peerjs/dist/peer.js

(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){
require('webrtc-adapter');

module.exports.RTCSessionDescription = window.RTCSessionDescription ||
	window.mozRTCSessionDescription;
module.exports.RTCPeerConnection = window.RTCPeerConnection ||
	window.mozRTCPeerConnection || window.webkitRTCPeerConnection;
module.exports.RTCIceCandidate = window.RTCIceCandidate ||
	window.mozRTCIceCandidate;

},{"webrtc-adapter":16}],2:[function(require,module,exports){
var util = require('./util');
var EventEmitter = require('eventemitter3');
var Negotiator = require('./negotiator');
var Reliable = require('reliable');

/**
 * Wraps a DataChannel between two Peers.
 */
function DataConnection(peer, provider, options) {
  if (!(this instanceof DataConnection)) return new DataConnection(peer, provider, options);
  EventEmitter.call(this);

  this.options = util.extend({
    serialization: 'binary',
    reliable: false
  }, options);

  // Connection is not open yet.
  this.open = false;
  this.type = 'data';
  this.peer = peer;
  this.provider = provider;

  this.id = this.options.connectionId || DataConnection._idPrefix + util.randomToken();

  this.label = this.options.label || this.id;
  this.metadata = this.options.metadata;
  this.serialization = this.options.serialization;
  this.reliable = this.options.reliable;

  // Data channel buffering.
  this._buffer = [];
  this._buffering = false;
  this.bufferSize = 0;

  // For storing large data.
  this._chunkedData = {};

  if (this.options._payload) {
    this._peerBrowser = this.options._payload.browser;
  }

  Negotiator.startConnection(
    this,
    this.options._payload || {
      originator: true
    }
  );
}

util.inherits(DataConnection, EventEmitter);

DataConnection._idPrefix = 'dc_';

/** Called by the Negotiator when the DataChannel is ready. */
DataConnection.prototype.initialize = function(dc) {
  this._dc = this.dataChannel = dc;
  this._configureDataChannel();
}

DataConnection.prototype._configureDataChannel = function() {
  var self = this;
  if (util.supports.sctp) {
    this._dc.binaryType = 'arraybuffer';
  }
  this._dc.onopen = function() {
    util.log('Data channel connection success');
    self.open = true;
    self.emit('open');
  }

  // Use the Reliable shim for non Firefox browsers
  if (!util.supports.sctp && this.reliable) {
    this._reliable = new Reliable(this._dc, util.debug);
  }

  if (this._reliable) {
    this._reliable.onmessage = function(msg) {
      self.emit('data', msg);
    };
  } else {
    this._dc.onmessage = function(e) {
      self._handleDataMessage(e);
    };
  }
  this._dc.onclose = function(e) {
    util.log('DataChannel closed for:', self.peer);
    self.close();
  };
}

// Handles a DataChannel message.
DataConnection.prototype._handleDataMessage = function(e) {
  var self = this;
  var data = e.data;
  var datatype = data.constructor;
  if (this.serialization === 'binary' || this.serialization === 'binary-utf8') {
    if (datatype === Blob) {
      // Datatype should never be blob
      util.blobToArrayBuffer(data, function(ab) {
        data = util.unpack(ab);
        self.emit('data', data);
      });
      return;
    } else if (datatype === ArrayBuffer) {
      data = util.unpack(data);
    } else if (datatype === String) {
      // String fallback for binary data for browsers that don't support binary yet
      var ab = util.binaryStringToArrayBuffer(data);
      data = util.unpack(ab);
    }
  } else if (this.serialization === 'json') {
    data = JSON.parse(data);
  }

  // Check if we've chunked--if so, piece things back together.
  // We're guaranteed that this isn't 0.
  if (data.__peerData) {
    var id = data.__peerData;
    var chunkInfo = this._chunkedData[id] || {data: [], count: 0, total: data.total};

    chunkInfo.data[data.n] = data.data;
    chunkInfo.count += 1;

    if (chunkInfo.total === chunkInfo.count) {
      // Clean up before making the recursive call to `_handleDataMessage`.
      delete this._chunkedData[id];

      // We've received all the chunks--time to construct the complete data.
      data = new Blob(chunkInfo.data);
      this._handleDataMessage({data: data});
    }

    this._chunkedData[id] = chunkInfo;
    return;
  }

  this.emit('data', data);
}

/**
 * Exposed functionality for users.
 */

/** Allows user to close connection. */
DataConnection.prototype.close = function() {
  if (!this.open) {
    return;
  }
  this.open = false;
  Negotiator.cleanup(this);
  this.emit('close');
}

/** Allows user to send data. */
DataConnection.prototype.send = function(data, chunked) {
  if (!this.open) {
    this.emit('error', new Error('Connection is not open. You should listen for the `open` event before sending messages.'));
    return;
  }
  if (this._reliable) {
    // Note: reliable shim sending will make it so that you cannot customize
    // serialization.
    this._reliable.send(data);
    return;
  }
  var self = this;
  if (this.serialization === 'json') {
    this._bufferedSend(JSON.stringify(data));
  } else if (this.serialization === 'binary' || this.serialization === 'binary-utf8') {
    var blob = util.pack(data);

    // For Chrome-Firefox interoperability, we need to make Firefox "chunk"
    // the data it sends out.
    var needsChunking = util.chunkedBrowsers[this._peerBrowser] || util.chunkedBrowsers[util.browser];
    if (needsChunking && !chunked && blob.size > util.chunkedMTU) {
      this._sendChunks(blob);
      return;
    }

    // DataChannel currently only supports strings.
    if (!util.supports.sctp) {
      util.blobToBinaryString(blob, function(str) {
        self._bufferedSend(str);
      });
    } else if (!util.supports.binaryBlob) {
      // We only do this if we really need to (e.g. blobs are not supported),
      // because this conversion is costly.
      util.blobToArrayBuffer(blob, function(ab) {
        self._bufferedSend(ab);
      });
    } else {
      this._bufferedSend(blob);
    }
  } else {
    this._bufferedSend(data);
  }
}

DataConnection.prototype._bufferedSend = function(msg) {
  if (this._buffering || !this._trySend(msg)) {
    this._buffer.push(msg);
    this.bufferSize = this._buffer.length;
  }
}

// Returns true if the send succeeds.
DataConnection.prototype._trySend = function(msg) {
  try {
    this._dc.send(msg);
  } catch (e) {
    this._buffering = true;

    var self = this;
    setTimeout(function() {
      // Try again.
      self._buffering = false;
      self._tryBuffer();
    }, 100);
    return false;
  }
  return true;
}

// Try to send the first message in the buffer.
DataConnection.prototype._tryBuffer = function() {
  if (this._buffer.length === 0) {
    return;
  }

  var msg = this._buffer[0];

  if (this._trySend(msg)) {
    this._buffer.shift();
    this.bufferSize = this._buffer.length;
    this._tryBuffer();
  }
}

DataConnection.prototype._sendChunks = function(blob) {
  var blobs = util.chunk(blob);
  for (var i = 0, ii = blobs.length; i < ii; i += 1) {
    var blob = blobs[i];
    this.send(blob, true);
  }
}

DataConnection.prototype.handleMessage = function(message) {
  var payload = message.payload;

  switch (message.type) {
    case 'ANSWER':
      this._peerBrowser = payload.browser;

      // Forward to negotiator
      Negotiator.handleSDP(message.type, this, payload.sdp);
      break;
    case 'CANDIDATE':
      Negotiator.handleCandidate(this, payload.candidate);
      break;
    default:
      util.warn('Unrecognized message type:', message.type, 'from peer:', this.peer);
      break;
  }
}

module.exports = DataConnection;

},{"./negotiator":5,"./util":8,"eventemitter3":9,"reliable":12}],3:[function(require,module,exports){
window.Socket = require('./socket');
window.MediaConnection = require('./mediaconnection');
window.DataConnection = require('./dataconnection');
window.Peer = require('./peer');
window.RTCPeerConnection = require('./adapter').RTCPeerConnection;
window.RTCSessionDescription = require('./adapter').RTCSessionDescription;
window.RTCIceCandidate = require('./adapter').RTCIceCandidate;
window.Negotiator = require('./negotiator');
window.util = require('./util');
window.BinaryPack = require('js-binarypack');

},{"./adapter":1,"./dataconnection":2,"./mediaconnection":4,"./negotiator":5,"./peer":6,"./socket":7,"./util":8,"js-binarypack":10}],4:[function(require,module,exports){
var util = require('./util');
var EventEmitter = require('eventemitter3');
var Negotiator = require('./negotiator');

/**
 * Wraps the streaming interface between two Peers.
 */
function MediaConnection(peer, provider, options) {
  if (!(this instanceof MediaConnection)) return new MediaConnection(peer, provider, options);
  EventEmitter.call(this);

  this.options = util.extend({}, options);

  this.open = false;
  this.type = 'media';
  this.peer = peer;
  this.provider = provider;
  this.metadata = this.options.metadata;
  this.localStream = this.options._stream;

  this.id = this.options.connectionId || MediaConnection._idPrefix + util.randomToken();
  if (this.localStream) {
    Negotiator.startConnection(
      this,
      {_stream: this.localStream, originator: true}
    );
  }
};

util.inherits(MediaConnection, EventEmitter);

MediaConnection._idPrefix = 'mc_';

MediaConnection.prototype.addStream = function(remoteStream) {
  util.log('Receiving stream', remoteStream);

  this.remoteStream = remoteStream;
  this.emit('stream', remoteStream); // Should we call this `open`?

};

MediaConnection.prototype.handleMessage = function(message) {
  var payload = message.payload;

  switch (message.type) {
    case 'ANSWER':
      // Forward to negotiator
      Negotiator.handleSDP(message.type, this, payload.sdp);
      this.open = true;
      break;
    case 'CANDIDATE':
      Negotiator.handleCandidate(this, payload.candidate);
      break;
    default:
      util.warn('Unrecognized message type:', message.type, 'from peer:', this.peer);
      break;
  }
}

MediaConnection.prototype.answer = function(stream) {
  if (this.localStream) {
    util.warn('Local stream already exists on this MediaConnection. Are you answering a call twice?');
    return;
  }

  this.options._payload._stream = stream;

  this.localStream = stream;
  Negotiator.startConnection(
    this,
    this.options._payload
  )
  // Retrieve lost messages stored because PeerConnection not set up.
  var messages = this.provider._getMessages(this.id);
  for (var i = 0, ii = messages.length; i < ii; i += 1) {
    this.handleMessage(messages[i]);
  }
  this.open = true;
};

/**
 * Exposed functionality for users.
 */

/** Allows user to close connection. */
MediaConnection.prototype.close = function() {
  if (!this.open) {
    return;
  }
  this.open = false;
  Negotiator.cleanup(this);
  this.emit('close')
};

module.exports = MediaConnection;

},{"./negotiator":5,"./util":8,"eventemitter3":9}],5:[function(require,module,exports){
var util = require("./util");
var RTCPeerConnection = require("./adapter").RTCPeerConnection;
var RTCSessionDescription = require("./adapter").RTCSessionDescription;
var RTCIceCandidate = require("./adapter").RTCIceCandidate;

/**
 * Manages all negotiations between Peers.
 */
var Negotiator = {
  pcs: {
    data: {},
    media: {}
  }, // type => {peerId: {pc_id: pc}}.
  //providers: {}, // provider's id => providers (there may be multiple providers/client.
  queue: [] // connections that are delayed due to a PC being in use.
};

Negotiator._idPrefix = "pc_";

/** Returns a PeerConnection object set up correctly (for data, media). */
Negotiator.startConnection = function(connection, options) {
  var pc = Negotiator._getPeerConnection(connection, options);

  // Set the connection's PC.
  connection.pc = connection.peerConnection = pc;

  if (connection.type === "media" && options._stream) {
    // Add the stream.
    pc.addStream(options._stream);
  }

  // What do we need to do now?
  if (options.originator) {
    if (connection.type === "data") {
      // Create the datachannel.
      var config = {};
      // Dropping reliable:false support, since it seems to be crashing
      // Chrome.
      /*if (util.supports.sctp && !options.reliable) {
        // If we have canonical reliable support...
        config = {maxRetransmits: 0};
      }*/
      // Fallback to ensure older browsers don't crash.
      if (!util.supports.sctp) {
        config = { reliable: options.reliable };
      }
      var dc = pc.createDataChannel(connection.label, config);
      connection.initialize(dc);
    }

    Negotiator._makeOffer(connection);
  } else {
    Negotiator.handleSDP("OFFER", connection, options.sdp);
  }
};

Negotiator._getPeerConnection = function(connection, options) {
  if (!Negotiator.pcs[connection.type]) {
    util.error(
      connection.type +
        " is not a valid connection type. Maybe you overrode the `type` property somewhere."
    );
  }

  if (!Negotiator.pcs[connection.type][connection.peer]) {
    Negotiator.pcs[connection.type][connection.peer] = {};
  }
  var peerConnections = Negotiator.pcs[connection.type][connection.peer];

  var pc;
  // Not multiplexing while FF and Chrome have not-great support for it.
  /*if (options.multiplex) {
    ids = Object.keys(peerConnections);
    for (var i = 0, ii = ids.length; i < ii; i += 1) {
      pc = peerConnections[ids[i]];
      if (pc.signalingState === 'stable') {
        break; // We can go ahead and use this PC.
      }
    }
  } else */
  if (options.pc) {
    // Simplest case: PC id already provided for us.
    pc = Negotiator.pcs[connection.type][connection.peer][options.pc];
  }

  if (!pc || pc.signalingState !== "stable") {
    pc = Negotiator._startPeerConnection(connection);
  }
  return pc;
};

/*
Negotiator._addProvider = function(provider) {
  if ((!provider.id && !provider.disconnected) || !provider.socket.open) {
    // Wait for provider to obtain an ID.
    provider.on('open', function(id) {
      Negotiator._addProvider(provider);
    });
  } else {
    Negotiator.providers[provider.id] = provider;
  }
}*/

/** Start a PC. */
Negotiator._startPeerConnection = function(connection) {
  util.log("Creating RTCPeerConnection.");

  var id = Negotiator._idPrefix + util.randomToken();
  var optional = {};

  if (connection.type === "data" && !util.supports.sctp) {
    optional = { optional: [{ RtpDataChannels: true }] };
  } else if (connection.type === "media") {
    // Interop req for chrome.
    optional = { optional: [{ DtlsSrtpKeyAgreement: true }] };
  }

  var pc = new RTCPeerConnection(connection.provider.options.config, optional);
  Negotiator.pcs[connection.type][connection.peer][id] = pc;

  Negotiator._setupListeners(connection, pc, id);

  return pc;
};

/** Set up various WebRTC listeners. */
Negotiator._setupListeners = function(connection, pc, pc_id) {
  var peerId = connection.peer;
  var connectionId = connection.id;
  var provider = connection.provider;

  // ICE CANDIDATES.
  util.log("Listening for ICE candidates.");
  pc.onicecandidate = function(evt) {
    if (evt.candidate) {
      util.log("Received ICE candidates for:", connection.peer);
      provider.socket.send({
        type: "CANDIDATE",
        payload: {
          candidate: evt.candidate,
          type: connection.type,
          connectionId: connection.id
        },
        dst: peerId
      });
    }
  };

  pc.oniceconnectionstatechange = function() {
    switch (pc.iceConnectionState) {
      case "failed":
        util.log(
          "iceConnectionState is disconnected, closing connections to " + peerId
        );
        connection.emit(
          "error",
          new Error("Negotiation of connection to " + peerId + " failed.")
        );
        connection.close();
        break;
      case "disconnected":
        util.log(
          "iceConnectionState is disconnected, closing connections to " + peerId
        );
        connection.close();
        break;
      case "completed":
        pc.onicecandidate = util.noop;
        break;
    }
  };

  // Fallback for older Chrome impls.
  pc.onicechange = pc.oniceconnectionstatechange;

  // DATACONNECTION.
  util.log("Listening for data channel");
  // Fired between offer and answer, so options should already be saved
  // in the options hash.
  pc.ondatachannel = function(evt) {
    util.log("Received data channel");
    var dc = evt.channel;
    var connection = provider.getConnection(peerId, connectionId);
    connection.initialize(dc);
  };

  // MEDIACONNECTION.
  util.log("Listening for remote stream");
  pc.ontrack = function(evt) {
    util.log("Received remote stream");
    var stream = evt.streams[0];
    var connection = provider.getConnection(peerId, connectionId);
    if (connection.type === "media") {
      connection.addStream(stream);
    }
  };
};

Negotiator.cleanup = function(connection) {
  util.log("Cleaning up PeerConnection to " + connection.peer);

  var pc = connection.pc;

  if (
    !!pc &&
    ((pc.readyState && pc.readyState !== "closed") ||
      pc.signalingState !== "closed")
  ) {
    pc.close();
    connection.pc = null;
  }
};

Negotiator._makeOffer = function(connection) {
  var pc = connection.pc;
  pc.createOffer(
    function(offer) {
      util.log("Created offer.");

      if (
        !util.supports.sctp &&
        connection.type === "data" &&
        connection.reliable
      ) {
        offer.sdp = Reliable.higherBandwidthSDP(offer.sdp);
      }

      pc.setLocalDescription(
        offer,
        function() {
          util.log("Set localDescription: offer", "for:", connection.peer);
          connection.provider.socket.send({
            type: "OFFER",
            payload: {
              sdp: offer,
              type: connection.type,
              label: connection.label,
              connectionId: connection.id,
              reliable: connection.reliable,
              serialization: connection.serialization,
              metadata: connection.metadata,
              browser: util.browser
            },
            dst: connection.peer
          });
        },
        function(err) {
          // TODO: investigate why _makeOffer is being called from the answer
          if (
            err !=
            "OperationError: Failed to set local offer sdp: Called in wrong state: kHaveRemoteOffer"
          ) {
            connection.provider.emitError("webrtc", err);
            util.log("Failed to setLocalDescription, ", err);
          }
        }
      );
    },
    function(err) {
      connection.provider.emitError("webrtc", err);
      util.log("Failed to createOffer, ", err);
    },
    connection.options.constraints
  );
};

Negotiator._makeAnswer = function(connection) {
  var pc = connection.pc;

  pc.createAnswer(
    function(answer) {
      util.log("Created answer.");

      if (
        !util.supports.sctp &&
        connection.type === "data" &&
        connection.reliable
      ) {
        answer.sdp = Reliable.higherBandwidthSDP(answer.sdp);
      }

      pc.setLocalDescription(
        answer,
        function() {
          util.log("Set localDescription: answer", "for:", connection.peer);
          connection.provider.socket.send({
            type: "ANSWER",
            payload: {
              sdp: answer,
              type: connection.type,
              connectionId: connection.id,
              browser: util.browser
            },
            dst: connection.peer
          });
        },
        function(err) {
          connection.provider.emitError("webrtc", err);
          util.log("Failed to setLocalDescription, ", err);
        }
      );
    },
    function(err) {
      connection.provider.emitError("webrtc", err);
      util.log("Failed to create answer, ", err);
    }
  );
};

/** Handle an SDP. */
Negotiator.handleSDP = function(type, connection, sdp) {
  sdp = new RTCSessionDescription(sdp);
  var pc = connection.pc;

  util.log("Setting remote description", sdp);
  pc.setRemoteDescription(
    sdp,
    function() {
      util.log("Set remoteDescription:", type, "for:", connection.peer);

      if (type === "OFFER") {
        Negotiator._makeAnswer(connection);
      }
    },
    function(err) {
      connection.provider.emitError("webrtc", err);
      util.log("Failed to setRemoteDescription, ", err);
    }
  );
};

/** Handle a candidate. */
Negotiator.handleCandidate = function(connection, ice) {
  var candidate = ice.candidate;
  var sdpMLineIndex = ice.sdpMLineIndex;
  connection.pc.addIceCandidate(
    new RTCIceCandidate({
      sdpMLineIndex: sdpMLineIndex,
      candidate: candidate
    })
  );
  util.log("Added ICE candidate for:", connection.peer);
};

module.exports = Negotiator;

},{"./adapter":1,"./util":8}],6:[function(require,module,exports){
var util = require("./util");
var EventEmitter = require("eventemitter3");
var Socket = require("./socket");
var MediaConnection = require("./mediaconnection");
var DataConnection = require("./dataconnection");

/**
 * A peer who can initiate connections with other peers.
 */
function Peer(id, options) {
  if (!(this instanceof Peer)) return new Peer(id, options);
  EventEmitter.call(this);

  // Deal with overloading
  if (id && id.constructor == Object) {
    options = id;
    id = undefined;
  } else if (id) {
    // Ensure id is a string
    id = id.toString();
  }
  //

  // Configurize options
  options = util.extend(
    {
      debug: 0, // 1: Errors, 2: Warnings, 3: All logs
      host: util.CLOUD_HOST,
      port: util.CLOUD_PORT,
      path: "/",
      token: util.randomToken(),
      config: util.defaultConfig
    },
    options
  );
  options.key = "peerjs";
  this.options = options;
  // Detect relative URL host.
  if (options.host === "/") {
    options.host = window.location.hostname;
  }
  // Set path correctly.
  if (options.path[0] !== "/") {
    options.path = "/" + options.path;
  }
  if (options.path[options.path.length - 1] !== "/") {
    options.path += "/";
  }

  // Set whether we use SSL to same as current host
  if (options.secure === undefined && options.host !== util.CLOUD_HOST) {
    options.secure = util.isSecure();
  } else if(options.host == util.CLOUD_HOST){
    options.secure = true;
  }
  // Set a custom log function if present
  if (options.logFunction) {
    util.setLogFunction(options.logFunction);
  }
  util.setLogLevel(options.debug);
  //

  // Sanity checks
  // Ensure WebRTC supported
  if (!util.supports.audioVideo && !util.supports.data) {
    this._delayedAbort(
      "browser-incompatible",
      "The current browser does not support WebRTC"
    );
    return;
  }
  // Ensure alphanumeric id
  if (!util.validateId(id)) {
    this._delayedAbort("invalid-id", 'ID "' + id + '" is invalid');
    return;
  }
  // Ensure valid key
  // if (!util.validateKey(options.key)) {
  //   this._delayedAbort(
  //     "invalid-key",
  //     'API KEY "' + options.key + '" is invalid'
  //   );
  //   return;
  // }
  // Ensure not using unsecure cloud server on SSL page
  // if (options.secure && options.host === "0.peerjs.com") {
  //   this._delayedAbort(
  //     "ssl-unavailable",
  //     "The cloud server currently does not support HTTPS. Please run your own PeerServer to use HTTPS."
  //   );
  //   return;
  // }
  //

  // States.
  this.destroyed = false; // Connections have been killed
  this.disconnected = false; // Connection to PeerServer killed but P2P connections still active
  this.open = false; // Sockets and such are not yet open.
  //

  // References
  this.connections = {}; // DataConnections for this peer.
  this._lostMessages = {}; // src => [list of messages]
  //

  // Start the server connection
  this._initializeServerConnection();
  if (id) {
    this._initialize(id);
  } else {
    this._retrieveId();
  }
  //
}

util.inherits(Peer, EventEmitter);

// Initialize the 'socket' (which is actually a mix of XHR streaming and
// websockets.)
Peer.prototype._initializeServerConnection = function() {
  var self = this;
  this.socket = new Socket(
    this.options.secure,
    this.options.host,
    this.options.port,
    this.options.path,
    this.options.key,
    this.options.wsport
  );
  this.socket.on("message", function(data) {
    self._handleMessage(data);
  });
  this.socket.on("error", function(error) {
    self._abort("socket-error", error);
  });
  this.socket.on("disconnected", function() {
    // If we haven't explicitly disconnected, emit error and disconnect.
    if (!self.disconnected) {
      self.emitError("network", "Lost connection to server.");
      self.disconnect();
    }
  });
  this.socket.on("close", function() {
    // If we haven't explicitly disconnected, emit error.
    if (!self.disconnected) {
      self._abort("socket-closed", "Underlying socket is already closed.");
    }
  });
};

/** Get a unique ID from the server via XHR. */
Peer.prototype._retrieveId = function(cb) {
  var self = this;
  var http = new XMLHttpRequest();
  var protocol = this.options.secure ? "https://" : "http://";
  var url =
    protocol +
    this.options.host +
    ":" +
    this.options.port +
    this.options.path +
    this.options.key +
    "/id";
  var queryString = "?ts=" + new Date().getTime() + "" + Math.random();
  url += queryString;

  // If there's no ID we need to wait for one before trying to init socket.
  http.open("get", url, true);
  http.onerror = function(e) {
    util.error("Error retrieving ID", e);
    var pathError = "";
    if (self.options.path === "/" && self.options.host !== util.CLOUD_HOST) {
      pathError =
        " If you passed in a `path` to your self-hosted PeerServer, " +
        "you'll also need to pass in that same path when creating a new " +
        "Peer.";
    }
    self._abort(
      "server-error",
      "Could not get an ID from the server." + pathError
    );
  };
  http.onreadystatechange = function() {
    if (http.readyState !== 4) {
      return;
    }
    if (http.status !== 200) {
      http.onerror();
      return;
    }
    self._initialize(http.responseText);
  };
  http.send(null);
};

/** Initialize a connection with the server. */
Peer.prototype._initialize = function(id) {
  this.id = id;
  this.socket.start(this.id, this.options.token);
};

/** Handles messages from the server. */
Peer.prototype._handleMessage = function(message) {
  var type = message.type;
  var payload = message.payload;
  var peer = message.src;
  var connection;

  switch (type) {
    case "OPEN": // The connection to the server is open.
      this.emit("open", this.id);
      this.open = true;
      break;
    case "ERROR": // Server error.
      this._abort("server-error", payload.msg);
      break;
    case "ID-TAKEN": // The selected ID is taken.
      this._abort("unavailable-id", "ID `" + this.id + "` is taken");
      break;
    case "INVALID-KEY": // The given API key cannot be found.
      this._abort(
        "invalid-key",
        'API KEY "' + this.options.key + '" is invalid'
      );
      break;

    //
    case "LEAVE": // Another peer has closed its connection to this peer.
      util.log("Received leave message from", peer);
      this._cleanupPeer(peer);
      break;

    case "EXPIRE": // The offer sent to a peer has expired without response.
      this.emitError("peer-unavailable", "Could not connect to peer " + peer);
      break;
    case "OFFER": // we should consider switching this to CALL/CONNECT, but this is the least breaking option.
      var connectionId = payload.connectionId;
      connection = this.getConnection(peer, connectionId);

      if (connection) {
        connection.close();
        util.warn("Offer received for existing Connection ID:", connectionId);
      }

      // Create a new connection.
      if (payload.type === "media") {
        connection = new MediaConnection(peer, this, {
          connectionId: connectionId,
          _payload: payload,
          metadata: payload.metadata
        });
        this._addConnection(peer, connection);
        this.emit("call", connection);
      } else if (payload.type === "data") {
        connection = new DataConnection(peer, this, {
          connectionId: connectionId,
          _payload: payload,
          metadata: payload.metadata,
          label: payload.label,
          serialization: payload.serialization,
          reliable: payload.reliable
        });
        this._addConnection(peer, connection);
        this.emit("connection", connection);
      } else {
        util.warn("Received malformed connection type:", payload.type);
        return;
      }
      // Find messages.
      var messages = this._getMessages(connectionId);
      for (var i = 0, ii = messages.length; i < ii; i += 1) {
        connection.handleMessage(messages[i]);
      }

      break;
    default:
      if (!payload) {
        util.warn(
          "You received a malformed message from " + peer + " of type " + type
        );
        return;
      }

      var id = payload.connectionId;
      connection = this.getConnection(peer, id);

      if (connection && connection.pc) {
        // Pass it on.
        connection.handleMessage(message);
      } else if (id) {
        // Store for possible later use
        this._storeMessage(id, message);
      } else {
        util.warn("You received an unrecognized message:", message);
      }
      break;
  }
};

/** Stores messages without a set up connection, to be claimed later. */
Peer.prototype._storeMessage = function(connectionId, message) {
  if (!this._lostMessages[connectionId]) {
    this._lostMessages[connectionId] = [];
  }
  this._lostMessages[connectionId].push(message);
};

/** Retrieve messages from lost message store */
Peer.prototype._getMessages = function(connectionId) {
  var messages = this._lostMessages[connectionId];
  if (messages) {
    delete this._lostMessages[connectionId];
    return messages;
  } else {
    return [];
  }
};

/**
 * Returns a DataConnection to the specified peer. See documentation for a
 * complete list of options.
 */
Peer.prototype.connect = function(peer, options) {
  if (this.disconnected) {
    util.warn(
      "You cannot connect to a new Peer because you called " +
        ".disconnect() on this Peer and ended your connection with the " +
        "server. You can create a new Peer to reconnect, or call reconnect " +
        "on this peer if you believe its ID to still be available."
    );
    this.emitError(
      "disconnected",
      "Cannot connect to new Peer after disconnecting from server."
    );
    return;
  }
  var connection = new DataConnection(peer, this, options);
  this._addConnection(peer, connection);
  return connection;
};

/**
 * Returns a MediaConnection to the specified peer. See documentation for a
 * complete list of options.
 */
Peer.prototype.call = function(peer, stream, options) {
  if (this.disconnected) {
    util.warn(
      "You cannot connect to a new Peer because you called " +
        ".disconnect() on this Peer and ended your connection with the " +
        "server. You can create a new Peer to reconnect."
    );
    this.emitError(
      "disconnected",
      "Cannot connect to new Peer after disconnecting from server."
    );
    return;
  }
  if (!stream) {
    util.error(
      "To call a peer, you must provide a stream from your browser's `getUserMedia`."
    );
    return;
  }
  options = options || {};
  options._stream = stream;
  var call = new MediaConnection(peer, this, options);
  this._addConnection(peer, call);
  return call;
};

