webaudio-peaks
Small library to extract peaks from an array of audio samples or a webaudio AudioBuffer.
Installation
npm install webaudio-peaks
Basic Usage
var extractPeaks = require('webaudio-peaks');
var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
//decode an ArrayBuffer into an AudioBuffer
audioCtx.decodeAudioData(audioData, function(decodedData) {
//calculate peaks from an AudioBuffer
var peaks = extractPeaks(decodedData, 10000, true);
});###extractPeaks(source, samplesPerPixel, isMono, cueIn, cueOut, bits) function to extract peaks from a TypedArray, or AudioBuffer
Params
- source
TypedArray|AudioBuffer- A source of audio samples. - samplesPerPixel
number- Number of samples used to calculate a single peak. - isMono
boolean- Combine all channels into one array of peaks or not. - cueIn
number- Sample to begin at. The offset is inclusive. - cueOut
number- Sample to end at. The offset is exclusive. - bits
(8|16|32)- Resolution of calculated peaks.
Returns: object
{
length: `number` //Number of calculated peaks,
//Computed peak data, length == #channels or 1 if isMono == true
//Each entry of type `Int{bits}Array`
data: `Array`
bits: `(8|16|32)` //Resolution of calculated peaks.
}