micselect.bundle.js

!function(e){if("object"==typeof exports&&"undefined"!=typeof module)module.exports=e();else if("function"==typeof define&&define.amd)define([],e);else{var f;"undefined"!=typeof window?f=window:"undefined"!=typeof global?f=global:"undefined"!=typeof self&&(f=self),f.micselect=e()}}(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
var support = require('webrtcsupport');
var hark = require('hark');
var EventEmitter2 = require('eventemitter2').EventEmitter2;
var util = require('util');
var adapter = require('webrtc-adapter-test');

function MicSelect() {
  if (!(this instanceof MicSelect)) {
    return new MicSelect();
  }
  EventEmitter2.call(this);

  var ms = this;
  ms.emitVol = false;
  ms.support = support.supportWebAudio && support.supportGetUserMedia;
  ms.supportMediaStream = support.supportMediaStream;
  if (!ms.support) {
    setTimeout(function errorTimeout() {
      ms.emit('error', {
        message: 'No WebRTC/WebAudio support',
        webAudio: support.supportWebAudio,
        getUserMedia: support.supportGetUserMedia
      });
    }, 0);
    return;
  }
  if(!ms.supportMediaStream) {
    setTimeout(function supportTimeout() {
      ms.emit('mediaStream', {
        message: 'No MediaStream support',
        mediaStream: support.supportMediaStream
      });
    }, 0);
  }
  ms.context = new support.AudioContext();
}
util.inherits(MicSelect, EventEmitter2);

MicSelect.prototype.setEmitVol = function setEmitVol(value) {
  var ms = this;
  ms.emitVol = value;
};

MicSelect.prototype.getMics = function getMics() {
  var ms = this;
  if (!ms.support) {
    return;
  }
  var gumOpts = {
    audio: true,
    video: false
  };
  adapter.getUserMedia(gumOpts, ms.onGetMics.bind(ms), ms.onError.bind(ms));
};

MicSelect.prototype.onError = function onError(err) {
  if (err && err.name !== 'DevicesNotFound') {
    return ms.emit('error', err);
  }
  
  var audioSources = {
    mics: []
  };

  if(err && err.name === 'DevicesNotFound') {
    ms.emit('audioSources', audioSources);
    return;
  }
}

MicSelect.prototype.onGetMics = function onGetMics(stream) {
  var ms = this;
  
  var audioSources = {
    mics: []
  };
  
  if(!ms.supportMediaStream) {
    audioSources.err = new Error('No MediaStream support');
    ms.emit('audioSources', audioSources);
    ms.onSetMic(err, stream);
  }
  else {
    navigator.mediaDevices.enumerateDevices()
      .then(function getSourcesResp(sources) {
        sources.forEach(function eachSource(source) {
          switch (source.kind) {
            case 'audioinput':
              audioSources.mics.push(source);
              break;
            default:
              break;
          }
        });
        ms.emit('audioSources', audioSources);
      })
      .catch(function(err) {
        ms.emit('audioSources', audioSources);
        return;
      });
  }
};

MicSelect.prototype.setMic = function setMic(source) {
  var ms = this;
  if (!ms.support || !ms.supportMediaStream) {
    return;
  }
  if (source.id) {
    source = source.id;
  }
  ms.source = source;
  var gumOpts = {
    audio: {optional: [{ sourceId: source}] },
    video: false
  };
  adapter.getUserMedia(gumOpts, ms.onSetMic.bind(ms), ms.onSetMicErr.bind(ms));
};

MicSelect.prototype.onSetMicErr = function onSetMicErr(err) {
  return ms.emit('error', err);
}

MicSelect.prototype.onSetMic = function onSetMic(stream) {
  var ms = this;
  var options = {
    threshold: -50,
    interval: 50
  };
  if (ms.hark) {
    ms.hark.stop();
    ms.hark.off('speaking');
    ms.hark.off('stopped_speaking');
    ms.hark = null;
  }
  ms.hark = hark(stream, options);

  ms.hark.on('speaking', function speaking() {
    ms.emit('speaking');
  });

  ms.hark.on('stopped_speaking', function stoppedSpeaking() {
    ms.emit('stopped_speaking');
  });

  if (ms.microphone) {
    ms.microphone.disconnect();
    ms.analyser.disconnect();
    ms.jsNode.disconnect();
    ms.microphone = null;
    ms.anaylser = null;
    ms.jsNode = null;
  }

  ms.microphone = ms.context.createMediaStreamSource(stream);
  ms.analyser = ms.context.createAnalyser();
  ms.analyser.smoothingTimeConstant = 0.3;
  ms.analyser.fftSize = 1024;
  ms.jsNode = ms.context.createScriptProcessor(4096, 1, 1);
  ms.jsNode.onaudioprocess = function onAudioProcess() {

    // get the average, bincount is fftsize / 2
    if (ms.emitVol) {
      var array =  new Uint8Array(ms.analyser.frequencyBinCount);
      ms.analyser.getByteFrequencyData(array);
      var average = getAverageVolume(array);
      ms.emit('volume', average);
    }
  };

  ms.microphone.connect(ms.analyser);
  ms.analyser.connect(ms.jsNode);
  ms.jsNode.connect(ms.context.destination);
};

function getAverageVolume(array) {
  var values = 0;
  var average;
  var length = array.length;
  // get all the frequency amplitudes
  for (var i = 0; i < length; i++) {
    values += array[i];
  }
  average = values / length;
  return average;
}

module.exports = MicSelect;

},{"eventemitter2":6,"hark":7,"util":5,"webrtc-adapter-test":9,"webrtcsupport":10}],2:[function(require,module,exports){
if (typeof Object.create === 'function') {
  // implementation from standard node.js 'util' module
  module.exports = function inherits(ctor, superCtor) {
    ctor.super_ = superCtor
    ctor.prototype = Object.create(superCtor.prototype, {
      constructor: {
        value: ctor,
        enumerable: false,
        writable: true,
        configurable: true
      }
    });
  };
} else {
  // old school shim for old browsers
  module.exports = function inherits(ctor, superCtor) {
    ctor.super_ = superCtor
    var TempCtor = function () {}
    TempCtor.prototype = superCtor.prototype
    ctor.prototype = new TempCtor()
    ctor.prototype.constructor = ctor
  }
}

},{}],3:[function(require,module,exports){
// shim for using process in browser

var process = module.exports = {};
var queue = [];
var draining = false;

function drainQueue() {
    if (draining) {
        return;
    }
    draining = true;
    var currentQueue;
    var len = queue.length;
    while(len) {
        currentQueue = queue;
        queue = [];
        var i = -1;
        while (++i < len) {
            currentQueue[i]();
        }
        len = queue.length;
    }
    draining = false;
}
process.nextTick = function (fun) {
    queue.push(fun);
    if (!draining) {
        setTimeout(drainQueue, 0);
    }
};

process.title = 'browser';
process.browser = true;
process.env = {};
process.argv = [];
process.version = ''; // empty string to avoid regexp issues
process.versions = {};

function noop() {}

process.on = noop;
process.addListener = noop;
process.once = noop;
process.off = noop;
process.removeListener = noop;
process.removeAllListeners = noop;
process.emit = noop;

process.binding = function (name) {
    throw new Error('process.binding is not supported');
};

// TODO(shtylman)
process.cwd = function () { return '/' };
process.chdir = function (dir) {
    throw new Error('process.chdir is not supported');
};
process.umask = function() { return 0; };

},{}],4:[function(require,module,exports){
module.exports = function isBuffer(arg) {
  return arg && typeof arg === 'object'
    && typeof arg.copy === 'function'
    && typeof arg.fill === 'function'
    && typeof arg.readUInt8 === 'function';
}
},{}],5:[function(require,module,exports){
(function (process,global){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

var formatRegExp = /%[sdj%]/g;
exports.format = function(f) {
  if (!isString(f)) {
    var objects = [];
    for (var i = 0; i < arguments.length; i++) {
      objects.push(inspect(arguments[i]));
    }
    return objects.join(' ');
  }

  var i = 1;
  var args = arguments;
  var len = args.length;
  var str = String(f).replace(formatRegExp, function(x) {
    if (x === '%%') return '%';
    if (i >= len) return x;
    switch (x) {
      case '%s': return String(args[i++]);
      case '%d': return Number(args[i++]);
      case '%j':
        try {
          return JSON.stringify(args[i++]);
        } catch (_) {
          return '[Circular]';
        }
      default:
        return x;
    }
  });
  for (var x = args[i]; i < len; x = args[++i]) {
    if (isNull(x) || !isObject(x)) {
      str += ' ' + x;
    } else {
      str += ' ' + inspect(x);
    }
  }
  return str;
};


// Mark that a method should not be used.
// Returns a modified function which warns once by default.
// If --no-deprecation is set, then it is a no-op.
exports.deprecate = function(fn, msg) {
  // Allow for deprecating things in the process of starting up.
  if (isUndefined(global.process)) {
    return function() {
      return exports.deprecate(fn, msg).apply(this, arguments);
    };
  }

  if (process.noDeprecation === true) {
    return fn;
  }

  var warned = false;
  function deprecated() {
    if (!warned) {
      if (process.throwDeprecation) {
        throw new Error(msg);
      } else if (process.traceDeprecation) {
        console.trace(msg);
      } else {
        console.error(msg);
      }
      warned = true;
    }
    return fn.apply(this, arguments);
  }

  return deprecated;
};


var debugs = {};
var debugEnviron;
exports.debuglog = function(set) {
  if (isUndefined(debugEnviron))
    debugEnviron = process.env.NODE_DEBUG || '';
  set = set.toUpperCase();
  if (!debugs[set]) {
    if (new RegExp('\\b' + set + '\\b', 'i').test(debugEnviron)) {
      var pid = process.pid;
      debugs[set] = function() {
        var msg = exports.format.apply(exports, arguments);
        console.error('%s %d: %s', set, pid, msg);
      };
    } else {
      debugs[set] = function() {};
    }
  }
  return debugs[set];
};


/**
 * Echos the value of a value. Trys to print the value out
 * in the best way possible given the different types.
 *
 * @param {Object} obj The object to print out.
 * @param {Object} opts Optional options object that alters the output.
 */
/* legacy: obj, showHidden, depth, colors*/
function inspect(obj, opts) {
  // default options
  var ctx = {
    seen: [],
    stylize: stylizeNoColor
  };
  // legacy...
  if (arguments.length >= 3) ctx.depth = arguments[2];
  if (arguments.length >= 4) ctx.colors = arguments[3];
  if (isBoolean(opts)) {
    // legacy...
    ctx.showHidden = opts;
  } else if (opts) {
    // got an "options" object
    exports._extend(ctx, opts);
  }
  // set default options
  if (isUndefined(ctx.showHidden)) ctx.showHidden = false;
  if (isUndefined(ctx.depth)) ctx.depth = 2;
  if (isUndefined(ctx.colors)) ctx.colors = false;
  if (isUndefined(ctx.customInspect)) ctx.customInspect = true;
  if (ctx.colors) ctx.stylize = stylizeWithColor;
  return formatValue(ctx, obj, ctx.depth);
}
exports.inspect = inspect;


// http://en.wikipedia.org/wiki/ANSI_escape_code#graphics
inspect.colors = {
  'bold' : [1, 22],
  'italic' : [3, 23],
  'underline' : [4, 24],
  'inverse' : [7, 27],
  'white' : [37, 39],
  'grey' : [90, 39],
  'black' : [30, 39],
  'blue' : [34, 39],
  'cyan' : [36, 39],
  'green' : [32, 39],
  'magenta' : [35, 39],
  'red' : [31, 39],
  'yellow' : [33, 39]
};

// Don't use 'blue' not visible on cmd.exe
inspect.styles = {
  'special': 'cyan',
  'number': 'yellow',
  'boolean': 'yellow',
  'undefined': 'grey',
  'null': 'bold',
  'string': 'green',
  'date': 'magenta',
  // "name": intentionally not styling
  'regexp': 'red'
};


function stylizeWithColor(str, styleType) {
  var style = inspect.styles[styleType];

  if (style) {
    return '\u001b[' + inspect.colors[style][0] + 'm' + str +
           '\u001b[' + inspect.colors[style][1] + 'm';
  } else {
    return str;
  }
}


function stylizeNoColor(str, styleType) {
  return str;
}


function arrayToHash(array) {
  var hash = {};

  array.forEach(function(val, idx) {
    hash[val] = true;
  });

  return hash;
}


function formatValue(ctx, value, recurseTimes) {
  // Provide a hook for user-specified inspect functions.
  // Check that value is an object with an inspect function on it
  if (ctx.customInspect &&
      value &&
      isFunction(value.inspect) &&
      // Filter out the util module, it's inspect function is special
      value.inspect !== exports.inspect &&
      // Also filter out any prototype objects using the circular check.
      !(value.constructor && value.constructor.prototype === value)) {
    var ret = value.inspect(recurseTimes, ctx);
    if (!isString(ret)) {
      ret = formatValue(ctx, ret, recurseTimes);
    }
    return ret;
  }

  // Primitive types cannot have properties
  var primitive = formatPrimitive(ctx, value);
  if (primitive) {
    return primitive;
  }