/** Add a data/media connection to this peer. */
Peer.prototype._addConnection = function(peer, connection) {
  if (!this.connections[peer]) {
    this.connections[peer] = [];
  }
  this.connections[peer].push(connection);
};

/** Retrieve a data/media connection for this peer. */
Peer.prototype.getConnection = function(peer, id) {
  var connections = this.connections[peer];
  if (!connections) {
    return null;
  }
  for (var i = 0, ii = connections.length; i < ii; i++) {
    if (connections[i].id === id) {
      return connections[i];
    }
  }
  return null;
};

Peer.prototype._delayedAbort = function(type, message) {
  var self = this;
  util.setZeroTimeout(function() {
    self._abort(type, message);
  });
};

/**
 * Destroys the Peer and emits an error message.
 * The Peer is not destroyed if it's in a disconnected state, in which case
 * it retains its disconnected state and its existing connections.
 */
Peer.prototype._abort = function(type, message) {
  util.error("Aborting!");
  if (!this._lastServerId) {
    this.destroy();
  } else {
    this.disconnect();
  }
  this.emitError(type, message);
};

/** Emits a typed error message. */
Peer.prototype.emitError = function(type, err) {
  util.error("Error:", err);
  if (typeof err === "string") {
    err = new Error(err);
  }
  err.type = type;
  this.emit("error", err);
};

/**
 * Destroys the Peer: closes all active connections as well as the connection
 *  to the server.
 * Warning: The peer can no longer create or accept connections after being
 *  destroyed.
 */
Peer.prototype.destroy = function() {
  if (!this.destroyed) {
    this._cleanup();
    this.disconnect();
    this.destroyed = true;
  }
};

/** Disconnects every connection on this peer. */
Peer.prototype._cleanup = function() {
  if (this.connections) {
    var peers = Object.keys(this.connections);
    for (var i = 0, ii = peers.length; i < ii; i++) {
      this._cleanupPeer(peers[i]);
    }
  }
  this.emit("close");
};

/** Closes all connections to this peer. */
Peer.prototype._cleanupPeer = function(peer) {
  var connections = this.connections[peer];
  for (var j = 0, jj = connections.length; j < jj; j += 1) {
    connections[j].close();
  }
};

/**
 * Disconnects the Peer's connection to the PeerServer. Does not close any
 *  active connections.
 * Warning: The peer can no longer create or accept connections after being
 *  disconnected. It also cannot reconnect to the server.
 */
Peer.prototype.disconnect = function() {
  var self = this;
  util.setZeroTimeout(function() {
    if (!self.disconnected) {
      self.disconnected = true;
      self.open = false;
      if (self.socket) {
        self.socket.close();
      }
      self.emit("disconnected", self.id);
      self._lastServerId = self.id;
      self.id = null;
    }
  });
};

/** Attempts to reconnect with the same ID. */
Peer.prototype.reconnect = function() {
  if (this.disconnected && !this.destroyed) {
    util.log("Attempting reconnection to server with ID " + this._lastServerId);
    this.disconnected = false;
    this._initializeServerConnection();
    this._initialize(this._lastServerId);
  } else if (this.destroyed) {
    throw new Error(
      "This peer cannot reconnect to the server. It has already been destroyed."
    );
  } else if (!this.disconnected && !this.open) {
    // Do nothing. We're still connecting the first time.
    util.error(
      "In a hurry? We're still trying to make the initial connection!"
    );
  } else {
    throw new Error(
      "Peer " +
        this.id +
        " cannot reconnect because it is not disconnected from the server!"
    );
  }
};

/**
 * Get a list of available peer IDs. If you're running your own server, you'll
 * want to set allow_discovery: true in the PeerServer options. If you're using
 * the cloud server, email team@peerjs.com to get the functionality enabled for
 * your key.
 */
Peer.prototype.listAllPeers = function(cb) {
  cb = cb || function() {};
  var self = this;
  var http = new XMLHttpRequest();
  var protocol = this.options.secure ? "https://" : "http://";
  var url =
    protocol +
    this.options.host +
    ":" +
    this.options.port +
    this.options.path +
    this.options.key +
    "/peers";
  var queryString = "?ts=" + new Date().getTime() + "" + Math.random();
  url += queryString;

  // If there's no ID we need to wait for one before trying to init socket.
  http.open("get", url, true);
  http.onerror = function(e) {
    self._abort("server-error", "Could not get peers from the server.");
    cb([]);
  };
  http.onreadystatechange = function() {
    if (http.readyState !== 4) {
      return;
    }
    if (http.status === 401) {
      var helpfulError = "";
      if (self.options.host !== util.CLOUD_HOST) {
        helpfulError =
          "It looks like you're using the cloud server. You can email " +
          "team@peerjs.com to enable peer listing for your API key.";
      } else {
        helpfulError =
          "You need to enable `allow_discovery` on your self-hosted " +
          "PeerServer to use this feature.";
      }
      cb([]);
      throw new Error(
        "It doesn't look like you have permission to list peers IDs. " +
          helpfulError
      );
    } else if (http.status !== 200) {
      cb([]);
    } else {
      cb(JSON.parse(http.responseText));
    }
  };
  http.send(null);
};

module.exports = Peer;

},{"./dataconnection":2,"./mediaconnection":4,"./socket":7,"./util":8,"eventemitter3":9}],7:[function(require,module,exports){
var util = require('./util');
var EventEmitter = require('eventemitter3');

/**
 * An abstraction on top of WebSockets and XHR streaming to provide fastest
 * possible connection for peers.
 */
function Socket(secure, host, port, path, key, wsport) {
  if (!(this instanceof Socket)) return new Socket(secure, host, port, path, key, wsport);

  wsport = wsport || port;

  EventEmitter.call(this);

  // Disconnected manually.
  this.disconnected = false;
  this._queue = [];

  var httpProtocol = secure ? 'https://' : 'http://';
  var wsProtocol = secure ? 'wss://' : 'ws://';
  this._httpUrl = httpProtocol + host + ':' + port + path + key;
  this._wsUrl = wsProtocol + host + ':' + wsport + path + 'peerjs?key=' + key;
}

util.inherits(Socket, EventEmitter);


/** Check in with ID or get one from server. */
Socket.prototype.start = function(id, token) {
  this.id = id;

  this._httpUrl += '/' + id + '/' + token;
  this._wsUrl += '&id=' + id + '&token=' + token;

  this._startXhrStream();
  this._startWebSocket();
}


/** Start up websocket communications. */
Socket.prototype._startWebSocket = function(id) {
  var self = this;

  if (this._socket) {
    return;
  }

  this._socket = new WebSocket(this._wsUrl);

  this._socket.onmessage = function(event) {
    try {
      var data = JSON.parse(event.data);
    } catch(e) {
      util.log('Invalid server message', event.data);
      return;
    }
    self.emit('message', data);
  };

  this._socket.onclose = function(event) {
    util.log('Socket closed.');
    self.disconnected = true;
    self.emit('disconnected');
  };

  // Take care of the queue of connections if necessary and make sure Peer knows
  // socket is open.
  this._socket.onopen = function() {
    if (self._timeout) {
      clearTimeout(self._timeout);
      setTimeout(function(){
        self._http.abort();
        self._http = null;
      }, 5000);
    }
    self._sendQueuedMessages();
    util.log('Socket open');
  };
}

/** Start XHR streaming. */
Socket.prototype._startXhrStream = function(n) {
  try {
    var self = this;
    this._http = new XMLHttpRequest();
    this._http._index = 1;
    this._http._streamIndex = n || 0;
    this._http.open('post', this._httpUrl + '/id?i=' + this._http._streamIndex, true);
    this._http.onerror = function() {
      // If we get an error, likely something went wrong.
      // Stop streaming.
      clearTimeout(self._timeout);
      self.emit('disconnected');
    }
    this._http.onreadystatechange = function() {
      if (this.readyState == 2 && this.old) {
        this.old.abort();
        delete this.old;
      } else if (this.readyState > 2 && this.status === 200 && this.responseText) {
        self._handleStream(this);
      }
    };
    this._http.send(null);
    this._setHTTPTimeout();
  } catch(e) {
    util.log('XMLHttpRequest not available; defaulting to WebSockets');
  }
}


/** Handles onreadystatechange response as a stream. */
Socket.prototype._handleStream = function(http) {
  // 3 and 4 are loading/done state. All others are not relevant.
  var messages = http.responseText.split('\n');

  // Check to see if anything needs to be processed on buffer.
  if (http._buffer) {
    while (http._buffer.length > 0) {
      var index = http._buffer.shift();
      var bufferedMessage = messages[index];
      try {
        bufferedMessage = JSON.parse(bufferedMessage);
      } catch(e) {
        http._buffer.shift(index);
        break;
      }
      this.emit('message', bufferedMessage);
    }
  }

  var message = messages[http._index];
  if (message) {
    http._index += 1;
    // Buffering--this message is incomplete and we'll get to it next time.
    // This checks if the httpResponse ended in a `\n`, in which case the last
    // element of messages should be the empty string.
    if (http._index === messages.length) {
      if (!http._buffer) {
        http._buffer = [];
      }
      http._buffer.push(http._index - 1);
    } else {
      try {
        message = JSON.parse(message);
      } catch(e) {
        util.log('Invalid server message', message);
        return;
      }
      this.emit('message', message);
    }
  }
}

Socket.prototype._setHTTPTimeout = function() {
  var self = this;
  this._timeout = setTimeout(function() {
    var old = self._http;
    if (!self._wsOpen()) {
      self._startXhrStream(old._streamIndex + 1);
      self._http.old = old;
    } else {
      old.abort();
    }
  }, 25000);
}

/** Is the websocket currently open? */
Socket.prototype._wsOpen = function() {
  return this._socket && this._socket.readyState == 1;
}

/** Send queued messages. */
Socket.prototype._sendQueuedMessages = function() {
  for (var i = 0, ii = this._queue.length; i < ii; i += 1) {
    this.send(this._queue[i]);
  }
}

/** Exposed send for DC & Peer. */
Socket.prototype.send = function(data) {
  if (this.disconnected) {
    return;
  }

  // If we didn't get an ID yet, we can't yet send anything so we should queue
  // up these messages.
  if (!this.id) {
    this._queue.push(data);
    return;
  }

  if (!data.type) {
    this.emit('error', 'Invalid message');
    return;
  }

  var message = JSON.stringify(data);
  if (this._wsOpen()) {
    this._socket.send(message);
  } else {
    var http = new XMLHttpRequest();
    var url = this._httpUrl + '/' + data.type.toLowerCase();
    http.open('post', url, true);
    http.setRequestHeader('Content-Type', 'application/json');
    http.send(message);
  }
}

Socket.prototype.close = function() {
  if (!this.disconnected && this._wsOpen()) {
    this._socket.close();
    this.disconnected = true;
  }
}

module.exports = Socket;

},{"./util":8,"eventemitter3":9}],8:[function(require,module,exports){
var defaultConfig = {'iceServers': [{ 'urls': 'stun:stun.l.google.com:19302' }]};
var dataCount = 1;

var BinaryPack = require("js-binarypack");
var RTCPeerConnection = require("./adapter").RTCPeerConnection;

var util = {
  noop: function() {},

  CLOUD_HOST: "0.peerjs.com",
  CLOUD_PORT: 443,

  // Browsers that need chunking:
  chunkedBrowsers: { Chrome: 1 },
  chunkedMTU: 16300, // The original 60000 bytes setting does not work when sending data from Firefox to Chrome, which is "cut off" after 16384 bytes and delivered individually.

  // Logging logic
  logLevel: 0,
  setLogLevel: function(level) {
    var debugLevel = parseInt(level, 10);
    if (!isNaN(parseInt(level, 10))) {
      util.logLevel = debugLevel;
    } else {
      // If they are using truthy/falsy values for debug
      util.logLevel = level ? 3 : 0;
    }
    util.log = util.warn = util.error = util.noop;
    if (util.logLevel > 0) {
      util.error = util._printWith("ERROR");
    }
    if (util.logLevel > 1) {
      util.warn = util._printWith("WARNING");
    }
    if (util.logLevel > 2) {
      util.log = util._print;
    }
  },
  setLogFunction: function(fn) {
    if (fn.constructor !== Function) {
      util.warn(
        "The log function you passed in is not a function. Defaulting to regular logs."
      );
    } else {
      util._print = fn;
    }
  },

  _printWith: function(prefix) {
    return function() {
      var copy = Array.prototype.slice.call(arguments);
      copy.unshift(prefix);
      util._print.apply(util, copy);
    };
  },
  _print: function() {
    var err = false;
    var copy = Array.prototype.slice.call(arguments);
    copy.unshift("PeerJS: ");
    for (var i = 0, l = copy.length; i < l; i++) {
      if (copy[i] instanceof Error) {
        copy[i] = "(" + copy[i].name + ") " + copy[i].message;
        err = true;
      }
    }
    err ? console.error.apply(console, copy) : console.log.apply(console, copy);
  },
  //

  // Returns browser-agnostic default config
  defaultConfig: defaultConfig,
  //

  // Returns the current browser.
  browser: (function() {
    if (window.mozRTCPeerConnection) {
      return "Firefox";
    } else if (window.webkitRTCPeerConnection) {
      return "Chrome";
    } else if (window.RTCPeerConnection) {
      return "Supported";
    } else {
      return "Unsupported";
    }
  })(),
  //

  // Lists which features are supported
  supports: (function() {
    if (typeof RTCPeerConnection === "undefined") {
      return {};
    }

    var data = true;
    var audioVideo = true;

    var binaryBlob = false;
    var sctp = false;
    var onnegotiationneeded = !!window.webkitRTCPeerConnection;

    var pc, dc;
    try {
      pc = new RTCPeerConnection(defaultConfig, {
        optional: [{ RtpDataChannels: true }]
      });
    } catch (e) {
      data = false;
      audioVideo = false;
    }

    if (data) {
      try {
        dc = pc.createDataChannel("_PEERJSTEST");
      } catch (e) {
        data = false;
      }
    }

    if (data) {
      // Binary test
      try {
        dc.binaryType = "blob";
        binaryBlob = true;
      } catch (e) {}

      // Reliable test.
      // Unfortunately Chrome is a bit unreliable about whether or not they
      // support reliable.
      var reliablePC = new RTCPeerConnection(defaultConfig, {});
      try {
        var reliableDC = reliablePC.createDataChannel(
          "_PEERJSRELIABLETEST",
          {}
        );
        sctp = reliableDC.reliable;
      } catch (e) {}
      reliablePC.close();
    }

    // FIXME: not really the best check...
    if (audioVideo) {
      audioVideo = !!pc.addStream;
    }

    // FIXME: this is not great because in theory it doesn't work for
    // av-only browsers (?).
    /*
    if (!onnegotiationneeded && data) {
      // sync default check.
      var negotiationPC = new RTCPeerConnection(defaultConfig, {optional: [{RtpDataChannels: true}]});
      negotiationPC.onnegotiationneeded = function() {
        onnegotiationneeded = true;
        // async check.
        if (util && util.supports) {
          util.supports.onnegotiationneeded = true;
        }
      };
      negotiationPC.createDataChannel('_PEERJSNEGOTIATIONTEST');

      setTimeout(function() {
        negotiationPC.close();
      }, 1000);
    }
    */

    if (pc) {
      pc.close();
    }

    return {
      audioVideo: audioVideo,
      data: data,
      binaryBlob: binaryBlob,
      binary: sctp, // deprecated; sctp implies binary support.
      reliable: sctp, // deprecated; sctp implies reliable data.
      sctp: sctp,
      onnegotiationneeded: onnegotiationneeded
    };
  })(),
  //

  // Ensure alphanumeric ids
  validateId: function(id) {
    // Allow empty ids
    return !id || /^[A-Za-z0-9]+(?:[ _-][A-Za-z0-9]+)*$/.exec(id);
  },

  validateKey: function(key) {
    // Allow empty keys
    return !key || /^[A-Za-z0-9]+(?:[ _-][A-Za-z0-9]+)*$/.exec(key);
  },

  debug: false,

  inherits: function(ctor, superCtor) {
    ctor.super_ = superCtor;
    ctor.prototype = Object.create(superCtor.prototype, {
      constructor: {
        value: ctor,
        enumerable: false,
        writable: true,
        configurable: true
      }
    });
  },
  extend: function(dest, source) {
    for (var key in source) {
      if (source.hasOwnProperty(key)) {
        dest[key] = source[key];
      }
    }
    return dest;
  },
  pack: BinaryPack.pack,
  unpack: BinaryPack.unpack,

  log: function() {
    if (util.debug) {
      var err = false;
      var copy = Array.prototype.slice.call(arguments);
      copy.unshift("PeerJS: ");
      for (var i = 0, l = copy.length; i < l; i++) {
        if (copy[i] instanceof Error) {
          copy[i] = "(" + copy[i].name + ") " + copy[i].message;
          err = true;
        }
      }
      err
        ? console.error.apply(console, copy)
        : console.log.apply(console, copy);
    }
  },

  setZeroTimeout: (function(global) {
    var timeouts = [];
    var messageName = "zero-timeout-message";

    // Like setTimeout, but only takes a function argument.	 There's
    // no time argument (always zero) and no arguments (you have to
    // use a closure).
    function setZeroTimeoutPostMessage(fn) {
      timeouts.push(fn);
      global.postMessage(messageName, "*");
    }

    function handleMessage(event) {
      if (event.source == global && event.data == messageName) {
        if (event.stopPropagation) {
          event.stopPropagation();
        }
        if (timeouts.length) {
          timeouts.shift()();
        }
      }
    }
    if (global.addEventListener) {
      global.addEventListener("message", handleMessage, true);
    } else if (global.attachEvent) {
      global.attachEvent("onmessage", handleMessage);
    }
    return setZeroTimeoutPostMessage;
  })(window),

  // Binary stuff

  // chunks a blob.
  chunk: function(bl) {
    var chunks = [];
    var size = bl.size;
    var start = (index = 0);
    var total = Math.ceil(size / util.chunkedMTU);
    while (start < size) {
      var end = Math.min(size, start + util.chunkedMTU);
      var b = bl.slice(start, end);

      var chunk = {
        __peerData: dataCount,
        n: index,
        data: b,
        total: total
      };

      chunks.push(chunk);

      start = end;
      index += 1;
    }
    dataCount += 1;
    return chunks;
  },

  blobToArrayBuffer: function(blob, cb) {
    var fr = new FileReader();
    fr.onload = function(evt) {
      cb(evt.target.result);
    };
    fr.readAsArrayBuffer(blob);
  },
  blobToBinaryString: function(blob, cb) {
    var fr = new FileReader();
    fr.onload = function(evt) {
      cb(evt.target.result);
    };
    fr.readAsBinaryString(blob);
  },
  binaryStringToArrayBuffer: function(binary) {
    var byteArray = new Uint8Array(binary.length);
    for (var i = 0; i < binary.length; i++) {
      byteArray[i] = binary.charCodeAt(i) & 0xff;
    }
    return byteArray.buffer;
  },
  randomToken: function() {
    return Math.random()
      .toString(36)
      .substr(2);
  },
  //

  isSecure: function() {
    return location.protocol === "https:";
  }
};

module.exports = util;

},{"./adapter":1,"js-binarypack":10}],9:[function(require,module,exports){
'use strict';

/**
 * Representation of a single EventEmitter function.
 *
 * @param {Function} fn Event handler to be called.
 * @param {Mixed} context Context for function execution.
 * @param {Boolean} once Only emit once
 * @api private
 */
function EE(fn, context, once) {
  this.fn = fn;
  this.context = context;
  this.once = once || false;
}

/**
 * Minimal EventEmitter interface that is molded against the Node.js
 * EventEmitter interface.
 *
 * @constructor
 * @api public
 */
function EventEmitter() { /* Nothing to set */ }

/**
 * Holds the assigned EventEmitters by name.
 *
 * @type {Object}
 * @private
 */
EventEmitter.prototype._events = undefined;

/**
 * Return a list of assigned event listeners.
 *
 * @param {String} event The events that should be listed.
 * @returns {Array}
 * @api public
 */
EventEmitter.prototype.listeners = function listeners(event) {
  if (!this._events || !this._events[event]) return [];
  if (this._events[event].fn) return [this._events[event].fn];

  for (var i = 0, l = this._events[event].length, ee = new Array(l); i < l; i++) {
    ee[i] = this._events[event][i].fn;
  }

  return ee;
};

/**
 * Emit an event to all registered event listeners.
 *
 * @param {String} event The name of the event.
 * @returns {Boolean} Indication if we've emitted an event.
 * @api public
 */
EventEmitter.prototype.emit = function emit(event, a1, a2, a3, a4, a5) {
  if (!this._events || !this._events[event]) return false;

  var listeners = this._events[event]
    , len = arguments.length
    , args
    , i;

  if ('function' === typeof listeners.fn) {
    if (listeners.once) this.removeListener(event, listeners.fn, true);

    switch (len) {
      case 1: return listeners.fn.call(listeners.context), true;
      case 2: return listeners.fn.call(listeners.context, a1), true;
      case 3: return listeners.fn.call(listeners.context, a1, a2), true;
      case 4: return listeners.fn.call(listeners.context, a1, a2, a3), true;
      case 5: return listeners.fn.call(listeners.context, a1, a2, a3, a4), true;
      case 6: return listeners.fn.call(listeners.context, a1, a2, a3, a4, a5), true;
    }

    for (i = 1, args = new Array(len -1); i < len; i++) {
      args[i - 1] = arguments[i];
    }

    listeners.fn.apply(listeners.context, args);
  } else {
    var length = listeners.length
      , j;

    for (i = 0; i < length; i++) {
      if (listeners[i].once) this.removeListener(event, listeners[i].fn, true);

      switch (len) {
        case 1: listeners[i].fn.call(listeners[i].context); break;
        case 2: listeners[i].fn.call(listeners[i].context, a1); break;
        case 3: listeners[i].fn.call(listeners[i].context, a1, a2); break;
        default:
          if (!args) for (j = 1, args = new Array(len -1); j < len; j++) {
            args[j - 1] = arguments[j];
          }

          listeners[i].fn.apply(listeners[i].context, args);
      }
    }
  }

  return true;
};

/**
 * Register a new EventListener for the given event.
 *
 * @param {String} event Name of the event.
 * @param {Functon} fn Callback function.
 * @param {Mixed} context The context of the function.
 * @api public
 */
EventEmitter.prototype.on = function on(event, fn, context) {
  var listener = new EE(fn, context || this);

  if (!this._events) this._events = {};
  if (!this._events[event]) this._events[event] = listener;
  else {
    if (!this._events[event].fn) this._events[event].push(listener);
    else this._events[event] = [
      this._events[event], listener
    ];
  }

  return this;
};

/**
 * Add an EventListener that's only called once.
 *
 * @param {String} event Name of the event.
 * @param {Function} fn Callback function.
 * @param {Mixed} context The context of the function.
 * @api public
 */
EventEmitter.prototype.once = function once(event, fn, context) {
  var listener = new EE(fn, context || this, true);

  if (!this._events) this._events = {};
  if (!this._events[event]) this._events[event] = listener;
  else {
    if (!this._events[event].fn) this._events[event].push(listener);
    else this._events[event] = [
      this._events[event], listener
    ];
  }

  return this;
};

/**
 * Remove event listeners.
 *
 * @param {String} event The event we want to remove.
 * @param {Function} fn The listener that we need to find.
 * @param {Boolean} once Only remove once listeners.
 * @api public
 */
EventEmitter.prototype.removeListener = function removeListener(event, fn, once) {
  if (!this._events || !this._events[event]) return this;

  var listeners = this._events[event]
    , events = [];

  if (fn) {
    if (listeners.fn && (listeners.fn !== fn || (once && !listeners.once))) {
      events.push(listeners);
    }
    if (!listeners.fn) for (var i = 0, length = listeners.length; i < length; i++) {
      if (listeners[i].fn !== fn || (once && !listeners[i].once)) {
        events.push(listeners[i]);
      }
    }
  }

  //
  // Reset the array, or remove it completely if we have no more listeners.
  //
  if (events.length) {
    this._events[event] = events.length === 1 ? events[0] : events;
  } else {
    delete this._events[event];
  }

  return this;
};

/**
 * Remove all listeners or only the listeners for the specified event.
 *
 * @param {String} event The event want to remove all listeners for.
 * @api public
 */
EventEmitter.prototype.removeAllListeners = function removeAllListeners(event) {
  if (!this._events) return this;

  if (event) delete this._events[event];
  else this._events = {};

  return this;
};

//
// Alias methods names because people roll like that.
//
EventEmitter.prototype.off = EventEmitter.prototype.removeListener;
EventEmitter.prototype.addListener = EventEmitter.prototype.on;

//
// This function doesn't apply anymore.
//
EventEmitter.prototype.setMaxListeners = function setMaxListeners() {
  return this;
};

//
// Expose the module.
//
EventEmitter.EventEmitter = EventEmitter;
EventEmitter.EventEmitter2 = EventEmitter;
EventEmitter.EventEmitter3 = EventEmitter;

//
// Expose the module.
//
module.exports = EventEmitter;

},{}],10:[function(require,module,exports){
var BufferBuilder = require('./bufferbuilder').BufferBuilder;
var binaryFeatures = require('./bufferbuilder').binaryFeatures;

var BinaryPack = {
  unpack: function(data){
    var unpacker = new Unpacker(data);
    return unpacker.unpack();
  },
  pack: function(data){
    var packer = new Packer();
    packer.pack(data);
    var buffer = packer.getBuffer();
    return buffer;
  }
};

module.exports = BinaryPack;

function Unpacker (data){
  // Data is ArrayBuffer
  this.index = 0;
  this.dataBuffer = data;
  this.dataView = new Uint8Array(this.dataBuffer);
  this.length = this.dataBuffer.byteLength;
}

Unpacker.prototype.unpack = function(){
  var type = this.unpack_uint8();
  if (type < 0x80){
    var positive_fixnum = type;
    return positive_fixnum;
  } else if ((type ^ 0xe0) < 0x20){
    var negative_fixnum = (type ^ 0xe0) - 0x20;
    return negative_fixnum;
  }
  var size;
  if ((size = type ^ 0xa0) <= 0x0f){
    return this.unpack_raw(size);
  } else if ((size = type ^ 0xb0) <= 0x0f){
    return this.unpack_string(size);
  } else if ((size = type ^ 0x90) <= 0x0f){
    return this.unpack_array(size);
  } else if ((size = type ^ 0x80) <= 0x0f){
    return this.unpack_map(size);
  }
  switch(type){
    case 0xc0:
      return null;
    case 0xc1:
      return undefined;
    case 0xc2:
      return false;
    case 0xc3:
      return true;
    case 0xca:
      return this.unpack_float();
    case 0xcb:
      return this.unpack_double();
    case 0xcc:
      return this.unpack_uint8();
    case 0xcd:
      return this.unpack_uint16();
    case 0xce:
      return this.unpack_uint32();
    case 0xcf:
      return this.unpack_uint64();
    case 0xd0:
      return this.unpack_int8();
    case 0xd1:
      return this.unpack_int16();
    case 0xd2:
      return this.unpack_int32();
    case 0xd3:
      return this.unpack_int64();
    case 0xd4:
      return undefined;
    case 0xd5:
      return undefined;
    case 0xd6:
      return undefined;
    case 0xd7:
      return undefined;
    case 0xd8:
      size = this.unpack_uint16();
      return this.unpack_string(size);
    case 0xd9:
      size = this.unpack_uint32();
      return this.unpack_string(size);
    case 0xda:
      size = this.unpack_uint16();
      return this.unpack_raw(size);
    case 0xdb:
      size = this.unpack_uint32();
      return this.unpack_raw(size);
    case 0xdc:
      size = this.unpack_uint16();
      return this.unpack_array(size);
    case 0xdd:
      size = this.unpack_uint32();
      return this.unpack_array(size);
    case 0xde:
      size = this.unpack_uint16();
      return this.unpack_map(size);
    case 0xdf:
      size = this.unpack_uint32();
      return this.unpack_map(size);
  }
}

Unpacker.prototype.unpack_uint8 = function(){
  var byte = this.dataView[this.index] & 0xff;
  this.index++;
  return byte;
};

Unpacker.prototype.unpack_uint16 = function(){
  var bytes = this.read(2);
  var uint16 =
    ((bytes[0] & 0xff) * 256) + (bytes[1] & 0xff);
  this.index += 2;
  return uint16;
}

Unpacker.prototype.unpack_uint32 = function(){
  var bytes = this.read(4);
  var uint32 =
     ((bytes[0]  * 256 +
       bytes[1]) * 256 +
       bytes[2]) * 256 +
       bytes[3];
  this.index += 4;
  return uint32;
}

Unpacker.prototype.unpack_uint64 = function(){
  var bytes = this.read(8);
  var uint64 =
   ((((((bytes[0]  * 256 +
       bytes[1]) * 256 +
       bytes[2]) * 256 +
       bytes[3]) * 256 +
       bytes[4]) * 256 +
       bytes[5]) * 256 +
       bytes[6]) * 256 +
       bytes[7];
  this.index += 8;
  return uint64;
}


Unpacker.prototype.unpack_int8 = function(){
  var uint8 = this.unpack_uint8();
  return (uint8 < 0x80 ) ? uint8 : uint8 - (1 << 8);
};

