(function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[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 _adapter_factory = require('./adapter_factory.js');

var adapter = (0, _adapter_factory.adapterFactory)({ window: window });
module.exports = adapter; // this is the difference from adapter_core.

},{"./adapter_factory.js":2}],2:[function(require,module,exports){
'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.adapterFactory = adapterFactory;

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

var utils = _interopRequireWildcard(_utils);

var _chrome_shim = require('./chrome/chrome_shim');

var chromeShim = _interopRequireWildcard(_chrome_shim);

var _edge_shim = require('./edge/edge_shim');

var edgeShim = _interopRequireWildcard(_edge_shim);

var _firefox_shim = require('./firefox/firefox_shim');

var firefoxShim = _interopRequireWildcard(_firefox_shim);

var _safari_shim = require('./safari/safari_shim');

var safariShim = _interopRequireWildcard(_safari_shim);

var _common_shim = require('./common_shim');

var commonShim = _interopRequireWildcard(_common_shim);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

// Shimming starts here.
/*
 *  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.
 */
function adapterFactory() {
  var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {},
      window = _ref.window;

  var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {
    shimChrome: true,
    shimFirefox: true,
    shimEdge: true,
    shimSafari: true
  };

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

  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;

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

      commonShim.shimRTCIceCandidate(window);
      commonShim.shimConnectionState(window);
      commonShim.shimMaxMessageSize(window);
      commonShim.shimSendThrowTypeError(window);
      commonShim.removeAllowExtmapMixed(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;

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

      commonShim.shimRTCIceCandidate(window);
      commonShim.shimConnectionState(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;

      edgeShim.shimGetUserMedia(window);
      edgeShim.shimGetDisplayMedia(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;

      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);
      commonShim.removeAllowExtmapMixed(window);
      break;
    default:
      logging('Unsupported browser!');
      break;
  }

  return adapter;
}

// Browser shims.

},{"./chrome/chrome_shim":3,"./common_shim":6,"./edge/edge_shim":12,"./firefox/firefox_shim":7,"./safari/safari_shim":10,"./utils":11}],3:[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';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.shimGetDisplayMedia = exports.shimGetUserMedia = undefined;

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

var _getusermedia = require('./getusermedia');

Object.defineProperty(exports, 'shimGetUserMedia', {
  enumerable: true,
  get: function get() {
    return _getusermedia.shimGetUserMedia;
  }
});

var _getdisplaymedia = require('./getdisplaymedia');

Object.defineProperty(exports, 'shimGetDisplayMedia', {
  enumerable: true,
  get: function get() {
    return _getdisplaymedia.shimGetDisplayMedia;
  }
});
exports.shimMediaStream = shimMediaStream;
exports.shimOnTrack = shimOnTrack;
exports.shimGetSendersWithDtmf = shimGetSendersWithDtmf;
exports.shimGetStats = shimGetStats;
exports.shimSenderReceiverGetStats = shimSenderReceiverGetStats;
exports.shimAddTrackRemoveTrackWithNative = shimAddTrackRemoveTrackWithNative;
exports.shimAddTrackRemoveTrack = shimAddTrackRemoveTrack;
exports.shimPeerConnection = shimPeerConnection;
exports.fixNegotiationNeeded = fixNegotiationNeeded;

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

var utils = _interopRequireWildcard(_utils);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

function shimMediaStream(window) {
  window.MediaStream = window.MediaStream || window.webkitMediaStream;
}

function shimOnTrack(window) {
  if ((typeof window === 'undefined' ? 'undefined' : _typeof(window)) === 'object' && window.RTCPeerConnection && !('ontrack' in window.RTCPeerConnection.prototype)) {
    Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
      get: function get() {
        return this._ontrack;
      },
      set: function set(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 setRemoteDescription() {
      var _this = this;

      if (!this._ontrackpoly) {
        this._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 = void 0;
            if (window.RTCPeerConnection.prototype.getReceivers) {
              receiver = _this.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];
            _this.dispatchEvent(event);
          });
          e.stream.getTracks().forEach(function (track) {
            var receiver = void 0;
            if (window.RTCPeerConnection.prototype.getReceivers) {
              receiver = _this.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];
            _this.dispatchEvent(event);
          });
        };
        this.addEventListener('addstream', this._ontrackpoly);
      }
      return origSetRemoteDescription.apply(this, 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;
    });
  }
}

function shimGetSendersWithDtmf(window) {
  // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
  if ((typeof window === 'undefined' ? 'undefined' : _typeof(window)) === 'object' && window.RTCPeerConnection && !('getSenders' in window.RTCPeerConnection.prototype) && 'createDTMFSender' in window.RTCPeerConnection.prototype) {
    var shimSenderWithDtmf = function shimSenderWithDtmf(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 getSenders() {
        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 addTrack(track, stream) {
        var sender = origAddTrack.apply(this, arguments);
        if (!sender) {
          sender = shimSenderWithDtmf(this, track);
          this._senders.push(sender);
        }
        return sender;
      };

