MediaStreamRecorder.js

// Muaz Khan     - https://github.com/muaz-khan 
// neizerth      - https://github.com/neizerth
// MIT License   - https://www.webrtc-experiment.com/licence/
// Documentation - https://github.com/streamproc/MediaStreamRecorder
// ==========================================================
// MediaStreamRecorder.js

function MediaStreamRecorder(mediaStream) {
    if (!mediaStream) throw 'MediaStream is mandatory.';

    // void start(optional long timeSlice)
    // timestamp to fire "ondataavailable"
    this.start = function(timeSlice) {
        // Media Stream Recording API has not been implemented in chrome yet;
        // That's why using WebAudio API to record stereo audio in WAV format
        var Recorder = IsChrome ? window.StereoRecorder : window.MediaRecorder;

        // video recorder (in WebM format)
        if (this.mimeType === 'video/webm') Recorder = window.WhammyRecorder;

        // video recorder (in GIF format)
        if (this.mimeType === 'image/gif') Recorder = window.GifRecorder;

        mediaRecorder = new Recorder(mediaStream);
        mediaRecorder.ondataavailable = this.ondataavailable;
        mediaRecorder.onstop = this.onstop;

        // Merge all data-types except "function"
        mediaRecorder = mergeProps(mediaRecorder, this);

        mediaRecorder.start(timeSlice);
    };

    this.stop = function() {
        if (mediaRecorder) mediaRecorder.stop();
    };

    this.ondataavailable = function(blob) {
        console.log('ondataavailable..', blob);
    };

    this.onstop = function() {
        console.log('stopped..');
    };

    // Reference to "MediaRecorder.js"
    var mediaRecorder;
}

// ==========================
// Cross-Browser Declarations

// Media Stream Recording API representer
MediaRecorderWrapper = window.MediaRecorder;

// animation-frame used in WebM recording
requestAnimationFrame = window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame;
cancelAnimationFrame = window.webkitCancelAnimationFrame || window.mozCancelAnimationFrame;

// WebAudio API representer
AudioContext = window.webkitAudioContext || window.mozAudioContext;

URL = window.URL || window.webkitURL;
navigator.getUserMedia = navigator.webkitGetUserMedia || navigator.mozGetUserMedia;

IsChrome = !!navigator.webkitGetUserMedia;

// Merge all other data-types except "function"
function mergeProps(mergein, mergeto) {
    for (var t in mergeto) {
        if (typeof mergeto[t] !== 'function') {
            mergein[t] = mergeto[t];
        }
    }
    return mergein;
}