Bare bones demo

* ICE candidate parser
* Simple demo.html
* Outline of tinyrtc.h

1 files changed, 3480 insertions, 0 deletions

diff --git a/example/adapter-8.0.0.js b/example/adapter-8.0.0.js
new file mode 100644
index 0000000..59e9bfe
--- /dev/null
+++ b/example/adapter-8.0.0.js
@@ -0,0 +1,3480 @@
+(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.adapter = f()}})(function(){var define,module,exports;return (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: typeof window === 'undefined' ? undefined : 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 _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);
+
+var _sdp = require('sdp');
+
+var sdp = _interopRequireWildcard(_sdp);
+
+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,
+    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,
+    // Expose sdp as a convenience. For production apps include directly.
+    sdp: sdp
+  };
+
+  // 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;
+      }
+      if (browserDetails.version === null) {
+        logging('Chrome shim can not determine version, not shimming.');
+        return adapter;
+      }
+      logging('adapter.js shimming chrome.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = chromeShim;
+
+      // Must be called before shimPeerConnection.
+      commonShim.shimAddIceCandidateNullOrEmpty(window, browserDetails);
+      commonShim.shimParameterlessSetLocalDescription(window, browserDetails);
+
+      chromeShim.shimGetUserMedia(window, browserDetails);
+      chromeShim.shimMediaStream(window, browserDetails);
+      chromeShim.shimPeerConnection(window, browserDetails);
+      chromeShim.shimOnTrack(window, browserDetails);
+      chromeShim.shimAddTrackRemoveTrack(window, browserDetails);
+      chromeShim.shimGetSendersWithDtmf(window, browserDetails);
+      chromeShim.shimGetStats(window, browserDetails);
+      chromeShim.shimSenderReceiverGetStats(window, browserDetails);
+      chromeShim.fixNegotiationNeeded(window, browserDetails);
+
+      commonShim.shimRTCIceCandidate(window, browserDetails);
+      commonShim.shimConnectionState(window, browserDetails);
+      commonShim.shimMaxMessageSize(window, browserDetails);
+      commonShim.shimSendThrowTypeError(window, browserDetails);
+      commonShim.removeExtmapAllowMixed(window, browserDetails);
+      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;
+
+      // Must be called before shimPeerConnection.
+      commonShim.shimAddIceCandidateNullOrEmpty(window, browserDetails);
+      commonShim.shimParameterlessSetLocalDescription(window, browserDetails);
+
+      firefoxShim.shimGetUserMedia(window, browserDetails);
+      firefoxShim.shimPeerConnection(window, browserDetails);
+      firefoxShim.shimOnTrack(window, browserDetails);
+      firefoxShim.shimRemoveStream(window, browserDetails);
+      firefoxShim.shimSenderGetStats(window, browserDetails);
+      firefoxShim.shimReceiverGetStats(window, browserDetails);
+      firefoxShim.shimRTCDataChannel(window, browserDetails);
+      firefoxShim.shimAddTransceiver(window, browserDetails);
+      firefoxShim.shimGetParameters(window, browserDetails);
+      firefoxShim.shimCreateOffer(window, browserDetails);
+      firefoxShim.shimCreateAnswer(window, browserDetails);
+
+      commonShim.shimRTCIceCandidate(window, browserDetails);
+      commonShim.shimConnectionState(window, browserDetails);
+      commonShim.shimMaxMessageSize(window, browserDetails);
+      commonShim.shimSendThrowTypeError(window, browserDetails);
+      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;
+
+      // Must be called before shimCallbackAPI.
+      commonShim.shimAddIceCandidateNullOrEmpty(window, browserDetails);
+      commonShim.shimParameterlessSetLocalDescription(window, browserDetails);
+
+      safariShim.shimRTCIceServerUrls(window, browserDetails);
+      safariShim.shimCreateOfferLegacy(window, browserDetails);
+      safariShim.shimCallbacksAPI(window, browserDetails);
+      safariShim.shimLocalStreamsAPI(window, browserDetails);
+      safariShim.shimRemoteStreamsAPI(window, browserDetails);
+      safariShim.shimTrackEventTransceiver(window, browserDetails);
+      safariShim.shimGetUserMedia(window, browserDetails);
+      safariShim.shimAudioContext(window, browserDetails);
+
+      commonShim.shimRTCIceCandidate(window, browserDetails);
+      commonShim.shimMaxMessageSize(window, browserDetails);
+      commonShim.shimSendThrowTypeError(window, browserDetails);
+      commonShim.removeExtmapAllowMixed(window, browserDetails);
+      break;
+    default:
+      logging('Unsupported browser!');
+      break;
+  }
+
+  return adapter;
+}
+
+// Browser shims.
+
+},{"./chrome/chrome_shim":3,"./common_shim":6,"./firefox/firefox_shim":7,"./safari/safari_shim":10,"./utils":11,"sdp":12}],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, browserDetails) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  // 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, browserDetails) {
+  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];
+    });
+  }
+}
+
+// Attempt to fix ONN in plan-b mode.