      var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
      window.RTCPeerConnection.prototype.removeTrack = function removeTrack(sender) {
        origRemoveTrack.apply(this, arguments);
        var idx = this._senders.indexOf(sender);
        if (idx !== -1) {
          this._senders.splice(idx, 1);
        }
      };
    }
    var origAddStream = window.RTCPeerConnection.prototype.addStream;
    window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
      var _this2 = this;

      this._senders = this._senders || [];
      origAddStream.apply(this, [stream]);
      stream.getTracks().forEach(function (track) {
        _this2._senders.push(shimSenderWithDtmf(_this2, track));
      });
    };

    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
    window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
      var _this3 = this;

      this._senders = this._senders || [];
      origRemoveStream.apply(this, [stream]);

      stream.getTracks().forEach(function (track) {
        var sender = _this3._senders.find(function (s) {
          return s.track === track;
        });
        if (sender) {
          // remove sender
          _this3._senders.splice(_this3._senders.indexOf(sender), 1);
        }
      });
    };
  } else if ((typeof window === 'undefined' ? 'undefined' : _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 getSenders() {
      var _this4 = this;

      var senders = origGetSenders.apply(this, []);
      senders.forEach(function (sender) {
        return sender._pc = _this4;
      });
      return senders;
    };

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

function shimGetStats(window) {
  if (!window.RTCPeerConnection) {
    return;
  }

  var origGetStats = window.RTCPeerConnection.prototype.getStats;
  window.RTCPeerConnection.prototype.getStats = function getStats() {
    var _this5 = this;

    var _arguments = Array.prototype.slice.call(arguments),
        selector = _arguments[0],
        onSucc = _arguments[1],
        onErr = _arguments[2];

    // 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 selector !== 'function')) {
      return origGetStats.apply(this, []);
    }

    var fixChromeStats_ = function fixChromeStats_(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 makeMapStats(stats) {
      return new Map(Object.keys(stats).map(function (key) {
        return [key, stats[key]];
      }));
    };

    if (arguments.length >= 2) {
      var successCallbackWrapper_ = function successCallbackWrapper_(response) {
        onSucc(makeMapStats(fixChromeStats_(response)));
      };

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

    // promise-support
    return new Promise(function (resolve, reject) {
      origGetStats.apply(_this5, [function (response) {
        resolve(makeMapStats(fixChromeStats_(response)));
      }, reject]);
    }).then(onSucc, onErr);
  };
}

function shimSenderReceiverGetStats(window) {
  if (!((typeof window === 'undefined' ? 'undefined' : _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 getSenders() {
        var _this6 = this;

        var senders = origGetSenders.apply(this, []);
        senders.forEach(function (sender) {
          return sender._pc = _this6;
        });
        return senders;
      };
    }

    var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
    if (origAddTrack) {
      window.RTCPeerConnection.prototype.addTrack = function addTrack() {
        var sender = origAddTrack.apply(this, arguments);
        sender._pc = this;
        return sender;
      };
    }
    window.RTCRtpSender.prototype.getStats = function getStats() {
      var sender = this;
      return this._pc.getStats().then(function (result) {
        return (
          /* 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.
           */
          utils.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 getReceivers() {
        var _this7 = this;

        var receivers = origGetReceivers.apply(this, []);
        receivers.forEach(function (receiver) {
          return receiver._pc = _this7;
        });
        return receivers;
      };
    }
    utils.wrapPeerConnectionEvent(window, 'track', function (e) {
      e.receiver._pc = e.srcElement;
      return e;
    });
    window.RTCRtpReceiver.prototype.getStats = function getStats() {
      var receiver = this;
      return this._pc.getStats().then(function (result) {
        return utils.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 getStats() {
    if (arguments.length > 0 && arguments[0] instanceof window.MediaStreamTrack) {
      var track = arguments[0];
      var sender = void 0;
      var receiver = void 0;
      var err = void 0;
      this.getSenders().forEach(function (s) {
        if (s.track === track) {
          if (sender) {
            err = true;
          } else {
            sender = s;
          }
        }
      });
      this.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(this, arguments);
  };
}

function shimAddTrackRemoveTrackWithNative(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 getLocalStreams() {
    var _this8 = this;

    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
    return Object.keys(this._shimmedLocalStreams).map(function (streamId) {
      return _this8._shimmedLocalStreams[streamId][0];
    });
  };

  var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
  window.RTCPeerConnection.prototype.addTrack = function addTrack(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 addStream(stream) {
    var _this9 = this;

    this._shimmedLocalStreams = this._shimmedLocalStreams || {};

    stream.getTracks().forEach(function (track) {
      var alreadyExists = _this9.getSenders().find(function (s) {
        return s.track === track;
      });
      if (alreadyExists) {
        throw new DOMException('Track already exists.', 'InvalidAccessError');
      }
    });
    var existingSenders = this.getSenders();
    origAddStream.apply(this, arguments);
    var newSenders = this.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 removeStream(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 removeTrack(sender) {
    var _this10 = this;

