.1.

npm install @audio/spectral-centroid

import { fft } from 'fourier-transform'
import centroid from '@audio/spectral-centroid'

let win = frame.map((x, i) => x * (0.5 - 0.5 * Math.cos(2 * Math.PI * i / (frame.length - 1))))
let [re, im] = fft(win)                          // frame.length a power of 2
let mag = re.map((r, k) => Math.hypot(r, im[k])) // magnitude spectrum, length frame.length/2+1

let hz = centroid(mag, { fs: 44100 })

Options: - fs — sample rate (default 44100, Hz) · n — FFT size the spectrum was taken at (default 2 * (mag.length - 1), inferred from mag.length)

Part of @audio/spectral.