  // Look up the keys of the object.
  var keys = Object.keys(value);
  var visibleKeys = arrayToHash(keys);

  if (ctx.showHidden) {
    keys = Object.getOwnPropertyNames(value);
  }

  // IE doesn't make error fields non-enumerable
  // http://msdn.microsoft.com/en-us/library/ie/dww52sbt(v=vs.94).aspx
  if (isError(value)
      && (keys.indexOf('message') >= 0 || keys.indexOf('description') >= 0)) {
    return formatError(value);
  }

  // Some type of object without properties can be shortcutted.
  if (keys.length === 0) {
    if (isFunction(value)) {
      var name = value.name ? ': ' + value.name : '';
      return ctx.stylize('[Function' + name + ']', 'special');
    }
    if (isRegExp(value)) {
      return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
    }
    if (isDate(value)) {
      return ctx.stylize(Date.prototype.toString.call(value), 'date');
    }
    if (isError(value)) {
      return formatError(value);
    }
  }

  var base = '', array = false, braces = ['{', '}'];

  // Make Array say that they are Array
  if (isArray(value)) {
    array = true;
    braces = ['[', ']'];
  }

  // Make functions say that they are functions
  if (isFunction(value)) {
    var n = value.name ? ': ' + value.name : '';
    base = ' [Function' + n + ']';
  }

  // Make RegExps say that they are RegExps
  if (isRegExp(value)) {
    base = ' ' + RegExp.prototype.toString.call(value);
  }

  // Make dates with properties first say the date
  if (isDate(value)) {
    base = ' ' + Date.prototype.toUTCString.call(value);
  }

  // Make error with message first say the error
  if (isError(value)) {
    base = ' ' + formatError(value);
  }

  if (keys.length === 0 && (!array || value.length == 0)) {
    return braces[0] + base + braces[1];
  }

  if (recurseTimes < 0) {
    if (isRegExp(value)) {
      return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
    } else {
      return ctx.stylize('[Object]', 'special');
    }
  }

  ctx.seen.push(value);

  var output;
  if (array) {
    output = formatArray(ctx, value, recurseTimes, visibleKeys, keys);
  } else {
    output = keys.map(function(key) {
      return formatProperty(ctx, value, recurseTimes, visibleKeys, key, array);
    });
  }

  ctx.seen.pop();

  return reduceToSingleString(output, base, braces);
}


function formatPrimitive(ctx, value) {
  if (isUndefined(value))
    return ctx.stylize('undefined', 'undefined');
  if (isString(value)) {
    var simple = '\'' + JSON.stringify(value).replace(/^"|"$/g, '')
                                             .replace(/'/g, "\\'")
                                             .replace(/\\"/g, '"') + '\'';
    return ctx.stylize(simple, 'string');
  }
  if (isNumber(value))
    return ctx.stylize('' + value, 'number');
  if (isBoolean(value))
    return ctx.stylize('' + value, 'boolean');
  // For some reason typeof null is "object", so special case here.
  if (isNull(value))
    return ctx.stylize('null', 'null');
}


function formatError(value) {
  return '[' + Error.prototype.toString.call(value) + ']';
}


function formatArray(ctx, value, recurseTimes, visibleKeys, keys) {
  var output = [];
  for (var i = 0, l = value.length; i < l; ++i) {
    if (hasOwnProperty(value, String(i))) {
      output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
          String(i), true));
    } else {
      output.push('');
    }
  }
  keys.forEach(function(key) {
    if (!key.match(/^\d+$/)) {
      output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
          key, true));
    }
  });
  return output;
}


function formatProperty(ctx, value, recurseTimes, visibleKeys, key, array) {
  var name, str, desc;
  desc = Object.getOwnPropertyDescriptor(value, key) || { value: value[key] };
  if (desc.get) {
    if (desc.set) {
      str = ctx.stylize('[Getter/Setter]', 'special');
    } else {
      str = ctx.stylize('[Getter]', 'special');
    }
  } else {
    if (desc.set) {
      str = ctx.stylize('[Setter]', 'special');
    }
  }
  if (!hasOwnProperty(visibleKeys, key)) {
    name = '[' + key + ']';
  }
  if (!str) {
    if (ctx.seen.indexOf(desc.value) < 0) {
      if (isNull(recurseTimes)) {
        str = formatValue(ctx, desc.value, null);
      } else {
        str = formatValue(ctx, desc.value, recurseTimes - 1);
      }
      if (str.indexOf('\n') > -1) {
        if (array) {
          str = str.split('\n').map(function(line) {
            return '  ' + line;
          }).join('\n').substr(2);
        } else {
          str = '\n' + str.split('\n').map(function(line) {
            return '   ' + line;
          }).join('\n');
        }
      }
    } else {
      str = ctx.stylize('[Circular]', 'special');
    }
  }
  if (isUndefined(name)) {
    if (array && key.match(/^\d+$/)) {
      return str;
    }
    name = JSON.stringify('' + key);
    if (name.match(/^"([a-zA-Z_][a-zA-Z_0-9]*)"$/)) {
      name = name.substr(1, name.length - 2);
      name = ctx.stylize(name, 'name');
    } else {
      name = name.replace(/'/g, "\\'")
                 .replace(/\\"/g, '"')
                 .replace(/(^"|"$)/g, "'");
      name = ctx.stylize(name, 'string');
    }
  }

  return name + ': ' + str;
}


function reduceToSingleString(output, base, braces) {
  var numLinesEst = 0;
  var length = output.reduce(function(prev, cur) {
    numLinesEst++;
    if (cur.indexOf('\n') >= 0) numLinesEst++;
    return prev + cur.replace(/\u001b\[\d\d?m/g, '').length + 1;
  }, 0);

  if (length > 60) {
    return braces[0] +
           (base === '' ? '' : base + '\n ') +
           ' ' +
           output.join(',\n  ') +
           ' ' +
           braces[1];
  }

  return braces[0] + base + ' ' + output.join(', ') + ' ' + braces[1];
}


// NOTE: These type checking functions intentionally don't use `instanceof`
// because it is fragile and can be easily faked with `Object.create()`.
function isArray(ar) {
  return Array.isArray(ar);
}
exports.isArray = isArray;

function isBoolean(arg) {
  return typeof arg === 'boolean';
}
exports.isBoolean = isBoolean;

function isNull(arg) {
  return arg === null;
}
exports.isNull = isNull;

function isNullOrUndefined(arg) {
  return arg == null;
}
exports.isNullOrUndefined = isNullOrUndefined;

function isNumber(arg) {
  return typeof arg === 'number';
}
exports.isNumber = isNumber;

function isString(arg) {
  return typeof arg === 'string';
}
exports.isString = isString;

function isSymbol(arg) {
  return typeof arg === 'symbol';
}
exports.isSymbol = isSymbol;

function isUndefined(arg) {
  return arg === void 0;
}
exports.isUndefined = isUndefined;

function isRegExp(re) {
  return isObject(re) && objectToString(re) === '[object RegExp]';
}
exports.isRegExp = isRegExp;

function isObject(arg) {
  return typeof arg === 'object' && arg !== null;
}
exports.isObject = isObject;

function isDate(d) {
  return isObject(d) && objectToString(d) === '[object Date]';
}
exports.isDate = isDate;

function isError(e) {
  return isObject(e) &&
      (objectToString(e) === '[object Error]' || e instanceof Error);
}
exports.isError = isError;

function isFunction(arg) {
  return typeof arg === 'function';
}
exports.isFunction = isFunction;

function isPrimitive(arg) {
  return arg === null ||
         typeof arg === 'boolean' ||
         typeof arg === 'number' ||
         typeof arg === 'string' ||
         typeof arg === 'symbol' ||  // ES6 symbol
         typeof arg === 'undefined';
}
exports.isPrimitive = isPrimitive;

exports.isBuffer = require('./support/isBuffer');

function objectToString(o) {
  return Object.prototype.toString.call(o);
}


function pad(n) {
  return n < 10 ? '0' + n.toString(10) : n.toString(10);
}


var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep',
              'Oct', 'Nov', 'Dec'];

// 26 Feb 16:19:34
function timestamp() {
  var d = new Date();
  var time = [pad(d.getHours()),
              pad(d.getMinutes()),
              pad(d.getSeconds())].join(':');
  return [d.getDate(), months[d.getMonth()], time].join(' ');
}


// log is just a thin wrapper to console.log that prepends a timestamp
exports.log = function() {
  console.log('%s - %s', timestamp(), exports.format.apply(exports, arguments));
};


/**
 * Inherit the prototype methods from one constructor into another.
 *
 * The Function.prototype.inherits from lang.js rewritten as a standalone
 * function (not on Function.prototype). NOTE: If this file is to be loaded
 * during bootstrapping this function needs to be rewritten using some native
 * functions as prototype setup using normal JavaScript does not work as
 * expected during bootstrapping (see mirror.js in r114903).
 *
 * @param {function} ctor Constructor function which needs to inherit the
 *     prototype.
 * @param {function} superCtor Constructor function to inherit prototype from.
 */
exports.inherits = require('inherits');

exports._extend = function(origin, add) {
  // Don't do anything if add isn't an object
  if (!add || !isObject(add)) return origin;

  var keys = Object.keys(add);
  var i = keys.length;
  while (i--) {
    origin[keys[i]] = add[keys[i]];
  }
  return origin;
};

function hasOwnProperty(obj, prop) {
  return Object.prototype.hasOwnProperty.call(obj, prop);
}

}).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./support/isBuffer":4,"_process":3,"inherits":2}],6:[function(require,module,exports){
/*!
 * EventEmitter2
 * https://github.com/hij1nx/EventEmitter2
 *
 * Copyright (c) 2013 hij1nx
 * Licensed under the MIT license.
 */
;!function(undefined) {

  var isArray = Array.isArray ? Array.isArray : function _isArray(obj) {
    return Object.prototype.toString.call(obj) === "[object Array]";
  };
  var defaultMaxListeners = 10;

  function init() {
    this._events = {};
    if (this._conf) {
      configure.call(this, this._conf);
    }
  }

  function configure(conf) {
    if (conf) {

      this._conf = conf;

      conf.delimiter && (this.delimiter = conf.delimiter);
      conf.maxListeners && (this._events.maxListeners = conf.maxListeners);
      conf.wildcard && (this.wildcard = conf.wildcard);
      conf.newListener && (this.newListener = conf.newListener);

      if (this.wildcard) {
        this.listenerTree = {};
      }
    }
  }

  function EventEmitter(conf) {
    this._events = {};
    this.newListener = false;
    configure.call(this, conf);
  }

  //
  // Attention, function return type now is array, always !
  // It has zero elements if no any matches found and one or more
  // elements (leafs) if there are matches
  //
  function searchListenerTree(handlers, type, tree, i) {
    if (!tree) {
      return [];
    }
    var listeners=[], leaf, len, branch, xTree, xxTree, isolatedBranch, endReached,
        typeLength = type.length, currentType = type[i], nextType = type[i+1];
    if (i === typeLength && tree._listeners) {
      //
      // If at the end of the event(s) list and the tree has listeners
      // invoke those listeners.
      //
      if (typeof tree._listeners === 'function') {
        handlers && handlers.push(tree._listeners);
        return [tree];
      } else {
        for (leaf = 0, len = tree._listeners.length; leaf < len; leaf++) {
          handlers && handlers.push(tree._listeners[leaf]);
        }
        return [tree];
      }
    }

    if ((currentType === '*' || currentType === '**') || tree[currentType]) {
      //
      // If the event emitted is '*' at this part
      // or there is a concrete match at this patch
      //
      if (currentType === '*') {
        for (branch in tree) {
          if (branch !== '_listeners' && tree.hasOwnProperty(branch)) {
            listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], i+1));
          }
        }
        return listeners;
      } else if(currentType === '**') {
        endReached = (i+1 === typeLength || (i+2 === typeLength && nextType === '*'));
        if(endReached && tree._listeners) {
          // The next element has a _listeners, add it to the handlers.
          listeners = listeners.concat(searchListenerTree(handlers, type, tree, typeLength));
        }

        for (branch in tree) {
          if (branch !== '_listeners' && tree.hasOwnProperty(branch)) {
            if(branch === '*' || branch === '**') {
              if(tree[branch]._listeners && !endReached) {
                listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], typeLength));
              }
              listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], i));
            } else if(branch === nextType) {
              listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], i+2));
            } else {
              // No match on this one, shift into the tree but not in the type array.
              listeners = listeners.concat(searchListenerTree(handlers, type, tree[branch], i));
            }
          }
        }
        return listeners;
      }

      listeners = listeners.concat(searchListenerTree(handlers, type, tree[currentType], i+1));
    }

    xTree = tree['*'];
    if (xTree) {
      //
      // If the listener tree will allow any match for this part,
      // then recursively explore all branches of the tree
      //
      searchListenerTree(handlers, type, xTree, i+1);
    }

    xxTree = tree['**'];
    if(xxTree) {
      if(i < typeLength) {
        if(xxTree._listeners) {
          // If we have a listener on a '**', it will catch all, so add its handler.
          searchListenerTree(handlers, type, xxTree, typeLength);
        }