Unpacker.prototype.unpack_int16 = function(){
  var uint16 = this.unpack_uint16();
  return (uint16 < 0x8000 ) ? uint16 : uint16 - (1 << 16);
}

Unpacker.prototype.unpack_int32 = function(){
  var uint32 = this.unpack_uint32();
  return (uint32 < Math.pow(2, 31) ) ? uint32 :
    uint32 - Math.pow(2, 32);
}

Unpacker.prototype.unpack_int64 = function(){
  var uint64 = this.unpack_uint64();
  return (uint64 < Math.pow(2, 63) ) ? uint64 :
    uint64 - Math.pow(2, 64);
}

Unpacker.prototype.unpack_raw = function(size){
  if ( this.length < this.index + size){
    throw new Error('BinaryPackFailure: index is out of range'
      + ' ' + this.index + ' ' + size + ' ' + this.length);
  }
  var buf = this.dataBuffer.slice(this.index, this.index + size);
  this.index += size;

    //buf = util.bufferToString(buf);

  return buf;
}

Unpacker.prototype.unpack_string = function(size){
  var bytes = this.read(size);
  var i = 0, str = '', c, code;
  while(i < size){
    c = bytes[i];
    if ( c < 128){
      str += String.fromCharCode(c);
      i++;
    } else if ((c ^ 0xc0) < 32){
      code = ((c ^ 0xc0) << 6) | (bytes[i+1] & 63);
      str += String.fromCharCode(code);
      i += 2;
    } else {
      code = ((c & 15) << 12) | ((bytes[i+1] & 63) << 6) |
        (bytes[i+2] & 63);
      str += String.fromCharCode(code);
      i += 3;
    }
  }
  this.index += size;
  return str;
}

Unpacker.prototype.unpack_array = function(size){
  var objects = new Array(size);
  for(var i = 0; i < size ; i++){
    objects[i] = this.unpack();
  }
  return objects;
}

Unpacker.prototype.unpack_map = function(size){
  var map = {};
  for(var i = 0; i < size ; i++){
    var key  = this.unpack();
    var value = this.unpack();
    map[key] = value;
  }
  return map;
}

Unpacker.prototype.unpack_float = function(){
  var uint32 = this.unpack_uint32();
  var sign = uint32 >> 31;
  var exp  = ((uint32 >> 23) & 0xff) - 127;
  var fraction = ( uint32 & 0x7fffff ) | 0x800000;
  return (sign == 0 ? 1 : -1) *
    fraction * Math.pow(2, exp - 23);
}

Unpacker.prototype.unpack_double = function(){
  var h32 = this.unpack_uint32();
  var l32 = this.unpack_uint32();
  var sign = h32 >> 31;
  var exp  = ((h32 >> 20) & 0x7ff) - 1023;
  var hfrac = ( h32 & 0xfffff ) | 0x100000;
  var frac = hfrac * Math.pow(2, exp - 20) +
    l32   * Math.pow(2, exp - 52);
  return (sign == 0 ? 1 : -1) * frac;
}

Unpacker.prototype.read = function(length){
  var j = this.index;
  if (j + length <= this.length) {
    return this.dataView.subarray(j, j + length);
  } else {
    throw new Error('BinaryPackFailure: read index out of range');
  }
}

function Packer(){
  this.bufferBuilder = new BufferBuilder();
}

Packer.prototype.getBuffer = function(){
  return this.bufferBuilder.getBuffer();
}

Packer.prototype.pack = function(value){
  var type = typeof(value);
  if (type == 'string'){
    this.pack_string(value);
  } else if (type == 'number'){
    if (Math.floor(value) === value){
      this.pack_integer(value);
    } else{
      this.pack_double(value);
    }
  } else if (type == 'boolean'){
    if (value === true){
      this.bufferBuilder.append(0xc3);
    } else if (value === false){
      this.bufferBuilder.append(0xc2);
    }
  } else if (type == 'undefined'){
    this.bufferBuilder.append(0xc0);
  } else if (type == 'object'){
    if (value === null){
      this.bufferBuilder.append(0xc0);
    } else {
      var constructor = value.constructor;
      if (constructor == Array){
        this.pack_array(value);
      } else if (constructor == Blob || constructor == File) {
        this.pack_bin(value);
      } else if (constructor == ArrayBuffer) {
        if(binaryFeatures.useArrayBufferView) {
          this.pack_bin(new Uint8Array(value));
        } else {
          this.pack_bin(value);
        }
      } else if ('BYTES_PER_ELEMENT' in value){
        if(binaryFeatures.useArrayBufferView) {
          this.pack_bin(new Uint8Array(value.buffer));
        } else {
          this.pack_bin(value.buffer);
        }
      } else if (constructor == Object){
        this.pack_object(value);
      } else if (constructor == Date){
        this.pack_string(value.toString());
      } else if (typeof value.toBinaryPack == 'function'){
        this.bufferBuilder.append(value.toBinaryPack());
      } else {
        throw new Error('Type "' + constructor.toString() + '" not yet supported');
      }
    }
  } else {
    throw new Error('Type "' + type + '" not yet supported');
  }
  this.bufferBuilder.flush();
}


Packer.prototype.pack_bin = function(blob){
  var length = blob.length || blob.byteLength || blob.size;
  if (length <= 0x0f){
    this.pack_uint8(0xa0 + length);
  } else if (length <= 0xffff){
    this.bufferBuilder.append(0xda) ;
    this.pack_uint16(length);
  } else if (length <= 0xffffffff){
    this.bufferBuilder.append(0xdb);
    this.pack_uint32(length);
  } else{
    throw new Error('Invalid length');
  }
  this.bufferBuilder.append(blob);
}

Packer.prototype.pack_string = function(str){
  var length = utf8Length(str);

  if (length <= 0x0f){
    this.pack_uint8(0xb0 + length);
  } else if (length <= 0xffff){
    this.bufferBuilder.append(0xd8) ;
    this.pack_uint16(length);
  } else if (length <= 0xffffffff){
    this.bufferBuilder.append(0xd9);
    this.pack_uint32(length);
  } else{
    throw new Error('Invalid length');
  }
  this.bufferBuilder.append(str);
}

Packer.prototype.pack_array = function(ary){
  var length = ary.length;
  if (length <= 0x0f){
    this.pack_uint8(0x90 + length);
  } else if (length <= 0xffff){
    this.bufferBuilder.append(0xdc)
    this.pack_uint16(length);
  } else if (length <= 0xffffffff){
    this.bufferBuilder.append(0xdd);
    this.pack_uint32(length);
  } else{
    throw new Error('Invalid length');
  }
  for(var i = 0; i < length ; i++){
    this.pack(ary[i]);
  }
}

Packer.prototype.pack_integer = function(num){
  if ( -0x20 <= num && num <= 0x7f){
    this.bufferBuilder.append(num & 0xff);
  } else if (0x00 <= num && num <= 0xff){
    this.bufferBuilder.append(0xcc);
    this.pack_uint8(num);
  } else if (-0x80 <= num && num <= 0x7f){
    this.bufferBuilder.append(0xd0);
    this.pack_int8(num);
  } else if ( 0x0000 <= num && num <= 0xffff){
    this.bufferBuilder.append(0xcd);
    this.pack_uint16(num);
  } else if (-0x8000 <= num && num <= 0x7fff){
    this.bufferBuilder.append(0xd1);
    this.pack_int16(num);
  } else if ( 0x00000000 <= num && num <= 0xffffffff){
    this.bufferBuilder.append(0xce);
    this.pack_uint32(num);
  } else if (-0x80000000 <= num && num <= 0x7fffffff){
    this.bufferBuilder.append(0xd2);
    this.pack_int32(num);
  } else if (-0x8000000000000000 <= num && num <= 0x7FFFFFFFFFFFFFFF){
    this.bufferBuilder.append(0xd3);
    this.pack_int64(num);
  } else if (0x0000000000000000 <= num && num <= 0xFFFFFFFFFFFFFFFF){
    this.bufferBuilder.append(0xcf);
    this.pack_uint64(num);
  } else{
    throw new Error('Invalid integer');
  }
}

Packer.prototype.pack_double = function(num){
  var sign = 0;
  if (num < 0){
    sign = 1;
    num = -num;
  }
  var exp  = Math.floor(Math.log(num) / Math.LN2);
  var frac0 = num / Math.pow(2, exp) - 1;
  var frac1 = Math.floor(frac0 * Math.pow(2, 52));
  var b32   = Math.pow(2, 32);
  var h32 = (sign << 31) | ((exp+1023) << 20) |
      (frac1 / b32) & 0x0fffff;
  var l32 = frac1 % b32;
  this.bufferBuilder.append(0xcb);
  this.pack_int32(h32);
  this.pack_int32(l32);
}

Packer.prototype.pack_object = function(obj){
  var keys = Object.keys(obj);
  var length = keys.length;
  if (length <= 0x0f){
    this.pack_uint8(0x80 + length);
  } else if (length <= 0xffff){
    this.bufferBuilder.append(0xde);
    this.pack_uint16(length);
  } else if (length <= 0xffffffff){
    this.bufferBuilder.append(0xdf);
    this.pack_uint32(length);
  } else{
    throw new Error('Invalid length');
  }
  for(var prop in obj){
    if (obj.hasOwnProperty(prop)){
      this.pack(prop);
      this.pack(obj[prop]);
    }
  }
}

Packer.prototype.pack_uint8 = function(num){
  this.bufferBuilder.append(num);
}

Packer.prototype.pack_uint16 = function(num){
  this.bufferBuilder.append(num >> 8);
  this.bufferBuilder.append(num & 0xff);
}

Packer.prototype.pack_uint32 = function(num){
  var n = num & 0xffffffff;
  this.bufferBuilder.append((n & 0xff000000) >>> 24);
  this.bufferBuilder.append((n & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((n & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((n & 0x000000ff));
}

Packer.prototype.pack_uint64 = function(num){
  var high = num / Math.pow(2, 32);
  var low  = num % Math.pow(2, 32);
  this.bufferBuilder.append((high & 0xff000000) >>> 24);
  this.bufferBuilder.append((high & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((high & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((high & 0x000000ff));
  this.bufferBuilder.append((low  & 0xff000000) >>> 24);
  this.bufferBuilder.append((low  & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((low  & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((low  & 0x000000ff));
}

Packer.prototype.pack_int8 = function(num){
  this.bufferBuilder.append(num & 0xff);
}

Packer.prototype.pack_int16 = function(num){
  this.bufferBuilder.append((num & 0xff00) >> 8);
  this.bufferBuilder.append(num & 0xff);
}

Packer.prototype.pack_int32 = function(num){
  this.bufferBuilder.append((num >>> 24) & 0xff);
  this.bufferBuilder.append((num & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((num & 0x0000ff00) >>> 8);
  this.bufferBuilder.append((num & 0x000000ff));
}

Packer.prototype.pack_int64 = function(num){
  var high = Math.floor(num / Math.pow(2, 32));
  var low  = num % Math.pow(2, 32);
  this.bufferBuilder.append((high & 0xff000000) >>> 24);
  this.bufferBuilder.append((high & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((high & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((high & 0x000000ff));
  this.bufferBuilder.append((low  & 0xff000000) >>> 24);
  this.bufferBuilder.append((low  & 0x00ff0000) >>> 16);
  this.bufferBuilder.append((low  & 0x0000ff00) >>>  8);
  this.bufferBuilder.append((low  & 0x000000ff));
}

function _utf8Replace(m){
  var code = m.charCodeAt(0);

  if(code <= 0x7ff) return '00';
  if(code <= 0xffff) return '000';
  if(code <= 0x1fffff) return '0000';
  if(code <= 0x3ffffff) return '00000';
  return '000000';
}

function utf8Length(str){
  if (str.length > 600) {
    // Blob method faster for large strings
    return (new Blob([str])).size;
  } else {
    return str.replace(/[^\u0000-\u007F]/g, _utf8Replace).length;
  }
}

},{"./bufferbuilder":11}],11:[function(require,module,exports){
var binaryFeatures = {};
binaryFeatures.useBlobBuilder = (function(){
  try {
    new Blob([]);
    return false;
  } catch (e) {
    return true;
  }
})();

binaryFeatures.useArrayBufferView = !binaryFeatures.useBlobBuilder && (function(){
  try {
    return (new Blob([new Uint8Array([])])).size === 0;
  } catch (e) {
    return true;
  }
})();

module.exports.binaryFeatures = binaryFeatures;
var BlobBuilder = module.exports.BlobBuilder;
if (typeof window != 'undefined') {
  BlobBuilder = module.exports.BlobBuilder = window.WebKitBlobBuilder ||
    window.MozBlobBuilder || window.MSBlobBuilder || window.BlobBuilder;
}

function BufferBuilder(){
  this._pieces = [];
  this._parts = [];
}

BufferBuilder.prototype.append = function(data) {
  if(typeof data === 'number') {
    this._pieces.push(data);
  } else {
    this.flush();
    this._parts.push(data);
  }
};

BufferBuilder.prototype.flush = function() {
  if (this._pieces.length > 0) {
    var buf = new Uint8Array(this._pieces);
    if(!binaryFeatures.useArrayBufferView) {
      buf = buf.buffer;
    }
    this._parts.push(buf);
    this._pieces = [];
  }
};

BufferBuilder.prototype.getBuffer = function() {
  this.flush();
  if(binaryFeatures.useBlobBuilder) {
    var builder = new BlobBuilder();
    for(var i = 0, ii = this._parts.length; i < ii; i++) {
      builder.append(this._parts[i]);
    }
    return builder.getBlob();
  } else {
    return new Blob(this._parts);
  }
};

module.exports.BufferBuilder = BufferBuilder;

},{}],12:[function(require,module,exports){
var util = require('./util');

/**
 * Reliable transfer for Chrome Canary DataChannel impl.
 * Author: @michellebu
 */
function Reliable(dc, debug) {
  if (!(this instanceof Reliable)) return new Reliable(dc);
  this._dc = dc;

  util.debug = debug;

  // Messages sent/received so far.
  // id: { ack: n, chunks: [...] }
  this._outgoing = {};
  // id: { ack: ['ack', id, n], chunks: [...] }
  this._incoming = {};
  this._received = {};

  // Window size.
  this._window = 1000;
  // MTU.
  this._mtu = 500;
  // Interval for setInterval. In ms.
  this._interval = 0;

  // Messages sent.
  this._count = 0;

  // Outgoing message queue.
  this._queue = [];

  this._setupDC();
};

// Send a message reliably.
Reliable.prototype.send = function(msg) {
  // Determine if chunking is necessary.
  var bl = util.pack(msg);
  if (bl.size < this._mtu) {
    this._handleSend(['no', bl]);
    return;
  }

  this._outgoing[this._count] = {
    ack: 0,
    chunks: this._chunk(bl)
  };

  if (util.debug) {
    this._outgoing[this._count].timer = new Date();
  }

  // Send prelim window.
  this._sendWindowedChunks(this._count);
  this._count += 1;
};

// Set up interval for processing queue.
Reliable.prototype._setupInterval = function() {
  // TODO: fail gracefully.

  var self = this;
  this._timeout = setInterval(function() {
    // FIXME: String stuff makes things terribly async.
    var msg = self._queue.shift();
    if (msg._multiple) {
      for (var i = 0, ii = msg.length; i < ii; i += 1) {
        self._intervalSend(msg[i]);
      }
    } else {
      self._intervalSend(msg);
    }
  }, this._interval);
};

Reliable.prototype._intervalSend = function(msg) {
  var self = this;
  msg = util.pack(msg);
  util.blobToBinaryString(msg, function(str) {
    self._dc.send(str);
  });
  if (self._queue.length === 0) {
    clearTimeout(self._timeout);
    self._timeout = null;
    //self._processAcks();
  }
};

// Go through ACKs to send missing pieces.
Reliable.prototype._processAcks = function() {
  for (var id in this._outgoing) {
    if (this._outgoing.hasOwnProperty(id)) {
      this._sendWindowedChunks(id);
    }
  }
};

// Handle sending a message.
// FIXME: Don't wait for interval time for all messages...
Reliable.prototype._handleSend = function(msg) {
  var push = true;
  for (var i = 0, ii = this._queue.length; i < ii; i += 1) {
    var item = this._queue[i];
    if (item === msg) {
      push = false;
    } else if (item._multiple && item.indexOf(msg) !== -1) {
      push = false;
    }
  }
  if (push) {
    this._queue.push(msg);
    if (!this._timeout) {
      this._setupInterval();
    }
  }
};

// Set up DataChannel handlers.
Reliable.prototype._setupDC = function() {
  // Handle various message types.
  var self = this;
  this._dc.onmessage = function(e) {
    var msg = e.data;
    var datatype = msg.constructor;
    // FIXME: msg is String until binary is supported.
    // Once that happens, this will have to be smarter.
    if (datatype === String) {
      var ab = util.binaryStringToArrayBuffer(msg);
      msg = util.unpack(ab);
      self._handleMessage(msg);
    }
  };
};

// Handles an incoming message.
Reliable.prototype._handleMessage = function(msg) {
  var id = msg[1];
  var idata = this._incoming[id];
  var odata = this._outgoing[id];
  var data;
  switch (msg[0]) {
    // No chunking was done.
    case 'no':
      var message = id;
      if (!!message) {
        this.onmessage(util.unpack(message));
      }
      break;
    // Reached the end of the message.
    case 'end':
      data = idata;

      // In case end comes first.
      this._received[id] = msg[2];

      if (!data) {
        break;
      }

      this._ack(id);
      break;
    case 'ack':
      data = odata;
      if (!!data) {
        var ack = msg[2];
        // Take the larger ACK, for out of order messages.
        data.ack = Math.max(ack, data.ack);

        // Clean up when all chunks are ACKed.
        if (data.ack >= data.chunks.length) {
          util.log('Time: ', new Date() - data.timer);
          delete this._outgoing[id];
        } else {
          this._processAcks();
        }
      }
      // If !data, just ignore.
      break;
    // Received a chunk of data.
    case 'chunk':
      // Create a new entry if none exists.
      data = idata;
      if (!data) {
        var end = this._received[id];
        if (end === true) {
          break;
        }
        data = {
          ack: ['ack', id, 0],
          chunks: []
        };
        this._incoming[id] = data;
      }

      var n = msg[2];
      var chunk = msg[3];
      data.chunks[n] = new Uint8Array(chunk);

      // If we get the chunk we're looking for, ACK for next missing.
      // Otherwise, ACK the same N again.
      if (n === data.ack[2]) {
        this._calculateNextAck(id);
      }
      this._ack(id);
      break;
    default:
      // Shouldn't happen, but would make sense for message to just go
      // through as is.
      this._handleSend(msg);
      break;
  }
};

// Chunks BL into smaller messages.
Reliable.prototype._chunk = function(bl) {
  var chunks = [];
  var size = bl.size;
  var start = 0;
  while (start < size) {
    var end = Math.min(size, start + this._mtu);
    var b = bl.slice(start, end);
    var chunk = {
      payload: b
    }
    chunks.push(chunk);
    start = end;
  }
  util.log('Created', chunks.length, 'chunks.');
  return chunks;
};

// Sends ACK N, expecting Nth blob chunk for message ID.
Reliable.prototype._ack = function(id) {
  var ack = this._incoming[id].ack;

  // if ack is the end value, then call _complete.
  if (this._received[id] === ack[2]) {
    this._complete(id);
    this._received[id] = true;
  }

  this._handleSend(ack);
};

// Calculates the next ACK number, given chunks.
Reliable.prototype._calculateNextAck = function(id) {
  var data = this._incoming[id];
  var chunks = data.chunks;
  for (var i = 0, ii = chunks.length; i < ii; i += 1) {
    // This chunk is missing!!! Better ACK for it.
    if (chunks[i] === undefined) {
      data.ack[2] = i;
      return;
    }
  }
  data.ack[2] = chunks.length;
};

// Sends the next window of chunks.
Reliable.prototype._sendWindowedChunks = function(id) {
  util.log('sendWindowedChunks for: ', id);
  var data = this._outgoing[id];
  var ch = data.chunks;
  var chunks = [];
  var limit = Math.min(data.ack + this._window, ch.length);
  for (var i = data.ack; i < limit; i += 1) {
    if (!ch[i].sent || i === data.ack) {
      ch[i].sent = true;
      chunks.push(['chunk', id, i, ch[i].payload]);
    }
  }
  if (data.ack + this._window >= ch.length) {
    chunks.push(['end', id, ch.length])
  }
  chunks._multiple = true;
  this._handleSend(chunks);
};

// Puts together a message from chunks.
Reliable.prototype._complete = function(id) {
  util.log('Completed called for', id);
  var self = this;
  var chunks = this._incoming[id].chunks;
  var bl = new Blob(chunks);
  util.blobToArrayBuffer(bl, function(ab) {
    self.onmessage(util.unpack(ab));
  });
  delete this._incoming[id];
};

// Ups bandwidth limit on SDP. Meant to be called during offer/answer.
Reliable.higherBandwidthSDP = function(sdp) {
  // AS stands for Application-Specific Maximum.
  // Bandwidth number is in kilobits / sec.
  // See RFC for more info: http://www.ietf.org/rfc/rfc2327.txt

  // Chrome 31+ doesn't want us munging the SDP, so we'll let them have their
  // way.
  var version = navigator.appVersion.match(/Chrome\/(.*?) /);
  if (version) {
    version = parseInt(version[1].split('.').shift());
    if (version < 31) {
      var parts = sdp.split('b=AS:30');
      var replace = 'b=AS:102400'; // 100 Mbps
      if (parts.length > 1) {
        return parts[0] + replace + parts[1];
      }
    }
  }

  return sdp;
};

// Overwritten, typically.
Reliable.prototype.onmessage = function(msg) {};

module.exports.Reliable = Reliable;

},{"./util":13}],13:[function(require,module,exports){
var BinaryPack = require('js-binarypack');

var util = {
  debug: false,
  
  inherits: function(ctor, superCtor) {
    ctor.super_ = superCtor;
    ctor.prototype = Object.create(superCtor.prototype, {
      constructor: {
        value: ctor,
        enumerable: false,
        writable: true,
        configurable: true
      }
    });
  },
  extend: function(dest, source) {
    for(var key in source) {
      if(source.hasOwnProperty(key)) {
        dest[key] = source[key];
      }
    }
    return dest;
  },
  pack: BinaryPack.pack,
  unpack: BinaryPack.unpack,
  
  log: function () {
    if (util.debug) {
      var copy = [];
      for (var i = 0; i < arguments.length; i++) {
        copy[i] = arguments[i];
      }
      copy.unshift('Reliable: ');
      console.log.apply(console, copy);
    }
  },

  setZeroTimeout: (function(global) {
    var timeouts = [];
    var messageName = 'zero-timeout-message';

    // Like setTimeout, but only takes a function argument.	 There's
    // no time argument (always zero) and no arguments (you have to
    // use a closure).
    function setZeroTimeoutPostMessage(fn) {
      timeouts.push(fn);
      global.postMessage(messageName, '*');
    }		

    function handleMessage(event) {
      if (event.source == global && event.data == messageName) {
        if (event.stopPropagation) {
          event.stopPropagation();
        }
        if (timeouts.length) {
          timeouts.shift()();
        }
      }
    }
    if (global.addEventListener) {
      global.addEventListener('message', handleMessage, true);
    } else if (global.attachEvent) {
      global.attachEvent('onmessage', handleMessage);
    }
    return setZeroTimeoutPostMessage;
  }(this)),
  
  blobToArrayBuffer: function(blob, cb){
    var fr = new FileReader();
    fr.onload = function(evt) {
      cb(evt.target.result);
    };
    fr.readAsArrayBuffer(blob);
  },
  blobToBinaryString: function(blob, cb){
    var fr = new FileReader();
    fr.onload = function(evt) {
      cb(evt.target.result);
    };
    fr.readAsBinaryString(blob);
  },
  binaryStringToArrayBuffer: function(binary) {
    var byteArray = new Uint8Array(binary.length);
    for (var i = 0; i < binary.length; i++) {
      byteArray[i] = binary.charCodeAt(i) & 0xff;
    }
    return byteArray.buffer;
  },
  randomToken: function () {
    return Math.random().toString(36).substr(2);
  }
};

module.exports = util;

},{"js-binarypack":10}],14:[function(require,module,exports){
/*
 *  Copyright (c) 2017 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.
 */
 /* eslint-env node */
'use strict';

var SDPUtils = require('sdp');

function fixStatsType(stat) {
  return {
    inboundrtp: 'inbound-rtp',
    outboundrtp: 'outbound-rtp',
    candidatepair: 'candidate-pair',
    localcandidate: 'local-candidate',
    remotecandidate: 'remote-candidate'
  }[stat.type] || stat.type;
}

function writeMediaSection(transceiver, caps, type, stream, dtlsRole) {
  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' : dtlsRole || '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';
  }

  if (transceiver.rtpSender) {
    var trackId = transceiver.rtpSender._initialTrackId ||
        transceiver.rtpSender.track.id;
    transceiver.rtpSender._initialTrackId = trackId;
    // spec.
    var msid = 'msid:' + (stream ? stream.id : '-') + ' ' +
        trackId + '\r\n';
    sdp += 'a=' + msid;
    // for Chrome. Legacy should no longer be required.
    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
        ' ' + msid;

    // RTX
    if (transceiver.sendEncodingParameters[0].rtx) {
      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
          ' ' + msid;
      sdp += 'a=ssrc-group:FID ' +
          transceiver.sendEncodingParameters[0].ssrc + ' ' +
          transceiver.sendEncodingParameters[0].rtx.ssrc +
          '\r\n';
    }
  }
  // FIXME: this should be written by writeRtpDescription.
  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
      ' cname:' + SDPUtils.localCName + '\r\n';
  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
        ' cname:' + SDPUtils.localCName + '\r\n';
  }
  return sdp;
}

// Edge does not like
// 1) stun: filtered after 14393 unless ?transport=udp is present
// 2) turn: that does not have all of turn:host:port?transport=udp
// 3) turn: with ipv6 addresses
// 4) turn: occurring muliple times
function filterIceServers(iceServers, edgeVersion) {
  var hasTurn = false;
  iceServers = JSON.parse(JSON.stringify(iceServers));
  return iceServers.filter(function(server) {
    if (server && (server.urls || server.url)) {
      var urls = server.urls || server.url;
      if (server.url && !server.urls) {
        console.warn('RTCIceServer.url is deprecated! Use urls instead.');
      }
      var isString = typeof urls === 'string';
      if (isString) {
        urls = [urls];
      }
      urls = urls.filter(function(url) {
        var validTurn = url.indexOf('turn:') === 0 &&
            url.indexOf('transport=udp') !== -1 &&
            url.indexOf('turn:[') === -1 &&
            !hasTurn;

        if (validTurn) {
          hasTurn = true;
          return true;
        }
        return url.indexOf('stun:') === 0 && edgeVersion >= 14393 &&
            url.indexOf('?transport=udp') === -1;
      });

      delete server.url;
      server.urls = isString ? urls[0] : urls;
      return !!urls.length;
    }
  });
}

// Determines the intersection of local and remote capabilities.
function getCommonCapabilities(localCapabilities, remoteCapabilities) {
  var commonCapabilities = {
    codecs: [],
    headerExtensions: [],
    fecMechanisms: []
  };

  var findCodecByPayloadType = function(pt, codecs) {
    pt = parseInt(pt, 10);
    for (var i = 0; i < codecs.length; i++) {
      if (codecs[i].payloadType === pt ||
          codecs[i].preferredPayloadType === pt) {
        return codecs[i];
      }
    }
  };

  var rtxCapabilityMatches = function(lRtx, rRtx, lCodecs, rCodecs) {
    var lCodec = findCodecByPayloadType(lRtx.parameters.apt, lCodecs);
    var rCodec = findCodecByPayloadType(rRtx.parameters.apt, rCodecs);
    return lCodec && rCodec &&
        lCodec.name.toLowerCase() === rCodec.name.toLowerCase();
  };

  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) {
        if (lCodec.name.toLowerCase() === 'rtx' &&
            lCodec.parameters && rCodec.parameters.apt) {
          // for RTX we need to find the local rtx that has a apt
          // which points to the same local codec as the remote one.
          if (!rtxCapabilityMatches(lCodec, rCodec,
              localCapabilities.codecs, remoteCapabilities.codecs)) {
            continue;
          }
        }
        rCodec = JSON.parse(JSON.stringify(rCodec)); // deepcopy
        // number of channels is the highest common number of channels
        rCodec.numChannels = Math.min(lCodec.numChannels,
            rCodec.numChannels);
        // push rCodec so we reply with offerer payload type
        commonCapabilities.codecs.push(rCodec);

        // determine common feedback mechanisms
        rCodec.rtcpFeedback = rCodec.rtcpFeedback.filter(function(fb) {
          for (var j = 0; j < lCodec.rtcpFeedback.length; j++) {
            if (lCodec.rtcpFeedback[j].type === fb.type &&
                lCodec.rtcpFeedback[j].parameter === fb.parameter) {
              return true;
            }
          }
          return false;
        });
        // FIXME: also need to determine .parameters
        //  see https://github.com/openpeer/ortc/issues/569
        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;
}

