webaudio-peaks

Small library to extract peaks from an array of audio samples or a webaudio AudioBuffer.

Installation

npm install webaudio-peaks --save

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.
}

License

MIT License