        // Build arrays of matching next branches and others.
        for(branch in xxTree) {
          if(branch !== '_listeners' && xxTree.hasOwnProperty(branch)) {
            if(branch === nextType) {
              // We know the next element will match, so jump twice.
              searchListenerTree(handlers, type, xxTree[branch], i+2);
            } else if(branch === currentType) {
              // Current node matches, move into the tree.
              searchListenerTree(handlers, type, xxTree[branch], i+1);
            } else {
              isolatedBranch = {};
              isolatedBranch[branch] = xxTree[branch];
              searchListenerTree(handlers, type, { '**': isolatedBranch }, i+1);
            }
          }
        }
      } else if(xxTree._listeners) {
        // We have reached the end and still on a '**'
        searchListenerTree(handlers, type, xxTree, typeLength);
      } else if(xxTree['*'] && xxTree['*']._listeners) {
        searchListenerTree(handlers, type, xxTree['*'], typeLength);
      }
    }

    return listeners;
  }

  function growListenerTree(type, listener) {

    type = typeof type === 'string' ? type.split(this.delimiter) : type.slice();

    //
    // Looks for two consecutive '**', if so, don't add the event at all.
    //
    for(var i = 0, len = type.length; i+1 < len; i++) {
      if(type[i] === '**' && type[i+1] === '**') {
        return;
      }
    }

    var tree = this.listenerTree;
    var name = type.shift();

    while (name) {

      if (!tree[name]) {
        tree[name] = {};
      }

      tree = tree[name];

      if (type.length === 0) {

        if (!tree._listeners) {
          tree._listeners = listener;
        }
        else if(typeof tree._listeners === 'function') {
          tree._listeners = [tree._listeners, listener];
        }
        else if (isArray(tree._listeners)) {

          tree._listeners.push(listener);

          if (!tree._listeners.warned) {

            var m = defaultMaxListeners;

            if (typeof this._events.maxListeners !== 'undefined') {
              m = this._events.maxListeners;
            }

            if (m > 0 && tree._listeners.length > m) {

              tree._listeners.warned = true;
              console.error('(node) warning: possible EventEmitter memory ' +
                            'leak detected. %d listeners added. ' +
                            'Use emitter.setMaxListeners() to increase limit.',
                            tree._listeners.length);
              console.trace();
            }
          }
        }
        return true;
      }
      name = type.shift();
    }
    return true;
  }

  // By default EventEmitters will print a warning if more than
  // 10 listeners are added to it. This is a useful default which
  // helps finding memory leaks.
  //
  // Obviously not all Emitters should be limited to 10. This function allows
  // that to be increased. Set to zero for unlimited.

  EventEmitter.prototype.delimiter = '.';

  EventEmitter.prototype.setMaxListeners = function(n) {
    this._events || init.call(this);
    this._events.maxListeners = n;
    if (!this._conf) this._conf = {};
    this._conf.maxListeners = n;
  };

  EventEmitter.prototype.event = '';

  EventEmitter.prototype.once = function(event, fn) {
    this.many(event, 1, fn);
    return this;
  };

  EventEmitter.prototype.many = function(event, ttl, fn) {
    var self = this;

    if (typeof fn !== 'function') {
      throw new Error('many only accepts instances of Function');
    }

    function listener() {
      if (--ttl === 0) {
        self.off(event, listener);
      }
      fn.apply(this, arguments);
    }

    listener._origin = fn;

    this.on(event, listener);

    return self;
  };

  EventEmitter.prototype.emit = function() {

    this._events || init.call(this);

    var type = arguments[0];

    if (type === 'newListener' && !this.newListener) {
      if (!this._events.newListener) { return false; }
    }

    // Loop through the *_all* functions and invoke them.
    if (this._all) {
      var l = arguments.length;
      var args = new Array(l - 1);
      for (var i = 1; i < l; i++) args[i - 1] = arguments[i];
      for (i = 0, l = this._all.length; i < l; i++) {
        this.event = type;
        this._all[i].apply(this, args);
      }
    }

    // If there is no 'error' event listener then throw.
    if (type === 'error') {

      if (!this._all &&
        !this._events.error &&
        !(this.wildcard && this.listenerTree.error)) {

        if (arguments[1] instanceof Error) {
          throw arguments[1]; // Unhandled 'error' event
        } else {
          throw new Error("Uncaught, unspecified 'error' event.");
        }
        return false;
      }
    }

    var handler;

    if(this.wildcard) {
      handler = [];
      var ns = typeof type === 'string' ? type.split(this.delimiter) : type.slice();
      searchListenerTree.call(this, handler, ns, this.listenerTree, 0);
    }
    else {
      handler = this._events[type];
    }

    if (typeof handler === 'function') {
      this.event = type;
      if (arguments.length === 1) {
        handler.call(this);
      }
      else if (arguments.length > 1)
        switch (arguments.length) {
          case 2:
            handler.call(this, arguments[1]);
            break;
          case 3:
            handler.call(this, arguments[1], arguments[2]);
            break;
          // slower
          default:
            var l = arguments.length;
            var args = new Array(l - 1);
            for (var i = 1; i < l; i++) args[i - 1] = arguments[i];
            handler.apply(this, args);
        }
      return true;
    }
    else if (handler) {
      var l = arguments.length;
      var args = new Array(l - 1);
      for (var i = 1; i < l; i++) args[i - 1] = arguments[i];

      var listeners = handler.slice();
      for (var i = 0, l = listeners.length; i < l; i++) {
        this.event = type;
        listeners[i].apply(this, args);
      }
      return (listeners.length > 0) || !!this._all;
    }
    else {
      return !!this._all;
    }

  };

  EventEmitter.prototype.on = function(type, listener) {

    if (typeof type === 'function') {
      this.onAny(type);
      return this;
    }

    if (typeof listener !== 'function') {
      throw new Error('on only accepts instances of Function');
    }
    this._events || init.call(this);

    // To avoid recursion in the case that type == "newListeners"! Before
    // adding it to the listeners, first emit "newListeners".
    this.emit('newListener', type, listener);

    if(this.wildcard) {
      growListenerTree.call(this, type, listener);
      return this;
    }

    if (!this._events[type]) {
      // Optimize the case of one listener. Don't need the extra array object.
      this._events[type] = listener;
    }
    else if(typeof this._events[type] === 'function') {
      // Adding the second element, need to change to array.
      this._events[type] = [this._events[type], listener];
    }
    else if (isArray(this._events[type])) {
      // If we've already got an array, just append.
      this._events[type].push(listener);

      // Check for listener leak
      if (!this._events[type].warned) {

        var m = defaultMaxListeners;

        if (typeof this._events.maxListeners !== 'undefined') {
          m = this._events.maxListeners;
        }

        if (m > 0 && this._events[type].length > m) {

          this._events[type].warned = true;
          console.error('(node) warning: possible EventEmitter memory ' +
                        'leak detected. %d listeners added. ' +
                        'Use emitter.setMaxListeners() to increase limit.',
                        this._events[type].length);
          console.trace();
        }
      }
    }
    return this;
  };

  EventEmitter.prototype.onAny = function(fn) {

    if (typeof fn !== 'function') {
      throw new Error('onAny only accepts instances of Function');
    }

    if(!this._all) {
      this._all = [];
    }

    // Add the function to the event listener collection.
    this._all.push(fn);
    return this;
  };

  EventEmitter.prototype.addListener = EventEmitter.prototype.on;

  EventEmitter.prototype.off = function(type, listener) {
    if (typeof listener !== 'function') {
      throw new Error('removeListener only takes instances of Function');
    }

    var handlers,leafs=[];

    if(this.wildcard) {
      var ns = typeof type === 'string' ? type.split(this.delimiter) : type.slice();
      leafs = searchListenerTree.call(this, null, ns, this.listenerTree, 0);
    }
    else {
      // does not use listeners(), so no side effect of creating _events[type]
      if (!this._events[type]) return this;
      handlers = this._events[type];
      leafs.push({_listeners:handlers});
    }

    for (var iLeaf=0; iLeaf<leafs.length; iLeaf++) {
      var leaf = leafs[iLeaf];
      handlers = leaf._listeners;
      if (isArray(handlers)) {

        var position = -1;

        for (var i = 0, length = handlers.length; i < length; i++) {
          if (handlers[i] === listener ||
            (handlers[i].listener && handlers[i].listener === listener) ||
            (handlers[i]._origin && handlers[i]._origin === listener)) {
            position = i;
            break;
          }
        }

        if (position < 0) {
          continue;
        }

        if(this.wildcard) {
          leaf._listeners.splice(position, 1);
        }
        else {
          this._events[type].splice(position, 1);
        }

        if (handlers.length === 0) {
          if(this.wildcard) {
            delete leaf._listeners;
          }
          else {
            delete this._events[type];
          }
        }
        return this;
      }
      else if (handlers === listener ||
        (handlers.listener && handlers.listener === listener) ||
        (handlers._origin && handlers._origin === listener)) {
        if(this.wildcard) {
          delete leaf._listeners;
        }
        else {
          delete this._events[type];
        }
      }
    }

    return this;
  };

  EventEmitter.prototype.offAny = function(fn) {
    var i = 0, l = 0, fns;
    if (fn && this._all && this._all.length > 0) {
      fns = this._all;
      for(i = 0, l = fns.length; i < l; i++) {
        if(fn === fns[i]) {
          fns.splice(i, 1);
          return this;
        }
      }
    } else {
      this._all = [];
    }
    return this;
  };

  EventEmitter.prototype.removeListener = EventEmitter.prototype.off;

  EventEmitter.prototype.removeAllListeners = function(type) {
    if (arguments.length === 0) {
      !this._events || init.call(this);
      return this;
    }

    if(this.wildcard) {
      var ns = typeof type === 'string' ? type.split(this.delimiter) : type.slice();
      var leafs = searchListenerTree.call(this, null, ns, this.listenerTree, 0);

      for (var iLeaf=0; iLeaf<leafs.length; iLeaf++) {
        var leaf = leafs[iLeaf];
        leaf._listeners = null;
      }
    }
    else {
      if (!this._events[type]) return this;
      this._events[type] = null;
    }
    return this;
  };

  EventEmitter.prototype.listeners = function(type) {
    if(this.wildcard) {
      var handlers = [];
      var ns = typeof type === 'string' ? type.split(this.delimiter) : type.slice();
      searchListenerTree.call(this, handlers, ns, this.listenerTree, 0);
      return handlers;
    }

    this._events || init.call(this);

    if (!this._events[type]) this._events[type] = [];
    if (!isArray(this._events[type])) {
      this._events[type] = [this._events[type]];
    }
    return this._events[type];
  };

  EventEmitter.prototype.listenersAny = function() {

    if(this._all) {
      return this._all;
    }
    else {
      return [];
    }

  };

  if (typeof define === 'function' && define.amd) {
     // AMD. Register as an anonymous module.
    define(function() {
      return EventEmitter;
    });
  } else if (typeof exports === 'object') {
    // CommonJS
    exports.EventEmitter2 = EventEmitter;
  }
  else {
    // Browser global.
    window.EventEmitter2 = EventEmitter;
  }
}();

},{}],7:[function(require,module,exports){
var WildEmitter = require('wildemitter');

function getMaxVolume (analyser, fftBins) {
  var maxVolume = -Infinity;
  analyser.getFloatFrequencyData(fftBins);

  for(var i=4, ii=fftBins.length; i < ii; i++) {
    if (fftBins[i] > maxVolume && fftBins[i] < 0) {
      maxVolume = fftBins[i];
    }
  };

  return maxVolume;
}


var audioContextType = window.AudioContext || window.webkitAudioContext;
// use a single audio context due to hardware limits
var audioContext = null;
module.exports = function(stream, options) {
  var harker = new WildEmitter();


  // make it not break in non-supported browsers
  if (!audioContextType) return harker;

  //Config
  var options = options || {},
      smoothing = (options.smoothing || 0.1),
      interval = (options.interval || 50),
      threshold = options.threshold,
      play = options.play,
      history = options.history || 10,
      running = true;

  //Setup Audio Context
  if (!audioContext) {
    audioContext = new audioContextType();
  }
  var sourceNode, fftBins, analyser;

  analyser = audioContext.createAnalyser();
  analyser.fftSize = 512;
  analyser.smoothingTimeConstant = smoothing;
  fftBins = new Float32Array(analyser.fftSize);

  if (stream.jquery) stream = stream[0];
  if (stream instanceof HTMLAudioElement || stream instanceof HTMLVideoElement) {
    //Audio Tag
    sourceNode = audioContext.createMediaElementSource(stream);
    if (typeof play === 'undefined') play = true;
    threshold = threshold || -50;
  } else {
    //WebRTC Stream
    sourceNode = audioContext.createMediaStreamSource(stream);
    threshold = threshold || -50;
  }

  sourceNode.connect(analyser);
  if (play) analyser.connect(audioContext.destination);

  harker.speaking = false;

  harker.setThreshold = function(t) {
    threshold = t;
  };

  harker.setInterval = function(i) {
    interval = i;
  };
  
  harker.stop = function() {
    running = false;
    harker.emit('volume_change', -100, threshold);
    if (harker.speaking) {
      harker.speaking = false;
      harker.emit('stopped_speaking');
    }
  };
  harker.speakingHistory = [];
  for (var i = 0; i < history; i++) {
      harker.speakingHistory.push(0);
  }

  // Poll the analyser node to determine if speaking
  // and emit events if changed
  var looper = function() {
    setTimeout(function() {
    
      //check if stop has been called
      if(!running) {
        return;
      }
      
      var currentVolume = getMaxVolume(analyser, fftBins);

      harker.emit('volume_change', currentVolume, threshold);

      var history = 0;
      if (currentVolume > threshold && !harker.speaking) {
        // trigger quickly, short history
        for (var i = harker.speakingHistory.length - 3; i < harker.speakingHistory.length; i++) {
          history += harker.speakingHistory[i];
        }
        if (history >= 2) {
          harker.speaking = true;
          harker.emit('speaking');
        }
      } else if (currentVolume < threshold && harker.speaking) {
        for (var i = 0; i < harker.speakingHistory.length; i++) {
          history += harker.speakingHistory[i];
        }
        if (history == 0) {
          harker.speaking = false;
          harker.emit('stopped_speaking');
        }
      }
      harker.speakingHistory.shift();
      harker.speakingHistory.push(0 + (currentVolume > threshold));

      looper();
    }, interval);
  };
  looper();


  return harker;
}

},{"wildemitter":8}],8:[function(require,module,exports){
/*
WildEmitter.js is a slim little event emitter by @henrikjoreteg largely based
on @visionmedia's Emitter from UI Kit.