// is action=setLocalDescription with type allowed in signalingState
function isActionAllowedInSignalingState(action, type, signalingState) {
  return {
    offer: {
      setLocalDescription: ['stable', 'have-local-offer'],
      setRemoteDescription: ['stable', 'have-remote-offer']
    },
    answer: {
      setLocalDescription: ['have-remote-offer', 'have-local-pranswer'],
      setRemoteDescription: ['have-local-offer', 'have-remote-pranswer']
    }
  }[type][action].indexOf(signalingState) !== -1;
}

function maybeAddCandidate(iceTransport, candidate) {
  // Edge's internal representation adds some fields therefore
  // not all fieldѕ are taken into account.
  var alreadyAdded = iceTransport.getRemoteCandidates()
      .find(function(remoteCandidate) {
        return candidate.foundation === remoteCandidate.foundation &&
            candidate.ip === remoteCandidate.ip &&
            candidate.port === remoteCandidate.port &&
            candidate.priority === remoteCandidate.priority &&
            candidate.protocol === remoteCandidate.protocol &&
            candidate.type === remoteCandidate.type;
      });
  if (!alreadyAdded) {
    iceTransport.addRemoteCandidate(candidate);
  }
  return !alreadyAdded;
}


function makeError(name, description) {
  var e = new Error(description);
  e.name = name;
  // legacy error codes from https://heycam.github.io/webidl/#idl-DOMException-error-names
  e.code = {
    NotSupportedError: 9,
    InvalidStateError: 11,
    InvalidAccessError: 15,
    TypeError: undefined,
    OperationError: undefined
  }[name];
  return e;
}

module.exports = function(window, edgeVersion) {
  // https://w3c.github.io/mediacapture-main/#mediastream
  // Helper function to add the track to the stream and
  // dispatch the event ourselves.
  function addTrackToStreamAndFireEvent(track, stream) {
    stream.addTrack(track);
    stream.dispatchEvent(new window.MediaStreamTrackEvent('addtrack',
        {track: track}));
  }

  function removeTrackFromStreamAndFireEvent(track, stream) {
    stream.removeTrack(track);
    stream.dispatchEvent(new window.MediaStreamTrackEvent('removetrack',
        {track: track}));
  }

  function fireAddTrack(pc, track, receiver, streams) {
    var trackEvent = new Event('track');
    trackEvent.track = track;
    trackEvent.receiver = receiver;
    trackEvent.transceiver = {receiver: receiver};
    trackEvent.streams = streams;
    window.setTimeout(function() {
      pc._dispatchEvent('track', trackEvent);
    });
  }

  var RTCPeerConnection = function(config) {
    var pc = this;

    var _eventTarget = document.createDocumentFragment();
    ['addEventListener', 'removeEventListener', 'dispatchEvent']
        .forEach(function(method) {
          pc[method] = _eventTarget[method].bind(_eventTarget);
        });

    this.canTrickleIceCandidates = null;

    this.needNegotiation = false;

    this.localStreams = [];
    this.remoteStreams = [];

    this._localDescription = null;
    this._remoteDescription = null;

    this.signalingState = 'stable';
    this.iceConnectionState = 'new';
    this.connectionState = 'new';
    this.iceGatheringState = 'new';

    config = JSON.parse(JSON.stringify(config || {}));

    this.usingBundle = config.bundlePolicy === 'max-bundle';
    if (config.rtcpMuxPolicy === 'negotiate') {
      throw(makeError('NotSupportedError',
          'rtcpMuxPolicy \'negotiate\' is not supported'));
    } else if (!config.rtcpMuxPolicy) {
      config.rtcpMuxPolicy = 'require';
    }

    switch (config.iceTransportPolicy) {
      case 'all':
      case 'relay':
        break;
      default:
        config.iceTransportPolicy = 'all';
        break;
    }

    switch (config.bundlePolicy) {
      case 'balanced':
      case 'max-compat':
      case 'max-bundle':
        break;
      default:
        config.bundlePolicy = 'balanced';
        break;
    }

    config.iceServers = filterIceServers(config.iceServers || [], edgeVersion);

    this._iceGatherers = [];
    if (config.iceCandidatePoolSize) {
      for (var i = config.iceCandidatePoolSize; i > 0; i--) {
        this._iceGatherers.push(new window.RTCIceGatherer({
          iceServers: config.iceServers,
          gatherPolicy: config.iceTransportPolicy
        }));
      }
    } else {
      config.iceCandidatePoolSize = 0;
    }

    this._config = config;

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

    this._sdpSessionId = SDPUtils.generateSessionId();
    this._sdpSessionVersion = 0;

    this._dtlsRole = undefined; // role for a=setup to use in answers.

    this._isClosed = false;
  };

  Object.defineProperty(RTCPeerConnection.prototype, 'localDescription', {
    configurable: true,
    get: function() {
      return this._localDescription;
    }
  });
  Object.defineProperty(RTCPeerConnection.prototype, 'remoteDescription', {
    configurable: true,
    get: function() {
      return this._remoteDescription;
    }
  });

  // set up event handlers on prototype
  RTCPeerConnection.prototype.onicecandidate = null;
  RTCPeerConnection.prototype.onaddstream = null;
  RTCPeerConnection.prototype.ontrack = null;
  RTCPeerConnection.prototype.onremovestream = null;
  RTCPeerConnection.prototype.onsignalingstatechange = null;
  RTCPeerConnection.prototype.oniceconnectionstatechange = null;
  RTCPeerConnection.prototype.onconnectionstatechange = null;
  RTCPeerConnection.prototype.onicegatheringstatechange = null;
  RTCPeerConnection.prototype.onnegotiationneeded = null;
  RTCPeerConnection.prototype.ondatachannel = null;

  RTCPeerConnection.prototype._dispatchEvent = function(name, event) {
    if (this._isClosed) {
      return;
    }
    this.dispatchEvent(event);
    if (typeof this['on' + name] === 'function') {
      this['on' + name](event);
    }
  };

  RTCPeerConnection.prototype._emitGatheringStateChange = function() {
    var event = new Event('icegatheringstatechange');
    this._dispatchEvent('icegatheringstatechange', event);
  };

  RTCPeerConnection.prototype.getConfiguration = function() {
    return this._config;
  };

  RTCPeerConnection.prototype.getLocalStreams = function() {
    return this.localStreams;
  };

  RTCPeerConnection.prototype.getRemoteStreams = function() {
    return this.remoteStreams;
  };

  // internal helper to create a transceiver object.
  // (which is not yet the same as the WebRTC 1.0 transceiver)
  RTCPeerConnection.prototype._createTransceiver = function(kind, doNotAdd) {
    var hasBundleTransport = this.transceivers.length > 0;
    var transceiver = {
      track: null,
      iceGatherer: null,
      iceTransport: null,
      dtlsTransport: null,
      localCapabilities: null,
      remoteCapabilities: null,
      rtpSender: null,
      rtpReceiver: null,
      kind: kind,
      mid: null,
      sendEncodingParameters: null,
      recvEncodingParameters: null,
      stream: null,
      associatedRemoteMediaStreams: [],
      wantReceive: true
    };
    if (this.usingBundle && hasBundleTransport) {
      transceiver.iceTransport = this.transceivers[0].iceTransport;
      transceiver.dtlsTransport = this.transceivers[0].dtlsTransport;
    } else {
      var transports = this._createIceAndDtlsTransports();
      transceiver.iceTransport = transports.iceTransport;
      transceiver.dtlsTransport = transports.dtlsTransport;
    }
    if (!doNotAdd) {
      this.transceivers.push(transceiver);
    }
    return transceiver;
  };

  RTCPeerConnection.prototype.addTrack = function(track, stream) {
    if (this._isClosed) {
      throw makeError('InvalidStateError',
          'Attempted to call addTrack on a closed peerconnection.');
    }

    var alreadyExists = this.transceivers.find(function(s) {
      return s.track === track;
    });

    if (alreadyExists) {
      throw makeError('InvalidAccessError', 'Track already exists.');
    }

    var transceiver;
    for (var i = 0; i < this.transceivers.length; i++) {
      if (!this.transceivers[i].track &&
          this.transceivers[i].kind === track.kind) {
        transceiver = this.transceivers[i];
      }
    }
    if (!transceiver) {
      transceiver = this._createTransceiver(track.kind);
    }

    this._maybeFireNegotiationNeeded();

    if (this.localStreams.indexOf(stream) === -1) {
      this.localStreams.push(stream);
    }

    transceiver.track = track;
    transceiver.stream = stream;
    transceiver.rtpSender = new window.RTCRtpSender(track,
        transceiver.dtlsTransport);
    return transceiver.rtpSender;
  };

  RTCPeerConnection.prototype.addStream = function(stream) {
    var pc = this;
    if (edgeVersion >= 15025) {
      stream.getTracks().forEach(function(track) {
        pc.addTrack(track, stream);
      });
    } else {
      // Clone is necessary for local demos mostly, attaching directly
      // to two different senders does not work (build 10547).
      // Fixed in 15025 (or earlier)
      var clonedStream = stream.clone();
      stream.getTracks().forEach(function(track, idx) {
        var clonedTrack = clonedStream.getTracks()[idx];
        track.addEventListener('enabled', function(event) {
          clonedTrack.enabled = event.enabled;
        });
      });
      clonedStream.getTracks().forEach(function(track) {
        pc.addTrack(track, clonedStream);
      });
    }
  };

  RTCPeerConnection.prototype.removeTrack = function(sender) {
    if (this._isClosed) {
      throw makeError('InvalidStateError',
          'Attempted to call removeTrack on a closed peerconnection.');
    }

    if (!(sender instanceof window.RTCRtpSender)) {
      throw new TypeError('Argument 1 of RTCPeerConnection.removeTrack ' +
          'does not implement interface RTCRtpSender.');
    }

    var transceiver = this.transceivers.find(function(t) {
      return t.rtpSender === sender;
    });

    if (!transceiver) {
      throw makeError('InvalidAccessError',
          'Sender was not created by this connection.');
    }
    var stream = transceiver.stream;

    transceiver.rtpSender.stop();
    transceiver.rtpSender = null;
    transceiver.track = null;
    transceiver.stream = null;

    // remove the stream from the set of local streams
    var localStreams = this.transceivers.map(function(t) {
      return t.stream;
    });
    if (localStreams.indexOf(stream) === -1 &&
        this.localStreams.indexOf(stream) > -1) {
      this.localStreams.splice(this.localStreams.indexOf(stream), 1);
    }

    this._maybeFireNegotiationNeeded();
  };

  RTCPeerConnection.prototype.removeStream = function(stream) {
    var pc = this;
    stream.getTracks().forEach(function(track) {
      var sender = pc.getSenders().find(function(s) {
        return s.track === track;
      });
      if (sender) {
        pc.removeTrack(sender);
      }
    });
  };

  RTCPeerConnection.prototype.getSenders = function() {
    return this.transceivers.filter(function(transceiver) {
      return !!transceiver.rtpSender;
    })
    .map(function(transceiver) {
      return transceiver.rtpSender;
    });
  };

  RTCPeerConnection.prototype.getReceivers = function() {
    return this.transceivers.filter(function(transceiver) {
      return !!transceiver.rtpReceiver;
    })
    .map(function(transceiver) {
      return transceiver.rtpReceiver;
    });
  };


  RTCPeerConnection.prototype._createIceGatherer = function(sdpMLineIndex,
      usingBundle) {
    var pc = this;
    if (usingBundle && sdpMLineIndex > 0) {
      return this.transceivers[0].iceGatherer;
    } else if (this._iceGatherers.length) {
      return this._iceGatherers.shift();
    }
    var iceGatherer = new window.RTCIceGatherer({
      iceServers: this._config.iceServers,
      gatherPolicy: this._config.iceTransportPolicy
    });
    Object.defineProperty(iceGatherer, 'state',
        {value: 'new', writable: true}
    );

    this.transceivers[sdpMLineIndex].bufferedCandidateEvents = [];
    this.transceivers[sdpMLineIndex].bufferCandidates = function(event) {
      var end = !event.candidate || Object.keys(event.candidate).length === 0;
      // polyfill since RTCIceGatherer.state is not implemented in
      // Edge 10547 yet.
      iceGatherer.state = end ? 'completed' : 'gathering';
      if (pc.transceivers[sdpMLineIndex].bufferedCandidateEvents !== null) {
        pc.transceivers[sdpMLineIndex].bufferedCandidateEvents.push(event);
      }
    };
    iceGatherer.addEventListener('localcandidate',
      this.transceivers[sdpMLineIndex].bufferCandidates);
    return iceGatherer;
  };

  // start gathering from an RTCIceGatherer.
  RTCPeerConnection.prototype._gather = function(mid, sdpMLineIndex) {
    var pc = this;
    var iceGatherer = this.transceivers[sdpMLineIndex].iceGatherer;
    if (iceGatherer.onlocalcandidate) {
      return;
    }
    var bufferedCandidateEvents =
      this.transceivers[sdpMLineIndex].bufferedCandidateEvents;
    this.transceivers[sdpMLineIndex].bufferedCandidateEvents = null;
    iceGatherer.removeEventListener('localcandidate',
      this.transceivers[sdpMLineIndex].bufferCandidates);
    iceGatherer.onlocalcandidate = function(evt) {
      if (pc.usingBundle && sdpMLineIndex > 0) {
        // if we know that we use bundle we can drop candidates with
        // ѕdpMLineIndex > 0. If we don't do this then our state gets
        // confused since we dispose the extra ice gatherer.
        return;
      }
      var event = new Event('icecandidate');
      event.candidate = {sdpMid: mid, sdpMLineIndex: sdpMLineIndex};

      var cand = evt.candidate;
      // Edge emits an empty object for RTCIceCandidateComplete‥
      var end = !cand || Object.keys(cand).length === 0;
      if (end) {
        // polyfill since RTCIceGatherer.state is not implemented in
        // Edge 10547 yet.
        if (iceGatherer.state === 'new' || iceGatherer.state === 'gathering') {
          iceGatherer.state = 'completed';
        }
      } else {
        if (iceGatherer.state === 'new') {
          iceGatherer.state = 'gathering';
        }
        // RTCIceCandidate doesn't have a component, needs to be added
        cand.component = 1;
        // also the usernameFragment. TODO: update SDP to take both variants.
        cand.ufrag = iceGatherer.getLocalParameters().usernameFragment;

        var serializedCandidate = SDPUtils.writeCandidate(cand);
        event.candidate = Object.assign(event.candidate,
            SDPUtils.parseCandidate(serializedCandidate));

        event.candidate.candidate = serializedCandidate;
        event.candidate.toJSON = function() {
          return {
            candidate: event.candidate.candidate,
            sdpMid: event.candidate.sdpMid,
            sdpMLineIndex: event.candidate.sdpMLineIndex,
            usernameFragment: event.candidate.usernameFragment
          };
        };
      }

      // update local description.
      var sections = SDPUtils.getMediaSections(pc._localDescription.sdp);
      if (!end) {
        sections[event.candidate.sdpMLineIndex] +=
            'a=' + event.candidate.candidate + '\r\n';
      } else {
        sections[event.candidate.sdpMLineIndex] +=
            'a=end-of-candidates\r\n';
      }
      pc._localDescription.sdp =
          SDPUtils.getDescription(pc._localDescription.sdp) +
          sections.join('');
      var complete = pc.transceivers.every(function(transceiver) {
        return transceiver.iceGatherer &&
            transceiver.iceGatherer.state === 'completed';
      });

      if (pc.iceGatheringState !== 'gathering') {
        pc.iceGatheringState = 'gathering';
        pc._emitGatheringStateChange();
      }

      // Emit candidate. Also emit null candidate when all gatherers are
      // complete.
      if (!end) {
        pc._dispatchEvent('icecandidate', event);
      }
      if (complete) {
        pc._dispatchEvent('icecandidate', new Event('icecandidate'));
        pc.iceGatheringState = 'complete';
        pc._emitGatheringStateChange();
      }
    };

    // emit already gathered candidates.
    window.setTimeout(function() {
      bufferedCandidateEvents.forEach(function(e) {
        iceGatherer.onlocalcandidate(e);
      });
    }, 0);
  };

  // Create ICE transport and DTLS transport.
  RTCPeerConnection.prototype._createIceAndDtlsTransports = function() {
    var pc = this;
    var iceTransport = new window.RTCIceTransport(null);
    iceTransport.onicestatechange = function() {
      pc._updateIceConnectionState();
      pc._updateConnectionState();
    };

    var dtlsTransport = new window.RTCDtlsTransport(iceTransport);
    dtlsTransport.ondtlsstatechange = function() {
      pc._updateConnectionState();
    };
    dtlsTransport.onerror = function() {
      // onerror does not set state to failed by itself.
      Object.defineProperty(dtlsTransport, 'state',
          {value: 'failed', writable: true});
      pc._updateConnectionState();
    };

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

  // Destroy ICE gatherer, ICE transport and DTLS transport.
  // Without triggering the callbacks.
  RTCPeerConnection.prototype._disposeIceAndDtlsTransports = function(
      sdpMLineIndex) {
    var iceGatherer = this.transceivers[sdpMLineIndex].iceGatherer;
    if (iceGatherer) {
      delete iceGatherer.onlocalcandidate;
      delete this.transceivers[sdpMLineIndex].iceGatherer;
    }
    var iceTransport = this.transceivers[sdpMLineIndex].iceTransport;
    if (iceTransport) {
      delete iceTransport.onicestatechange;
      delete this.transceivers[sdpMLineIndex].iceTransport;
    }
    var dtlsTransport = this.transceivers[sdpMLineIndex].dtlsTransport;
    if (dtlsTransport) {
      delete dtlsTransport.ondtlsstatechange;
      delete dtlsTransport.onerror;
      delete this.transceivers[sdpMLineIndex].dtlsTransport;
    }
  };

  // Start the RTP Sender and Receiver for a transceiver.
  RTCPeerConnection.prototype._transceive = function(transceiver,
      send, recv) {
    var params = getCommonCapabilities(transceiver.localCapabilities,
        transceiver.remoteCapabilities);
    if (send && transceiver.rtpSender) {
      params.encodings = transceiver.sendEncodingParameters;
      params.rtcp = {
        cname: SDPUtils.localCName,
        compound: transceiver.rtcpParameters.compound
      };
      if (transceiver.recvEncodingParameters.length) {
        params.rtcp.ssrc = transceiver.recvEncodingParameters[0].ssrc;
      }
      transceiver.rtpSender.send(params);
    }
    if (recv && transceiver.rtpReceiver && params.codecs.length > 0) {
      // remove RTX field in Edge 14942
      if (transceiver.kind === 'video'
          && transceiver.recvEncodingParameters
          && edgeVersion < 15019) {
        transceiver.recvEncodingParameters.forEach(function(p) {
          delete p.rtx;
        });
      }
      if (transceiver.recvEncodingParameters.length) {
        params.encodings = transceiver.recvEncodingParameters;
      } else {
        params.encodings = [{}];
      }
      params.rtcp = {
        compound: transceiver.rtcpParameters.compound
      };
      if (transceiver.rtcpParameters.cname) {
        params.rtcp.cname = transceiver.rtcpParameters.cname;
      }
      if (transceiver.sendEncodingParameters.length) {
        params.rtcp.ssrc = transceiver.sendEncodingParameters[0].ssrc;
      }
      transceiver.rtpReceiver.receive(params);
    }
  };

  RTCPeerConnection.prototype.setLocalDescription = function(description) {
    var pc = this;

    // Note: pranswer is not supported.
    if (['offer', 'answer'].indexOf(description.type) === -1) {
      return Promise.reject(makeError('TypeError',
          'Unsupported type "' + description.type + '"'));
    }

    if (!isActionAllowedInSignalingState('setLocalDescription',
        description.type, pc.signalingState) || pc._isClosed) {
      return Promise.reject(makeError('InvalidStateError',
          'Can not set local ' + description.type +
          ' in state ' + pc.signalingState));
    }

    var sections;
    var sessionpart;
    if (description.type === 'offer') {
      // VERY limited support for SDP munging. Limited to:
      // * changing the order of codecs
      sections = SDPUtils.splitSections(description.sdp);
      sessionpart = sections.shift();
      sections.forEach(function(mediaSection, sdpMLineIndex) {
        var caps = SDPUtils.parseRtpParameters(mediaSection);
        pc.transceivers[sdpMLineIndex].localCapabilities = caps;
      });

      pc.transceivers.forEach(function(transceiver, sdpMLineIndex) {
        pc._gather(transceiver.mid, sdpMLineIndex);
      });
    } else if (description.type === 'answer') {
      sections = SDPUtils.splitSections(pc._remoteDescription.sdp);
      sessionpart = sections.shift();
      var isIceLite = SDPUtils.matchPrefix(sessionpart,
          'a=ice-lite').length > 0;
      sections.forEach(function(mediaSection, sdpMLineIndex) {
        var transceiver = pc.transceivers[sdpMLineIndex];
        var iceGatherer = transceiver.iceGatherer;
        var iceTransport = transceiver.iceTransport;
        var dtlsTransport = transceiver.dtlsTransport;
        var localCapabilities = transceiver.localCapabilities;
        var remoteCapabilities = transceiver.remoteCapabilities;

        // treat bundle-only as not-rejected.
        var rejected = SDPUtils.isRejected(mediaSection) &&
            SDPUtils.matchPrefix(mediaSection, 'a=bundle-only').length === 0;

        if (!rejected && !transceiver.rejected) {
          var remoteIceParameters = SDPUtils.getIceParameters(
              mediaSection, sessionpart);
          var remoteDtlsParameters = SDPUtils.getDtlsParameters(
              mediaSection, sessionpart);
          if (isIceLite) {
            remoteDtlsParameters.role = 'server';
          }

          if (!pc.usingBundle || sdpMLineIndex === 0) {
            pc._gather(transceiver.mid, sdpMLineIndex);
            if (iceTransport.state === 'new') {
              iceTransport.start(iceGatherer, remoteIceParameters,
                  isIceLite ? 'controlling' : 'controlled');
            }
            if (dtlsTransport.state === 'new') {
              dtlsTransport.start(remoteDtlsParameters);
            }
          }

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

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

    pc._localDescription = {
      type: description.type,
      sdp: description.sdp
    };
    if (description.type === 'offer') {
      pc._updateSignalingState('have-local-offer');
    } else {
      pc._updateSignalingState('stable');
    }

    return Promise.resolve();
  };

  RTCPeerConnection.prototype.setRemoteDescription = function(description) {
    var pc = this;

    // Note: pranswer is not supported.
    if (['offer', 'answer'].indexOf(description.type) === -1) {
      return Promise.reject(makeError('TypeError',
          'Unsupported type "' + description.type + '"'));
    }

    if (!isActionAllowedInSignalingState('setRemoteDescription',
        description.type, pc.signalingState) || pc._isClosed) {
      return Promise.reject(makeError('InvalidStateError',
          'Can not set remote ' + description.type +
          ' in state ' + pc.signalingState));
    }

    var streams = {};
    pc.remoteStreams.forEach(function(stream) {
      streams[stream.id] = stream;
    });
    var receiverList = [];
    var sections = SDPUtils.splitSections(description.sdp);
    var sessionpart = sections.shift();
    var isIceLite = SDPUtils.matchPrefix(sessionpart,
        'a=ice-lite').length > 0;
    var usingBundle = SDPUtils.matchPrefix(sessionpart,
        'a=group:BUNDLE ').length > 0;
    pc.usingBundle = usingBundle;
    var iceOptions = SDPUtils.matchPrefix(sessionpart,
        'a=ice-options:')[0];
    if (iceOptions) {
      pc.canTrickleIceCandidates = iceOptions.substr(14).split(' ')
          .indexOf('trickle') >= 0;
    } else {
      pc.canTrickleIceCandidates = false;
    }

    sections.forEach(function(mediaSection, sdpMLineIndex) {
      var lines = SDPUtils.splitLines(mediaSection);
      var kind = SDPUtils.getKind(mediaSection);
      // treat bundle-only as not-rejected.
      var rejected = SDPUtils.isRejected(mediaSection) &&
          SDPUtils.matchPrefix(mediaSection, 'a=bundle-only').length === 0;
      var protocol = lines[0].substr(2).split(' ')[2];

      var direction = SDPUtils.getDirection(mediaSection, sessionpart);
      var remoteMsid = SDPUtils.parseMsid(mediaSection);

      var mid = SDPUtils.getMid(mediaSection) || SDPUtils.generateIdentifier();

      // Reject datachannels which are not implemented yet.
      if (rejected || (kind === 'application' && (protocol === 'DTLS/SCTP' ||
          protocol === 'UDP/DTLS/SCTP'))) {
        // TODO: this is dangerous in the case where a non-rejected m-line
        //     becomes rejected.
        pc.transceivers[sdpMLineIndex] = {
          mid: mid,
          kind: kind,
          protocol: protocol,
          rejected: true
        };
        return;
      }

      if (!rejected && pc.transceivers[sdpMLineIndex] &&
          pc.transceivers[sdpMLineIndex].rejected) {
        // recycle a rejected transceiver.
        pc.transceivers[sdpMLineIndex] = pc._createTransceiver(kind, true);
      }

      var transceiver;
      var iceGatherer;
      var iceTransport;
      var dtlsTransport;
      var rtpReceiver;
      var sendEncodingParameters;
      var recvEncodingParameters;
      var localCapabilities;

      var track;
      // 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);
        remoteDtlsParameters.role = 'client';
      }
      recvEncodingParameters =
          SDPUtils.parseRtpEncodingParameters(mediaSection);

      var rtcpParameters = SDPUtils.parseRtcpParameters(mediaSection);

      var isComplete = SDPUtils.matchPrefix(mediaSection,
          'a=end-of-candidates', sessionpart).length > 0;
      var cands = SDPUtils.matchPrefix(mediaSection, 'a=candidate:')
          .map(function(cand) {
            return SDPUtils.parseCandidate(cand);
          })
          .filter(function(cand) {
            return cand.component === 1;
          });

      // Check if we can use BUNDLE and dispose transports.
      if ((description.type === 'offer' || description.type === 'answer') &&
          !rejected && usingBundle && sdpMLineIndex > 0 &&
          pc.transceivers[sdpMLineIndex]) {
        pc._disposeIceAndDtlsTransports(sdpMLineIndex);
        pc.transceivers[sdpMLineIndex].iceGatherer =
            pc.transceivers[0].iceGatherer;
        pc.transceivers[sdpMLineIndex].iceTransport =
            pc.transceivers[0].iceTransport;
        pc.transceivers[sdpMLineIndex].dtlsTransport =
            pc.transceivers[0].dtlsTransport;
        if (pc.transceivers[sdpMLineIndex].rtpSender) {
          pc.transceivers[sdpMLineIndex].rtpSender.setTransport(
              pc.transceivers[0].dtlsTransport);
        }
        if (pc.transceivers[sdpMLineIndex].rtpReceiver) {
          pc.transceivers[sdpMLineIndex].rtpReceiver.setTransport(
              pc.transceivers[0].dtlsTransport);
        }
      }
      if (description.type === 'offer' && !rejected) {
        transceiver = pc.transceivers[sdpMLineIndex] ||
            pc._createTransceiver(kind);
        transceiver.mid = mid;

        if (!transceiver.iceGatherer) {
          transceiver.iceGatherer = pc._createIceGatherer(sdpMLineIndex,
              usingBundle);
        }

        if (cands.length && transceiver.iceTransport.state === 'new') {
          if (isComplete && (!usingBundle || sdpMLineIndex === 0)) {
            transceiver.iceTransport.setRemoteCandidates(cands);
          } else {
            cands.forEach(function(candidate) {
              maybeAddCandidate(transceiver.iceTransport, candidate);
            });
          }
        }

        localCapabilities = window.RTCRtpReceiver.getCapabilities(kind);

        // filter RTX until additional stuff needed for RTX is implemented
        // in adapter.js
        if (edgeVersion < 15019) {
          localCapabilities.codecs = localCapabilities.codecs.filter(
              function(codec) {
                return codec.name !== 'rtx';
              });
        }

        sendEncodingParameters = transceiver.sendEncodingParameters || [{
          ssrc: (2 * sdpMLineIndex + 2) * 1001
        }];

        // TODO: rewrite to use http://w3c.github.io/webrtc-pc/#set-associated-remote-streams
        var isNewTrack = false;
        if (direction === 'sendrecv' || direction === 'sendonly') {
          isNewTrack = !transceiver.rtpReceiver;
          rtpReceiver = transceiver.rtpReceiver ||
              new window.RTCRtpReceiver(transceiver.dtlsTransport, kind);

          if (isNewTrack) {
            var stream;
            track = rtpReceiver.track;
            // FIXME: does not work with Plan B.
            if (remoteMsid && remoteMsid.stream === '-') {
              // no-op. a stream id of '-' means: no associated stream.
            } else if (remoteMsid) {
              if (!streams[remoteMsid.stream]) {
                streams[remoteMsid.stream] = new window.MediaStream();
                Object.defineProperty(streams[remoteMsid.stream], 'id', {
                  get: function() {
                    return remoteMsid.stream;
                  }
                });
              }
              Object.defineProperty(track, 'id', {
                get: function() {
                  return remoteMsid.track;
                }
              });
              stream = streams[remoteMsid.stream];
            } else {
              if (!streams.default) {
                streams.default = new window.MediaStream();
              }
              stream = streams.default;
            }
            if (stream) {
              addTrackToStreamAndFireEvent(track, stream);
              transceiver.associatedRemoteMediaStreams.push(stream);
            }
            receiverList.push([track, rtpReceiver, stream]);
          }
        } else if (transceiver.rtpReceiver && transceiver.rtpReceiver.track) {
          transceiver.associatedRemoteMediaStreams.forEach(function(s) {
            var nativeTrack = s.getTracks().find(function(t) {
              return t.id === transceiver.rtpReceiver.track.id;
            });
            if (nativeTrack) {
              removeTrackFromStreamAndFireEvent(nativeTrack, s);
            }
          });
          transceiver.associatedRemoteMediaStreams = [];
        }

        transceiver.localCapabilities = localCapabilities;
        transceiver.remoteCapabilities = remoteCapabilities;
        transceiver.rtpReceiver = rtpReceiver;
        transceiver.rtcpParameters = rtcpParameters;
        transceiver.sendEncodingParameters = sendEncodingParameters;
        transceiver.recvEncodingParameters = recvEncodingParameters;