    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
    if (sender) {
      Object.keys(this._shimmedLocalStreams).forEach(function (streamId) {
        var idx = _this10._shimmedLocalStreams[streamId].indexOf(sender);
        if (idx !== -1) {
          _this10._shimmedLocalStreams[streamId].splice(idx, 1);
        }
        if (_this10._shimmedLocalStreams[streamId].length === 1) {
          delete _this10._shimmedLocalStreams[streamId];
        }
      });
    }
    return origRemoveTrack.apply(this, arguments);
  };
}

function shimAddTrackRemoveTrack(window) {
  if (!window.RTCPeerConnection) {
    return;
  }
  var browserDetails = utils.detectBrowser(window);
  // shim addTrack and removeTrack.
  if (window.RTCPeerConnection.prototype.addTrack && browserDetails.version >= 65) {
    return 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 getLocalStreams() {
    var _this11 = this;

    var nativeStreams = origGetLocalStreams.apply(this);
    this._reverseStreams = this._reverseStreams || {};
    return nativeStreams.map(function (stream) {
      return _this11._reverseStreams[stream.id];
    });
  };

  var origAddStream = window.RTCPeerConnection.prototype.addStream;
  window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
    var _this12 = this;

    this._streams = this._streams || {};
    this._reverseStreams = this._reverseStreams || {};

    stream.getTracks().forEach(function (track) {
      var alreadyExists = _this12.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 (!this._reverseStreams[stream.id]) {
      var newStream = new window.MediaStream(stream.getTracks());
      this._streams[stream.id] = newStream;
      this._reverseStreams[newStream.id] = stream;
      stream = newStream;
    }
    origAddStream.apply(this, [stream]);
  };

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

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

  window.RTCPeerConnection.prototype.addTrack = function addTrack(track, stream) {
    var _this13 = this;

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

    this._streams = this._streams || {};
    this._reverseStreams = this._reverseStreams || {};
    var oldStream = this._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 () {
        _this13.dispatchEvent(new Event('negotiationneeded'));
      });
    } else {
      var newStream = new window.MediaStream([track]);
      this._streams[stream.id] = newStream;
      this._reverseStreams[newStream.id] = stream;
      this.addStream(newStream);
    }
    return this.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];
    var methodObj = _defineProperty({}, method, function () {
      var _this14 = this;

      var args = arguments;
      var isLegacyCall = arguments.length && typeof arguments[0] === 'function';
      if (isLegacyCall) {
        return nativeMethod.apply(this, [function (description) {
          var desc = replaceInternalStreamId(_this14, description);
          args[0].apply(null, [desc]);
        }, function (err) {
          if (args[1]) {
            args[1].apply(null, err);
          }
        }, arguments[2]]);
      }
      return nativeMethod.apply(this, arguments).then(function (description) {
        return replaceInternalStreamId(_this14, description);
      });
    });
    window.RTCPeerConnection.prototype[method] = methodObj[method];
  });

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

  window.RTCPeerConnection.prototype.removeTrack = function removeTrack(sender) {
    var _this15 = this;

    if (this.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 === this;
    if (!isLocal) {
      throw new DOMException('Sender was not created by this connection.', 'InvalidAccessError');
    }

    // Search for the native stream the senders track belongs to.
    this._streams = this._streams || {};
    var stream = void 0;
    Object.keys(this._streams).forEach(function (streamid) {
      var hasTrack = _this15._streams[streamid].getTracks().find(function (track) {
        return sender.track === track;
      });
      if (hasTrack) {
        stream = _this15._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.
        this.removeStream(this._reverseStreams[stream.id]);
      } else {
        // relying on the same odd chrome behaviour as above.
        stream.removeTrack(sender.track);
      }
      this.dispatchEvent(new Event('negotiationneeded'));
    }
  };
}

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

  if (!window.RTCPeerConnection && window.webkitRTCPeerConnection) {
    // very basic support for old versions.
    window.RTCPeerConnection = window.webkitRTCPeerConnection;
  }
  if (!window.RTCPeerConnection) {
    return;
  }

  // shim implicit creation of RTCSessionDescription/RTCIceCandidate
  if (browserDetails.version < 53) {
    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate'].forEach(function (method) {
      var nativeMethod = window.RTCPeerConnection.prototype[method];
      var methodObj = _defineProperty({}, method, function () {
        arguments[0] = new (method === 'addIceCandidate' ? window.RTCIceCandidate : window.RTCSessionDescription)(arguments[0]);
        return nativeMethod.apply(this, arguments);
      });
      window.RTCPeerConnection.prototype[method] = methodObj[method];
    });
  }