+function fixNegotiationNeeded(window, browserDetails) {
+  utils.wrapPeerConnectionEvent(window, 'negotiationneeded', function (e) {
+    var pc = e.target;
+    if (browserDetails.version < 72 || pc.getConfiguration && pc.getConfiguration().sdpSemantics === 'plan-b') {
+      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, browserDetails) {
+  var navigator = window && window.navigator;
+
+  if (!navigator.mediaDevices) {
+    return;
+  }
+
+  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.removeExtmapAllowMixed = removeExtmapAllowMixed;
+exports.shimAddIceCandidateNullOrEmpty = shimAddIceCandidateNullOrEmpty;
+exports.shimParameterlessSetLocalDescription = shimParameterlessSetLocalDescription;
+
+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, browserDetails) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+
+  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 removeExtmapAllowMixed(window, browserDetails) {
+  /* remove a=extmap-allow-mixed for webrtc.org < M71 */
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  if (browserDetails.browser === 'chrome' && browserDetails.version >= 71) {
+    return;
+  }
+  if (browserDetails.browser === 'safari' && browserDetails.version >= 605) {
+    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) {
+      var sdp = desc.sdp.split('\n').filter(function (line) {
+        return line.trim() !== 'a=extmap-allow-mixed';
+      }).join('\n');
+      // Safari enforces read-only-ness of RTCSessionDescription fields.
+      if (window.RTCSessionDescription && desc instanceof window.RTCSessionDescription) {
+        arguments[0] = new window.RTCSessionDescription({
+          type: desc.type,
+          sdp: sdp
+        });
+      } else {
+        desc.sdp = sdp;
+      }
+    }
+    return nativeSRD.apply(this, arguments);
+  };
+}
+
+function shimAddIceCandidateNullOrEmpty(window, browserDetails) {
+  // Support for addIceCandidate(null or undefined)
+  // as well as addIceCandidate({candidate: "", ...})
+  // https://bugs.chromium.org/p/chromium/issues/detail?id=978582
+  // Note: must be called before other polyfills which change the signature.
+  if (!(window.RTCPeerConnection && window.RTCPeerConnection.prototype)) {
+    return;
+  }
+  var nativeAddIceCandidate = window.RTCPeerConnection.prototype.addIceCandidate;
+  if (!nativeAddIceCandidate || nativeAddIceCandidate.length === 0) {
+    return;
+  }
+  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 for ignoring exists for Chrome M77+.
+    // Safari ignores as well, exact version unknown but works in the same
+    // version that also ignores addIceCandidate(null).
+    if ((browserDetails.browser === 'chrome' && browserDetails.version < 78 || browserDetails.browser === 'firefox' && browserDetails.version < 68 || browserDetails.browser === 'safari') && arguments[0] && arguments[0].candidate === '') {
+      return Promise.resolve();
+    }
+    return nativeAddIceCandidate.apply(this, arguments);
+  };
+}
+
+// Note: Make sure to call this ahead of APIs that modify
+// setLocalDescription.length
+function shimParameterlessSetLocalDescription(window, browserDetails) {
+  if (!(window.RTCPeerConnection && window.RTCPeerConnection.prototype)) {
+    return;
+  }
+  var nativeSetLocalDescription = window.RTCPeerConnection.prototype.setLocalDescription;
+  if (!nativeSetLocalDescription || nativeSetLocalDescription.length === 0) {
+    return;
+  }
+  window.RTCPeerConnection.prototype.setLocalDescription = function setLocalDescription() {
+    var _this = this;
+
+    var desc = arguments[0] || {};
+    if ((typeof desc === 'undefined' ? 'undefined' : _typeof(desc)) !== 'object' || desc.type && desc.sdp) {
+      return nativeSetLocalDescription.apply(this, arguments);
+    }
+    // The remaining steps should technically happen when SLD comes off the
+    // RTCPeerConnection's operations chain (not ahead of going on it), but
+    // this is too difficult to shim. Instead, this shim only covers the
+    // common case where the operations chain is empty. This is imperfect, but
+    // should cover many cases. Rationale: Even if we can't reduce the glare
+    // window to zero on imperfect implementations, there's value in tapping
+    // into the perfect negotiation pattern that several browsers support.