Why? I wanted it standalone.

I also wanted support for wildcard emitters like this:

emitter.on('*', function (eventName, other, event, payloads) {

});

emitter.on('somenamespace*', function (eventName, payloads) {

});

Please note that callbacks triggered by wildcard registered events also get
the event name as the first argument.
*/

module.exports = WildEmitter;

function WildEmitter() { }

WildEmitter.mixin = function (constructor) {
    var prototype = constructor.prototype || constructor;

    prototype.isWildEmitter= true;

    // Listen on the given `event` with `fn`. Store a group name if present.
    prototype.on = function (event, groupName, fn) {
        this.callbacks = this.callbacks || {};
        var hasGroup = (arguments.length === 3),
            group = hasGroup ? arguments[1] : undefined,
            func = hasGroup ? arguments[2] : arguments[1];
        func._groupName = group;
        (this.callbacks[event] = this.callbacks[event] || []).push(func);
        return this;
    };

    // Adds an `event` listener that will be invoked a single
    // time then automatically removed.
    prototype.once = function (event, groupName, fn) {
        var self = this,
            hasGroup = (arguments.length === 3),
            group = hasGroup ? arguments[1] : undefined,
            func = hasGroup ? arguments[2] : arguments[1];
        function on() {
            self.off(event, on);
            func.apply(this, arguments);
        }
        this.on(event, group, on);
        return this;
    };

    // Unbinds an entire group
    prototype.releaseGroup = function (groupName) {
        this.callbacks = this.callbacks || {};
        var item, i, len, handlers;
        for (item in this.callbacks) {
            handlers = this.callbacks[item];
            for (i = 0, len = handlers.length; i < len; i++) {
                if (handlers[i]._groupName === groupName) {
                    //console.log('removing');
                    // remove it and shorten the array we're looping through
                    handlers.splice(i, 1);
                    i--;
                    len--;
                }
            }
        }
        return this;
    };

    // Remove the given callback for `event` or all
    // registered callbacks.
    prototype.off = function (event, fn) {
        this.callbacks = this.callbacks || {};
        var callbacks = this.callbacks[event],
            i;

        if (!callbacks) return this;

        // remove all handlers
        if (arguments.length === 1) {
            delete this.callbacks[event];
            return this;
        }

        // remove specific handler
        i = callbacks.indexOf(fn);
        callbacks.splice(i, 1);
        if (callbacks.length === 0) {
            delete this.callbacks[event];
        }
        return this;
    };

    /// Emit `event` with the given args.
    // also calls any `*` handlers
    prototype.emit = function (event) {
        this.callbacks = this.callbacks || {};
        var args = [].slice.call(arguments, 1),
            callbacks = this.callbacks[event],
            specialCallbacks = this.getWildcardCallbacks(event),
            i,
            len,
            item,
            listeners;

        if (callbacks) {
            listeners = callbacks.slice();
            for (i = 0, len = listeners.length; i < len; ++i) {
                if (!listeners[i]) {
                    break;
                }
                listeners[i].apply(this, args);
            }
        }

        if (specialCallbacks) {
            len = specialCallbacks.length;
            listeners = specialCallbacks.slice();
            for (i = 0, len = listeners.length; i < len; ++i) {
                if (!listeners[i]) {
                    break;
                }
                listeners[i].apply(this, [event].concat(args));
            }
        }

        return this;
    };

    // Helper for for finding special wildcard event handlers that match the event
    prototype.getWildcardCallbacks = function (eventName) {
        this.callbacks = this.callbacks || {};
        var item,
            split,
            result = [];

        for (item in this.callbacks) {
            split = item.split('*');
            if (item === '*' || (split.length === 2 && eventName.slice(0, split[0].length) === split[0])) {
                result = result.concat(this.callbacks[item]);
            }
        }
        return result;
    };

};

WildEmitter.mixin(WildEmitter);

},{}],9:[function(require,module,exports){
/*
 *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree.
 */

/* More information about these options at jshint.com/docs/options */
/* jshint browser: true, camelcase: true, curly: true, devel: true,
   eqeqeq: true, forin: false, globalstrict: true, node: true,
   quotmark: single, undef: true, unused: strict */
/* global mozRTCIceCandidate, mozRTCPeerConnection, Promise,
mozRTCSessionDescription, webkitRTCPeerConnection, MediaStreamTrack,
MediaStream, RTCIceGatherer, RTCIceTransport, RTCDtlsTransport,
RTCRtpSender, RTCRtpReceiver*/
/* exported trace,requestUserMedia */

'use strict';

var getUserMedia = null;
var attachMediaStream = null;
var reattachMediaStream = null;
var webrtcDetectedBrowser = null;
var webrtcDetectedVersion = null;
var webrtcMinimumVersion = null;
var webrtcUtils = {
  log: function() {
    // suppress console.log output when being included as a module.
    if (typeof module !== 'undefined' ||
        typeof require === 'function' && typeof define === 'function') {
      return;
    }
    console.log.apply(console, arguments);
  },
  extractVersion: function(uastring, expr, pos) {
    var match = uastring.match(expr);
    return match && match.length >= pos && parseInt(match[pos], 10);
  }
};

function trace(text) {
  // This function is used for logging.
  if (text[text.length - 1] === '\n') {
    text = text.substring(0, text.length - 1);
  }
  if (window.performance) {
    var now = (window.performance.now() / 1000).toFixed(3);
    webrtcUtils.log(now + ': ' + text);
  } else {
    webrtcUtils.log(text);
  }
}

if (typeof window === 'object') {
  if (window.HTMLMediaElement &&
    !('srcObject' in window.HTMLMediaElement.prototype)) {
    // Shim the srcObject property, once, when HTMLMediaElement is found.
    Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
      get: function() {
        // If prefixed srcObject property exists, return it.
        // Otherwise use the shimmed property, _srcObject
        return 'mozSrcObject' in this ? this.mozSrcObject : this._srcObject;
      },
      set: function(stream) {
        if ('mozSrcObject' in this) {
          this.mozSrcObject = stream;
        } else {
          // Use _srcObject as a private property for this shim
          this._srcObject = stream;
          // TODO: revokeObjectUrl(this.src) when !stream to release resources?
          this.src = URL.createObjectURL(stream);
        }
      }
    });
  }
  // Proxy existing globals
  getUserMedia = window.navigator && window.navigator.getUserMedia;
}

// Attach a media stream to an element.
attachMediaStream = function(element, stream) {
  element.srcObject = stream;
};

reattachMediaStream = function(to, from) {
  to.srcObject = from.srcObject;
};

if (typeof window === 'undefined' || !window.navigator) {
  webrtcUtils.log('This does not appear to be a browser');
  webrtcDetectedBrowser = 'not a browser';
} else if (navigator.mozGetUserMedia && window.mozRTCPeerConnection) {
  webrtcUtils.log('This appears to be Firefox');

  webrtcDetectedBrowser = 'firefox';

  // the detected firefox version.
  webrtcDetectedVersion = webrtcUtils.extractVersion(navigator.userAgent,
      /Firefox\/([0-9]+)\./, 1);

  // the minimum firefox version still supported by adapter.
  webrtcMinimumVersion = 31;

  // The RTCPeerConnection object.
  window.RTCPeerConnection = function(pcConfig, pcConstraints) {
    if (webrtcDetectedVersion < 38) {
      // .urls is not supported in FF < 38.
      // create RTCIceServers with a single url.
      if (pcConfig && pcConfig.iceServers) {
        var newIceServers = [];
        for (var i = 0; i < pcConfig.iceServers.length; i++) {
          var server = pcConfig.iceServers[i];
          if (server.hasOwnProperty('urls')) {
            for (var j = 0; j < server.urls.length; j++) {
              var newServer = {
                url: server.urls[j]
              };
              if (server.urls[j].indexOf('turn') === 0) {
                newServer.username = server.username;
                newServer.credential = server.credential;
              }
              newIceServers.push(newServer);
            }
          } else {
            newIceServers.push(pcConfig.iceServers[i]);
          }
        }
        pcConfig.iceServers = newIceServers;
      }
    }
    return new mozRTCPeerConnection(pcConfig, pcConstraints); // jscs:ignore requireCapitalizedConstructors
  };

  // wrap static methods. Currently just generateCertificate.
  if (mozRTCPeerConnection.generateCertificate) {
    Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
      get: function() {
        if (arguments.length) {
          return mozRTCPeerConnection.generateCertificate.apply(null,
              arguments);
        } else {
          return mozRTCPeerConnection.generateCertificate;
        }
      }
    });
  }

  // The RTCSessionDescription object.
  if (!window.RTCSessionDescription) {
    window.RTCSessionDescription = mozRTCSessionDescription;
  }

  // The RTCIceCandidate object.
  if (!window.RTCIceCandidate) {
    window.RTCIceCandidate = mozRTCIceCandidate;
  }

  // getUserMedia constraints shim.
  getUserMedia = function(constraints, onSuccess, onError) {
    var constraintsToFF37 = function(c) {
      if (typeof c !== 'object' || c.require) {
        return c;
      }
      var require = [];
      Object.keys(c).forEach(function(key) {
        if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
          return;
        }
        var r = c[key] = (typeof c[key] === 'object') ?
            c[key] : {ideal: c[key]};
        if (r.min !== undefined ||
            r.max !== undefined || r.exact !== undefined) {
          require.push(key);
        }
        if (r.exact !== undefined) {
          if (typeof r.exact === 'number') {
            r.min = r.max = r.exact;
          } else {
            c[key] = r.exact;
          }
          delete r.exact;
        }
        if (r.ideal !== undefined) {
          c.advanced = c.advanced || [];
          var oc = {};
          if (typeof r.ideal === 'number') {
            oc[key] = {min: r.ideal, max: r.ideal};
          } else {
            oc[key] = r.ideal;
          }
          c.advanced.push(oc);
          delete r.ideal;
          if (!Object.keys(r).length) {
            delete c[key];
          }
        }
      });
      if (require.length) {
        c.require = require;
      }
      return c;
    };
    if (webrtcDetectedVersion < 38) {
      webrtcUtils.log('spec: ' + JSON.stringify(constraints));
      if (constraints.audio) {
        constraints.audio = constraintsToFF37(constraints.audio);
      }
      if (constraints.video) {
        constraints.video = constraintsToFF37(constraints.video);
      }
      webrtcUtils.log('ff37: ' + JSON.stringify(constraints));
    }
    return navigator.mozGetUserMedia(constraints, onSuccess, onError);
  };

  navigator.getUserMedia = getUserMedia;

  // Shim for mediaDevices on older versions.
  if (!navigator.mediaDevices) {
    navigator.mediaDevices = {getUserMedia: requestUserMedia,
      addEventListener: function() { },
      removeEventListener: function() { }
    };
  }
  navigator.mediaDevices.enumerateDevices =
      navigator.mediaDevices.enumerateDevices || function() {
    return new Promise(function(resolve) {
      var infos = [
        {kind: 'audioinput', deviceId: 'default', label: '', groupId: ''},
        {kind: 'videoinput', deviceId: 'default', label: '', groupId: ''}
      ];
      resolve(infos);
    });
  };

  if (webrtcDetectedVersion < 41) {
    // Work around http://bugzil.la/1169665
    var orgEnumerateDevices =
        navigator.mediaDevices.enumerateDevices.bind(navigator.mediaDevices);
    navigator.mediaDevices.enumerateDevices = function() {
      return orgEnumerateDevices().then(undefined, function(e) {
        if (e.name === 'NotFoundError') {
          return [];
        }
        throw e;
      });
    };
  }
} else if (navigator.webkitGetUserMedia && window.webkitRTCPeerConnection) {
  webrtcUtils.log('This appears to be Chrome');

  webrtcDetectedBrowser = 'chrome';

  // the detected chrome version.
  webrtcDetectedVersion = webrtcUtils.extractVersion(navigator.userAgent,
      /Chrom(e|ium)\/([0-9]+)\./, 2);

  // the minimum chrome version still supported by adapter.
  webrtcMinimumVersion = 38;