  // support for addIceCandidate(null or undefined)
  var nativeAddIceCandidate = window.RTCPeerConnection.prototype.addIceCandidate;
  window.RTCPeerConnection.prototype.addIceCandidate = function addIceCandidate() {
    if (!arguments[0]) {
      if (arguments[1]) {
        arguments[1].apply(null);
      }
      return Promise.resolve();
    }
    // Firefox 68+ emits and processes {candidate: "", ...}, ignore
    // in older versions. Native support planned for Chrome M77.
    if (browserDetails.version < 78 && arguments[0] && arguments[0].candidate === '') {
      return Promise.resolve();
    }
    return nativeAddIceCandidate.apply(this, arguments);
  };
}

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

},{"../utils.js":11,"./getdisplaymedia":4,"./getusermedia":5}],4:[function(require,module,exports){
/*
 *  Copyright (c) 2018 The adapter.js 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';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.shimGetDisplayMedia = shimGetDisplayMedia;
function shimGetDisplayMedia(window, getSourceId) {
  if (window.navigator.mediaDevices && 'getDisplayMedia' in window.navigator.mediaDevices) {
    return;
  }
  if (!window.navigator.mediaDevices) {
    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;
  }
  window.navigator.mediaDevices.getDisplayMedia = function getDisplayMedia(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 window.navigator.mediaDevices.getUserMedia(constraints);
    });
  };
}

},{}],5:[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';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.shimGetUserMedia = shimGetUserMedia;

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

var utils = _interopRequireWildcard(_utils);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

var logging = utils.log;

function shimGetUserMedia(window) {
  var navigator = window && window.navigator;

  if (!navigator.mediaDevices) {
    return;
  }

  var browserDetails = utils.detectBrowser(window);

  var constraintsToChrome_ = function constraintsToChrome_(c) {
    if ((typeof c === 'undefined' ? 'undefined' : _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 oldname_(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 shimConstraints_(constraints, func) {
    if (browserDetails.version >= 61) {
      return func(constraints);
    }
    constraints = JSON.parse(JSON.stringify(constraints));
    if (constraints && _typeof(constraints.audio) === 'object') {
      var remap = function remap(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 === 'undefined' ? 'undefined' : _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 = void 0;
        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().includes(match);
              });
            });
            if (!dev && devices.length && matches.includes('back')) {
              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 shimError_(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 toString() {
        return this.name + (this.message && ': ') + this.message;
      }
    };
  };

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

  // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
  // function which returns a Promise, it does not accept spec-style
  // constraints.
  if (navigator.mediaDevices.getUserMedia) {
    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));
        });
      });
    };
  }
}

},{"../utils.js":11}],6:[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';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.shimRTCIceCandidate = shimRTCIceCandidate;
exports.shimMaxMessageSize = shimMaxMessageSize;
exports.shimSendThrowTypeError = shimSendThrowTypeError;
exports.shimConnectionState = shimConnectionState;
exports.removeAllowExtmapMixed = removeAllowExtmapMixed;

var _sdp = require('sdp');

var _sdp2 = _interopRequireDefault(_sdp);

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

var utils = _interopRequireWildcard(_utils);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function shimRTCIceCandidate(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 RTCIceCandidate(args) {
    // Remove the a= which shouldn't be part of the candidate string.
    if ((typeof args === 'undefined' ? 'undefined' : _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 = _sdp2.default.parseCandidate(args.candidate);
      var augmentedCandidate = Object.assign(nativeCandidate, parsedCandidate);

      // Add a serializer that does not serialize the extra attributes.
      augmentedCandidate.toJSON = function toJSON() {
        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;
  });
}

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

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

  var sctpInDescription = function sctpInDescription(description) {
    if (!description || !description.sdp) {
      return false;
    }
    var sections = _sdp2.default.splitSections(description.sdp);
    sections.shift();
    return sections.some(function (mediaSection) {
      var mLine = _sdp2.default.parseMLine(mediaSection);
      return mLine && mLine.kind === 'application' && mLine.protocol.indexOf('SCTP') !== -1;
    });
  };

  var getRemoteFirefoxVersion = function getRemoteFirefoxVersion(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 getCanSendMaxMessageSize(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 getMaxMessageSize(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 = _sdp2.default.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 setRemoteDescription() {
    this._sctp = null;
    // Chrome decided to not expose .sctp in plan-b mode.
    // As usual, adapter.js has to do an 'ugly worakaround'
    // to cover up the mess.
    if (browserDetails.browser === 'chrome' && browserDetails.version >= 76) {
      var _getConfiguration = this.getConfiguration(),
          sdpSemantics = _getConfiguration.sdpSemantics;

      if (sdpSemantics === 'plan-b') {
        Object.defineProperty(this, 'sctp', {
          get: function get() {
            return typeof this._sctp === 'undefined' ? null : this._sctp;
          },

          enumerable: true,
          configurable: true
        });
      }
    }

    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 = void 0;
      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 get() {
          return maxMessageSize;
        }
      });
      this._sctp = sctp;
    }