        // Start the RTCRtpReceiver now. The RTPSender is started in
        // setLocalDescription.
        pc._transceive(pc.transceivers[sdpMLineIndex],
            false,
            isNewTrack);
      } else if (description.type === 'answer' && !rejected) {
        transceiver = pc.transceivers[sdpMLineIndex];
        iceGatherer = transceiver.iceGatherer;
        iceTransport = transceiver.iceTransport;
        dtlsTransport = transceiver.dtlsTransport;
        rtpReceiver = transceiver.rtpReceiver;
        sendEncodingParameters = transceiver.sendEncodingParameters;
        localCapabilities = transceiver.localCapabilities;

        pc.transceivers[sdpMLineIndex].recvEncodingParameters =
            recvEncodingParameters;
        pc.transceivers[sdpMLineIndex].remoteCapabilities =
            remoteCapabilities;
        pc.transceivers[sdpMLineIndex].rtcpParameters = rtcpParameters;

        if (cands.length && iceTransport.state === 'new') {
          if ((isIceLite || isComplete) &&
              (!usingBundle || sdpMLineIndex === 0)) {
            iceTransport.setRemoteCandidates(cands);
          } else {
            cands.forEach(function(candidate) {
              maybeAddCandidate(transceiver.iceTransport, candidate);
            });
          }
        }

        if (!usingBundle || sdpMLineIndex === 0) {
          if (iceTransport.state === 'new') {
            iceTransport.start(iceGatherer, remoteIceParameters,
                'controlling');
          }
          if (dtlsTransport.state === 'new') {
            dtlsTransport.start(remoteDtlsParameters);
          }
        }

        // If the offer contained RTX but the answer did not,
        // remove RTX from sendEncodingParameters.
        var commonCapabilities = getCommonCapabilities(
          transceiver.localCapabilities,
          transceiver.remoteCapabilities);

        var hasRtx = commonCapabilities.codecs.filter(function(c) {
          return c.name.toLowerCase() === 'rtx';
        }).length;
        if (!hasRtx && transceiver.sendEncodingParameters[0].rtx) {
          delete transceiver.sendEncodingParameters[0].rtx;
        }

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

        // TODO: rewrite to use http://w3c.github.io/webrtc-pc/#set-associated-remote-streams
        if (rtpReceiver &&
            (direction === 'sendrecv' || direction === 'sendonly')) {
          track = rtpReceiver.track;
          if (remoteMsid) {
            if (!streams[remoteMsid.stream]) {
              streams[remoteMsid.stream] = new window.MediaStream();
            }
            addTrackToStreamAndFireEvent(track, streams[remoteMsid.stream]);
            receiverList.push([track, rtpReceiver, streams[remoteMsid.stream]]);
          } else {
            if (!streams.default) {
              streams.default = new window.MediaStream();
            }
            addTrackToStreamAndFireEvent(track, streams.default);
            receiverList.push([track, rtpReceiver, streams.default]);
          }
        } else {
          // FIXME: actually the receiver should be created later.
          delete transceiver.rtpReceiver;
        }
      }
    });

    if (pc._dtlsRole === undefined) {
      pc._dtlsRole = description.type === 'offer' ? 'active' : 'passive';
    }

    pc._remoteDescription = {
      type: description.type,
      sdp: description.sdp
    };
    if (description.type === 'offer') {
      pc._updateSignalingState('have-remote-offer');
    } else {
      pc._updateSignalingState('stable');
    }
    Object.keys(streams).forEach(function(sid) {
      var stream = streams[sid];
      if (stream.getTracks().length) {
        if (pc.remoteStreams.indexOf(stream) === -1) {
          pc.remoteStreams.push(stream);
          var event = new Event('addstream');
          event.stream = stream;
          window.setTimeout(function() {
            pc._dispatchEvent('addstream', event);
          });
        }

        receiverList.forEach(function(item) {
          var track = item[0];
          var receiver = item[1];
          if (stream.id !== item[2].id) {
            return;
          }
          fireAddTrack(pc, track, receiver, [stream]);
        });
      }
    });
    receiverList.forEach(function(item) {
      if (item[2]) {
        return;
      }
      fireAddTrack(pc, item[0], item[1], []);
    });

    // check whether addIceCandidate({}) was called within four seconds after
    // setRemoteDescription.
    window.setTimeout(function() {
      if (!(pc && pc.transceivers)) {
        return;
      }
      pc.transceivers.forEach(function(transceiver) {
        if (transceiver.iceTransport &&
            transceiver.iceTransport.state === 'new' &&
            transceiver.iceTransport.getRemoteCandidates().length > 0) {
          console.warn('Timeout for addRemoteCandidate. Consider sending ' +
              'an end-of-candidates notification');
          transceiver.iceTransport.addRemoteCandidate({});
        }
      });
    }, 4000);

    return Promise.resolve();
  };

  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._isClosed = true;
    this._updateSignalingState('closed');
  };

  // Update the signaling state.
  RTCPeerConnection.prototype._updateSignalingState = function(newState) {
    this.signalingState = newState;
    var event = new Event('signalingstatechange');
    this._dispatchEvent('signalingstatechange', event);
  };

  // Determine whether to fire the negotiationneeded event.
  RTCPeerConnection.prototype._maybeFireNegotiationNeeded = function() {
    var pc = this;
    if (this.signalingState !== 'stable' || this.needNegotiation === true) {
      return;
    }
    this.needNegotiation = true;
    window.setTimeout(function() {
      if (pc.needNegotiation) {
        pc.needNegotiation = false;
        var event = new Event('negotiationneeded');
        pc._dispatchEvent('negotiationneeded', event);
      }
    }, 0);
  };

  // Update the ice connection state.
  RTCPeerConnection.prototype._updateIceConnectionState = function() {
    var newState;
    var states = {
      'new': 0,
      closed: 0,
      checking: 0,
      connected: 0,
      completed: 0,
      disconnected: 0,
      failed: 0
    };
    this.transceivers.forEach(function(transceiver) {
      states[transceiver.iceTransport.state]++;
    });

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

    if (newState !== this.iceConnectionState) {
      this.iceConnectionState = newState;
      var event = new Event('iceconnectionstatechange');
      this._dispatchEvent('iceconnectionstatechange', event);
    }
  };

  // Update the connection state.
  RTCPeerConnection.prototype._updateConnectionState = function() {
    var newState;
    var states = {
      'new': 0,
      closed: 0,
      connecting: 0,
      connected: 0,
      completed: 0,
      disconnected: 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) {
      newState = 'connecting';
    } else if (states.disconnected > 0) {
      newState = 'disconnected';
    } else if (states.new > 0) {
      newState = 'new';
    } else if (states.connected > 0) {
      newState = 'connected';
    }

    if (newState !== this.connectionState) {
      this.connectionState = newState;
      var event = new Event('connectionstatechange');
      this._dispatchEvent('connectionstatechange', event);
    }
  };

  RTCPeerConnection.prototype.createOffer = function() {
    var pc = this;

    if (pc._isClosed) {
      return Promise.reject(makeError('InvalidStateError',
          'Can not call createOffer after close'));
    }

    var numAudioTracks = pc.transceivers.filter(function(t) {
      return t.kind === 'audio';
    }).length;
    var numVideoTracks = pc.transceivers.filter(function(t) {
      return t.kind === 'video';
    }).length;

    // Determine number of audio and video tracks we need to send/recv.
    var offerOptions = arguments[0];
    if (offerOptions) {
      // Reject Chrome legacy constraints.
      if (offerOptions.mandatory || offerOptions.optional) {
        throw new TypeError(
            'Legacy mandatory/optional constraints not supported.');
      }
      if (offerOptions.offerToReceiveAudio !== undefined) {
        if (offerOptions.offerToReceiveAudio === true) {
          numAudioTracks = 1;
        } else if (offerOptions.offerToReceiveAudio === false) {
          numAudioTracks = 0;
        } else {
          numAudioTracks = offerOptions.offerToReceiveAudio;
        }
      }
      if (offerOptions.offerToReceiveVideo !== undefined) {
        if (offerOptions.offerToReceiveVideo === true) {
          numVideoTracks = 1;
        } else if (offerOptions.offerToReceiveVideo === false) {
          numVideoTracks = 0;
        } else {
          numVideoTracks = offerOptions.offerToReceiveVideo;
        }
      }
    }

    pc.transceivers.forEach(function(transceiver) {
      if (transceiver.kind === 'audio') {
        numAudioTracks--;
        if (numAudioTracks < 0) {
          transceiver.wantReceive = false;
        }
      } else if (transceiver.kind === 'video') {
        numVideoTracks--;
        if (numVideoTracks < 0) {
          transceiver.wantReceive = false;
        }
      }
    });

    // Create M-lines for recvonly streams.
    while (numAudioTracks > 0 || numVideoTracks > 0) {
      if (numAudioTracks > 0) {
        pc._createTransceiver('audio');
        numAudioTracks--;
      }
      if (numVideoTracks > 0) {
        pc._createTransceiver('video');
        numVideoTracks--;
      }
    }

    var sdp = SDPUtils.writeSessionBoilerplate(pc._sdpSessionId,
        pc._sdpSessionVersion++);
    pc.transceivers.forEach(function(transceiver, sdpMLineIndex) {
      // For each track, create an ice gatherer, ice transport,
      // dtls transport, potentially rtpsender and rtpreceiver.
      var track = transceiver.track;
      var kind = transceiver.kind;
      var mid = transceiver.mid || SDPUtils.generateIdentifier();
      transceiver.mid = mid;

      if (!transceiver.iceGatherer) {
        transceiver.iceGatherer = pc._createIceGatherer(sdpMLineIndex,
            pc.usingBundle);
      }

      var localCapabilities = window.RTCRtpSender.getCapabilities(kind);
      // filter RTX until additional stuff needed for RTX is implemented
      // in adapter.js
      if (edgeVersion < 15019) {
        localCapabilities.codecs = localCapabilities.codecs.filter(
            function(codec) {
              return codec.name !== 'rtx';
            });
      }
      localCapabilities.codecs.forEach(function(codec) {
        // work around https://bugs.chromium.org/p/webrtc/issues/detail?id=6552
        // by adding level-asymmetry-allowed=1
        if (codec.name === 'H264' &&
            codec.parameters['level-asymmetry-allowed'] === undefined) {
          codec.parameters['level-asymmetry-allowed'] = '1';
        }

        // for subsequent offers, we might have to re-use the payload
        // type of the last offer.
        if (transceiver.remoteCapabilities &&
            transceiver.remoteCapabilities.codecs) {
          transceiver.remoteCapabilities.codecs.forEach(function(remoteCodec) {
            if (codec.name.toLowerCase() === remoteCodec.name.toLowerCase() &&
                codec.clockRate === remoteCodec.clockRate) {
              codec.preferredPayloadType = remoteCodec.payloadType;
            }
          });
        }
      });
      localCapabilities.headerExtensions.forEach(function(hdrExt) {
        var remoteExtensions = transceiver.remoteCapabilities &&
            transceiver.remoteCapabilities.headerExtensions || [];
        remoteExtensions.forEach(function(rHdrExt) {
          if (hdrExt.uri === rHdrExt.uri) {
            hdrExt.id = rHdrExt.id;
          }
        });
      });

      // generate an ssrc now, to be used later in rtpSender.send
      var sendEncodingParameters = transceiver.sendEncodingParameters || [{
        ssrc: (2 * sdpMLineIndex + 1) * 1001
      }];
      if (track) {
        // add RTX
        if (edgeVersion >= 15019 && kind === 'video' &&
            !sendEncodingParameters[0].rtx) {
          sendEncodingParameters[0].rtx = {
            ssrc: sendEncodingParameters[0].ssrc + 1
          };
        }
      }

      if (transceiver.wantReceive) {
        transceiver.rtpReceiver = new window.RTCRtpReceiver(
            transceiver.dtlsTransport, kind);
      }

      transceiver.localCapabilities = localCapabilities;
      transceiver.sendEncodingParameters = sendEncodingParameters;
    });

    // always offer BUNDLE and dispose on return if not supported.
    if (pc._config.bundlePolicy !== 'max-compat') {
      sdp += 'a=group:BUNDLE ' + pc.transceivers.map(function(t) {
        return t.mid;
      }).join(' ') + '\r\n';
    }
    sdp += 'a=ice-options:trickle\r\n';

    pc.transceivers.forEach(function(transceiver, sdpMLineIndex) {
      sdp += writeMediaSection(transceiver, transceiver.localCapabilities,
          'offer', transceiver.stream, pc._dtlsRole);
      sdp += 'a=rtcp-rsize\r\n';

      if (transceiver.iceGatherer && pc.iceGatheringState !== 'new' &&
          (sdpMLineIndex === 0 || !pc.usingBundle)) {
        transceiver.iceGatherer.getLocalCandidates().forEach(function(cand) {
          cand.component = 1;
          sdp += 'a=' + SDPUtils.writeCandidate(cand) + '\r\n';
        });

        if (transceiver.iceGatherer.state === 'completed') {
          sdp += 'a=end-of-candidates\r\n';
        }
      }
    });

    var desc = new window.RTCSessionDescription({
      type: 'offer',
      sdp: sdp
    });
    return Promise.resolve(desc);
  };

  RTCPeerConnection.prototype.createAnswer = function() {
    var pc = this;

    if (pc._isClosed) {
      return Promise.reject(makeError('InvalidStateError',
          'Can not call createAnswer after close'));
    }

    if (!(pc.signalingState === 'have-remote-offer' ||
        pc.signalingState === 'have-local-pranswer')) {
      return Promise.reject(makeError('InvalidStateError',
          'Can not call createAnswer in signalingState ' + pc.signalingState));
    }

    var sdp = SDPUtils.writeSessionBoilerplate(pc._sdpSessionId,
        pc._sdpSessionVersion++);
    if (pc.usingBundle) {
      sdp += 'a=group:BUNDLE ' + pc.transceivers.map(function(t) {
        return t.mid;
      }).join(' ') + '\r\n';
    }
    sdp += 'a=ice-options:trickle\r\n';

    var mediaSectionsInOffer = SDPUtils.getMediaSections(
        pc._remoteDescription.sdp).length;
    pc.transceivers.forEach(function(transceiver, sdpMLineIndex) {
      if (sdpMLineIndex + 1 > mediaSectionsInOffer) {
        return;
      }
      if (transceiver.rejected) {
        if (transceiver.kind === 'application') {
          if (transceiver.protocol === 'DTLS/SCTP') { // legacy fmt
            sdp += 'm=application 0 DTLS/SCTP 5000\r\n';
          } else {
            sdp += 'm=application 0 ' + transceiver.protocol +
                ' webrtc-datachannel\r\n';
          }
        } else if (transceiver.kind === 'audio') {
          sdp += 'm=audio 0 UDP/TLS/RTP/SAVPF 0\r\n' +
              'a=rtpmap:0 PCMU/8000\r\n';
        } else if (transceiver.kind === 'video') {
          sdp += 'm=video 0 UDP/TLS/RTP/SAVPF 120\r\n' +
              'a=rtpmap:120 VP8/90000\r\n';
        }
        sdp += 'c=IN IP4 0.0.0.0\r\n' +
            'a=inactive\r\n' +
            'a=mid:' + transceiver.mid + '\r\n';
        return;
      }

      // FIXME: look at direction.
      if (transceiver.stream) {
        var localTrack;
        if (transceiver.kind === 'audio') {
          localTrack = transceiver.stream.getAudioTracks()[0];
        } else if (transceiver.kind === 'video') {
          localTrack = transceiver.stream.getVideoTracks()[0];
        }
        if (localTrack) {
          // add RTX
          if (edgeVersion >= 15019 && transceiver.kind === 'video' &&
              !transceiver.sendEncodingParameters[0].rtx) {
            transceiver.sendEncodingParameters[0].rtx = {
              ssrc: transceiver.sendEncodingParameters[0].ssrc + 1
            };
          }
        }
      }

      // Calculate intersection of capabilities.
      var commonCapabilities = getCommonCapabilities(
          transceiver.localCapabilities,
          transceiver.remoteCapabilities);

      var hasRtx = commonCapabilities.codecs.filter(function(c) {
        return c.name.toLowerCase() === 'rtx';
      }).length;
      if (!hasRtx && transceiver.sendEncodingParameters[0].rtx) {
        delete transceiver.sendEncodingParameters[0].rtx;
      }

      sdp += writeMediaSection(transceiver, commonCapabilities,
          'answer', transceiver.stream, pc._dtlsRole);
      if (transceiver.rtcpParameters &&
          transceiver.rtcpParameters.reducedSize) {
        sdp += 'a=rtcp-rsize\r\n';
      }
    });

    var desc = new window.RTCSessionDescription({
      type: 'answer',
      sdp: sdp
    });
    return Promise.resolve(desc);
  };

  RTCPeerConnection.prototype.addIceCandidate = function(candidate) {
    var pc = this;
    var sections;
    if (candidate && !(candidate.sdpMLineIndex !== undefined ||
        candidate.sdpMid)) {
      return Promise.reject(new TypeError('sdpMLineIndex or sdpMid required'));
    }

    // TODO: needs to go into ops queue.
    return new Promise(function(resolve, reject) {
      if (!pc._remoteDescription) {
        return reject(makeError('InvalidStateError',
            'Can not add ICE candidate without a remote description'));
      } else if (!candidate || candidate.candidate === '') {
        for (var j = 0; j < pc.transceivers.length; j++) {
          if (pc.transceivers[j].rejected) {
            continue;
          }
          pc.transceivers[j].iceTransport.addRemoteCandidate({});
          sections = SDPUtils.getMediaSections(pc._remoteDescription.sdp);
          sections[j] += 'a=end-of-candidates\r\n';
          pc._remoteDescription.sdp =
              SDPUtils.getDescription(pc._remoteDescription.sdp) +
              sections.join('');
          if (pc.usingBundle) {
            break;
          }
        }
      } else {
        var sdpMLineIndex = candidate.sdpMLineIndex;
        if (candidate.sdpMid) {
          for (var i = 0; i < pc.transceivers.length; i++) {
            if (pc.transceivers[i].mid === candidate.sdpMid) {
              sdpMLineIndex = i;
              break;
            }
          }
        }
        var transceiver = pc.transceivers[sdpMLineIndex];
        if (transceiver) {
          if (transceiver.rejected) {
            return resolve();
          }
          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 || cand.port === 9)) {
            return resolve();
          }
          // Ignore RTCP candidates, we assume RTCP-MUX.
          if (cand.component && cand.component !== 1) {
            return resolve();
          }
          // when using bundle, avoid adding candidates to the wrong
          // ice transport. And avoid adding candidates added in the SDP.
          if (sdpMLineIndex === 0 || (sdpMLineIndex > 0 &&
              transceiver.iceTransport !== pc.transceivers[0].iceTransport)) {
            if (!maybeAddCandidate(transceiver.iceTransport, cand)) {
              return reject(makeError('OperationError',
                  'Can not add ICE candidate'));
            }
          }

          // update the remoteDescription.
          var candidateString = candidate.candidate.trim();
          if (candidateString.indexOf('a=') === 0) {
            candidateString = candidateString.substr(2);
          }
          sections = SDPUtils.getMediaSections(pc._remoteDescription.sdp);
          sections[sdpMLineIndex] += 'a=' +
              (cand.type ? candidateString : 'end-of-candidates')
              + '\r\n';
          pc._remoteDescription.sdp =
              SDPUtils.getDescription(pc._remoteDescription.sdp) +
              sections.join('');
        } else {
          return reject(makeError('OperationError',
              'Can not add ICE candidate'));
        }
      }
      resolve();
    });
  };

  RTCPeerConnection.prototype.getStats = function(selector) {
    if (selector && selector instanceof window.MediaStreamTrack) {
      var senderOrReceiver = null;
      this.transceivers.forEach(function(transceiver) {
        if (transceiver.rtpSender &&
            transceiver.rtpSender.track === selector) {
          senderOrReceiver = transceiver.rtpSender;
        } else if (transceiver.rtpReceiver &&
            transceiver.rtpReceiver.track === selector) {
          senderOrReceiver = transceiver.rtpReceiver;
        }
      });
      if (!senderOrReceiver) {
        throw makeError('InvalidAccessError', 'Invalid selector.');
      }
      return senderOrReceiver.getStats();
    }

    var promises = [];
    this.transceivers.forEach(function(transceiver) {
      ['rtpSender', 'rtpReceiver', 'iceGatherer', 'iceTransport',
          'dtlsTransport'].forEach(function(method) {
            if (transceiver[method]) {
              promises.push(transceiver[method].getStats());
            }
          });
    });
    return Promise.all(promises).then(function(allStats) {
      var results = new Map();
      allStats.forEach(function(stats) {
        stats.forEach(function(stat) {
          results.set(stat.id, stat);
        });
      });
      return results;
    });
  };

  // fix low-level stat names and return Map instead of object.
  var ortcObjects = ['RTCRtpSender', 'RTCRtpReceiver', 'RTCIceGatherer',
    'RTCIceTransport', 'RTCDtlsTransport'];
  ortcObjects.forEach(function(ortcObjectName) {
    var obj = window[ortcObjectName];
    if (obj && obj.prototype && obj.prototype.getStats) {
      var nativeGetstats = obj.prototype.getStats;
      obj.prototype.getStats = function() {
        return nativeGetstats.apply(this)
        .then(function(nativeStats) {
          var mapStats = new Map();
          Object.keys(nativeStats).forEach(function(id) {
            nativeStats[id].type = fixStatsType(nativeStats[id]);
            mapStats.set(id, nativeStats[id]);
          });
          return mapStats;
        });
      };
    }
  });

  // legacy callback shims. Should be moved to adapter.js some days.
  var methods = ['createOffer', 'createAnswer'];
  methods.forEach(function(method) {
    var nativeMethod = RTCPeerConnection.prototype[method];
    RTCPeerConnection.prototype[method] = function() {
      var args = arguments;
      if (typeof args[0] === 'function' ||
          typeof args[1] === 'function') { // legacy
        return nativeMethod.apply(this, [arguments[2]])
        .then(function(description) {
          if (typeof args[0] === 'function') {
            args[0].apply(null, [description]);
          }
        }, function(error) {
          if (typeof args[1] === 'function') {
            args[1].apply(null, [error]);
          }
        });
      }
      return nativeMethod.apply(this, arguments);
    };
  });

  methods = ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate'];
  methods.forEach(function(method) {
    var nativeMethod = RTCPeerConnection.prototype[method];
    RTCPeerConnection.prototype[method] = function() {
      var args = arguments;
      if (typeof args[1] === 'function' ||
          typeof args[2] === 'function') { // legacy
        return nativeMethod.apply(this, arguments)
        .then(function() {
          if (typeof args[1] === 'function') {
            args[1].apply(null);
          }
        }, function(error) {
          if (typeof args[2] === 'function') {
            args[2].apply(null, [error]);
          }
        });
      }
      return nativeMethod.apply(this, arguments);
    };
  });

  // getStats is special. It doesn't have a spec legacy method yet we support
  // getStats(something, cb) without error callbacks.
  ['getStats'].forEach(function(method) {
    var nativeMethod = RTCPeerConnection.prototype[method];
    RTCPeerConnection.prototype[method] = function() {
      var args = arguments;
      if (typeof args[1] === 'function') {
        return nativeMethod.apply(this, arguments)
        .then(function() {
          if (typeof args[1] === 'function') {
            args[1].apply(null);
          }
        });
      }
      return nativeMethod.apply(this, arguments);
    };
  });

  return RTCPeerConnection;
};

},{"sdp":15}],15:[function(require,module,exports){
 /* eslint-env node */
'use strict';

// SDP helpers.
var SDPUtils = {};

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

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

// 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('\nm=');
  return parts.map(function(part, index) {
    return (index > 0 ? 'm=' + part : part).trim() + '\r\n';
  });
};

// returns the session description.
SDPUtils.getDescription = function(blob) {
  var sections = SDPUtils.splitSections(blob);
  return sections && sections[0];
};

// returns the individual media sections.
SDPUtils.getMediaSections = function(blob) {
  var sections = SDPUtils.splitSections(blob);
  sections.shift();
  return sections;
};

// 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: parseInt(parts[1], 10),
    protocol: parts[2].toLowerCase(),
    priority: parseInt(parts[3], 10),
    ip: parts[4],
    address: parts[4], // address is an alias for ip.
    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;
      case 'ufrag':
        candidate.ufrag = parts[i + 1]; // for backward compability.
        candidate.usernameFragment = parts[i + 1];
        break;
      default: // extension handling, in particular ufrag
        candidate[parts[i]] = parts[i + 1];
        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.address || 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);
    sdp.push('rport');
    sdp.push(candidate.relatedPort);
  }
  if (candidate.tcpType && candidate.protocol.toLowerCase() === 'tcp') {
    sdp.push('tcptype');
    sdp.push(candidate.tcpType);
  }
  if (candidate.usernameFragment || candidate.ufrag) {
    sdp.push('ufrag');
    sdp.push(candidate.usernameFragment || candidate.ufrag);
  }
  return 'candidate:' + sdp.join(' ');
};

// Parses an ice-options line, returns an array of option tags.
// a=ice-options:foo bar
SDPUtils.parseIceOptions = function(line) {
  return line.substr(14).split(' ');
};

// 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.channels = parts.length === 3 ? parseInt(parts[2], 10) : 1;
  // legacy alias, got renamed back to channels in ORTC.
  parsed.numChannels = parsed.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;
  }
  var channels = codec.channels || codec.numChannels || 1;
  return 'a=rtpmap:' + pt + ' ' + codec.name + '/' + codec.clockRate +
      (channels !== 1 ? '/' + channels : '') + '\r\n';
};

// Parses an a=extmap line (headerextension from RFC 5285). Sample input:
// a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
// a=extmap:2/sendonly urn:ietf:params:rtp-hdrext:toffset
SDPUtils.parseExtmap = function(line) {
  var parts = line.substr(9).split(' ');
  return {
    id: parseInt(parts[0], 10),
    direction: parts[0].indexOf('/') > 0 ? parts[0].split('/')[1] : 'sendrecv',
    uri: parts[1]
  };
};

// Generates a=extmap line from RTCRtpHeaderExtensionParameters or
// RTCRtpHeaderExtension.
SDPUtils.writeExtmap = function(headerExtension) {
  return 'a=extmap:' + (headerExtension.id || headerExtension.preferredId) +
      (headerExtension.direction && headerExtension.direction !== 'sendrecv'
          ? '/' + headerExtension.direction
          : '') +
      ' ' + headerExtension.uri + '\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.writeFmtp = function(codec) {
  var line = '';
  var pt = codec.payloadType;
  if (codec.preferredPayloadType !== undefined) {
    pt = codec.preferredPayloadType;
  }
  if (codec.parameters && Object.keys(codec.parameters).length) {
    var params = [];
    Object.keys(codec.parameters).forEach(function(param) {
      if (codec.parameters[param]) {
        params.push(param + '=' + codec.parameters[param]);
      } else {
        params.push(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 && fb.parameter.length ? ' ' + 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: parseInt(line.substr(7, sp - 7), 10)
  };
  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;
};

SDPUtils.parseSsrcGroup = function(line) {
  var parts = line.substr(13).split(' ');
  return {
    semantics: parts.shift(),
    ssrcs: parts.map(function(ssrc) {
      return parseInt(ssrc, 10);
    })
  };
};

// Extracts the MID (RFC 5888) from a media section.
// returns the MID or undefined if no mid line was found.
SDPUtils.getMid = function(mediaSection) {
  var mid = SDPUtils.matchPrefix(mediaSection, 'a=mid:')[0];
  if (mid) {
    return mid.substr(6);
  }
};

SDPUtils.parseFingerprint = function(line) {
  var parts = line.substr(14).split(' ');
  return {
    algorithm: parts[0].toLowerCase(), // algorithm is case-sensitive in Edge.
    value: parts[1]
  };
};

// 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.matchPrefix(mediaSection + sessionpart,
      'a=fingerprint:');
  // Note: a=setup line is ignored since we use the 'auto' role.
  // Note2: 'algorithm' is not case sensitive except in Edge.
  return {
    role: 'auto',
    fingerprints: lines.map(SDPUtils.parseFingerprint)
  };
};

// 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);
  // Search in session part, too.
  lines = lines.concat(SDPUtils.splitLines(sessionpart));
  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);
      // parse FEC mechanisms from rtpmap lines.
      switch (codec.name.toUpperCase()) {
        case 'RED':
        case 'ULPFEC':
          description.fecMechanisms.push(codec.name.toUpperCase());
          break;
        default: // only RED and ULPFEC are recognized as FEC mechanisms.
          break;
      }
    }
  }
  SDPUtils.matchPrefix(mediaSection, 'a=extmap:').forEach(function(line) {
    description.headerExtensions.push(SDPUtils.parseExtmap(line));
  });
  // FIXME: parse 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.writeFmtp(codec);
    sdp += SDPUtils.writeRtcpFb(codec);
  });
  var maxptime = 0;
  caps.codecs.forEach(function(codec) {
    if (codec.maxptime > maxptime) {
      maxptime = codec.maxptime;
    }
  });
  if (maxptime > 0) {
    sdp += 'a=maxptime:' + maxptime + '\r\n';
  }
  sdp += 'a=rtcp-mux\r\n';

  if (caps.headerExtensions) {
    caps.headerExtensions.forEach(function(extension) {
      sdp += SDPUtils.writeExtmap(extension);
    });
  }
  // FIXME: write fecMechanisms.
  return sdp;
};