  // The RTCPeerConnection object.
  window.RTCPeerConnection = function(pcConfig, pcConstraints) {
    // Translate iceTransportPolicy to iceTransports,
    // see https://code.google.com/p/webrtc/issues/detail?id=4869
    if (pcConfig && pcConfig.iceTransportPolicy) {
      pcConfig.iceTransports = pcConfig.iceTransportPolicy;
    }

    var pc = new webkitRTCPeerConnection(pcConfig, pcConstraints); // jscs:ignore requireCapitalizedConstructors
    var origGetStats = pc.getStats.bind(pc);
    pc.getStats = function(selector, successCallback, errorCallback) { // jshint ignore: line
      var self = this;
      var args = arguments;

      // If selector is a function then we are in the old style stats so just
      // pass back the original getStats format to avoid breaking old users.
      if (arguments.length > 0 && typeof selector === 'function') {
        return origGetStats(selector, successCallback);
      }

      var fixChromeStats = function(response) {
        var standardReport = {};
        var reports = response.result();
        reports.forEach(function(report) {
          var standardStats = {
            id: report.id,
            timestamp: report.timestamp,
            type: report.type
          };
          report.names().forEach(function(name) {
            standardStats[name] = report.stat(name);
          });
          standardReport[standardStats.id] = standardStats;
        });

        return standardReport;
      };

      if (arguments.length >= 2) {
        var successCallbackWrapper = function(response) {
          args[1](fixChromeStats(response));
        };

        return origGetStats.apply(this, [successCallbackWrapper, arguments[0]]);
      }

      // promise-support
      return new Promise(function(resolve, reject) {
        if (args.length === 1 && selector === null) {
          origGetStats.apply(self, [
              function(response) {
                resolve.apply(null, [fixChromeStats(response)]);
              }, reject]);
        } else {
          origGetStats.apply(self, [resolve, reject]);
        }
      });
    };

    return pc;
  };

  // wrap static methods. Currently just generateCertificate.
  if (webkitRTCPeerConnection.generateCertificate) {
    Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
      get: function() {
        if (arguments.length) {
          return webkitRTCPeerConnection.generateCertificate.apply(null,
              arguments);
        } else {
          return webkitRTCPeerConnection.generateCertificate;
        }
      }
    });
  }

  // add promise support
  ['createOffer', 'createAnswer'].forEach(function(method) {
    var nativeMethod = webkitRTCPeerConnection.prototype[method];
    webkitRTCPeerConnection.prototype[method] = function() {
      var self = this;
      if (arguments.length < 1 || (arguments.length === 1 &&
          typeof(arguments[0]) === 'object')) {
        var opts = arguments.length === 1 ? arguments[0] : undefined;
        return new Promise(function(resolve, reject) {
          nativeMethod.apply(self, [resolve, reject, opts]);
        });
      } else {
        return nativeMethod.apply(this, arguments);
      }
    };
  });

  ['setLocalDescription', 'setRemoteDescription',
      'addIceCandidate'].forEach(function(method) {
    var nativeMethod = webkitRTCPeerConnection.prototype[method];
    webkitRTCPeerConnection.prototype[method] = function() {
      var args = arguments;
      var self = this;
      return new Promise(function(resolve, reject) {
        nativeMethod.apply(self, [args[0],
            function() {
              resolve();
              if (args.length >= 2) {
                args[1].apply(null, []);
              }
            },
            function(err) {
              reject(err);
              if (args.length >= 3) {
                args[2].apply(null, [err]);
              }
            }]
          );
      });
    };
  });

  // getUserMedia constraints shim.
  var constraintsToChrome = function(c) {
    if (typeof c !== 'object' || c.mandatory || c.optional) {
      return c;
    }
    var cc = {};
    Object.keys(c).forEach(function(key) {
      if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
        return;
      }
      var r = (typeof c[key] === 'object') ? c[key] : {ideal: c[key]};
      if (r.exact !== undefined && typeof r.exact === 'number') {
        r.min = r.max = r.exact;
      }
      var oldname = function(prefix, name) {
        if (prefix) {
          return prefix + name.charAt(0).toUpperCase() + name.slice(1);
        }
        return (name === 'deviceId') ? 'sourceId' : name;
      };
      if (r.ideal !== undefined) {
        cc.optional = cc.optional || [];
        var oc = {};
        if (typeof r.ideal === 'number') {
          oc[oldname('min', key)] = r.ideal;
          cc.optional.push(oc);
          oc = {};
          oc[oldname('max', key)] = r.ideal;
          cc.optional.push(oc);
        } else {
          oc[oldname('', key)] = r.ideal;
          cc.optional.push(oc);
        }
      }
      if (r.exact !== undefined && typeof r.exact !== 'number') {
        cc.mandatory = cc.mandatory || {};
        cc.mandatory[oldname('', key)] = r.exact;
      } else {
        ['min', 'max'].forEach(function(mix) {
          if (r[mix] !== undefined) {
            cc.mandatory = cc.mandatory || {};
            cc.mandatory[oldname(mix, key)] = r[mix];
          }
        });
      }
    });
    if (c.advanced) {
      cc.optional = (cc.optional || []).concat(c.advanced);
    }
    return cc;
  };

  getUserMedia = function(constraints, onSuccess, onError) {
    if (constraints.audio) {
      constraints.audio = constraintsToChrome(constraints.audio);
    }
    if (constraints.video) {
      constraints.video = constraintsToChrome(constraints.video);
    }
    webrtcUtils.log('chrome: ' + JSON.stringify(constraints));
    return navigator.webkitGetUserMedia(constraints, onSuccess, onError);
  };
  navigator.getUserMedia = getUserMedia;

  if (!navigator.mediaDevices) {
    navigator.mediaDevices = {getUserMedia: requestUserMedia,
                              enumerateDevices: function() {
      return new Promise(function(resolve) {
        var kinds = {audio: 'audioinput', video: 'videoinput'};
        return MediaStreamTrack.getSources(function(devices) {
          resolve(devices.map(function(device) {
            return {label: device.label,
                    kind: kinds[device.kind],
                    deviceId: device.id,
                    groupId: ''};
          }));
        });
      });
    }};
  }

  // A shim for getUserMedia method on the mediaDevices object.
  // TODO(KaptenJansson) remove once implemented in Chrome stable.
  if (!navigator.mediaDevices.getUserMedia) {
    navigator.mediaDevices.getUserMedia = function(constraints) {
      return requestUserMedia(constraints);
    };
  } else {
    // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
    // function which returns a Promise, it does not accept spec-style
    // constraints.
    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
        bind(navigator.mediaDevices);
    navigator.mediaDevices.getUserMedia = function(c) {
      webrtcUtils.log('spec:   ' + JSON.stringify(c)); // whitespace for alignment
      c.audio = constraintsToChrome(c.audio);
      c.video = constraintsToChrome(c.video);
      webrtcUtils.log('chrome: ' + JSON.stringify(c));
      return origGetUserMedia(c);
    };
  }

  // Dummy devicechange event methods.
  // TODO(KaptenJansson) remove once implemented in Chrome stable.
  if (typeof navigator.mediaDevices.addEventListener === 'undefined') {
    navigator.mediaDevices.addEventListener = function() {
      webrtcUtils.log('Dummy mediaDevices.addEventListener called.');
    };
  }
  if (typeof navigator.mediaDevices.removeEventListener === 'undefined') {
    navigator.mediaDevices.removeEventListener = function() {
      webrtcUtils.log('Dummy mediaDevices.removeEventListener called.');
    };
  }

  // Attach a media stream to an element.
  attachMediaStream = function(element, stream) {
    if (webrtcDetectedVersion >= 43) {
      element.srcObject = stream;
    } else if (typeof element.src !== 'undefined') {
      element.src = URL.createObjectURL(stream);
    } else {
      webrtcUtils.log('Error attaching stream to element.');
    }
  };
  reattachMediaStream = function(to, from) {
    if (webrtcDetectedVersion >= 43) {
      to.srcObject = from.srcObject;
    } else {
      to.src = from.src;
    }
  };

} else if (navigator.mediaDevices && navigator.userAgent.match(
    /Edge\/(\d+).(\d+)$/)) {
  webrtcUtils.log('This appears to be Edge');
  webrtcDetectedBrowser = 'edge';

  webrtcDetectedVersion = webrtcUtils.extractVersion(navigator.userAgent,
      /Edge\/(\d+).(\d+)$/, 2);

  // The minimum version still supported by adapter.
  // This is the build number for Edge.
  webrtcMinimumVersion = 10547;

  if (RTCIceGatherer) {
    // Generate an alphanumeric identifier for cname or mids.
    // TODO: use UUIDs instead? https://gist.github.com/jed/982883
    var generateIdentifier = function() {
      return Math.random().toString(36).substr(2, 10);
    };

    // The RTCP CNAME used by all peerconnections from the same JS.
    var localCName = generateIdentifier();

    // SDP helpers - to be moved into separate module.
    var SDPUtils = {};

    // Splits SDP into lines, dealing with both CRLF and LF.
    SDPUtils.splitLines = function(blob) {
      return blob.trim().split('\n').map(function(line) {
        return line.trim();
      });
    };

    // Splits SDP into sessionpart and mediasections. Ensures CRLF.
    SDPUtils.splitSections = function(blob) {
      var parts = blob.split('\r\nm=');
      return parts.map(function(part, index) {
        return (index > 0 ? 'm=' + part : part).trim() + '\r\n';
      });
    };

    // Returns lines that start with a certain prefix.
    SDPUtils.matchPrefix = function(blob, prefix) {
      return SDPUtils.splitLines(blob).filter(function(line) {
        return line.indexOf(prefix) === 0;
      });
    };

    // Parses an ICE candidate line. Sample input:
    // candidate:702786350 2 udp 41819902 8.8.8.8 60769 typ relay raddr 8.8.8.8 rport 55996"
    SDPUtils.parseCandidate = function(line) {
      var parts;
      // Parse both variants.
      if (line.indexOf('a=candidate:') === 0) {
        parts = line.substring(12).split(' ');
      } else {
        parts = line.substring(10).split(' ');
      }

      var candidate = {
        foundation: parts[0],
        component: parts[1],
        protocol: parts[2].toLowerCase(),
        priority: parseInt(parts[3], 10),
        ip: parts[4],
        port: parseInt(parts[5], 10),
        // skip parts[6] == 'typ'
        type: parts[7]
      };

      for (var i = 8; i < parts.length; i += 2) {
        switch (parts[i]) {
          case 'raddr':
            candidate.relatedAddress = parts[i + 1];
            break;
          case 'rport':
            candidate.relatedPort = parseInt(parts[i + 1], 10);
            break;
          case 'tcptype':
            candidate.tcpType = parts[i + 1];
            break;
          default: // Unknown extensions are silently ignored.
            break;
        }
      }
      return candidate;
    };

    // Translates a candidate object into SDP candidate attribute.
    SDPUtils.writeCandidate = function(candidate) {
      var sdp = [];
      sdp.push(candidate.foundation);
      sdp.push(candidate.component);
      sdp.push(candidate.protocol.toUpperCase());
      sdp.push(candidate.priority);
      sdp.push(candidate.ip);
      sdp.push(candidate.port);

      var type = candidate.type;
      sdp.push('typ');
      sdp.push(type);
      if (type !== 'host' && candidate.relatedAddress &&
          candidate.relatedPort) {
        sdp.push('raddr');
        sdp.push(candidate.relatedAddress); // was: relAddr
        sdp.push('rport');
        sdp.push(candidate.relatedPort); // was: relPort
      }
      if (candidate.tcpType && candidate.protocol.toLowerCase() === 'tcp') {
        sdp.push('tcptype');
        sdp.push(candidate.tcpType);
      }
      return 'candidate:' + sdp.join(' ');
    };

    // Parses an rtpmap line, returns RTCRtpCoddecParameters. Sample input:
    // a=rtpmap:111 opus/48000/2
    SDPUtils.parseRtpMap = function(line) {
      var parts = line.substr(9).split(' ');
      var parsed = {
        payloadType: parseInt(parts.shift(), 10) // was: id
      };

      parts = parts[0].split('/');

      parsed.name = parts[0];
      parsed.clockRate = parseInt(parts[1], 10); // was: clockrate
      parsed.numChannels = parts.length === 3 ? parseInt(parts[2], 10) : 1; // was: channels
      return parsed;
    };

    // Generate an a=rtpmap line from RTCRtpCodecCapability or RTCRtpCodecParameters.
    SDPUtils.writeRtpMap = function(codec) {
      var pt = codec.payloadType;
      if (codec.preferredPayloadType !== undefined) {
        pt = codec.preferredPayloadType;
      }
      return 'a=rtpmap:' + pt + ' ' + codec.name + '/' + codec.clockRate +
          (codec.numChannels !== 1 ? '/' + codec.numChannels : '') + '\r\n';
    };

    // Parses an ftmp line, returns dictionary. Sample input:
    // a=fmtp:96 vbr=on;cng=on
    // Also deals with vbr=on; cng=on
    SDPUtils.parseFmtp = function(line) {
      var parsed = {};
      var kv;
      var parts = line.substr(line.indexOf(' ') + 1).split(';');
      for (var j = 0; j < parts.length; j++) {
        kv = parts[j].trim().split('=');
        parsed[kv[0].trim()] = kv[1];
      }
      return parsed;
    };