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

function shimSendThrowTypeError(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 send() {
      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 createDataChannel() {
    var dataChannel = origCreateDataChannel.apply(this, arguments);
    wrapDcSend(dataChannel, this);
    return dataChannel;
  };
  utils.wrapPeerConnectionEvent(window, 'datachannel', function (e) {
    wrapDcSend(e.channel, e.target);
    return e;
  });
}

/* shims RTCConnectionState by pretending it is the same as iceConnectionState.
 * See https://bugs.chromium.org/p/webrtc/issues/detail?id=6145#c12
 * for why this is a valid hack in Chrome. In Firefox it is slightly incorrect
 * since DTLS failures would be hidden. See
 * https://bugzilla.mozilla.org/show_bug.cgi?id=1265827
 * for the Firefox tracking bug.
 */
function shimConnectionState(window) {
  if (!window.RTCPeerConnection || 'connectionState' in window.RTCPeerConnection.prototype) {
    return;
  }
  var proto = window.RTCPeerConnection.prototype;
  Object.defineProperty(proto, 'connectionState', {
    get: function get() {
      return {
        completed: 'connected',
        checking: 'connecting'
      }[this.iceConnectionState] || this.iceConnectionState;
    },

    enumerable: true,
    configurable: true
  });
  Object.defineProperty(proto, 'onconnectionstatechange', {
    get: function get() {
      return this._onconnectionstatechange || null;
    },
    set: function set(cb) {
      if (this._onconnectionstatechange) {
        this.removeEventListener('connectionstatechange', this._onconnectionstatechange);
        delete this._onconnectionstatechange;
      }
      if (cb) {
        this.addEventListener('connectionstatechange', this._onconnectionstatechange = cb);
      }
    },

    enumerable: true,
    configurable: true
  });

  ['setLocalDescription', 'setRemoteDescription'].forEach(function (method) {
    var origMethod = proto[method];
    proto[method] = function () {
      if (!this._connectionstatechangepoly) {
        this._connectionstatechangepoly = function (e) {
          var pc = e.target;
          if (pc._lastConnectionState !== pc.connectionState) {
            pc._lastConnectionState = pc.connectionState;
            var newEvent = new Event('connectionstatechange', e);
            pc.dispatchEvent(newEvent);
          }
          return e;
        };
        this.addEventListener('iceconnectionstatechange', this._connectionstatechangepoly);
      }
      return origMethod.apply(this, arguments);
    };
  });
}

function removeAllowExtmapMixed(window) {
  /* remove a=extmap-allow-mixed for Chrome < M71 */
  if (!window.RTCPeerConnection) {
    return;
  }
  var browserDetails = utils.detectBrowser(window);
  if (browserDetails.browser === 'chrome' && browserDetails.version >= 71) {
    return;
  }
  var nativeSRD = window.RTCPeerConnection.prototype.setRemoteDescription;
  window.RTCPeerConnection.prototype.setRemoteDescription = function setRemoteDescription(desc) {
    if (desc && desc.sdp && desc.sdp.indexOf('\na=extmap-allow-mixed') !== -1) {
      desc.sdp = desc.sdp.split('\n').filter(function (line) {
        return line.trim() !== 'a=extmap-allow-mixed';
      }).join('\n');
    }
    return nativeSRD.apply(this, arguments);
  };
}

},{"./utils":11,"sdp":13}],7:[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';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.shimGetDisplayMedia = exports.shimGetUserMedia = undefined;

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

var _getusermedia = require('./getusermedia');

Object.defineProperty(exports, 'shimGetUserMedia', {
  enumerable: true,
  get: function get() {
    return _getusermedia.shimGetUserMedia;
  }
});

var _getdisplaymedia = require('./getdisplaymedia');

Object.defineProperty(exports, 'shimGetDisplayMedia', {
  enumerable: true,
  get: function get() {
    return _getdisplaymedia.shimGetDisplayMedia;
  }
});
exports.shimOnTrack = shimOnTrack;
exports.shimPeerConnection = shimPeerConnection;
exports.shimSenderGetStats = shimSenderGetStats;
exports.shimReceiverGetStats = shimReceiverGetStats;
exports.shimRemoveStream = shimRemoveStream;
exports.shimRTCDataChannel = shimRTCDataChannel;

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

var utils = _interopRequireWildcard(_utils);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

function shimOnTrack(window) {
  if ((typeof window === 'undefined' ? 'undefined' : _typeof(window)) === 'object' && window.RTCTrackEvent && 'receiver' in window.RTCTrackEvent.prototype && !('transceiver' in window.RTCTrackEvent.prototype)) {
    Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
      get: function get() {
        return { receiver: this.receiver };
      }
    });
  }
}