// Parses the SDP media section and returns an array of
// RTCRtpEncodingParameters.
SDPUtils.parseRtpEncodingParameters = function(mediaSection) {
  var encodingParameters = [];
  var description = SDPUtils.parseRtpParameters(mediaSection);
  var hasRed = description.fecMechanisms.indexOf('RED') !== -1;
  var hasUlpfec = description.fecMechanisms.indexOf('ULPFEC') !== -1;

  // filter a=ssrc:... cname:, ignore PlanB-msid
  var ssrcs = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
  .map(function(line) {
    return SDPUtils.parseSsrcMedia(line);
  })
  .filter(function(parts) {
    return parts.attribute === 'cname';
  });
  var primarySsrc = ssrcs.length > 0 && ssrcs[0].ssrc;
  var secondarySsrc;

  var flows = SDPUtils.matchPrefix(mediaSection, 'a=ssrc-group:FID')
  .map(function(line) {
    var parts = line.substr(17).split(' ');
    return parts.map(function(part) {
      return parseInt(part, 10);
    });
  });
  if (flows.length > 0 && flows[0].length > 1 && flows[0][0] === primarySsrc) {
    secondarySsrc = flows[0][1];
  }

  description.codecs.forEach(function(codec) {
    if (codec.name.toUpperCase() === 'RTX' && codec.parameters.apt) {
      var encParam = {
        ssrc: primarySsrc,
        codecPayloadType: parseInt(codec.parameters.apt, 10)
      };
      if (primarySsrc && secondarySsrc) {
        encParam.rtx = {ssrc: secondarySsrc};
      }
      encodingParameters.push(encParam);
      if (hasRed) {
        encParam = JSON.parse(JSON.stringify(encParam));
        encParam.fec = {
          ssrc: primarySsrc,
          mechanism: hasUlpfec ? 'red+ulpfec' : 'red'
        };
        encodingParameters.push(encParam);
      }
    }
  });
  if (encodingParameters.length === 0 && primarySsrc) {
    encodingParameters.push({
      ssrc: primarySsrc
    });
  }

  // we support both b=AS and b=TIAS but interpret AS as TIAS.
  var bandwidth = SDPUtils.matchPrefix(mediaSection, 'b=');
  if (bandwidth.length) {
    if (bandwidth[0].indexOf('b=TIAS:') === 0) {
      bandwidth = parseInt(bandwidth[0].substr(7), 10);
    } else if (bandwidth[0].indexOf('b=AS:') === 0) {
      // use formula from JSEP to convert b=AS to TIAS value.
      bandwidth = parseInt(bandwidth[0].substr(5), 10) * 1000 * 0.95
          - (50 * 40 * 8);
    } else {
      bandwidth = undefined;
    }
    encodingParameters.forEach(function(params) {
      params.maxBitrate = bandwidth;
    });
  }
  return encodingParameters;
};

// parses http://draft.ortc.org/#rtcrtcpparameters*
SDPUtils.parseRtcpParameters = function(mediaSection) {
  var rtcpParameters = {};

  // Gets the first SSRC. Note tha 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) {
    rtcpParameters.cname = remoteSsrc.value;
    rtcpParameters.ssrc = remoteSsrc.ssrc;
  }

  // Edge uses the compound attribute instead of reducedSize
  // compound is !reducedSize
  var rsize = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-rsize');
  rtcpParameters.reducedSize = rsize.length > 0;
  rtcpParameters.compound = rsize.length === 0;

  // parses the rtcp-mux attrіbute.
  // Note that Edge does not support unmuxed RTCP.
  var mux = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-mux');
  rtcpParameters.mux = mux.length > 0;

  return rtcpParameters;
};

// parses either a=msid: or a=ssrc:... msid lines and returns
// the id of the MediaStream and MediaStreamTrack.
SDPUtils.parseMsid = function(mediaSection) {
  var parts;
  var spec = SDPUtils.matchPrefix(mediaSection, 'a=msid:');
  if (spec.length === 1) {
    parts = spec[0].substr(7).split(' ');
    return {stream: parts[0], track: parts[1]};
  }
  var planB = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
  .map(function(line) {
    return SDPUtils.parseSsrcMedia(line);
  })
  .filter(function(msidParts) {
    return msidParts.attribute === 'msid';
  });
  if (planB.length > 0) {
    parts = planB[0].value.split(' ');
    return {stream: parts[0], track: parts[1]};
  }
};

// Generate a session ID for SDP.
// https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-20#section-5.2.1
// recommends using a cryptographically random +ve 64-bit value
// but right now this should be acceptable and within the right range
SDPUtils.generateSessionId = function() {
  return Math.random().toString().substr(2, 21);
};

// Write boilder plate for start of SDP
// sessId argument is optional - if not supplied it will
// be generated randomly
// sessVersion is optional and defaults to 2
// sessUser is optional and defaults to 'thisisadapterortc'
SDPUtils.writeSessionBoilerplate = function(sessId, sessVer, sessUser) {
  var sessionId;
  var version = sessVer !== undefined ? sessVer : 2;
  if (sessId) {
    sessionId = sessId;
  } else {
    sessionId = SDPUtils.generateSessionId();
  }
  var user = sessUser || 'thisisadapterortc';
  // FIXME: sess-id should be an NTP timestamp.
  return 'v=0\r\n' +
      'o=' + user + ' ' + sessionId + ' ' + version +
        ' 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.direction) {
    sdp += 'a=' + transceiver.direction + '\r\n';
  } else 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';
  }

  if (transceiver.rtpSender) {
    // spec.
    var msid = 'msid:' + stream.id + ' ' +
        transceiver.rtpSender.track.id + '\r\n';
    sdp += 'a=' + msid;

    // for Chrome.
    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
        ' ' + msid;
    if (transceiver.sendEncodingParameters[0].rtx) {
      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
          ' ' + msid;
      sdp += 'a=ssrc-group:FID ' +
          transceiver.sendEncodingParameters[0].ssrc + ' ' +
          transceiver.sendEncodingParameters[0].rtx.ssrc +
          '\r\n';
    }
  }
  // FIXME: this should be written by writeRtpDescription.
  sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
      ' cname:' + SDPUtils.localCName + '\r\n';
  if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
        ' cname:' + SDPUtils.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);
      default:
        // FIXME: What should happen here?
    }
  }
  if (sessionpart) {
    return SDPUtils.getDirection(sessionpart);
  }
  return 'sendrecv';
};

SDPUtils.getKind = function(mediaSection) {
  var lines = SDPUtils.splitLines(mediaSection);
  var mline = lines[0].split(' ');
  return mline[0].substr(2);
};

SDPUtils.isRejected = function(mediaSection) {
  return mediaSection.split(' ', 2)[1] === '0';
};

SDPUtils.parseMLine = function(mediaSection) {
  var lines = SDPUtils.splitLines(mediaSection);
  var parts = lines[0].substr(2).split(' ');
  return {
    kind: parts[0],
    port: parseInt(parts[1], 10),
    protocol: parts[2],
    fmt: parts.slice(3).join(' ')
  };
};

SDPUtils.parseOLine = function(mediaSection) {
  var line = SDPUtils.matchPrefix(mediaSection, 'o=')[0];
  var parts = line.substr(2).split(' ');
  return {
    username: parts[0],
    sessionId: parts[1],
    sessionVersion: parseInt(parts[2], 10),
    netType: parts[3],
    addressType: parts[4],
    address: parts[5]
  };
};

// a very naive interpretation of a valid SDP.
SDPUtils.isValidSDP = function(blob) {
  if (typeof blob !== 'string' || blob.length === 0) {
    return false;
  }
  var lines = SDPUtils.splitLines(blob);
  for (var i = 0; i < lines.length; i++) {
    if (lines[i].length < 2 || lines[i].charAt(1) !== '=') {
      return false;
    }
    // TODO: check the modifier a bit more.
  }
  return true;
};

// Expose public methods.
if (typeof module === 'object') {
  module.exports = SDPUtils;
}

},{}],16:[function(require,module,exports){
(function (global){
/*
 *  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.
 */
 /* eslint-env node */

'use strict';

var adapterFactory = require('./adapter_factory.js');
module.exports = adapterFactory({window: global.window});

}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"./adapter_factory.js":17}],17:[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.
 */
 /* eslint-env node */

'use strict';

var utils = require('./utils');
// Shimming starts here.
module.exports = function(dependencies, opts) {
  var window = dependencies && dependencies.window;

  var options = {
    shimChrome: true,
    shimFirefox: true,
    shimEdge: true,
    shimSafari: true,
  };

  for (var key in opts) {
    if (hasOwnProperty.call(opts, key)) {
      options[key] = opts[key];
    }
  }

  // Utils.
  var logging = utils.log;
  var browserDetails = utils.detectBrowser(window);

  // Uncomment the line below if you want logging to occur, including logging
  // for the switch statement below. Can also be turned on in the browser via
  // adapter.disableLog(false), but then logging from the switch statement below
  // will not appear.
  // require('./utils').disableLog(false);

  // Browser shims.
  var chromeShim = require('./chrome/chrome_shim') || null;
  var edgeShim = require('./edge/edge_shim') || null;
  var firefoxShim = require('./firefox/firefox_shim') || null;
  var safariShim = require('./safari/safari_shim') || null;
  var commonShim = require('./common_shim') || null;

  // Export to the adapter global object visible in the browser.
  var adapter = {
    browserDetails: browserDetails,
    commonShim: commonShim,
    extractVersion: utils.extractVersion,
    disableLog: utils.disableLog,
    disableWarnings: utils.disableWarnings
  };

  // Shim browser if found.
  switch (browserDetails.browser) {
    case 'chrome':
      if (!chromeShim || !chromeShim.shimPeerConnection ||
          !options.shimChrome) {
        logging('Chrome shim is not included in this adapter release.');
        return adapter;
      }
      logging('adapter.js shimming chrome.');
      // Export to the adapter global object visible in the browser.
      adapter.browserShim = chromeShim;
      commonShim.shimCreateObjectURL(window);

      chromeShim.shimGetUserMedia(window);
      chromeShim.shimMediaStream(window);
      chromeShim.shimSourceObject(window);
      chromeShim.shimPeerConnection(window);
      chromeShim.shimOnTrack(window);
      chromeShim.shimAddTrackRemoveTrack(window);
      chromeShim.shimGetSendersWithDtmf(window);
      chromeShim.shimSenderReceiverGetStats(window);
      chromeShim.fixNegotiationNeeded(window);

      commonShim.shimRTCIceCandidate(window);
      commonShim.shimMaxMessageSize(window);
      commonShim.shimSendThrowTypeError(window);
      break;
    case 'firefox':
      if (!firefoxShim || !firefoxShim.shimPeerConnection ||
          !options.shimFirefox) {
        logging('Firefox shim is not included in this adapter release.');
        return adapter;
      }
      logging('adapter.js shimming firefox.');
      // Export to the adapter global object visible in the browser.
      adapter.browserShim = firefoxShim;
      commonShim.shimCreateObjectURL(window);

      firefoxShim.shimGetUserMedia(window);
      firefoxShim.shimSourceObject(window);
      firefoxShim.shimPeerConnection(window);
      firefoxShim.shimOnTrack(window);
      firefoxShim.shimRemoveStream(window);
      firefoxShim.shimSenderGetStats(window);
      firefoxShim.shimReceiverGetStats(window);
      firefoxShim.shimRTCDataChannel(window);

      commonShim.shimRTCIceCandidate(window);
      commonShim.shimMaxMessageSize(window);
      commonShim.shimSendThrowTypeError(window);
      break;
    case 'edge':
      if (!edgeShim || !edgeShim.shimPeerConnection || !options.shimEdge) {
        logging('MS edge shim is not included in this adapter release.');
        return adapter;
      }
      logging('adapter.js shimming edge.');
      // Export to the adapter global object visible in the browser.
      adapter.browserShim = edgeShim;
      commonShim.shimCreateObjectURL(window);

      edgeShim.shimGetUserMedia(window);
      edgeShim.shimPeerConnection(window);
      edgeShim.shimReplaceTrack(window);

      // the edge shim implements the full RTCIceCandidate object.

      commonShim.shimMaxMessageSize(window);
      commonShim.shimSendThrowTypeError(window);
      break;
    case 'safari':
      if (!safariShim || !options.shimSafari) {
        logging('Safari shim is not included in this adapter release.');
        return adapter;
      }
      logging('adapter.js shimming safari.');
      // Export to the adapter global object visible in the browser.
      adapter.browserShim = safariShim;
      commonShim.shimCreateObjectURL(window);

      safariShim.shimRTCIceServerUrls(window);
      safariShim.shimCreateOfferLegacy(window);
      safariShim.shimCallbacksAPI(window);
      safariShim.shimLocalStreamsAPI(window);
      safariShim.shimRemoteStreamsAPI(window);
      safariShim.shimTrackEventTransceiver(window);
      safariShim.shimGetUserMedia(window);

      commonShim.shimRTCIceCandidate(window);
      commonShim.shimMaxMessageSize(window);
      commonShim.shimSendThrowTypeError(window);
      break;
    default:
      logging('Unsupported browser!');
      break;
  }

  return adapter;
};

},{"./chrome/chrome_shim":18,"./common_shim":20,"./edge/edge_shim":21,"./firefox/firefox_shim":24,"./safari/safari_shim":26,"./utils":27}],18:[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.
 */
 /* eslint-env node */
'use strict';
var utils = require('../utils.js');
var logging = utils.log;

/* iterates the stats graph recursively. */
function walkStats(stats, base, resultSet) {
  if (!base || resultSet.has(base.id)) {
    return;
  }
  resultSet.set(base.id, base);
  Object.keys(base).forEach(function(name) {
    if (name.endsWith('Id')) {
      walkStats(stats, stats.get(base[name]), resultSet);
    } else if (name.endsWith('Ids')) {
      base[name].forEach(function(id) {
        walkStats(stats, stats.get(id), resultSet);
      });
    }
  });
}

/* filter getStats for a sender/receiver track. */
function filterStats(result, track, outbound) {
  var streamStatsType = outbound ? 'outbound-rtp' : 'inbound-rtp';
  var filteredResult = new Map();
  if (track === null) {
    return filteredResult;
  }
  var trackStats = [];
  result.forEach(function(value) {
    if (value.type === 'track' &&
        value.trackIdentifier === track.id) {
      trackStats.push(value);
    }
  });
  trackStats.forEach(function(trackStat) {
    result.forEach(function(stats) {
      if (stats.type === streamStatsType && stats.trackId === trackStat.id) {
        walkStats(result, stats, filteredResult);
      }
    });
  });
  return filteredResult;
}

module.exports = {
  shimGetUserMedia: require('./getusermedia'),
  shimMediaStream: function(window) {
    window.MediaStream = window.MediaStream || window.webkitMediaStream;
  },

  shimOnTrack: function(window) {
    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
        window.RTCPeerConnection.prototype)) {
      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
        get: function() {
          return this._ontrack;
        },
        set: function(f) {
          if (this._ontrack) {
            this.removeEventListener('track', this._ontrack);
          }
          this.addEventListener('track', this._ontrack = f);
        },
        enumerable: true,
        configurable: true
      });
      var origSetRemoteDescription =
          window.RTCPeerConnection.prototype.setRemoteDescription;
      window.RTCPeerConnection.prototype.setRemoteDescription = function() {
        var pc = this;
        if (!pc._ontrackpoly) {
          pc._ontrackpoly = function(e) {
            // onaddstream does not fire when a track is added to an existing
            // stream. But stream.onaddtrack is implemented so we use that.
            e.stream.addEventListener('addtrack', function(te) {
              var receiver;
              if (window.RTCPeerConnection.prototype.getReceivers) {
                receiver = pc.getReceivers().find(function(r) {
                  return r.track && r.track.id === te.track.id;
                });
              } else {
                receiver = {track: te.track};
              }

              var event = new Event('track');
              event.track = te.track;
              event.receiver = receiver;
              event.transceiver = {receiver: receiver};
              event.streams = [e.stream];
              pc.dispatchEvent(event);
            });
            e.stream.getTracks().forEach(function(track) {
              var receiver;
              if (window.RTCPeerConnection.prototype.getReceivers) {
                receiver = pc.getReceivers().find(function(r) {
                  return r.track && r.track.id === track.id;
                });
              } else {
                receiver = {track: track};
              }
              var event = new Event('track');
              event.track = track;
              event.receiver = receiver;
              event.transceiver = {receiver: receiver};
              event.streams = [e.stream];
              pc.dispatchEvent(event);
            });
          };
          pc.addEventListener('addstream', pc._ontrackpoly);
        }
        return origSetRemoteDescription.apply(pc, arguments);
      };
    } else {
      // even if RTCRtpTransceiver is in window, it is only used and
      // emitted in unified-plan. Unfortunately this means we need
      // to unconditionally wrap the event.
      utils.wrapPeerConnectionEvent(window, 'track', function(e) {
        if (!e.transceiver) {
          Object.defineProperty(e, 'transceiver',
            {value: {receiver: e.receiver}});
        }
        return e;
      });
    }
  },

  shimGetSendersWithDtmf: function(window) {
    // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
    if (typeof window === 'object' && window.RTCPeerConnection &&
        !('getSenders' in window.RTCPeerConnection.prototype) &&
        'createDTMFSender' in window.RTCPeerConnection.prototype) {
      var shimSenderWithDtmf = function(pc, track) {
        return {
          track: track,
          get dtmf() {
            if (this._dtmf === undefined) {
              if (track.kind === 'audio') {
                this._dtmf = pc.createDTMFSender(track);
              } else {
                this._dtmf = null;
              }
            }
            return this._dtmf;
          },
          _pc: pc
        };
      };

      // augment addTrack when getSenders is not available.
      if (!window.RTCPeerConnection.prototype.getSenders) {
        window.RTCPeerConnection.prototype.getSenders = function() {
          this._senders = this._senders || [];
          return this._senders.slice(); // return a copy of the internal state.
        };
        var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
        window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
          var pc = this;
          var sender = origAddTrack.apply(pc, arguments);
          if (!sender) {
            sender = shimSenderWithDtmf(pc, track);
            pc._senders.push(sender);
          }
          return sender;
        };

        var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
        window.RTCPeerConnection.prototype.removeTrack = function(sender) {
          var pc = this;
          origRemoveTrack.apply(pc, arguments);
          var idx = pc._senders.indexOf(sender);
          if (idx !== -1) {
            pc._senders.splice(idx, 1);
          }
        };
      }
      var origAddStream = window.RTCPeerConnection.prototype.addStream;
      window.RTCPeerConnection.prototype.addStream = function(stream) {
        var pc = this;
        pc._senders = pc._senders || [];
        origAddStream.apply(pc, [stream]);
        stream.getTracks().forEach(function(track) {
          pc._senders.push(shimSenderWithDtmf(pc, track));
        });
      };

      var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
      window.RTCPeerConnection.prototype.removeStream = function(stream) {
        var pc = this;
        pc._senders = pc._senders || [];
        origRemoveStream.apply(pc, [stream]);

        stream.getTracks().forEach(function(track) {
          var sender = pc._senders.find(function(s) {
            return s.track === track;
          });
          if (sender) {
            pc._senders.splice(pc._senders.indexOf(sender), 1); // remove sender
          }
        });
      };
    } else if (typeof window === 'object' && window.RTCPeerConnection &&
               'getSenders' in window.RTCPeerConnection.prototype &&
               'createDTMFSender' in window.RTCPeerConnection.prototype &&
               window.RTCRtpSender &&
               !('dtmf' in window.RTCRtpSender.prototype)) {
      var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
      window.RTCPeerConnection.prototype.getSenders = function() {
        var pc = this;
        var senders = origGetSenders.apply(pc, []);
        senders.forEach(function(sender) {
          sender._pc = pc;
        });
        return senders;
      };

      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
        get: function() {
          if (this._dtmf === undefined) {
            if (this.track.kind === 'audio') {
              this._dtmf = this._pc.createDTMFSender(this.track);
            } else {
              this._dtmf = null;
            }
          }
          return this._dtmf;
        }
      });
    }
  },

  shimSenderReceiverGetStats: function(window) {
    if (!(typeof window === 'object' && window.RTCPeerConnection &&
        window.RTCRtpSender && window.RTCRtpReceiver)) {
      return;
    }

    // shim sender stats.
    if (!('getStats' in window.RTCRtpSender.prototype)) {
      var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
      if (origGetSenders) {
        window.RTCPeerConnection.prototype.getSenders = function() {
          var pc = this;
          var senders = origGetSenders.apply(pc, []);
          senders.forEach(function(sender) {
            sender._pc = pc;
          });
          return senders;
        };
      }

      var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
      if (origAddTrack) {
        window.RTCPeerConnection.prototype.addTrack = function() {
          var sender = origAddTrack.apply(this, arguments);
          sender._pc = this;
          return sender;
        };
      }
      window.RTCRtpSender.prototype.getStats = function() {
        var sender = this;
        return this._pc.getStats().then(function(result) {
          /* Note: this will include stats of all senders that
           *   send a track with the same id as sender.track as
           *   it is not possible to identify the RTCRtpSender.
           */
          return filterStats(result, sender.track, true);
        });
      };
    }

    // shim receiver stats.
    if (!('getStats' in window.RTCRtpReceiver.prototype)) {
      var origGetReceivers = window.RTCPeerConnection.prototype.getReceivers;
      if (origGetReceivers) {
        window.RTCPeerConnection.prototype.getReceivers = function() {
          var pc = this;
          var receivers = origGetReceivers.apply(pc, []);
          receivers.forEach(function(receiver) {
            receiver._pc = pc;
          });
          return receivers;
        };
      }
      utils.wrapPeerConnectionEvent(window, 'track', function(e) {
        e.receiver._pc = e.srcElement;
        return e;
      });
      window.RTCRtpReceiver.prototype.getStats = function() {
        var receiver = this;
        return this._pc.getStats().then(function(result) {
          return filterStats(result, receiver.track, false);
        });
      };
    }

    if (!('getStats' in window.RTCRtpSender.prototype &&
        'getStats' in window.RTCRtpReceiver.prototype)) {
      return;
    }

    // shim RTCPeerConnection.getStats(track).
    var origGetStats = window.RTCPeerConnection.prototype.getStats;
    window.RTCPeerConnection.prototype.getStats = function() {
      var pc = this;
      if (arguments.length > 0 &&
          arguments[0] instanceof window.MediaStreamTrack) {
        var track = arguments[0];
        var sender;
        var receiver;
        var err;
        pc.getSenders().forEach(function(s) {
          if (s.track === track) {
            if (sender) {
              err = true;
            } else {
              sender = s;
            }
          }
        });
        pc.getReceivers().forEach(function(r) {
          if (r.track === track) {
            if (receiver) {
              err = true;
            } else {
              receiver = r;
            }
          }
          return r.track === track;
        });
        if (err || (sender && receiver)) {
          return Promise.reject(new DOMException(
            'There are more than one sender or receiver for the track.',
            'InvalidAccessError'));
        } else if (sender) {
          return sender.getStats();
        } else if (receiver) {
          return receiver.getStats();
        }
        return Promise.reject(new DOMException(
          'There is no sender or receiver for the track.',
          'InvalidAccessError'));
      }
      return origGetStats.apply(pc, arguments);
    };
  },

  shimSourceObject: function(window) {
    var URL = window && window.URL;

    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() {
            return this._srcObject;
          },
          set: function(stream) {
            var self = this;
            // Use _srcObject as a private property for this shim
            this._srcObject = stream;
            if (this.src) {
              URL.revokeObjectURL(this.src);
            }

            if (!stream) {
              this.src = '';
              return undefined;
            }
            this.src = URL.createObjectURL(stream);
            // We need to recreate the blob url when a track is added or
            // removed. Doing it manually since we want to avoid a recursion.
            stream.addEventListener('addtrack', function() {
              if (self.src) {
                URL.revokeObjectURL(self.src);
              }
              self.src = URL.createObjectURL(stream);
            });
            stream.addEventListener('removetrack', function() {
              if (self.src) {
                URL.revokeObjectURL(self.src);
              }
              self.src = URL.createObjectURL(stream);
            });
          }
        });
      }
    }
  },

  shimAddTrackRemoveTrackWithNative: function(window) {
    // shim addTrack/removeTrack with native variants in order to make
    // the interactions with legacy getLocalStreams behave as in other browsers.
    // Keeps a mapping stream.id => [stream, rtpsenders...]
    window.RTCPeerConnection.prototype.getLocalStreams = function() {
      var pc = this;
      this._shimmedLocalStreams = this._shimmedLocalStreams || {};
      return Object.keys(this._shimmedLocalStreams).map(function(streamId) {
        return pc._shimmedLocalStreams[streamId][0];
      });
    };

    var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
    window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
      if (!stream) {
        return origAddTrack.apply(this, arguments);
      }
      this._shimmedLocalStreams = this._shimmedLocalStreams || {};

      var sender = origAddTrack.apply(this, arguments);
      if (!this._shimmedLocalStreams[stream.id]) {
        this._shimmedLocalStreams[stream.id] = [stream, sender];
      } else if (this._shimmedLocalStreams[stream.id].indexOf(sender) === -1) {
        this._shimmedLocalStreams[stream.id].push(sender);
      }
      return sender;
    };

    var origAddStream = window.RTCPeerConnection.prototype.addStream;
    window.RTCPeerConnection.prototype.addStream = function(stream) {
      var pc = this;
      this._shimmedLocalStreams = this._shimmedLocalStreams || {};

      stream.getTracks().forEach(function(track) {
        var alreadyExists = pc.getSenders().find(function(s) {
          return s.track === track;
        });
        if (alreadyExists) {
          throw new DOMException('Track already exists.',
              'InvalidAccessError');
        }
      });
      var existingSenders = pc.getSenders();
      origAddStream.apply(this, arguments);
      var newSenders = pc.getSenders().filter(function(newSender) {
        return existingSenders.indexOf(newSender) === -1;
      });
      this._shimmedLocalStreams[stream.id] = [stream].concat(newSenders);
    };

    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
    window.RTCPeerConnection.prototype.removeStream = function(stream) {
      this._shimmedLocalStreams = this._shimmedLocalStreams || {};
      delete this._shimmedLocalStreams[stream.id];
      return origRemoveStream.apply(this, arguments);
    };

    var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
    window.RTCPeerConnection.prototype.removeTrack = function(sender) {
      var pc = this;
      this._shimmedLocalStreams = this._shimmedLocalStreams || {};
      if (sender) {
        Object.keys(this._shimmedLocalStreams).forEach(function(streamId) {
          var idx = pc._shimmedLocalStreams[streamId].indexOf(sender);
          if (idx !== -1) {
            pc._shimmedLocalStreams[streamId].splice(idx, 1);
          }
          if (pc._shimmedLocalStreams[streamId].length === 1) {
            delete pc._shimmedLocalStreams[streamId];
          }
        });
      }
      return origRemoveTrack.apply(this, arguments);
    };
  },

  shimAddTrackRemoveTrack: function(window) {
    var browserDetails = utils.detectBrowser(window);
    // shim addTrack and removeTrack.
    if (window.RTCPeerConnection.prototype.addTrack &&
        browserDetails.version >= 65) {
      return this.shimAddTrackRemoveTrackWithNative(window);
    }

    // also shim pc.getLocalStreams when addTrack is shimmed
    // to return the original streams.
    var origGetLocalStreams = window.RTCPeerConnection.prototype
        .getLocalStreams;
    window.RTCPeerConnection.prototype.getLocalStreams = function() {
      var pc = this;
      var nativeStreams = origGetLocalStreams.apply(this);
      pc._reverseStreams = pc._reverseStreams || {};
      return nativeStreams.map(function(stream) {
        return pc._reverseStreams[stream.id];
      });
    };

    var origAddStream = window.RTCPeerConnection.prototype.addStream;
    window.RTCPeerConnection.prototype.addStream = function(stream) {
      var pc = this;
      pc._streams = pc._streams || {};
      pc._reverseStreams = pc._reverseStreams || {};

      stream.getTracks().forEach(function(track) {
        var alreadyExists = pc.getSenders().find(function(s) {
          return s.track === track;
        });
        if (alreadyExists) {
          throw new DOMException('Track already exists.',
              'InvalidAccessError');
        }
      });
      // Add identity mapping for consistency with addTrack.
      // Unless this is being used with a stream from addTrack.
      if (!pc._reverseStreams[stream.id]) {
        var newStream = new window.MediaStream(stream.getTracks());
        pc._streams[stream.id] = newStream;
        pc._reverseStreams[newStream.id] = stream;
        stream = newStream;
      }
      origAddStream.apply(pc, [stream]);
    };