    // Generates an a=ftmp line from RTCRtpCodecCapability or RTCRtpCodecParameters.
    SDPUtils.writeFtmp = function(codec) {
      var line = '';
      var pt = codec.payloadType;
      if (codec.preferredPayloadType !== undefined) {
        pt = codec.preferredPayloadType;
      }
      if (codec.parameters && codec.parameters.length) {
        var params = [];
        Object.keys(codec.parameters).forEach(function(param) {
          params.push(param + '=' + codec.parameters[param]);
        });
        line += 'a=fmtp:' + pt + ' ' + params.join(';') + '\r\n';
      }
      return line;
    };

    // Parses an rtcp-fb line, returns RTCPRtcpFeedback object. Sample input:
    // a=rtcp-fb:98 nack rpsi
    SDPUtils.parseRtcpFb = function(line) {
      var parts = line.substr(line.indexOf(' ') + 1).split(' ');
      return {
        type: parts.shift(),
        parameter: parts.join(' ')
      };
    };
    // Generate a=rtcp-fb lines from RTCRtpCodecCapability or RTCRtpCodecParameters.
    SDPUtils.writeRtcpFb = function(codec) {
      var lines = '';
      var pt = codec.payloadType;
      if (codec.preferredPayloadType !== undefined) {
        pt = codec.preferredPayloadType;
      }
      if (codec.rtcpFeedback && codec.rtcpFeedback.length) {
        // FIXME: special handling for trr-int?
        codec.rtcpFeedback.forEach(function(fb) {
          lines += 'a=rtcp-fb:' + pt + ' ' + fb.type + ' ' + fb.parameter +
              '\r\n';
        });
      }
      return lines;
    };

    // Parses an RFC 5576 ssrc media attribute. Sample input:
    // a=ssrc:3735928559 cname:something
    SDPUtils.parseSsrcMedia = function(line) {
      var sp = line.indexOf(' ');
      var parts = {
        ssrc: line.substr(7, sp - 7),
      };
      var colon = line.indexOf(':', sp);
      if (colon > -1) {
        parts.attribute = line.substr(sp + 1, colon - sp - 1);
        parts.value = line.substr(colon + 1);
      } else {
        parts.attribute = line.substr(sp + 1);
      }
      return parts;
    };

    // Extracts DTLS parameters from SDP media section or sessionpart.
    // FIXME: for consistency with other functions this should only
    //   get the fingerprint line as input. See also getIceParameters.
    SDPUtils.getDtlsParameters = function(mediaSection, sessionpart) {
      var lines = SDPUtils.splitLines(mediaSection);
      lines = lines.concat(SDPUtils.splitLines(sessionpart)); // Search in session part, too.
      var fpLine = lines.filter(function(line) {
        return line.indexOf('a=fingerprint:') === 0;
      })[0].substr(14);
      // Note: a=setup line is ignored since we use the 'auto' role.
      var dtlsParameters = {
        role: 'auto',
        fingerprints: [{
          algorithm: fpLine.split(' ')[0],
          value: fpLine.split(' ')[1]
        }]
      };
      return dtlsParameters;
    };

    // Serializes DTLS parameters to SDP.
    SDPUtils.writeDtlsParameters = function(params, setupType) {
      var sdp = 'a=setup:' + setupType + '\r\n';
      params.fingerprints.forEach(function(fp) {
        sdp += 'a=fingerprint:' + fp.algorithm + ' ' + fp.value + '\r\n';
      });
      return sdp;
    };
    // Parses ICE information from SDP media section or sessionpart.
    // FIXME: for consistency with other functions this should only
    //   get the ice-ufrag and ice-pwd lines as input.
    SDPUtils.getIceParameters = function(mediaSection, sessionpart) {
      var lines = SDPUtils.splitLines(mediaSection);
      lines = lines.concat(SDPUtils.splitLines(sessionpart)); // Search in session part, too.
      var iceParameters = {
        usernameFragment: lines.filter(function(line) {
          return line.indexOf('a=ice-ufrag:') === 0;
        })[0].substr(12),
        password: lines.filter(function(line) {
          return line.indexOf('a=ice-pwd:') === 0;
        })[0].substr(10)
      };
      return iceParameters;
    };

    // Serializes ICE parameters to SDP.
    SDPUtils.writeIceParameters = function(params) {
      return 'a=ice-ufrag:' + params.usernameFragment + '\r\n' +
          'a=ice-pwd:' + params.password + '\r\n';
    };

    // Parses the SDP media section and returns RTCRtpParameters.
    SDPUtils.parseRtpParameters = function(mediaSection) {
      var description = {
        codecs: [],
        headerExtensions: [],
        fecMechanisms: [],
        rtcp: []
      };
      var lines = SDPUtils.splitLines(mediaSection);
      var mline = lines[0].split(' ');
      for (var i = 3; i < mline.length; i++) { // find all codecs from mline[3..]
        var pt = mline[i];
        var rtpmapline = SDPUtils.matchPrefix(
            mediaSection, 'a=rtpmap:' + pt + ' ')[0];
        if (rtpmapline) {
          var codec = SDPUtils.parseRtpMap(rtpmapline);
          var fmtps = SDPUtils.matchPrefix(
              mediaSection, 'a=fmtp:' + pt + ' ');
          // Only the first a=fmtp:<pt> is considered.
          codec.parameters = fmtps.length ? SDPUtils.parseFmtp(fmtps[0]) : {};
          codec.rtcpFeedback = SDPUtils.matchPrefix(
              mediaSection, 'a=rtcp-fb:' + pt + ' ')
            .map(SDPUtils.parseRtcpFb);
          description.codecs.push(codec);
        }
      }
      // FIXME: parse headerExtensions, fecMechanisms and rtcp.
      return description;
    };

    // Generates parts of the SDP media section describing the capabilities / parameters.
    SDPUtils.writeRtpDescription = function(kind, caps) {
      var sdp = '';

      // Build the mline.
      sdp += 'm=' + kind + ' ';
      sdp += caps.codecs.length > 0 ? '9' : '0'; // reject if no codecs.
      sdp += ' UDP/TLS/RTP/SAVPF ';
      sdp += caps.codecs.map(function(codec) {
        if (codec.preferredPayloadType !== undefined) {
          return codec.preferredPayloadType;
        }
        return codec.payloadType;
      }).join(' ') + '\r\n';

      sdp += 'c=IN IP4 0.0.0.0\r\n';
      sdp += 'a=rtcp:9 IN IP4 0.0.0.0\r\n';

      // Add a=rtpmap lines for each codec. Also fmtp and rtcp-fb.
      caps.codecs.forEach(function(codec) {
        sdp += SDPUtils.writeRtpMap(codec);
        sdp += SDPUtils.writeFtmp(codec);
        sdp += SDPUtils.writeRtcpFb(codec);
      });
      // FIXME: add headerExtensions, fecMechanismş and rtcp.
      sdp += 'a=rtcp-mux\r\n';
      return sdp;
    };

    SDPUtils.writeSessionBoilerplate = function() {
      // FIXME: sess-id should be an NTP timestamp.
      return 'v=0\r\n' +
          'o=thisisadapterortc 8169639915646943137 2 IN IP4 127.0.0.1\r\n' +
          's=-\r\n' +
          't=0 0\r\n';
    };

    SDPUtils.writeMediaSection = function(transceiver, caps, type, stream) {
      var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);

      // Map ICE parameters (ufrag, pwd) to SDP.
      sdp += SDPUtils.writeIceParameters(
          transceiver.iceGatherer.getLocalParameters());

      // Map DTLS parameters to SDP.
      sdp += SDPUtils.writeDtlsParameters(
          transceiver.dtlsTransport.getLocalParameters(),
          type === 'offer' ? 'actpass' : 'active');

      sdp += 'a=mid:' + transceiver.mid + '\r\n';

      if (transceiver.rtpSender && transceiver.rtpReceiver) {
        sdp += 'a=sendrecv\r\n';
      } else if (transceiver.rtpSender) {
        sdp += 'a=sendonly\r\n';
      } else if (transceiver.rtpReceiver) {
        sdp += 'a=recvonly\r\n';
      } else {
        sdp += 'a=inactive\r\n';
      }

      // FIXME: for RTX there might be multiple SSRCs. Not implemented in Edge yet.
      if (transceiver.rtpSender) {
        var msid = 'msid:' + stream.id + ' ' +
            transceiver.rtpSender.track.id + '\r\n';
        sdp += 'a=' + msid;
        sdp += 'a=ssrc:' + transceiver.sendSsrc + ' ' + msid;
      }
      // FIXME: this should be written by writeRtpDescription.
      sdp += 'a=ssrc:' + transceiver.sendSsrc + ' cname:' +
          localCName + '\r\n';
      return sdp;
    };

    // Gets the direction from the mediaSection or the sessionpart.
    SDPUtils.getDirection = function(mediaSection, sessionpart) {
      // Look for sendrecv, sendonly, recvonly, inactive, default to sendrecv.
      var lines = SDPUtils.splitLines(mediaSection);
      for (var i = 0; i < lines.length; i++) {
        switch (lines[i]) {
          case 'a=sendrecv':
          case 'a=sendonly':
          case 'a=recvonly':
          case 'a=inactive':
            return lines[i].substr(2);
        }
      }
      if (sessionpart) {
        return SDPUtils.getDirection(sessionpart);
      }
      return 'sendrecv';
    };

    // ORTC defines an RTCIceCandidate object but no constructor.
    // Not implemented in Edge.
    if (!window.RTCIceCandidate) {
      window.RTCIceCandidate = function(args) {
        return args;
      };
    }
    // ORTC does not have a session description object but
    // other browsers (i.e. Chrome) that will support both PC and ORTC
    // in the future might have this defined already.
    if (!window.RTCSessionDescription) {
      window.RTCSessionDescription = function(args) {
        return args;
      };
    }

    window.RTCPeerConnection = function(config) {
      var self = this;

      this.onicecandidate = null;
      this.onaddstream = null;
      this.onremovestream = null;
      this.onsignalingstatechange = null;
      this.oniceconnectionstatechange = null;
      this.onnegotiationneeded = null;
      this.ondatachannel = null;

      this.localStreams = [];
      this.remoteStreams = [];
      this.getLocalStreams = function() { return self.localStreams; };
      this.getRemoteStreams = function() { return self.remoteStreams; };

      this.localDescription = new RTCSessionDescription({
        type: '',
        sdp: ''
      });
      this.remoteDescription = new RTCSessionDescription({
        type: '',
        sdp: ''
      });
      this.signalingState = 'stable';
      this.iceConnectionState = 'new';

      this.iceOptions = {
        gatherPolicy: 'all',
        iceServers: []
      };
      if (config && config.iceTransportPolicy) {
        switch (config.iceTransportPolicy) {
          case 'all':
          case 'relay':
            this.iceOptions.gatherPolicy = config.iceTransportPolicy;
            break;
          case 'none':
            // FIXME: remove once implementation and spec have added this.
            throw new TypeError('iceTransportPolicy "none" not supported');
        }
      }
      if (config && config.iceServers) {
        // Edge does not like
        // 1) stun:
        // 2) turn: that does not have all of turn:host:port?transport=udp
        // 3) an array of urls
        config.iceServers.forEach(function(server) {
          if (server.urls) {
            var url;
            if (typeof(server.urls) === 'string') {
              url = server.urls;
            } else {
              url = server.urls[0];
            }
            if (url.indexOf('transport=udp') !== -1) {
              self.iceServers.push({
                username: server.username,
                credential: server.credential,
                urls: url
              });
            }
          }
        });
      }

      // per-track iceGathers, iceTransports, dtlsTransports, rtpSenders, ...
      // everything that is needed to describe a SDP m-line.
      this.transceivers = [];

      // since the iceGatherer is currently created in createOffer but we
      // must not emit candidates until after setLocalDescription we buffer
      // them in this array.
      this._localIceCandidatesBuffer = [];
    };

    window.RTCPeerConnection.prototype._emitBufferedCandidates = function() {
      var self = this;
      // FIXME: need to apply ice candidates in a way which is async but in-order
      this._localIceCandidatesBuffer.forEach(function(event) {
        if (self.onicecandidate !== null) {
          self.onicecandidate(event);
        }
      });
      this._localIceCandidatesBuffer = [];
    };

    window.RTCPeerConnection.prototype.addStream = function(stream) {
      // Clone is necessary for local demos mostly, attaching directly
      // to two different senders does not work (build 10547).
      this.localStreams.push(stream.clone());
      this._maybeFireNegotiationNeeded();
    };

    window.RTCPeerConnection.prototype.removeStream = function(stream) {
      var idx = this.localStreams.indexOf(stream);
      if (idx > -1) {
        this.localStreams.splice(idx, 1);
        this._maybeFireNegotiationNeeded();
      }
    };