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

  if ((typeof window === 'undefined' ? 'undefined' : _typeof(window)) !== 'object' || !(window.RTCPeerConnection || window.mozRTCPeerConnection)) {
    return; // probably media.peerconnection.enabled=false in about:config
  }
  if (!window.RTCPeerConnection && window.mozRTCPeerConnection) {
    // very basic support for old versions.
    window.RTCPeerConnection = window.mozRTCPeerConnection;
  }

  if (browserDetails.version < 53) {
    // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate'].forEach(function (method) {
      var nativeMethod = window.RTCPeerConnection.prototype[method];
      var methodObj = _defineProperty({}, method, function () {
        arguments[0] = new (method === 'addIceCandidate' ? window.RTCIceCandidate : window.RTCSessionDescription)(arguments[0]);
        return nativeMethod.apply(this, arguments);
      });
      window.RTCPeerConnection.prototype[method] = methodObj[method];
    });
  }

  // support for addIceCandidate(null or undefined)
  var nativeAddIceCandidate = window.RTCPeerConnection.prototype.addIceCandidate;
  window.RTCPeerConnection.prototype.addIceCandidate = function addIceCandidate() {
    if (!arguments[0]) {
      if (arguments[1]) {
        arguments[1].apply(null);
      }
      return Promise.resolve();
    }
    // Firefox 68+ emits and processes {candidate: "", ...}, ignore
    // in older versions.
    if (browserDetails.version < 68 && arguments[0] && arguments[0].candidate === '') {
      return Promise.resolve();
    }
    return nativeAddIceCandidate.apply(this, arguments);
  };

  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 getStats() {
    var _arguments = Array.prototype.slice.call(arguments),
        selector = _arguments[0],
        onSucc = _arguments[1],
        onErr = _arguments[2];

    return nativeGetStats.apply(this, [selector || null]).then(function (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);
  };
}

function shimSenderGetStats(window) {
  if (!((typeof window === 'undefined' ? 'undefined' : _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 getSenders() {
      var _this = this;

      var senders = origGetSenders.apply(this, []);
      senders.forEach(function (sender) {
        return sender._pc = _this;
      });
      return senders;
    };
  }

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

function shimReceiverGetStats(window) {
  if (!((typeof window === 'undefined' ? 'undefined' : _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 getReceivers() {
      var _this2 = this;

      var receivers = origGetReceivers.apply(this, []);
      receivers.forEach(function (receiver) {
        return receiver._pc = _this2;
      });
      return receivers;
    };
  }
  utils.wrapPeerConnectionEvent(window, 'track', function (e) {
    e.receiver._pc = e.srcElement;
    return e;
  });
  window.RTCRtpReceiver.prototype.getStats = function getStats() {
    return this._pc.getStats(this.track);
  };
}

function shimRemoveStream(window) {
  if (!window.RTCPeerConnection || 'removeStream' in window.RTCPeerConnection.prototype) {
    return;
  }
  window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
    var _this3 = this;

    utils.deprecated('removeStream', 'removeTrack');
    this.getSenders().forEach(function (sender) {
      if (sender.track && stream.getTracks().includes(sender.track)) {
        _this3.removeTrack(sender);
      }
    });
  };
}

function shimRTCDataChannel(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;
  }
}

},{"../utils":11,"./getdisplaymedia":8,"./getusermedia":9}],8:[function(require,module,exports){
/*
 *  Copyright (c) 2018 The adapter.js 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';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.shimGetDisplayMedia = shimGetDisplayMedia;
function shimGetDisplayMedia(window, preferredMediaSource) {
  if (window.navigator.mediaDevices && 'getDisplayMedia' in window.navigator.mediaDevices) {
    return;
  }
  if (!window.navigator.mediaDevices) {
    return;
  }
  window.navigator.mediaDevices.getDisplayMedia = function getDisplayMedia(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 window.navigator.mediaDevices.getUserMedia(constraints);
  };
}

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

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.shimGetUserMedia = shimGetUserMedia;

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

var utils = _interopRequireWildcard(_utils);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

function shimGetUserMedia(window) {
  var browserDetails = utils.detectBrowser(window);
  var navigator = window && window.navigator;
  var MediaStreamTrack = window && window.MediaStreamTrack;

  navigator.getUserMedia = function (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);
  };

  if (!(browserDetails.version > 55 && 'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
    var remap = function remap(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 === 'undefined' ? 'undefined' : _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 === 'undefined' ? 'undefined' : _typeof(c)) === 'object') {
          c = JSON.parse(JSON.stringify(c));
          remap(c, 'autoGainControl', 'mozAutoGainControl');
          remap(c, 'noiseSuppression', 'mozNoiseSuppression');
        }
        return nativeApplyConstraints.apply(this, [c]);
      };
    }
  }
}

