import OnsetDetection from 'music-tempo/src/OnsetDetection.js'

public class | source

OnsetDetection

Spectral flux calculating and peaks finding

Static Method Summary

Static Public Methods
public static	calculateSF(audioData: Float32Array, fft: Object, params: Object): Array Get spectral flux
public static	findPeaks(spectralFlux: Array, params: Object): Array Finding local maxima in an array
public static	normalize(data: Array) Normalize data to have a mean of 0 and standard deviation of 1

Get spectral flux

Name	Type	Attribute	Description
audioData	Float32Array		non-interleaved IEEE 32-bit linear PCM with a nominal range of -1 -> +1 (Web Audio API - Audio Buffer)
fft	Object		object with methods for performing FFT
params	Object	optional default: {}	parameters
params.bufferSize	Number	optional default: 2048	FFT windows size
params.hopSize	Number	optional default: 441	spacing of audio frames in samples

spectralFlux - the array of spectral flux values

Finding local maxima in an array

Name	Type	Attribute	Description
spectralFlux	Array		input data
params	Object	optional default: {}	parametrs
params.decayRate	Number	optional default: 0.84	how quickly previous peaks are forgotten
params.peakFindingWindow	Number	optional default: 6	minimum distance between peaks
params.meanWndMultiplier	Number	optional default: 3	multiplier for peak finding window
params.peakThreshold	Number	optional default: 0.35	minimum value of peaks

peaks - array of peak indexes

Normalize data to have a mean of 0 and standard deviation of 1

Name	Type	Attribute	Description
data	Array		data array