    // Determines the intersection of local and remote capabilities.
    window.RTCPeerConnection.prototype._getCommonCapabilities =
        function(localCapabilities, remoteCapabilities) {
      var commonCapabilities = {
        codecs: [],
        headerExtensions: [],
        fecMechanisms: []
      };
      localCapabilities.codecs.forEach(function(lCodec) {
        for (var i = 0; i < remoteCapabilities.codecs.length; i++) {
          var rCodec = remoteCapabilities.codecs[i];
          if (lCodec.name.toLowerCase() === rCodec.name.toLowerCase() &&
              lCodec.clockRate === rCodec.clockRate &&
              lCodec.numChannels === rCodec.numChannels) {
            // push rCodec so we reply with offerer payload type
            commonCapabilities.codecs.push(rCodec);

            // FIXME: also need to determine intersection between
            // .rtcpFeedback and .parameters
            break;
          }
        }
      });

      localCapabilities.headerExtensions.forEach(function(lHeaderExtension) {
        for (var i = 0; i < remoteCapabilities.headerExtensions.length; i++) {
          var rHeaderExtension = remoteCapabilities.headerExtensions[i];
          if (lHeaderExtension.uri === rHeaderExtension.uri) {
            commonCapabilities.headerExtensions.push(rHeaderExtension);
            break;
          }
        }
      });

      // FIXME: fecMechanisms
      return commonCapabilities;
    };

    // Create ICE gatherer, ICE transport and DTLS transport.
    window.RTCPeerConnection.prototype._createIceAndDtlsTransports =
        function(mid, sdpMLineIndex) {
      var self = this;
      var iceGatherer = new RTCIceGatherer(self.iceOptions);
      var iceTransport = new RTCIceTransport(iceGatherer);
      iceGatherer.onlocalcandidate = function(evt) {
        var event = {};
        event.candidate = {sdpMid: mid, sdpMLineIndex: sdpMLineIndex};

        var cand = evt.candidate;
        // Edge emits an empty object for RTCIceCandidateComplete‥
        if (!cand || Object.keys(cand).length === 0) {
          // polyfill since RTCIceGatherer.state is not implemented in Edge 10547 yet.
          if (iceGatherer.state === undefined) {
            iceGatherer.state = 'completed';
          }

          // Emit a candidate with type endOfCandidates to make the samples work.
          // Edge requires addIceCandidate with this empty candidate to start checking.
          // The real solution is to signal end-of-candidates to the other side when
          // getting the null candidate but some apps (like the samples) don't do that.
          event.candidate.candidate =
              'candidate:1 1 udp 1 0.0.0.0 9 typ endOfCandidates';
        } else {
          // RTCIceCandidate doesn't have a component, needs to be added
          cand.component = iceTransport.component === 'RTCP' ? 2 : 1;
          event.candidate.candidate = SDPUtils.writeCandidate(cand);
        }

        var complete = self.transceivers.every(function(transceiver) {
          return transceiver.iceGatherer &&
              transceiver.iceGatherer.state === 'completed';
        });
        // FIXME: update .localDescription with candidate and (potentially) end-of-candidates.
        //     To make this harder, the gatherer might emit candidates before localdescription
        //     is set. To make things worse, gather.getLocalCandidates still errors in
        //     Edge 10547 when no candidates have been gathered yet.

        if (self.onicecandidate !== null) {
          // Emit candidate if localDescription is set.
          // Also emits null candidate when all gatherers are complete.
          if (self.localDescription && self.localDescription.type === '') {
            self._localIceCandidatesBuffer.push(event);
            if (complete) {
              self._localIceCandidatesBuffer.push({});
            }
          } else {
            self.onicecandidate(event);
            if (complete) {
              self.onicecandidate({});
            }
          }
        }
      };
      iceTransport.onicestatechange = function() {
        self._updateConnectionState();
      };

      var dtlsTransport = new RTCDtlsTransport(iceTransport);
      dtlsTransport.ondtlsstatechange = function() {
        self._updateConnectionState();
      };
      dtlsTransport.onerror = function() {
        // onerror does not set state to failed by itself.
        dtlsTransport.state = 'failed';
        self._updateConnectionState();
      };

      return {
        iceGatherer: iceGatherer,
        iceTransport: iceTransport,
        dtlsTransport: dtlsTransport
      };
    };

    // Start the RTP Sender and Receiver for a transceiver.
    window.RTCPeerConnection.prototype._transceive = function(transceiver,
        send, recv) {
      var params = this._getCommonCapabilities(transceiver.localCapabilities,
          transceiver.remoteCapabilities);
      if (send && transceiver.rtpSender) {
        params.encodings = [{
          ssrc: transceiver.sendSsrc
        }];
        params.rtcp = {
          cname: localCName,
          ssrc: transceiver.recvSsrc
        };
        transceiver.rtpSender.send(params);
      }
      if (recv && transceiver.rtpReceiver) {
        params.encodings = [{
          ssrc: transceiver.recvSsrc
        }];
        params.rtcp = {
          cname: transceiver.cname,
          ssrc: transceiver.sendSsrc
        };
        transceiver.rtpReceiver.receive(params);
      }
    };

    window.RTCPeerConnection.prototype.setLocalDescription =
        function(description) {
      var self = this;
      if (description.type === 'offer') {
        if (!this._pendingOffer) {
        } else {
          this.transceivers = this._pendingOffer;
          delete this._pendingOffer;
        }
      } else if (description.type === 'answer') {
        var sections = SDPUtils.splitSections(self.remoteDescription.sdp);
        var sessionpart = sections.shift();
        sections.forEach(function(mediaSection, sdpMLineIndex) {
          var transceiver = self.transceivers[sdpMLineIndex];
          var iceGatherer = transceiver.iceGatherer;
          var iceTransport = transceiver.iceTransport;
          var dtlsTransport = transceiver.dtlsTransport;
          var localCapabilities = transceiver.localCapabilities;
          var remoteCapabilities = transceiver.remoteCapabilities;
          var rejected = mediaSection.split('\n', 1)[0]
              .split(' ', 2)[1] === '0';

          if (!rejected) {
            var remoteIceParameters = SDPUtils.getIceParameters(mediaSection,
                sessionpart);
            iceTransport.start(iceGatherer, remoteIceParameters, 'controlled');

            var remoteDtlsParameters = SDPUtils.getDtlsParameters(mediaSection,
              sessionpart);
            dtlsTransport.start(remoteDtlsParameters);

            // Calculate intersection of capabilities.
            var params = self._getCommonCapabilities(localCapabilities,
                remoteCapabilities);

            // Start the RTCRtpSender. The RTCRtpReceiver for this transceiver
            // has already been started in setRemoteDescription.
            self._transceive(transceiver,
                params.codecs.length > 0,
                false);
          }
        });
      }

      this.localDescription = description;
      switch (description.type) {
        case 'offer':
          this._updateSignalingState('have-local-offer');
          break;
        case 'answer':
          this._updateSignalingState('stable');
          break;
        default:
          throw new TypeError('unsupported type "' + description.type + '"');
      }

      // If a success callback was provided, emit ICE candidates after it has been
      // executed. Otherwise, emit callback after the Promise is resolved.
      var hasCallback = arguments.length > 1 &&
        typeof arguments[1] === 'function';
      if (hasCallback) {
        var cb = arguments[1];
        window.setTimeout(function() {
          cb();
          self._emitBufferedCandidates();
        }, 0);
      }
      var p = Promise.resolve();
      p.then(function() {
        if (!hasCallback) {
          window.setTimeout(self._emitBufferedCandidates.bind(self), 0);
        }
      });
      return p;
    };

    window.RTCPeerConnection.prototype.setRemoteDescription =
        function(description) {
      var self = this;
      var stream = new MediaStream();
      var sections = SDPUtils.splitSections(description.sdp);
      var sessionpart = sections.shift();
      sections.forEach(function(mediaSection, sdpMLineIndex) {
        var lines = SDPUtils.splitLines(mediaSection);
        var mline = lines[0].substr(2).split(' ');
        var kind = mline[0];
        var rejected = mline[1] === '0';
        var direction = SDPUtils.getDirection(mediaSection, sessionpart);

        var transceiver;
        var iceGatherer;
        var iceTransport;
        var dtlsTransport;
        var rtpSender;
        var rtpReceiver;
        var sendSsrc;
        var recvSsrc;
        var localCapabilities;

        // FIXME: ensure the mediaSection has rtcp-mux set.
        var remoteCapabilities = SDPUtils.parseRtpParameters(mediaSection);
        var remoteIceParameters;
        var remoteDtlsParameters;
        if (!rejected) {
          remoteIceParameters = SDPUtils.getIceParameters(mediaSection,
              sessionpart);
          remoteDtlsParameters = SDPUtils.getDtlsParameters(mediaSection,
              sessionpart);
        }
        var mid = SDPUtils.matchPrefix(mediaSection, 'a=mid:')[0].substr(6);

        var cname;
        // Gets the first SSRC. Note that with RTX there might be multiple SSRCs.
        var remoteSsrc = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
            .map(function(line) {
              return SDPUtils.parseSsrcMedia(line);
            })
            .filter(function(obj) {
              return obj.attribute === 'cname';
            })[0];
        if (remoteSsrc) {
          recvSsrc = parseInt(remoteSsrc.ssrc, 10);
          cname = remoteSsrc.value;
        }

        if (description.type === 'offer') {
          var transports = self._createIceAndDtlsTransports(mid, sdpMLineIndex);

          localCapabilities = RTCRtpReceiver.getCapabilities(kind);
          sendSsrc = (2 * sdpMLineIndex + 2) * 1001;

          rtpReceiver = new RTCRtpReceiver(transports.dtlsTransport, kind);

          // FIXME: not correct when there are multiple streams but that is
          // not currently supported in this shim.
          stream.addTrack(rtpReceiver.track);

          // FIXME: look at direction.
          if (self.localStreams.length > 0 &&
              self.localStreams[0].getTracks().length >= sdpMLineIndex) {
            // FIXME: actually more complicated, needs to match types etc
            var localtrack = self.localStreams[0].getTracks()[sdpMLineIndex];
            rtpSender = new RTCRtpSender(localtrack, transports.dtlsTransport);
          }

          self.transceivers[sdpMLineIndex] = {
            iceGatherer: transports.iceGatherer,
            iceTransport: transports.iceTransport,
            dtlsTransport: transports.dtlsTransport,
            localCapabilities: localCapabilities,
            remoteCapabilities: remoteCapabilities,
            rtpSender: rtpSender,
            rtpReceiver: rtpReceiver,
            kind: kind,
            mid: mid,
            cname: cname,
            sendSsrc: sendSsrc,
            recvSsrc: recvSsrc
          };
          // Start the RTCRtpReceiver now. The RTPSender is started in setLocalDescription.
          self._transceive(self.transceivers[sdpMLineIndex],
              false,
              direction === 'sendrecv' || direction === 'sendonly');
        } else if (description.type === 'answer' && !rejected) {
          transceiver = self.transceivers[sdpMLineIndex];
          iceGatherer = transceiver.iceGatherer;
          iceTransport = transceiver.iceTransport;
          dtlsTransport = transceiver.dtlsTransport;
          rtpSender = transceiver.rtpSender;
          rtpReceiver = transceiver.rtpReceiver;
          sendSsrc = transceiver.sendSsrc;
          //recvSsrc = transceiver.recvSsrc;
          localCapabilities = transceiver.localCapabilities;

          self.transceivers[sdpMLineIndex].recvSsrc = recvSsrc;
          self.transceivers[sdpMLineIndex].remoteCapabilities =
              remoteCapabilities;
          self.transceivers[sdpMLineIndex].cname = cname;

          iceTransport.start(iceGatherer, remoteIceParameters, 'controlling');
          dtlsTransport.start(remoteDtlsParameters);

          self._transceive(transceiver,
              direction === 'sendrecv' || direction === 'recvonly',
              direction === 'sendrecv' || direction === 'sendonly');

          if (rtpReceiver &&
              (direction === 'sendrecv' || direction === 'sendonly')) {
            stream.addTrack(rtpReceiver.track);
          } else {
            // FIXME: actually the receiver should be created later.
            delete transceiver.rtpReceiver;
          }
        }
      });

      this.remoteDescription = description;
      switch (description.type) {
        case 'offer':
          this._updateSignalingState('have-remote-offer');
          break;
        case 'answer':
          this._updateSignalingState('stable');
          break;
        default:
          throw new TypeError('unsupported type "' + description.type + '"');
      }
      window.setTimeout(function() {
        if (self.onaddstream !== null && stream.getTracks().length) {
          self.remoteStreams.push(stream);
          window.setTimeout(function() {
            self.onaddstream({stream: stream});
          }, 0);
        }
      }, 0);
      if (arguments.length > 1 && typeof arguments[1] === 'function') {
        window.setTimeout(arguments[1], 0);
      }
      return Promise.resolve();
    };

    window.RTCPeerConnection.prototype.close = function() {
      this.transceivers.forEach(function(transceiver) {
        /* not yet
        if (transceiver.iceGatherer) {
          transceiver.iceGatherer.close();
        }
        */
        if (transceiver.iceTransport) {
          transceiver.iceTransport.stop();
        }
        if (transceiver.dtlsTransport) {
          transceiver.dtlsTransport.stop();
        }
        if (transceiver.rtpSender) {
          transceiver.rtpSender.stop();
        }
        if (transceiver.rtpReceiver) {
          transceiver.rtpReceiver.stop();
        }
      });
      // FIXME: clean up tracks, local streams, remote streams, etc
      this._updateSignalingState('closed');
    };