},{"../utils":11}],10:[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';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.shimLocalStreamsAPI = shimLocalStreamsAPI;
exports.shimRemoteStreamsAPI = shimRemoteStreamsAPI;
exports.shimCallbacksAPI = shimCallbacksAPI;
exports.shimGetUserMedia = shimGetUserMedia;
exports.shimConstraints = shimConstraints;
exports.shimRTCIceServerUrls = shimRTCIceServerUrls;
exports.shimTrackEventTransceiver = shimTrackEventTransceiver;
exports.shimCreateOfferLegacy = shimCreateOfferLegacy;

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

var utils = _interopRequireWildcard(_utils);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

function shimLocalStreamsAPI(window) {
  if ((typeof window === 'undefined' ? 'undefined' : _typeof(window)) !== 'object' || !window.RTCPeerConnection) {
    return;
  }
  if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
    window.RTCPeerConnection.prototype.getLocalStreams = function getLocalStreams() {
      if (!this._localStreams) {
        this._localStreams = [];
      }
      return this._localStreams;
    };
  }
  if (!('addStream' in window.RTCPeerConnection.prototype)) {
    var _addTrack = window.RTCPeerConnection.prototype.addTrack;
    window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
      var _this = this;

      if (!this._localStreams) {
        this._localStreams = [];
      }
      if (!this._localStreams.includes(stream)) {
        this._localStreams.push(stream);
      }
      // Try to emulate Chrome's behaviour of adding in audio-video order.
      // Safari orders by track id.
      stream.getAudioTracks().forEach(function (track) {
        return _addTrack.call(_this, track, stream);
      });
      stream.getVideoTracks().forEach(function (track) {
        return _addTrack.call(_this, track, stream);
      });
    };

    window.RTCPeerConnection.prototype.addTrack = function addTrack(track) {
      var stream = arguments[1];
      if (stream) {
        if (!this._localStreams) {
          this._localStreams = [stream];
        } else if (!this._localStreams.includes(stream)) {
          this._localStreams.push(stream);
        }
      }
      return _addTrack.apply(this, arguments);
    };
  }
  if (!('removeStream' in window.RTCPeerConnection.prototype)) {
    window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
      var _this2 = this;

      if (!this._localStreams) {
        this._localStreams = [];
      }
      var index = this._localStreams.indexOf(stream);
      if (index === -1) {
        return;
      }
      this._localStreams.splice(index, 1);
      var tracks = stream.getTracks();
      this.getSenders().forEach(function (sender) {
        if (tracks.includes(sender.track)) {
          _this2.removeTrack(sender);
        }
      });
    };
  }
}

function shimRemoteStreamsAPI(window) {
  if ((typeof window === 'undefined' ? 'undefined' : _typeof(window)) !== 'object' || !window.RTCPeerConnection) {
    return;
  }
  if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
    window.RTCPeerConnection.prototype.getRemoteStreams = function getRemoteStreams() {
      return this._remoteStreams ? this._remoteStreams : [];
    };
  }
  if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
    Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
      get: function get() {
        return this._onaddstream;
      },
      set: function set(f) {
        var _this3 = this;

        if (this._onaddstream) {
          this.removeEventListener('addstream', this._onaddstream);
          this.removeEventListener('track', this._onaddstreampoly);
        }
        this.addEventListener('addstream', this._onaddstream = f);
        this.addEventListener('track', this._onaddstreampoly = function (e) {
          e.streams.forEach(function (stream) {
            if (!_this3._remoteStreams) {
              _this3._remoteStreams = [];
            }
            if (_this3._remoteStreams.includes(stream)) {
              return;
            }
            _this3._remoteStreams.push(stream);
            var event = new Event('addstream');
            event.stream = stream;
            _this3.dispatchEvent(event);
          });
        });
      }
    });
    var origSetRemoteDescription = window.RTCPeerConnection.prototype.setRemoteDescription;
    window.RTCPeerConnection.prototype.setRemoteDescription = function setRemoteDescription() {
      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);
    };
  }
}

function shimCallbacksAPI(window) {
  if ((typeof window === 'undefined' ? 'undefined' : _typeof(window)) !== 'object' || !window.RTCPeerConnection) {
    return;
  }
  var prototype = window.RTCPeerConnection.prototype;
  var origCreateOffer = prototype.createOffer;
  var origCreateAnswer = prototype.createAnswer;
  var setLocalDescription = prototype.setLocalDescription;
  var setRemoteDescription = prototype.setRemoteDescription;
  var addIceCandidate = prototype.addIceCandidate;