    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
    window.RTCPeerConnection.prototype.removeStream = function(stream) {
      var pc = this;
      pc._streams = pc._streams || {};
      pc._reverseStreams = pc._reverseStreams || {};

      origRemoveStream.apply(pc, [(pc._streams[stream.id] || stream)]);
      delete pc._reverseStreams[(pc._streams[stream.id] ?
          pc._streams[stream.id].id : stream.id)];
      delete pc._streams[stream.id];
    };

    window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
      var pc = this;
      if (pc.signalingState === 'closed') {
        throw new DOMException(
          'The RTCPeerConnection\'s signalingState is \'closed\'.',
          'InvalidStateError');
      }
      var streams = [].slice.call(arguments, 1);
      if (streams.length !== 1 ||
          !streams[0].getTracks().find(function(t) {
            return t === track;
          })) {
        // this is not fully correct but all we can manage without
        // [[associated MediaStreams]] internal slot.
        throw new DOMException(
          'The adapter.js addTrack polyfill only supports a single ' +
          ' stream which is associated with the specified track.',
          'NotSupportedError');
      }

      var alreadyExists = pc.getSenders().find(function(s) {
        return s.track === track;
      });
      if (alreadyExists) {
        throw new DOMException('Track already exists.',
            'InvalidAccessError');
      }

      pc._streams = pc._streams || {};
      pc._reverseStreams = pc._reverseStreams || {};
      var oldStream = pc._streams[stream.id];
      if (oldStream) {
        // this is using odd Chrome behaviour, use with caution:
        // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
        // Note: we rely on the high-level addTrack/dtmf shim to
        // create the sender with a dtmf sender.
        oldStream.addTrack(track);

        // Trigger ONN async.
        Promise.resolve().then(function() {
          pc.dispatchEvent(new Event('negotiationneeded'));
        });
      } else {
        var newStream = new window.MediaStream([track]);
        pc._streams[stream.id] = newStream;
        pc._reverseStreams[newStream.id] = stream;
        pc.addStream(newStream);
      }
      return pc.getSenders().find(function(s) {
        return s.track === track;
      });
    };

    // replace the internal stream id with the external one and
    // vice versa.
    function replaceInternalStreamId(pc, description) {
      var sdp = description.sdp;
      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
        var externalStream = pc._reverseStreams[internalId];
        var internalStream = pc._streams[externalStream.id];
        sdp = sdp.replace(new RegExp(internalStream.id, 'g'),
            externalStream.id);
      });
      return new RTCSessionDescription({
        type: description.type,
        sdp: sdp
      });
    }
    function replaceExternalStreamId(pc, description) {
      var sdp = description.sdp;
      Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
        var externalStream = pc._reverseStreams[internalId];
        var internalStream = pc._streams[externalStream.id];
        sdp = sdp.replace(new RegExp(externalStream.id, 'g'),
            internalStream.id);
      });
      return new RTCSessionDescription({
        type: description.type,
        sdp: sdp
      });
    }
    ['createOffer', 'createAnswer'].forEach(function(method) {
      var nativeMethod = window.RTCPeerConnection.prototype[method];
      window.RTCPeerConnection.prototype[method] = function() {
        var pc = this;
        var args = arguments;
        var isLegacyCall = arguments.length &&
            typeof arguments[0] === 'function';
        if (isLegacyCall) {
          return nativeMethod.apply(pc, [
            function(description) {
              var desc = replaceInternalStreamId(pc, description);
              args[0].apply(null, [desc]);
            },
            function(err) {
              if (args[1]) {
                args[1].apply(null, err);
              }
            }, arguments[2]
          ]);
        }
        return nativeMethod.apply(pc, arguments)
        .then(function(description) {
          return replaceInternalStreamId(pc, description);
        });
      };
    });

    var origSetLocalDescription =
        window.RTCPeerConnection.prototype.setLocalDescription;
    window.RTCPeerConnection.prototype.setLocalDescription = function() {
      var pc = this;
      if (!arguments.length || !arguments[0].type) {
        return origSetLocalDescription.apply(pc, arguments);
      }
      arguments[0] = replaceExternalStreamId(pc, arguments[0]);
      return origSetLocalDescription.apply(pc, arguments);
    };

    // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier

    var origLocalDescription = Object.getOwnPropertyDescriptor(
        window.RTCPeerConnection.prototype, 'localDescription');
    Object.defineProperty(window.RTCPeerConnection.prototype,
        'localDescription', {
          get: function() {
            var pc = this;
            var description = origLocalDescription.get.apply(this);
            if (description.type === '') {
              return description;
            }
            return replaceInternalStreamId(pc, description);
          }
        });

    window.RTCPeerConnection.prototype.removeTrack = function(sender) {
      var pc = this;
      if (pc.signalingState === 'closed') {
        throw new DOMException(
          'The RTCPeerConnection\'s signalingState is \'closed\'.',
          'InvalidStateError');
      }
      // We can not yet check for sender instanceof RTCRtpSender
      // since we shim RTPSender. So we check if sender._pc is set.
      if (!sender._pc) {
        throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' +
            'does not implement interface RTCRtpSender.', 'TypeError');
      }
      var isLocal = sender._pc === pc;
      if (!isLocal) {
        throw new DOMException('Sender was not created by this connection.',
            'InvalidAccessError');
      }

      // Search for the native stream the senders track belongs to.
      pc._streams = pc._streams || {};
      var stream;
      Object.keys(pc._streams).forEach(function(streamid) {
        var hasTrack = pc._streams[streamid].getTracks().find(function(track) {
          return sender.track === track;
        });
        if (hasTrack) {
          stream = pc._streams[streamid];
        }
      });

      if (stream) {
        if (stream.getTracks().length === 1) {
          // if this is the last track of the stream, remove the stream. This
          // takes care of any shimmed _senders.
          pc.removeStream(pc._reverseStreams[stream.id]);
        } else {
          // relying on the same odd chrome behaviour as above.
          stream.removeTrack(sender.track);
        }
        pc.dispatchEvent(new Event('negotiationneeded'));
      }
    };
  },

  shimPeerConnection: function(window) {
    var browserDetails = utils.detectBrowser(window);

    // The RTCPeerConnection object.
    if (!window.RTCPeerConnection && window.webkitRTCPeerConnection) {
      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
        // Translate iceTransportPolicy to iceTransports,
        // see https://code.google.com/p/webrtc/issues/detail?id=4869
        // this was fixed in M56 along with unprefixing RTCPeerConnection.
        logging('PeerConnection');
        if (pcConfig && pcConfig.iceTransportPolicy) {
          pcConfig.iceTransports = pcConfig.iceTransportPolicy;
        }

        return new window.webkitRTCPeerConnection(pcConfig, pcConstraints);
      };
      window.RTCPeerConnection.prototype =
          window.webkitRTCPeerConnection.prototype;
      // wrap static methods. Currently just generateCertificate.
      if (window.webkitRTCPeerConnection.generateCertificate) {
        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
          get: function() {
            return window.webkitRTCPeerConnection.generateCertificate;
          }
        });
      }
    }

    var origGetStats = window.RTCPeerConnection.prototype.getStats;
    window.RTCPeerConnection.prototype.getStats = function(selector,
        successCallback, errorCallback) {
      var pc = 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.apply(this, arguments);
      }

      // When spec-style getStats is supported, return those when called with
      // either no arguments or the selector argument is null.
      if (origGetStats.length === 0 && (arguments.length === 0 ||
          typeof arguments[0] !== 'function')) {
        return origGetStats.apply(this, []);
      }

      var fixChromeStats_ = function(response) {
        var standardReport = {};
        var reports = response.result();
        reports.forEach(function(report) {
          var standardStats = {
            id: report.id,
            timestamp: report.timestamp,
            type: {
              localcandidate: 'local-candidate',
              remotecandidate: 'remote-candidate'
            }[report.type] || report.type
          };
          report.names().forEach(function(name) {
            standardStats[name] = report.stat(name);
          });
          standardReport[standardStats.id] = standardStats;
        });

        return standardReport;
      };

      // shim getStats with maplike support
      var makeMapStats = function(stats) {
        return new Map(Object.keys(stats).map(function(key) {
          return [key, stats[key]];
        }));
      };

      if (arguments.length >= 2) {
        var successCallbackWrapper_ = function(response) {
          args[1](makeMapStats(fixChromeStats_(response)));
        };

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

      // promise-support
      return new Promise(function(resolve, reject) {
        origGetStats.apply(pc, [
          function(response) {
            resolve(makeMapStats(fixChromeStats_(response)));
          }, reject]);
      }).then(successCallback, errorCallback);
    };

    // add promise support -- natively available in Chrome 51
    if (browserDetails.version < 51) {
      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
          .forEach(function(method) {
            var nativeMethod = window.RTCPeerConnection.prototype[method];
            window.RTCPeerConnection.prototype[method] = function() {
              var args = arguments;
              var pc = this;
              var promise = new Promise(function(resolve, reject) {
                nativeMethod.apply(pc, [args[0], resolve, reject]);
              });
              if (args.length < 2) {
                return promise;
              }
              return promise.then(function() {
                args[1].apply(null, []);
              },
              function(err) {
                if (args.length >= 3) {
                  args[2].apply(null, [err]);
                }
              });
            };
          });
    }

    // promise support for createOffer and createAnswer. Available (without
    // bugs) since M52: crbug/619289
    if (browserDetails.version < 52) {
      ['createOffer', 'createAnswer'].forEach(function(method) {
        var nativeMethod = window.RTCPeerConnection.prototype[method];
        window.RTCPeerConnection.prototype[method] = function() {
          var pc = 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(pc, [resolve, reject, opts]);
            });
          }
          return nativeMethod.apply(this, arguments);
        };
      });
    }

    // shim implicit creation of RTCSessionDescription/RTCIceCandidate
    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
        .forEach(function(method) {
          var nativeMethod = window.RTCPeerConnection.prototype[method];
          window.RTCPeerConnection.prototype[method] = function() {
            arguments[0] = new ((method === 'addIceCandidate') ?
                window.RTCIceCandidate :
                window.RTCSessionDescription)(arguments[0]);
            return nativeMethod.apply(this, arguments);
          };
        });

    // support for addIceCandidate(null or undefined)
    var nativeAddIceCandidate =
        window.RTCPeerConnection.prototype.addIceCandidate;
    window.RTCPeerConnection.prototype.addIceCandidate = function() {
      if (!arguments[0]) {
        if (arguments[1]) {
          arguments[1].apply(null);
        }
        return Promise.resolve();
      }
      return nativeAddIceCandidate.apply(this, arguments);
    };
  },

  fixNegotiationNeeded: function(window) {
    utils.wrapPeerConnectionEvent(window, 'negotiationneeded', function(e) {
      var pc = e.target;
      if (pc.signalingState !== 'stable') {
        return;
      }
      return e;
    });
  },

  shimGetDisplayMedia: function(window, getSourceId) {
    if ('getDisplayMedia' in window.navigator) {
      return;
    }
    // getSourceId is a function that returns a promise resolving with
    // the sourceId of the screen/window/tab to be shared.
    if (typeof getSourceId !== 'function') {
      console.error('shimGetDisplayMedia: getSourceId argument is not ' +
          'a function');
      return;
    }
    navigator.getDisplayMedia = function(constraints) {
      return getSourceId(constraints)
        .then(function(sourceId) {
          var widthSpecified = constraints.video && constraints.video.width;
          var heightSpecified = constraints.video && constraints.video.height;
          var frameRateSpecified = constraints.video &&
            constraints.video.frameRate;
          constraints.video = {
            mandatory: {
              chromeMediaSource: 'desktop',
              chromeMediaSourceId: sourceId,
              maxFrameRate: frameRateSpecified || 3
            }
          };
          if (widthSpecified) {
            constraints.video.mandatory.maxWidth = widthSpecified;
          }
          if (heightSpecified) {
            constraints.video.mandatory.maxHeight = heightSpecified;
          }
          return navigator.mediaDevices.getUserMedia(constraints);
        });
    };
  }
};

},{"../utils.js":27,"./getusermedia":19}],19:[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.
 */
 /* eslint-env node */
'use strict';
var utils = require('../utils.js');
var logging = utils.log;

// Expose public methods.
module.exports = function(window) {
  var browserDetails = utils.detectBrowser(window);
  var navigator = window && window.navigator;

  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;
  };

  var shimConstraints_ = function(constraints, func) {
    if (browserDetails.version >= 61) {
      return func(constraints);
    }
    constraints = JSON.parse(JSON.stringify(constraints));
    if (constraints && typeof constraints.audio === 'object') {
      var remap = function(obj, a, b) {
        if (a in obj && !(b in obj)) {
          obj[b] = obj[a];
          delete obj[a];
        }
      };
      constraints = JSON.parse(JSON.stringify(constraints));
      remap(constraints.audio, 'autoGainControl', 'googAutoGainControl');
      remap(constraints.audio, 'noiseSuppression', 'googNoiseSuppression');
      constraints.audio = constraintsToChrome_(constraints.audio);
    }
    if (constraints && typeof constraints.video === 'object') {
      // Shim facingMode for mobile & surface pro.
      var face = constraints.video.facingMode;
      face = face && ((typeof face === 'object') ? face : {ideal: face});
      var getSupportedFacingModeLies = browserDetails.version < 66;

      if ((face && (face.exact === 'user' || face.exact === 'environment' ||
                    face.ideal === 'user' || face.ideal === 'environment')) &&
          !(navigator.mediaDevices.getSupportedConstraints &&
            navigator.mediaDevices.getSupportedConstraints().facingMode &&
            !getSupportedFacingModeLies)) {
        delete constraints.video.facingMode;
        var matches;
        if (face.exact === 'environment' || face.ideal === 'environment') {
          matches = ['back', 'rear'];
        } else if (face.exact === 'user' || face.ideal === 'user') {
          matches = ['front'];
        }
        if (matches) {
          // Look for matches in label, or use last cam for back (typical).
          return navigator.mediaDevices.enumerateDevices()
          .then(function(devices) {
            devices = devices.filter(function(d) {
              return d.kind === 'videoinput';
            });
            var dev = devices.find(function(d) {
              return matches.some(function(match) {
                return d.label.toLowerCase().indexOf(match) !== -1;
              });
            });
            if (!dev && devices.length && matches.indexOf('back') !== -1) {
              dev = devices[devices.length - 1]; // more likely the back cam
            }
            if (dev) {
              constraints.video.deviceId = face.exact ? {exact: dev.deviceId} :
                                                        {ideal: dev.deviceId};
            }
            constraints.video = constraintsToChrome_(constraints.video);
            logging('chrome: ' + JSON.stringify(constraints));
            return func(constraints);
          });
        }
      }
      constraints.video = constraintsToChrome_(constraints.video);
    }
    logging('chrome: ' + JSON.stringify(constraints));
    return func(constraints);
  };

  var shimError_ = function(e) {
    if (browserDetails.version >= 64) {
      return e;
    }
    return {
      name: {
        PermissionDeniedError: 'NotAllowedError',
        PermissionDismissedError: 'NotAllowedError',
        InvalidStateError: 'NotAllowedError',
        DevicesNotFoundError: 'NotFoundError',
        ConstraintNotSatisfiedError: 'OverconstrainedError',
        TrackStartError: 'NotReadableError',
        MediaDeviceFailedDueToShutdown: 'NotAllowedError',
        MediaDeviceKillSwitchOn: 'NotAllowedError',
        TabCaptureError: 'AbortError',
        ScreenCaptureError: 'AbortError',
        DeviceCaptureError: 'AbortError'
      }[e.name] || e.name,
      message: e.message,
      constraint: e.constraint || e.constraintName,
      toString: function() {
        return this.name + (this.message && ': ') + this.message;
      }
    };
  };

  var getUserMedia_ = function(constraints, onSuccess, onError) {
    shimConstraints_(constraints, function(c) {
      navigator.webkitGetUserMedia(c, onSuccess, function(e) {
        if (onError) {
          onError(shimError_(e));
        }
      });
    });
  };

  navigator.getUserMedia = getUserMedia_;

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

  if (!navigator.mediaDevices) {
    navigator.mediaDevices = {
      getUserMedia: getUserMediaPromise_,
      enumerateDevices: function() {
        return new Promise(function(resolve) {
          var kinds = {audio: 'audioinput', video: 'videoinput'};
          return window.MediaStreamTrack.getSources(function(devices) {
            resolve(devices.map(function(device) {
              return {label: device.label,
                kind: kinds[device.kind],
                deviceId: device.id,
                groupId: ''};
            }));
          });
        });
      },
      getSupportedConstraints: function() {
        return {
          deviceId: true, echoCancellation: true, facingMode: true,
          frameRate: true, height: true, width: true
        };
      }
    };
  }

  // 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 getUserMediaPromise_(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(cs) {
      return shimConstraints_(cs, function(c) {
        return origGetUserMedia(c).then(function(stream) {
          if (c.audio && !stream.getAudioTracks().length ||
              c.video && !stream.getVideoTracks().length) {
            stream.getTracks().forEach(function(track) {
              track.stop();
            });
            throw new DOMException('', 'NotFoundError');
          }
          return stream;
        }, function(e) {
          return Promise.reject(shimError_(e));
        });
      });
    };
  }

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

},{"../utils.js":27}],20:[function(require,module,exports){
/*
 *  Copyright (c) 2017 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.
 */
 /* eslint-env node */
'use strict';

var SDPUtils = require('sdp');
var utils = require('./utils');

module.exports = {
  shimRTCIceCandidate: function(window) {
    // foundation is arbitrarily chosen as an indicator for full support for
    // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
    if (!window.RTCIceCandidate || (window.RTCIceCandidate && 'foundation' in
        window.RTCIceCandidate.prototype)) {
      return;
    }

    var NativeRTCIceCandidate = window.RTCIceCandidate;
    window.RTCIceCandidate = function(args) {
      // Remove the a= which shouldn't be part of the candidate string.
      if (typeof args === 'object' && args.candidate &&
          args.candidate.indexOf('a=') === 0) {
        args = JSON.parse(JSON.stringify(args));
        args.candidate = args.candidate.substr(2);
      }

      if (args.candidate && args.candidate.length) {
        // Augment the native candidate with the parsed fields.
        var nativeCandidate = new NativeRTCIceCandidate(args);
        var parsedCandidate = SDPUtils.parseCandidate(args.candidate);
        var augmentedCandidate = Object.assign(nativeCandidate,
            parsedCandidate);

        // Add a serializer that does not serialize the extra attributes.
        augmentedCandidate.toJSON = function() {
          return {
            candidate: augmentedCandidate.candidate,
            sdpMid: augmentedCandidate.sdpMid,
            sdpMLineIndex: augmentedCandidate.sdpMLineIndex,
            usernameFragment: augmentedCandidate.usernameFragment,
          };
        };
        return augmentedCandidate;
      }
      return new NativeRTCIceCandidate(args);
    };
    window.RTCIceCandidate.prototype = NativeRTCIceCandidate.prototype;

    // Hook up the augmented candidate in onicecandidate and
    // addEventListener('icecandidate', ...)
    utils.wrapPeerConnectionEvent(window, 'icecandidate', function(e) {
      if (e.candidate) {
        Object.defineProperty(e, 'candidate', {
          value: new window.RTCIceCandidate(e.candidate),
          writable: 'false'
        });
      }
      return e;
    });
  },

  // shimCreateObjectURL must be called before shimSourceObject to avoid loop.

  shimCreateObjectURL: function(window) {
    var URL = window && window.URL;

    if (!(typeof window === 'object' && window.HTMLMediaElement &&
          'srcObject' in window.HTMLMediaElement.prototype &&
        URL.createObjectURL && URL.revokeObjectURL)) {
      // Only shim CreateObjectURL using srcObject if srcObject exists.
      return undefined;
    }

    var nativeCreateObjectURL = URL.createObjectURL.bind(URL);
    var nativeRevokeObjectURL = URL.revokeObjectURL.bind(URL);
    var streams = new Map(), newId = 0;

    URL.createObjectURL = function(stream) {
      if ('getTracks' in stream) {
        var url = 'polyblob:' + (++newId);
        streams.set(url, stream);
        utils.deprecated('URL.createObjectURL(stream)',
            'elem.srcObject = stream');
        return url;
      }
      return nativeCreateObjectURL(stream);
    };
    URL.revokeObjectURL = function(url) {
      nativeRevokeObjectURL(url);
      streams.delete(url);
    };

    var dsc = Object.getOwnPropertyDescriptor(window.HTMLMediaElement.prototype,
                                              'src');
    Object.defineProperty(window.HTMLMediaElement.prototype, 'src', {
      get: function() {
        return dsc.get.apply(this);
      },
      set: function(url) {
        this.srcObject = streams.get(url) || null;
        return dsc.set.apply(this, [url]);
      }
    });

    var nativeSetAttribute = window.HTMLMediaElement.prototype.setAttribute;
    window.HTMLMediaElement.prototype.setAttribute = function() {
      if (arguments.length === 2 &&
          ('' + arguments[0]).toLowerCase() === 'src') {
        this.srcObject = streams.get(arguments[1]) || null;
      }
      return nativeSetAttribute.apply(this, arguments);
    };
  },

  shimMaxMessageSize: function(window) {
    if (window.RTCSctpTransport || !window.RTCPeerConnection) {
      return;
    }
    var browserDetails = utils.detectBrowser(window);

    if (!('sctp' in window.RTCPeerConnection.prototype)) {
      Object.defineProperty(window.RTCPeerConnection.prototype, 'sctp', {
        get: function() {
          return typeof this._sctp === 'undefined' ? null : this._sctp;
        }
      });
    }

    var sctpInDescription = function(description) {
      var sections = SDPUtils.splitSections(description.sdp);
      sections.shift();
      return sections.some(function(mediaSection) {
        var mLine = SDPUtils.parseMLine(mediaSection);
        return mLine && mLine.kind === 'application'
            && mLine.protocol.indexOf('SCTP') !== -1;
      });
    };

    var getRemoteFirefoxVersion = function(description) {
      // TODO: Is there a better solution for detecting Firefox?
      var match = description.sdp.match(/mozilla...THIS_IS_SDPARTA-(\d+)/);
      if (match === null || match.length < 2) {
        return -1;
      }
      var version = parseInt(match[1], 10);
      // Test for NaN (yes, this is ugly)
      return version !== version ? -1 : version;
    };

    var getCanSendMaxMessageSize = function(remoteIsFirefox) {
      // Every implementation we know can send at least 64 KiB.
      // Note: Although Chrome is technically able to send up to 256 KiB, the
      //       data does not reach the other peer reliably.
      //       See: https://bugs.chromium.org/p/webrtc/issues/detail?id=8419
      var canSendMaxMessageSize = 65536;
      if (browserDetails.browser === 'firefox') {
        if (browserDetails.version < 57) {
          if (remoteIsFirefox === -1) {
            // FF < 57 will send in 16 KiB chunks using the deprecated PPID
            // fragmentation.
            canSendMaxMessageSize = 16384;
          } else {
            // However, other FF (and RAWRTC) can reassemble PPID-fragmented
            // messages. Thus, supporting ~2 GiB when sending.
            canSendMaxMessageSize = 2147483637;
          }
        } else if (browserDetails.version < 60) {
          // Currently, all FF >= 57 will reset the remote maximum message size
          // to the default value when a data channel is created at a later
          // stage. :(
          // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
          canSendMaxMessageSize =
            browserDetails.version === 57 ? 65535 : 65536;
        } else {
          // FF >= 60 supports sending ~2 GiB
          canSendMaxMessageSize = 2147483637;
        }
      }
      return canSendMaxMessageSize;
    };

    var getMaxMessageSize = function(description, remoteIsFirefox) {
      // Note: 65536 bytes is the default value from the SDP spec. Also,
      //       every implementation we know supports receiving 65536 bytes.
      var maxMessageSize = 65536;

      // FF 57 has a slightly incorrect default remote max message size, so
      // we need to adjust it here to avoid a failure when sending.
      // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1425697
      if (browserDetails.browser === 'firefox'
           && browserDetails.version === 57) {
        maxMessageSize = 65535;
      }

      var match = SDPUtils.matchPrefix(description.sdp, 'a=max-message-size:');
      if (match.length > 0) {
        maxMessageSize = parseInt(match[0].substr(19), 10);
      } else if (browserDetails.browser === 'firefox' &&
                  remoteIsFirefox !== -1) {
        // If the maximum message size is not present in the remote SDP and
        // both local and remote are Firefox, the remote peer can receive
        // ~2 GiB.
        maxMessageSize = 2147483637;
      }
      return maxMessageSize;
    };

    var origSetRemoteDescription =
        window.RTCPeerConnection.prototype.setRemoteDescription;
    window.RTCPeerConnection.prototype.setRemoteDescription = function() {
      var pc = this;
      pc._sctp = null;

      if (sctpInDescription(arguments[0])) {
        // Check if the remote is FF.
        var isFirefox = getRemoteFirefoxVersion(arguments[0]);

        // Get the maximum message size the local peer is capable of sending
        var canSendMMS = getCanSendMaxMessageSize(isFirefox);

        // Get the maximum message size of the remote peer.
        var remoteMMS = getMaxMessageSize(arguments[0], isFirefox);

        // Determine final maximum message size
        var maxMessageSize;
        if (canSendMMS === 0 && remoteMMS === 0) {
          maxMessageSize = Number.POSITIVE_INFINITY;
        } else if (canSendMMS === 0 || remoteMMS === 0) {
          maxMessageSize = Math.max(canSendMMS, remoteMMS);
        } else {
          maxMessageSize = Math.min(canSendMMS, remoteMMS);
        }

        // Create a dummy RTCSctpTransport object and the 'maxMessageSize'
        // attribute.
        var sctp = {};
        Object.defineProperty(sctp, 'maxMessageSize', {
          get: function() {
            return maxMessageSize;
          }
        });
        pc._sctp = sctp;
      }

      return origSetRemoteDescription.apply(pc, arguments);
    };
  },

  shimSendThrowTypeError: function(window) {
    if (!(window.RTCPeerConnection &&
        'createDataChannel' in window.RTCPeerConnection.prototype)) {
      return;
    }

    // Note: Although Firefox >= 57 has a native implementation, the maximum
    //       message size can be reset for all data channels at a later stage.
    //       See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831

    function wrapDcSend(dc, pc) {
      var origDataChannelSend = dc.send;
      dc.send = function() {
        var data = arguments[0];
        var length = data.length || data.size || data.byteLength;
        if (dc.readyState === 'open' &&
            pc.sctp && length > pc.sctp.maxMessageSize) {
          throw new TypeError('Message too large (can send a maximum of ' +
            pc.sctp.maxMessageSize + ' bytes)');
        }
        return origDataChannelSend.apply(dc, arguments);
      };
    }
    var origCreateDataChannel =
      window.RTCPeerConnection.prototype.createDataChannel;
    window.RTCPeerConnection.prototype.createDataChannel = function() {
      var pc = this;
      var dataChannel = origCreateDataChannel.apply(pc, arguments);
      wrapDcSend(dataChannel, pc);
      return dataChannel;
    };
    utils.wrapPeerConnectionEvent(window, 'datachannel', function(e) {
      wrapDcSend(e.channel, e.target);
      return e;
    });
  }
};

},{"./utils":27,"sdp":15}],21:[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.
 */
 /* eslint-env node */
'use strict';

var utils = require('../utils');
var filterIceServers = require('./filtericeservers');
var shimRTCPeerConnection = require('rtcpeerconnection-shim');

module.exports = {
  shimGetUserMedia: require('./getusermedia'),
  shimPeerConnection: function(window) {
    var browserDetails = utils.detectBrowser(window);

    if (window.RTCIceGatherer) {
      if (!window.RTCIceCandidate) {
        window.RTCIceCandidate = function(args) {
          return args;
        };
      }
      if (!window.RTCSessionDescription) {
        window.RTCSessionDescription = function(args) {
          return args;
        };
      }
      // this adds an additional event listener to MediaStrackTrack that signals
      // when a tracks enabled property was changed. Workaround for a bug in
      // addStream, see below. No longer required in 15025+
      if (browserDetails.version < 15025) {
        var origMSTEnabled = Object.getOwnPropertyDescriptor(
            window.MediaStreamTrack.prototype, 'enabled');
        Object.defineProperty(window.MediaStreamTrack.prototype, 'enabled', {
          set: function(value) {
            origMSTEnabled.set.call(this, value);
            var ev = new Event('enabled');
            ev.enabled = value;
            this.dispatchEvent(ev);
          }
        });
      }
    }

    // ORTC defines the DTMF sender a bit different.
    // https://github.com/w3c/ortc/issues/714
    if (window.RTCRtpSender && !('dtmf' in window.RTCRtpSender.prototype)) {
      Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
        get: function() {
          if (this._dtmf === undefined) {
            if (this.track.kind === 'audio') {
              this._dtmf = new window.RTCDtmfSender(this);
            } else if (this.track.kind === 'video') {
              this._dtmf = null;
            }
          }
          return this._dtmf;
        }
      });
    }
    // Edge currently only implements the RTCDtmfSender, not the
    // RTCDTMFSender alias. See http://draft.ortc.org/#rtcdtmfsender2*
    if (window.RTCDtmfSender && !window.RTCDTMFSender) {
      window.RTCDTMFSender = window.RTCDtmfSender;
    }

    var RTCPeerConnectionShim = shimRTCPeerConnection(window,
        browserDetails.version);
    window.RTCPeerConnection = function(config) {
      if (config && config.iceServers) {
        config.iceServers = filterIceServers(config.iceServers);
      }
      return new RTCPeerConnectionShim(config);
    };
    window.RTCPeerConnection.prototype = RTCPeerConnectionShim.prototype;
  },
  shimReplaceTrack: function(window) {
    // ORTC has replaceTrack -- https://github.com/w3c/ortc/issues/614
    if (window.RTCRtpSender &&
        !('replaceTrack' in window.RTCRtpSender.prototype)) {
      window.RTCRtpSender.prototype.replaceTrack =
          window.RTCRtpSender.prototype.setTrack;
    }
  }
};

