analyzer

A multi channel WebAudio analyzer that does all the nasty plumbing with JavaScriptSourceNodes and AnalyzerNodes for you.

Example

Analyze the input stream from your computer's microphone and log results to the console:

var Analyzer = require('analyzer');
var AudioContext = window.audioContext || window.webkitAudioContext;

var context = new AudioContext();
var analyzer = Analyzer(context)
  .add('left', source, 0)
  .add('right', source, 1);

analyzer.on('float frequency data', function(chunk) {
  console.log('float frequency data', chunk);
  // { left: [ ... ], right: [ ... ] }
});

Installation

Install with component(1):

$ component install juliangruber/analyzer

API

Analyzer([opts, ]ctx)

Create a new Analyzer for the WebAudio context. Inherits from component/emitter.

Possible options:

• smoothing: The smoothing time constant, can be between 0 and 1.

Analyzer#add(name, node[, channel])

Start analyzing node and expose it in events under name. channel is the output channel you care about and defaults to 0.

Analyzer#resume()

Resume analyzing.

Analyzer#pause()

Pause analyzing.

Analyzer#on('float frequency data', fn)

Call fn with a Float32Array(fftSize / 2) for each new chunk.

Analyzer#on('byte frequency data', fn)

Call fn with a Uint8Array(fftSize / 2) for each new chunk.

Analyzer#on('byte time domain data', fn)

Call fn with a Float32Array(fftSize) for each new chunk.

License

MIT