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

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

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

function shimGetUserMedia(window) {
  var navigator = window && window.navigator;

  if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
    // shim not needed in Safari 12.1
    var mediaDevices = navigator.mediaDevices;
    var _getUserMedia = mediaDevices.getUserMedia.bind(mediaDevices);
    navigator.mediaDevices.getUserMedia = function (constraints) {
      return _getUserMedia(shimConstraints(constraints));
    };
  }

  if (!navigator.getUserMedia && navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
    navigator.getUserMedia = function getUserMedia(constraints, cb, errcb) {
      navigator.mediaDevices.getUserMedia(constraints).then(cb, errcb);
    }.bind(navigator);
  }
}

function shimConstraints(constraints) {
  if (constraints && constraints.video !== undefined) {
    return Object.assign({}, constraints, { video: utils.compactObject(constraints.video) });
  }

  return constraints;
}

function shimRTCIceServerUrls(window) {
  // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
  var OrigPeerConnection = window.RTCPeerConnection;
  window.RTCPeerConnection = function RTCPeerConnection(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 get() {
        return OrigPeerConnection.generateCertificate;
      }
    });
  }
}

function shimTrackEventTransceiver(window) {
  // Add event.transceiver member over deprecated event.receiver
  if ((typeof window === 'undefined' ? 'undefined' : _typeof(window)) === 'object' && window.RTCTrackEvent && 'receiver' in window.RTCTrackEvent.prototype && !('transceiver' in window.RTCTrackEvent.prototype)) {
    Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
      get: function get() {
        return { receiver: this.receiver };
      }
    });
  }
}

function shimCreateOfferLegacy(window) {
  var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
  window.RTCPeerConnection.prototype.createOffer = function createOffer(offerOptions) {
    if (offerOptions) {
      if (typeof offerOptions.offerToReceiveAudio !== 'undefined') {
        // support bit values
        offerOptions.offerToReceiveAudio = !!offerOptions.offerToReceiveAudio;
      }
      var audioTransceiver = this.getTransceivers().find(function (transceiver) {
        return transceiver.receiver.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) {
        this.addTransceiver('audio');
      }

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

},{"../utils":11}],11:[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';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.extractVersion = extractVersion;
exports.wrapPeerConnectionEvent = wrapPeerConnectionEvent;
exports.disableLog = disableLog;
exports.disableWarnings = disableWarnings;
exports.log = log;
exports.deprecated = deprecated;
exports.detectBrowser = detectBrowser;
exports.compactObject = compactObject;
exports.walkStats = walkStats;
exports.filterStats = filterStats;

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

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 wrappedCallback(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 get() {
      return this['_on' + eventNameToWrap];
    },
    set: function set(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
  });
}

function disableLog(bool) {
  if (typeof bool !== 'boolean') {
    return new Error('Argument type: ' + (typeof bool === 'undefined' ? 'undefined' : _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.
 */
function disableWarnings(bool) {
  if (typeof bool !== 'boolean') {
    return new Error('Argument type: ' + (typeof bool === 'undefined' ? 'undefined' : _typeof(bool)) + '. Please use a boolean.');
  }
  deprecationWarnings_ = !bool;
  return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
}

function log() {
  if ((typeof window === 'undefined' ? 'undefined' : _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.
 */
function deprecated(oldMethod, newMethod) {
  if (!deprecationWarnings_) {
    return;
  }
  console.warn(oldMethod + ' is deprecated, please use ' + newMethod + ' instead.');
}

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

  // Returned result object.

  var result = { browser: null, 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 || window.isSecureContext === false && window.webkitRTCPeerConnection && !window.RTCIceGatherer) {
    // Chrome, Chromium, Webview, Opera.
    // Version matches Chrome/WebRTC version.
    // Chrome 74 removed webkitGetUserMedia on http as well so we need the
    // more complicated fallback to webkitRTCPeerConnection.
    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);
    result.supportsUnifiedPlan = window.RTCRtpTransceiver && 'currentDirection' in window.RTCRtpTransceiver.prototype;
  } else {
    // Default fallthrough: not supported.
    result.browser = 'Not a supported browser.';
    return result;
  }

  return result;
}

/**
 * Checks if something is an object.
 *
 * @param {*} val The something you want to check.
 * @return true if val is an object, false otherwise.
 */
function isObject(val) {
  return Object.prototype.toString.call(val) === '[object Object]';
}

/**
 * Remove all empty objects and undefined values
 * from a nested object -- an enhanced and vanilla version
 * of Lodash's `compact`.
 */
function compactObject(data) {
  if (!isObject(data)) {
    return data;
  }

  return Object.keys(data).reduce(function (accumulator, key) {
    var isObj = isObject(data[key]);
    var value = isObj ? compactObject(data[key]) : data[key];
    var isEmptyObject = isObj && !Object.keys(value).length;
    if (value === undefined || isEmptyObject) {
      return accumulator;
    }
    return Object.assign(accumulator, _defineProperty({}, key, value));
  }, {});
}

/* 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;
}

},{}],12:[function(require,module,exports){

},{}],13:[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;
}

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