},{"../utils":27,"./filtericeservers":22,"./getusermedia":23,"rtcpeerconnection-shim":14}],22:[function(require,module,exports){
/*
 *  Copyright (c) 2018 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.
 */
 /* eslint-env node */
'use strict';

var utils = require('../utils');
// Edge does not like
// 1) stun: filtered after 14393 unless ?transport=udp is present
// 2) turn: that does not have all of turn:host:port?transport=udp
// 3) turn: with ipv6 addresses
// 4) turn: occurring muliple times
module.exports = function(iceServers, edgeVersion) {
  var hasTurn = false;
  iceServers = JSON.parse(JSON.stringify(iceServers));
  return iceServers.filter(function(server) {
    if (server && (server.urls || server.url)) {
      var urls = server.urls || server.url;
      if (server.url && !server.urls) {
        utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
      }
      var isString = typeof urls === 'string';
      if (isString) {
        urls = [urls];
      }
      urls = urls.filter(function(url) {
        var validTurn = url.indexOf('turn:') === 0 &&
            url.indexOf('transport=udp') !== -1 &&
            url.indexOf('turn:[') === -1 &&
            !hasTurn;

        if (validTurn) {
          hasTurn = true;
          return true;
        }
        return url.indexOf('stun:') === 0 && edgeVersion >= 14393 &&
            url.indexOf('?transport=udp') === -1;
      });

      delete server.url;
      server.urls = isString ? urls[0] : urls;
      return !!urls.length;
    }
  });
};

},{"../utils":27}],23:[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.
 */
 /* eslint-env node */
'use strict';

// Expose public methods.
module.exports = function(window) {
  var navigator = window && window.navigator;

  var shimError_ = function(e) {
    return {
      name: {PermissionDeniedError: 'NotAllowedError'}[e.name] || e.name,
      message: e.message,
      constraint: e.constraint,
      toString: function() {
        return this.name;
      }
    };
  };

  // getUserMedia error shim.
  var origGetUserMedia = navigator.mediaDevices.getUserMedia.
      bind(navigator.mediaDevices);
  navigator.mediaDevices.getUserMedia = function(c) {
    return origGetUserMedia(c).catch(function(e) {
      return Promise.reject(shimError_(e));
    });
  };
};

},{}],24:[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.
 */
 /* eslint-env node */
'use strict';

var utils = require('../utils');

module.exports = {
  shimGetUserMedia: require('./getusermedia'),
  shimOnTrack: function(window) {
    if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
        window.RTCPeerConnection.prototype)) {
      Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
        get: function() {
          return this._ontrack;
        },
        set: function(f) {
          if (this._ontrack) {
            this.removeEventListener('track', this._ontrack);
            this.removeEventListener('addstream', this._ontrackpoly);
          }
          this.addEventListener('track', this._ontrack = f);
          this.addEventListener('addstream', this._ontrackpoly = function(e) {
            e.stream.getTracks().forEach(function(track) {
              var event = new Event('track');
              event.track = track;
              event.receiver = {track: track};
              event.transceiver = {receiver: event.receiver};
              event.streams = [e.stream];
              this.dispatchEvent(event);
            }.bind(this));
          }.bind(this));
        },
        enumerable: true,
        configurable: true
      });
    }
    if (typeof window === 'object' && window.RTCTrackEvent &&
        ('receiver' in window.RTCTrackEvent.prototype) &&
        !('transceiver' in window.RTCTrackEvent.prototype)) {
      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
        get: function() {
          return {receiver: this.receiver};
        }
      });
    }
  },

  shimSourceObject: function(window) {
    // Firefox has supported mozSrcObject since FF22, unprefixed in 42.
    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() {
            return this.mozSrcObject;
          },
          set: function(stream) {
            this.mozSrcObject = stream;
          }
        });
      }
    }
  },

  shimPeerConnection: function(window) {
    var browserDetails = utils.detectBrowser(window);

    if (typeof window !== 'object' || !(window.RTCPeerConnection ||
        window.mozRTCPeerConnection)) {
      return; // probably media.peerconnection.enabled=false in about:config
    }
    // The RTCPeerConnection object.
    if (!window.RTCPeerConnection) {
      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
        if (browserDetails.version < 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 window.mozRTCPeerConnection(pcConfig, pcConstraints);
      };
      window.RTCPeerConnection.prototype =
          window.mozRTCPeerConnection.prototype;

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

      window.RTCSessionDescription = window.mozRTCSessionDescription;
      window.RTCIceCandidate = window.mozRTCIceCandidate;
    }

    // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
        .forEach(function(method) {
          var nativeMethod = window.RTCPeerConnection.prototype[method];
          window.RTCPeerConnection.prototype[method] = function() {
            arguments[0] = new ((method === 'addIceCandidate') ?
                window.RTCIceCandidate :
                window.RTCSessionDescription)(arguments[0]);
            return nativeMethod.apply(this, arguments);
          };
        });

    // support for addIceCandidate(null or undefined)
    var nativeAddIceCandidate =
        window.RTCPeerConnection.prototype.addIceCandidate;
    window.RTCPeerConnection.prototype.addIceCandidate = function() {
      if (!arguments[0]) {
        if (arguments[1]) {
          arguments[1].apply(null);
        }
        return Promise.resolve();
      }
      return nativeAddIceCandidate.apply(this, arguments);
    };

    // shim getStats with maplike support
    var makeMapStats = function(stats) {
      var map = new Map();
      Object.keys(stats).forEach(function(key) {
        map.set(key, stats[key]);
        map[key] = stats[key];
      });
      return map;
    };

    var modernStatsTypes = {
      inboundrtp: 'inbound-rtp',
      outboundrtp: 'outbound-rtp',
      candidatepair: 'candidate-pair',
      localcandidate: 'local-candidate',
      remotecandidate: 'remote-candidate'
    };

    var nativeGetStats = window.RTCPeerConnection.prototype.getStats;
    window.RTCPeerConnection.prototype.getStats = function(
      selector,
      onSucc,
      onErr
    ) {
      return nativeGetStats.apply(this, [selector || null])
        .then(function(stats) {
          if (browserDetails.version < 48) {
            stats = makeMapStats(stats);
          }
          if (browserDetails.version < 53 && !onSucc) {
            // Shim only promise getStats with spec-hyphens in type names
            // Leave callback version alone; misc old uses of forEach before Map
            try {
              stats.forEach(function(stat) {
                stat.type = modernStatsTypes[stat.type] || stat.type;
              });
            } catch (e) {
              if (e.name !== 'TypeError') {
                throw e;
              }
              // Avoid TypeError: "type" is read-only, in old versions. 34-43ish
              stats.forEach(function(stat, i) {
                stats.set(i, Object.assign({}, stat, {
                  type: modernStatsTypes[stat.type] || stat.type
                }));
              });
            }
          }
          return stats;
        })
        .then(onSucc, onErr);
    };
  },

  shimSenderGetStats: function(window) {
    if (!(typeof window === 'object' && window.RTCPeerConnection &&
        window.RTCRtpSender)) {
      return;
    }
    if (window.RTCRtpSender && 'getStats' in window.RTCRtpSender.prototype) {
      return;
    }
    var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
    if (origGetSenders) {
      window.RTCPeerConnection.prototype.getSenders = function() {
        var pc = this;
        var senders = origGetSenders.apply(pc, []);
        senders.forEach(function(sender) {
          sender._pc = pc;
        });
        return senders;
      };
    }

    var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
    if (origAddTrack) {
      window.RTCPeerConnection.prototype.addTrack = function() {
        var sender = origAddTrack.apply(this, arguments);
        sender._pc = this;
        return sender;
      };
    }
    window.RTCRtpSender.prototype.getStats = function() {
      return this.track ? this._pc.getStats(this.track) :
          Promise.resolve(new Map());
    };
  },

  shimReceiverGetStats: function(window) {
    if (!(typeof window === 'object' && window.RTCPeerConnection &&
        window.RTCRtpSender)) {
      return;
    }
    if (window.RTCRtpSender && 'getStats' in window.RTCRtpReceiver.prototype) {
      return;
    }
    var origGetReceivers = window.RTCPeerConnection.prototype.getReceivers;
    if (origGetReceivers) {
      window.RTCPeerConnection.prototype.getReceivers = function() {
        var pc = this;
        var receivers = origGetReceivers.apply(pc, []);
        receivers.forEach(function(receiver) {
          receiver._pc = pc;
        });
        return receivers;
      };
    }
    utils.wrapPeerConnectionEvent(window, 'track', function(e) {
      e.receiver._pc = e.srcElement;
      return e;
    });
    window.RTCRtpReceiver.prototype.getStats = function() {
      return this._pc.getStats(this.track);
    };
  },

  shimRemoveStream: function(window) {
    if (!window.RTCPeerConnection ||
        'removeStream' in window.RTCPeerConnection.prototype) {
      return;
    }
    window.RTCPeerConnection.prototype.removeStream = function(stream) {
      var pc = this;
      utils.deprecated('removeStream', 'removeTrack');
      this.getSenders().forEach(function(sender) {
        if (sender.track && stream.getTracks().indexOf(sender.track) !== -1) {
          pc.removeTrack(sender);
        }
      });
    };
  },

  shimRTCDataChannel: function(window) {
    // rename DataChannel to RTCDataChannel (native fix in FF60):
    // https://bugzilla.mozilla.org/show_bug.cgi?id=1173851
    if (window.DataChannel && !window.RTCDataChannel) {
      window.RTCDataChannel = window.DataChannel;
    }
  },

  shimGetDisplayMedia: function(window, preferredMediaSource) {
    if ('getDisplayMedia' in window.navigator) {
      return;
    }
    navigator.getDisplayMedia = function(constraints) {
      if (!(constraints && constraints.video)) {
        var err = new DOMException('getDisplayMedia without video ' +
            'constraints is undefined');
        err.name = 'NotFoundError';
        // from https://heycam.github.io/webidl/#idl-DOMException-error-names
        err.code = 8;
        return Promise.reject(err);
      }
      if (constraints.video === true) {
        constraints.video = {mediaSource: preferredMediaSource};
      } else {
        constraints.video.mediaSource = preferredMediaSource;
      }
      return navigator.mediaDevices.getUserMedia(constraints);
    };
  }
};

},{"../utils":27,"./getusermedia":25}],25:[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.
 */
 /* eslint-env node */
'use strict';

var utils = require('../utils');
var logging = utils.log;

// Expose public methods.
module.exports = function(window) {
  var browserDetails = utils.detectBrowser(window);
  var navigator = window && window.navigator;
  var MediaStreamTrack = window && window.MediaStreamTrack;

  var shimError_ = function(e) {
    return {
      name: {
        InternalError: 'NotReadableError',
        NotSupportedError: 'TypeError',
        PermissionDeniedError: 'NotAllowedError',
        SecurityError: 'NotAllowedError'
      }[e.name] || e.name,
      message: {
        'The operation is insecure.': 'The request is not allowed by the ' +
        'user agent or the platform in the current context.'
      }[e.message] || e.message,
      constraint: e.constraint,
      toString: function() {
        return this.name + (this.message && ': ') + this.message;
      }
    };
  };

  // getUserMedia constraints shim.
  var 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;
    };
    constraints = JSON.parse(JSON.stringify(constraints));
    if (browserDetails.version < 38) {
      logging('spec: ' + JSON.stringify(constraints));
      if (constraints.audio) {
        constraints.audio = constraintsToFF37_(constraints.audio);
      }
      if (constraints.video) {
        constraints.video = constraintsToFF37_(constraints.video);
      }
      logging('ff37: ' + JSON.stringify(constraints));
    }
    return navigator.mozGetUserMedia(constraints, onSuccess, function(e) {
      onError(shimError_(e));
    });
  };

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

  // Shim for mediaDevices on older versions.
  if (!navigator.mediaDevices) {
    navigator.mediaDevices = {getUserMedia: getUserMediaPromise_,
      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 (browserDetails.version < 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;
      });
    };
  }
  if (browserDetails.version < 49) {
    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
        bind(navigator.mediaDevices);
    navigator.mediaDevices.getUserMedia = function(c) {
      return origGetUserMedia(c).then(function(stream) {
        // Work around https://bugzil.la/802326
        if (c.audio && !stream.getAudioTracks().length ||
            c.video && !stream.getVideoTracks().length) {
          stream.getTracks().forEach(function(track) {
            track.stop();
          });
          throw new DOMException('The object can not be found here.',
                                 'NotFoundError');
        }
        return stream;
      }, function(e) {
        return Promise.reject(shimError_(e));
      });
    };
  }
  if (!(browserDetails.version > 55 &&
      'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
    var remap = function(obj, a, b) {
      if (a in obj && !(b in obj)) {
        obj[b] = obj[a];
        delete obj[a];
      }
    };

    var nativeGetUserMedia = navigator.mediaDevices.getUserMedia.
        bind(navigator.mediaDevices);
    navigator.mediaDevices.getUserMedia = function(c) {
      if (typeof c === 'object' && typeof c.audio === 'object') {
        c = JSON.parse(JSON.stringify(c));
        remap(c.audio, 'autoGainControl', 'mozAutoGainControl');
        remap(c.audio, 'noiseSuppression', 'mozNoiseSuppression');
      }
      return nativeGetUserMedia(c);
    };

    if (MediaStreamTrack && MediaStreamTrack.prototype.getSettings) {
      var nativeGetSettings = MediaStreamTrack.prototype.getSettings;
      MediaStreamTrack.prototype.getSettings = function() {
        var obj = nativeGetSettings.apply(this, arguments);
        remap(obj, 'mozAutoGainControl', 'autoGainControl');
        remap(obj, 'mozNoiseSuppression', 'noiseSuppression');
        return obj;
      };
    }

    if (MediaStreamTrack && MediaStreamTrack.prototype.applyConstraints) {
      var nativeApplyConstraints = MediaStreamTrack.prototype.applyConstraints;
      MediaStreamTrack.prototype.applyConstraints = function(c) {
        if (this.kind === 'audio' && typeof c === 'object') {
          c = JSON.parse(JSON.stringify(c));
          remap(c, 'autoGainControl', 'mozAutoGainControl');
          remap(c, 'noiseSuppression', 'mozNoiseSuppression');
        }
        return nativeApplyConstraints.apply(this, [c]);
      };
    }
  }
  navigator.getUserMedia = function(constraints, onSuccess, onError) {
    if (browserDetails.version < 44) {
      return getUserMedia_(constraints, onSuccess, onError);
    }
    // Replace Firefox 44+'s deprecation warning with unprefixed version.
    utils.deprecated('navigator.getUserMedia',
        'navigator.mediaDevices.getUserMedia');
    navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
  };
};

},{"../utils":27}],26:[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.
 */
'use strict';
var utils = require('../utils');

module.exports = {
  shimLocalStreamsAPI: function(window) {
    if (typeof window !== 'object' || !window.RTCPeerConnection) {
      return;
    }
    if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
      window.RTCPeerConnection.prototype.getLocalStreams = function() {
        if (!this._localStreams) {
          this._localStreams = [];
        }
        return this._localStreams;
      };
    }
    if (!('getStreamById' in window.RTCPeerConnection.prototype)) {
      window.RTCPeerConnection.prototype.getStreamById = function(id) {
        var result = null;
        if (this._localStreams) {
          this._localStreams.forEach(function(stream) {
            if (stream.id === id) {
              result = stream;
            }
          });
        }
        if (this._remoteStreams) {
          this._remoteStreams.forEach(function(stream) {
            if (stream.id === id) {
              result = stream;
            }
          });
        }
        return result;
      };
    }
    if (!('addStream' in window.RTCPeerConnection.prototype)) {
      var _addTrack = window.RTCPeerConnection.prototype.addTrack;
      window.RTCPeerConnection.prototype.addStream = function(stream) {
        if (!this._localStreams) {
          this._localStreams = [];
        }
        if (this._localStreams.indexOf(stream) === -1) {
          this._localStreams.push(stream);
        }
        var pc = this;
        stream.getTracks().forEach(function(track) {
          _addTrack.call(pc, track, stream);
        });
      };

      window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
        if (stream) {
          if (!this._localStreams) {
            this._localStreams = [stream];
          } else if (this._localStreams.indexOf(stream) === -1) {
            this._localStreams.push(stream);
          }
        }
        return _addTrack.call(this, track, stream);
      };
    }
    if (!('removeStream' in window.RTCPeerConnection.prototype)) {
      window.RTCPeerConnection.prototype.removeStream = function(stream) {
        if (!this._localStreams) {
          this._localStreams = [];
        }
        var index = this._localStreams.indexOf(stream);
        if (index === -1) {
          return;
        }
        this._localStreams.splice(index, 1);
        var pc = this;
        var tracks = stream.getTracks();
        this.getSenders().forEach(function(sender) {
          if (tracks.indexOf(sender.track) !== -1) {
            pc.removeTrack(sender);
          }
        });
      };
    }
  },
  shimRemoteStreamsAPI: function(window) {
    if (typeof window !== 'object' || !window.RTCPeerConnection) {
      return;
    }
    if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
      window.RTCPeerConnection.prototype.getRemoteStreams = function() {
        return this._remoteStreams ? this._remoteStreams : [];
      };
    }
    if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
      Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
        get: function() {
          return this._onaddstream;
        },
        set: function(f) {
          if (this._onaddstream) {
            this.removeEventListener('addstream', this._onaddstream);
          }
          this.addEventListener('addstream', this._onaddstream = f);
        }
      });
      var origSetRemoteDescription =
          window.RTCPeerConnection.prototype.setRemoteDescription;
      window.RTCPeerConnection.prototype.setRemoteDescription = function() {
        var pc = this;
        if (!this._onaddstreampoly) {
          this.addEventListener('track', this._onaddstreampoly = function(e) {
            e.streams.forEach(function(stream) {
              if (!pc._remoteStreams) {
                pc._remoteStreams = [];
              }
              if (pc._remoteStreams.indexOf(stream) >= 0) {
                return;
              }
              pc._remoteStreams.push(stream);
              var event = new Event('addstream');
              event.stream = stream;
              pc.dispatchEvent(event);
            });
          });
        }
        return origSetRemoteDescription.apply(pc, arguments);
      };
    }
  },
  shimCallbacksAPI: function(window) {
    if (typeof window !== 'object' || !window.RTCPeerConnection) {
      return;
    }
    var prototype = window.RTCPeerConnection.prototype;
    var createOffer = prototype.createOffer;
    var createAnswer = prototype.createAnswer;
    var setLocalDescription = prototype.setLocalDescription;
    var setRemoteDescription = prototype.setRemoteDescription;
    var addIceCandidate = prototype.addIceCandidate;

    prototype.createOffer = function(successCallback, failureCallback) {
      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
      var promise = createOffer.apply(this, [options]);
      if (!failureCallback) {
        return promise;
      }
      promise.then(successCallback, failureCallback);
      return Promise.resolve();
    };

    prototype.createAnswer = function(successCallback, failureCallback) {
      var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
      var promise = createAnswer.apply(this, [options]);
      if (!failureCallback) {
        return promise;
      }
      promise.then(successCallback, failureCallback);
      return Promise.resolve();
    };

    var withCallback = function(description, successCallback, failureCallback) {
      var promise = setLocalDescription.apply(this, [description]);
      if (!failureCallback) {
        return promise;
      }
      promise.then(successCallback, failureCallback);
      return Promise.resolve();
    };
    prototype.setLocalDescription = withCallback;

    withCallback = function(description, successCallback, failureCallback) {
      var promise = setRemoteDescription.apply(this, [description]);
      if (!failureCallback) {
        return promise;
      }
      promise.then(successCallback, failureCallback);
      return Promise.resolve();
    };
    prototype.setRemoteDescription = withCallback;

    withCallback = function(candidate, successCallback, failureCallback) {
      var promise = addIceCandidate.apply(this, [candidate]);
      if (!failureCallback) {
        return promise;
      }
      promise.then(successCallback, failureCallback);
      return Promise.resolve();
    };
    prototype.addIceCandidate = withCallback;
  },
  shimGetUserMedia: function(window) {
    var navigator = window && window.navigator;

    if (!navigator.getUserMedia) {
      if (navigator.webkitGetUserMedia) {
        navigator.getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
      } else if (navigator.mediaDevices &&
          navigator.mediaDevices.getUserMedia) {
        navigator.getUserMedia = function(constraints, cb, errcb) {
          navigator.mediaDevices.getUserMedia(constraints)
          .then(cb, errcb);
        }.bind(navigator);
      }
    }
  },
  shimRTCIceServerUrls: function(window) {
    // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
    var OrigPeerConnection = window.RTCPeerConnection;
    window.RTCPeerConnection = function(pcConfig, pcConstraints) {
      if (pcConfig && pcConfig.iceServers) {
        var newIceServers = [];
        for (var i = 0; i < pcConfig.iceServers.length; i++) {
          var server = pcConfig.iceServers[i];
          if (!server.hasOwnProperty('urls') &&
              server.hasOwnProperty('url')) {
            utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
            server = JSON.parse(JSON.stringify(server));
            server.urls = server.url;
            delete server.url;
            newIceServers.push(server);
          } else {
            newIceServers.push(pcConfig.iceServers[i]);
          }
        }
        pcConfig.iceServers = newIceServers;
      }
      return new OrigPeerConnection(pcConfig, pcConstraints);
    };
    window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
    // wrap static methods. Currently just generateCertificate.
    if ('generateCertificate' in window.RTCPeerConnection) {
      Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
        get: function() {
          return OrigPeerConnection.generateCertificate;
        }
      });
    }
  },
  shimTrackEventTransceiver: function(window) {
    // Add event.transceiver member over deprecated event.receiver
    if (typeof window === 'object' && window.RTCPeerConnection &&
        ('receiver' in window.RTCTrackEvent.prototype) &&
        // can't check 'transceiver' in window.RTCTrackEvent.prototype, as it is
        // defined for some reason even when window.RTCTransceiver is not.
        !window.RTCTransceiver) {
      Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
        get: function() {
          return {receiver: this.receiver};
        }
      });
    }
  },

  shimCreateOfferLegacy: function(window) {
    var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
    window.RTCPeerConnection.prototype.createOffer = function(offerOptions) {
      var pc = this;
      if (offerOptions) {
        if (typeof offerOptions.offerToReceiveAudio !== 'undefined') {
          // support bit values
          offerOptions.offerToReceiveAudio = !!offerOptions.offerToReceiveAudio;
        }
        var audioTransceiver = pc.getTransceivers().find(function(transceiver) {
          return transceiver.sender.track &&
              transceiver.sender.track.kind === 'audio';
        });
        if (offerOptions.offerToReceiveAudio === false && audioTransceiver) {
          if (audioTransceiver.direction === 'sendrecv') {
            if (audioTransceiver.setDirection) {
              audioTransceiver.setDirection('sendonly');
            } else {
              audioTransceiver.direction = 'sendonly';
            }
          } else if (audioTransceiver.direction === 'recvonly') {
            if (audioTransceiver.setDirection) {
              audioTransceiver.setDirection('inactive');
            } else {
              audioTransceiver.direction = 'inactive';
            }
          }
        } else if (offerOptions.offerToReceiveAudio === true &&
            !audioTransceiver) {
          pc.addTransceiver('audio');
        }


        if (typeof offerOptions.offerToReceiveVideo !== 'undefined') {
          // support bit values
          offerOptions.offerToReceiveVideo = !!offerOptions.offerToReceiveVideo;
        }
        var videoTransceiver = pc.getTransceivers().find(function(transceiver) {
          return transceiver.sender.track &&
              transceiver.sender.track.kind === 'video';
        });
        if (offerOptions.offerToReceiveVideo === false && videoTransceiver) {
          if (videoTransceiver.direction === 'sendrecv') {
            videoTransceiver.setDirection('sendonly');
          } else if (videoTransceiver.direction === 'recvonly') {
            videoTransceiver.setDirection('inactive');
          }
        } else if (offerOptions.offerToReceiveVideo === true &&
            !videoTransceiver) {
          pc.addTransceiver('video');
        }
      }
      return origCreateOffer.apply(pc, arguments);
    };
  }
};

},{"../utils":27}],27:[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.
 */
 /* eslint-env node */
'use strict';

var logDisabled_ = true;
var deprecationWarnings_ = true;

/**
 * Extract browser version out of the provided user agent string.
 *
 * @param {!string} uastring userAgent string.
 * @param {!string} expr Regular expression used as match criteria.
 * @param {!number} pos position in the version string to be returned.
 * @return {!number} browser version.
 */
function extractVersion(uastring, expr, pos) {
  var match = uastring.match(expr);
  return match && match.length >= pos && parseInt(match[pos], 10);
}

// Wraps the peerconnection event eventNameToWrap in a function
// which returns the modified event object (or false to prevent
// the event).
function wrapPeerConnectionEvent(window, eventNameToWrap, wrapper) {
  if (!window.RTCPeerConnection) {
    return;
  }
  var proto = window.RTCPeerConnection.prototype;
  var nativeAddEventListener = proto.addEventListener;
  proto.addEventListener = function(nativeEventName, cb) {
    if (nativeEventName !== eventNameToWrap) {
      return nativeAddEventListener.apply(this, arguments);
    }
    var wrappedCallback = function(e) {
      var modifiedEvent = wrapper(e);
      if (modifiedEvent) {
        cb(modifiedEvent);
      }
    };
    this._eventMap = this._eventMap || {};
    this._eventMap[cb] = wrappedCallback;
    return nativeAddEventListener.apply(this, [nativeEventName,
      wrappedCallback]);
  };

  var nativeRemoveEventListener = proto.removeEventListener;
  proto.removeEventListener = function(nativeEventName, cb) {
    if (nativeEventName !== eventNameToWrap || !this._eventMap
        || !this._eventMap[cb]) {
      return nativeRemoveEventListener.apply(this, arguments);
    }
    var unwrappedCb = this._eventMap[cb];
    delete this._eventMap[cb];
    return nativeRemoveEventListener.apply(this, [nativeEventName,
      unwrappedCb]);
  };

  Object.defineProperty(proto, 'on' + eventNameToWrap, {
    get: function() {
      return this['_on' + eventNameToWrap];
    },
    set: function(cb) {
      if (this['_on' + eventNameToWrap]) {
        this.removeEventListener(eventNameToWrap,
            this['_on' + eventNameToWrap]);
        delete this['_on' + eventNameToWrap];
      }
      if (cb) {
        this.addEventListener(eventNameToWrap,
            this['_on' + eventNameToWrap] = cb);
      }
    },
    enumerable: true,
    configurable: true
  });
}

// Utility methods.
module.exports = {
  extractVersion: extractVersion,
  wrapPeerConnectionEvent: wrapPeerConnectionEvent,
  disableLog: function(bool) {
    if (typeof bool !== 'boolean') {
      return new Error('Argument type: ' + typeof bool +
          '. Please use a boolean.');
    }
    logDisabled_ = bool;
    return (bool) ? 'adapter.js logging disabled' :
        'adapter.js logging enabled';
  },

  /**
   * Disable or enable deprecation warnings
   * @param {!boolean} bool set to true to disable warnings.
   */
  disableWarnings: function(bool) {
    if (typeof bool !== 'boolean') {
      return new Error('Argument type: ' + typeof bool +
          '. Please use a boolean.');
    }
    deprecationWarnings_ = !bool;
    return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
  },

  log: function() {
    if (typeof window === 'object') {
      if (logDisabled_) {
        return;
      }
      if (typeof console !== 'undefined' && typeof console.log === 'function') {
        console.log.apply(console, arguments);
      }
    }
  },

  /**
   * Shows a deprecation warning suggesting the modern and spec-compatible API.
   */
  deprecated: function(oldMethod, newMethod) {
    if (!deprecationWarnings_) {
      return;
    }
    console.warn(oldMethod + ' is deprecated, please use ' + newMethod +
        ' instead.');
  },

  /**
   * Browser detector.
   *
   * @return {object} result containing browser and version
   *     properties.
   */
  detectBrowser: function(window) {
    var navigator = window && window.navigator;

    // Returned result object.
    var result = {};
    result.browser = null;
    result.version = null;

    // Fail early if it's not a browser
    if (typeof window === 'undefined' || !window.navigator) {
      result.browser = 'Not a browser.';
      return result;
    }

    if (navigator.mozGetUserMedia) { // Firefox.
      result.browser = 'firefox';
      result.version = extractVersion(navigator.userAgent,
          /Firefox\/(\d+)\./, 1);
    } else if (navigator.webkitGetUserMedia) {
      // Chrome, Chromium, Webview, Opera.
      // Version matches Chrome/WebRTC version.
      result.browser = 'chrome';
      result.version = extractVersion(navigator.userAgent,
          /Chrom(e|ium)\/(\d+)\./, 2);
    } else if (navigator.mediaDevices &&
        navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) { // Edge.
      result.browser = 'edge';
      result.version = extractVersion(navigator.userAgent,
          /Edge\/(\d+).(\d+)$/, 2);
    } else if (window.RTCPeerConnection &&
        navigator.userAgent.match(/AppleWebKit\/(\d+)\./)) { // Safari.
      result.browser = 'safari';
      result.version = extractVersion(navigator.userAgent,
          /AppleWebKit\/(\d+)\./, 1);
    } else { // Default fallthrough: not supported.
      result.browser = 'Not a supported browser.';
      return result;
    }

    return result;
  }
};

},{}]},{},[3]);