    // Update the signaling state.
    window.RTCPeerConnection.prototype._updateSignalingState =
        function(newState) {
      this.signalingState = newState;
      if (this.onsignalingstatechange !== null) {
        this.onsignalingstatechange();
      }
    };

    // Determine whether to fire the negotiationneeded event.
    window.RTCPeerConnection.prototype._maybeFireNegotiationNeeded =
        function() {
      // Fire away (for now).
      if (this.onnegotiationneeded !== null) {
        this.onnegotiationneeded();
      }
    };

    // Update the connection state.
    window.RTCPeerConnection.prototype._updateConnectionState =
        function() {
      var self = this;
      var newState;
      var states = {
        'new': 0,
        closed: 0,
        connecting: 0,
        checking: 0,
        connected: 0,
        completed: 0,
        failed: 0
      };
      this.transceivers.forEach(function(transceiver) {
        states[transceiver.iceTransport.state]++;
        states[transceiver.dtlsTransport.state]++;
      });
      // ICETransport.completed and connected are the same for this purpose.
      states.connected += states.completed;

      newState = 'new';
      if (states.failed > 0) {
        newState = 'failed';
      } else if (states.connecting > 0 || states.checking > 0) {
        newState = 'connecting';
      } else if (states.disconnected > 0) {
        newState = 'disconnected';
      } else if (states.new > 0) {
        newState = 'new';
      } else if (states.connecting > 0 || states.completed > 0) {
        newState = 'connected';
      }

      if (newState !== self.iceConnectionState) {
        self.iceConnectionState = newState;
        if (this.oniceconnectionstatechange !== null) {
          this.oniceconnectionstatechange();
        }
      }
    };

    window.RTCPeerConnection.prototype.createOffer = function() {
      var self = this;
      if (this._pendingOffer) {
        throw new Error('createOffer called while there is a pending offer.');
      }
      var offerOptions;
      if (arguments.length === 1 && typeof arguments[0] !== 'function') {
        offerOptions = arguments[0];
      } else if (arguments.length === 3) {
        offerOptions = arguments[2];
      }

      var tracks = [];
      var numAudioTracks = 0;
      var numVideoTracks = 0;
      // Default to sendrecv.
      if (this.localStreams.length) {
        numAudioTracks = this.localStreams[0].getAudioTracks().length;
        numVideoTracks = this.localStreams[0].getVideoTracks().length;
      }
      // Determine number of audio and video tracks we need to send/recv.
      if (offerOptions) {
        // Reject Chrome legacy constraints.
        if (offerOptions.mandatory || offerOptions.optional) {
          throw new TypeError(
              'Legacy mandatory/optional constraints not supported.');
        }
        if (offerOptions.offerToReceiveAudio !== undefined) {
          numAudioTracks = offerOptions.offerToReceiveAudio;
        }
        if (offerOptions.offerToReceiveVideo !== undefined) {
          numVideoTracks = offerOptions.offerToReceiveVideo;
        }
      }
      if (this.localStreams.length) {
        // Push local streams.
        this.localStreams[0].getTracks().forEach(function(track) {
          tracks.push({
            kind: track.kind,
            track: track,
            wantReceive: track.kind === 'audio' ?
                numAudioTracks > 0 : numVideoTracks > 0
          });
          if (track.kind === 'audio') {
            numAudioTracks--;
          } else if (track.kind === 'video') {
            numVideoTracks--;
          }
        });
      }
      // Create M-lines for recvonly streams.
      while (numAudioTracks > 0 || numVideoTracks > 0) {
        if (numAudioTracks > 0) {
          tracks.push({
            kind: 'audio',
            wantReceive: true
          });
          numAudioTracks--;
        }
        if (numVideoTracks > 0) {
          tracks.push({
            kind: 'video',
            wantReceive: true
          });
          numVideoTracks--;
        }
      }

      var sdp = SDPUtils.writeSessionBoilerplate();
      var transceivers = [];
      tracks.forEach(function(mline, sdpMLineIndex) {
        // For each track, create an ice gatherer, ice transport, dtls transport,
        // potentially rtpsender and rtpreceiver.
        var track = mline.track;
        var kind = mline.kind;
        var mid = generateIdentifier();

        var transports = self._createIceAndDtlsTransports(mid, sdpMLineIndex);

        var localCapabilities = RTCRtpSender.getCapabilities(kind);
        var rtpSender;
        var rtpReceiver;

        // generate an ssrc now, to be used later in rtpSender.send
        var sendSsrc = (2 * sdpMLineIndex + 1) * 1001;
        if (track) {
          rtpSender = new RTCRtpSender(track, transports.dtlsTransport);
        }

        if (mline.wantReceive) {
          rtpReceiver = new RTCRtpReceiver(transports.dtlsTransport, kind);
        }

        transceivers[sdpMLineIndex] = {
          iceGatherer: transports.iceGatherer,
          iceTransport: transports.iceTransport,
          dtlsTransport: transports.dtlsTransport,
          localCapabilities: localCapabilities,
          remoteCapabilities: null,
          rtpSender: rtpSender,
          rtpReceiver: rtpReceiver,
          kind: kind,
          mid: mid,
          sendSsrc: sendSsrc,
          recvSsrc: null
        };
        var transceiver = transceivers[sdpMLineIndex];
        sdp += SDPUtils.writeMediaSection(transceiver,
            transceiver.localCapabilities, 'offer', self.localStreams[0]);
      });

      this._pendingOffer = transceivers;
      var desc = new RTCSessionDescription({
        type: 'offer',
        sdp: sdp
      });
      if (arguments.length && typeof arguments[0] === 'function') {
        window.setTimeout(arguments[0], 0, desc);
      }
      return Promise.resolve(desc);
    };

    window.RTCPeerConnection.prototype.createAnswer = function() {
      var self = this;
      var answerOptions;
      if (arguments.length === 1 && typeof arguments[0] !== 'function') {
        answerOptions = arguments[0];
      } else if (arguments.length === 3) {
        answerOptions = arguments[2];
      }

      var sdp = SDPUtils.writeSessionBoilerplate();
      this.transceivers.forEach(function(transceiver) {
        // Calculate intersection of capabilities.
        var commonCapabilities = self._getCommonCapabilities(
            transceiver.localCapabilities,
            transceiver.remoteCapabilities);

        sdp += SDPUtils.writeMediaSection(transceiver, commonCapabilities,
            'answer', self.localStreams[0]);
      });

      var desc = new RTCSessionDescription({
        type: 'answer',
        sdp: sdp
      });
      if (arguments.length && typeof arguments[0] === 'function') {
        window.setTimeout(arguments[0], 0, desc);
      }
      return Promise.resolve(desc);
    };

    window.RTCPeerConnection.prototype.addIceCandidate = function(candidate) {
      var mLineIndex = candidate.sdpMLineIndex;
      if (candidate.sdpMid) {
        for (var i = 0; i < this.transceivers.length; i++) {
          if (this.transceivers[i].mid === candidate.sdpMid) {
            mLineIndex = i;
            break;
          }
        }
      }
      var transceiver = this.transceivers[mLineIndex];
      if (transceiver) {
        var cand = Object.keys(candidate.candidate).length > 0 ?
            SDPUtils.parseCandidate(candidate.candidate) : {};
        // Ignore Chrome's invalid candidates since Edge does not like them.
        if (cand.protocol === 'tcp' && cand.port === 0) {
          return;
        }
        // Ignore RTCP candidates, we assume RTCP-MUX.
        if (cand.component !== '1') {
          return;
        }
        // A dirty hack to make samples work.
        if (cand.type === 'endOfCandidates') {
          cand = {};
        }
        transceiver.iceTransport.addRemoteCandidate(cand);
      }
      if (arguments.length > 1 && typeof arguments[1] === 'function') {
        window.setTimeout(arguments[1], 0);
      }
      return Promise.resolve();
    };

    window.RTCPeerConnection.prototype.getStats = function() {
      var promises = [];
      this.transceivers.forEach(function(transceiver) {
        ['rtpSender', 'rtpReceiver', 'iceGatherer', 'iceTransport',
            'dtlsTransport'].forEach(function(method) {
          if (transceiver[method]) {
            promises.push(transceiver[method].getStats());
          }
        });
      });
      var cb = arguments.length > 1 && typeof arguments[1] === 'function' &&
          arguments[1];
      return new Promise(function(resolve) {
        var results = {};
        Promise.all(promises).then(function(res) {
          res.forEach(function(result) {
            Object.keys(result).forEach(function(id) {
              results[id] = result[id];
            });
          });
          if (cb) {
            window.setTimeout(cb, 0, results);
          }
          resolve(results);
        });
      });
    };
  }
} else {
  webrtcUtils.log('Browser does not appear to be WebRTC-capable');
}

// Returns the result of getUserMedia as a Promise.
function requestUserMedia(constraints) {
  return new Promise(function(resolve, reject) {
    getUserMedia(constraints, resolve, reject);
  });
}

var webrtcTesting = {};
try {
  Object.defineProperty(webrtcTesting, 'version', {
    set: function(version) {
      webrtcDetectedVersion = version;
    }
  });
} catch (e) {}

if (typeof module !== 'undefined') {
  var RTCPeerConnection;
  var RTCIceCandidate;
  var RTCSessionDescription;
  if (typeof window !== 'undefined') {
    RTCPeerConnection = window.RTCPeerConnection;
    RTCIceCandidate = window.RTCIceCandidate;
    RTCSessionDescription = window.RTCSessionDescription;
  }
  module.exports = {
    RTCPeerConnection: RTCPeerConnection,
    RTCIceCandidate: RTCIceCandidate,
    RTCSessionDescription: RTCSessionDescription,
    getUserMedia: getUserMedia,
    attachMediaStream: attachMediaStream,
    reattachMediaStream: reattachMediaStream,
    webrtcDetectedBrowser: webrtcDetectedBrowser,
    webrtcDetectedVersion: webrtcDetectedVersion,
    webrtcMinimumVersion: webrtcMinimumVersion,
    webrtcTesting: webrtcTesting,
    webrtcUtils: webrtcUtils
    //requestUserMedia: not exposed on purpose.
    //trace: not exposed on purpose.
  };
} else if ((typeof require === 'function') && (typeof define === 'function')) {
  // Expose objects and functions when RequireJS is doing the loading.
  define([], function() {
    return {
      RTCPeerConnection: window.RTCPeerConnection,
      RTCIceCandidate: window.RTCIceCandidate,
      RTCSessionDescription: window.RTCSessionDescription,
      getUserMedia: getUserMedia,
      attachMediaStream: attachMediaStream,
      reattachMediaStream: reattachMediaStream,
      webrtcDetectedBrowser: webrtcDetectedBrowser,
      webrtcDetectedVersion: webrtcDetectedVersion,
      webrtcMinimumVersion: webrtcMinimumVersion,
      webrtcTesting: webrtcTesting,
      webrtcUtils: webrtcUtils
      //requestUserMedia: not exposed on purpose.
      //trace: not exposed on purpose.
    };
  });
}

},{}],10:[function(require,module,exports){
// created by @HenrikJoreteg
var prefix;
var version;

if (window.mozRTCPeerConnection || navigator.mozGetUserMedia) {
    prefix = 'moz';
    version = parseInt(navigator.userAgent.match(/Firefox\/([0-9]+)\./)[1], 10);
} else if (window.webkitRTCPeerConnection || navigator.webkitGetUserMedia) {
    prefix = 'webkit';
    version = navigator.userAgent.match(/Chrom(e|ium)/) && parseInt(navigator.userAgent.match(/Chrom(e|ium)\/([0-9]+)\./)[2], 10);
}

var PC = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection;
var IceCandidate = window.mozRTCIceCandidate || window.RTCIceCandidate;
var SessionDescription = window.mozRTCSessionDescription || window.RTCSessionDescription;
var MediaStream = window.webkitMediaStream || window.MediaStream;
var screenSharing = window.location.protocol === 'https:' &&
    ((prefix === 'webkit' && version >= 26) ||
     (prefix === 'moz' && version >= 33))
var AudioContext = window.AudioContext || window.webkitAudioContext;
var videoEl = document.createElement('video');
var supportVp8 = videoEl && videoEl.canPlayType && videoEl.canPlayType('video/webm; codecs="vp8", vorbis') === "probably";
var getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.msGetUserMedia || navigator.mozGetUserMedia;

// export support flags and constructors.prototype && PC
module.exports = {
    prefix: prefix,
    browserVersion: version,
    support: !!PC && !!getUserMedia,
    // new support style
    supportRTCPeerConnection: !!PC,
    supportVp8: supportVp8,
    supportGetUserMedia: !!getUserMedia,
    supportDataChannel: !!(PC && PC.prototype && PC.prototype.createDataChannel),
    supportWebAudio: !!(AudioContext && AudioContext.prototype.createMediaStreamSource),
    supportMediaStream: !!(MediaStream && MediaStream.prototype.removeTrack),
    supportScreenSharing: !!screenSharing,
    // constructors
    AudioContext: AudioContext,
    PeerConnection: PC,
    SessionDescription: SessionDescription,
    IceCandidate: IceCandidate,
    MediaStream: MediaStream,
    getUserMedia: getUserMedia
};

},{}]},{},[1])(1)
});