Tone.js/Tone/source/Microphone.js

///////////////////////////////////////////////////////////////////////////////
//
//	WEB RTC MICROPHONE
//
///////////////////////////////////////////////////////////////////////////////

define(["Tone/core/Tone"], function(Tone){

	//@param {number=} inputNum
	Tone.Microphone = function(inputNum){
		//extend the base class
		Tone.call(this);

		//components
		this.mediaStream = null;
		this.stream = null;
		this.constraints = {"audio" : true};
		//get that option
		var self = this;
		MediaStreamTrack.getSources(function (media_sources) {
			if (inputNum < media_sources.length){
				self.constraints.audio = {
					optional : [{ sourceId: media_sources[inputNum].id}]
				}
			}
		});		
	}

	Tone.extend(Tone.Microphone, Tone);

	//stop the WebRTC connection
	Tone.Microphone.prototype.start = function(){
		// Only get the audio stream.
		navigator.getUserMedia(this.constraints, this._onStream.bind(this), this._onStreamError.bind(this));
	}

	//stop the WebRTC connection
	Tone.Microphone.prototype.stop = function(){
		if (this.stream){
			this.stream.stop();
		}
	}

	//when the stream is setup
	Tone.Microphone.prototype._onStream = function(stream) {
		this.stream = stream;
		// Wrap a MediaStreamSourceNode around the live input stream.
		this.mediaStream =  this.context.createMediaStreamSource(stream);
		this.mediaStream.connect(this.output);
	};

	//on error
	Tone.Microphone.prototype._onStreamError = function(e) {
		console.error(e);
	};

	//polyfill
	navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia 
		|| navigator.mozGetUserMedia || navigator.msGetUserMedia;

	return Tone.Microphone;
});