+    desc = { type: desc.type, sdp: desc.sdp };
+    if (!desc.type) {
+      switch (this.signalingState) {
+        case 'stable':
+        case 'have-local-offer':
+        case 'have-remote-pranswer':
+          desc.type = 'offer';
+          break;
+        default:
+          desc.type = 'answer';
+          break;
+      }
+    }
+    if (desc.sdp || desc.type !== 'offer' && desc.type !== 'answer') {
+      return nativeSetLocalDescription.apply(this, [desc]);
+    }
+    var func = desc.type === 'offer' ? this.createOffer : this.createAnswer;
+    return func.apply(this).then(function (d) {
+      return nativeSetLocalDescription.apply(_this, [d]);
+    });
+  };
+}
+
+},{"./utils":11,"sdp":12}],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;
+exports.shimAddTransceiver = shimAddTransceiver;
+exports.shimGetParameters = shimGetParameters;
+exports.shimCreateOffer = shimCreateOffer;
+exports.shimCreateAnswer = shimCreateAnswer;
+
+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, browserDetails) {
+  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];
+    });
+  }
+
+  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;
+  }
+}
+
+function shimAddTransceiver(window) {
+  // https://github.com/webrtcHacks/adapter/issues/998#issuecomment-516921647
+  // Firefox ignores the init sendEncodings options passed to addTransceiver
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1396918
+  if (!((typeof window === 'undefined' ? 'undefined' : _typeof(window)) === 'object' && window.RTCPeerConnection)) {
+    return;
+  }
+  var origAddTransceiver = window.RTCPeerConnection.prototype.addTransceiver;
+  if (origAddTransceiver) {
+    window.RTCPeerConnection.prototype.addTransceiver = function addTransceiver() {
+      this.setParametersPromises = [];
+      var initParameters = arguments[1];
+      var shouldPerformCheck = initParameters && 'sendEncodings' in initParameters;
+      if (shouldPerformCheck) {
+        // If sendEncodings params are provided, validate grammar
+        initParameters.sendEncodings.forEach(function (encodingParam) {
+          if ('rid' in encodingParam) {
+            var ridRegex = /^[a-z0-9]{0,16}$/i;
+            if (!ridRegex.test(encodingParam.rid)) {
+              throw new TypeError('Invalid RID value provided.');
+            }
+          }
+          if ('scaleResolutionDownBy' in encodingParam) {
+            if (!(parseFloat(encodingParam.scaleResolutionDownBy) >= 1.0)) {
+              throw new RangeError('scale_resolution_down_by must be >= 1.0');
+            }
+          }
+          if ('maxFramerate' in encodingParam) {
+            if (!(parseFloat(encodingParam.maxFramerate) >= 0)) {
+              throw new RangeError('max_framerate must be >= 0.0');
+            }
+          }
+        });
+      }
+      var transceiver = origAddTransceiver.apply(this, arguments);
+      if (shouldPerformCheck) {
+        // Check if the init options were applied. If not we do this in an
+        // asynchronous way and save the promise reference in a global object.
+        // This is an ugly hack, but at the same time is way more robust than
+        // checking the sender parameters before and after the createOffer
+        // Also note that after the createoffer we are not 100% sure that
+        // the params were asynchronously applied so we might miss the
+        // opportunity to recreate offer.
+        var sender = transceiver.sender;
+
+        var params = sender.getParameters();
+        if (!('encodings' in params) ||
+        // Avoid being fooled by patched getParameters() below.
+        params.encodings.length === 1 && Object.keys(params.encodings[0]).length === 0) {
+          params.encodings = initParameters.sendEncodings;
+          sender.sendEncodings = initParameters.sendEncodings;
+          this.setParametersPromises.push(sender.setParameters(params).then(function () {
+            delete sender.sendEncodings;
+          }).catch(function () {
+            delete sender.sendEncodings;
+          }));
+        }
+      }
+      return transceiver;
+    };
+  }
+}
+
+function shimGetParameters(window) {
+  if (!((typeof window === 'undefined' ? 'undefined' : _typeof(window)) === 'object' && window.RTCRtpSender)) {
+    return;
+  }
+  var origGetParameters = window.RTCRtpSender.prototype.getParameters;
+  if (origGetParameters) {
+    window.RTCRtpSender.prototype.getParameters = function getParameters() {
+      var params = origGetParameters.apply(this, arguments);
+      if (!('encodings' in params)) {
+        params.encodings = [].concat(this.sendEncodings || [{}]);
+      }
+      return params;
+    };
+  }
+}
+
+function shimCreateOffer(window) {
+  // https://github.com/webrtcHacks/adapter/issues/998#issuecomment-516921647
+  // Firefox ignores the init sendEncodings options passed to addTransceiver
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1396918
+  if (!((typeof window === 'undefined' ? 'undefined' : _typeof(window)) === 'object' && window.RTCPeerConnection)) {
+    return;
+  }
+  var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+  window.RTCPeerConnection.prototype.createOffer = function createOffer() {
+    var _this4 = this,
+        _arguments2 = arguments;
+
+    if (this.setParametersPromises && this.setParametersPromises.length) {
+      return Promise.all(this.setParametersPromises).then(function () {
+        return origCreateOffer.apply(_this4, _arguments2);
+      }).finally(function () {
+        _this4.setParametersPromises = [];
+      });
+    }
+    return origCreateOffer.apply(this, arguments);
+  };
+}
+
+function shimCreateAnswer(window) {
+  // https://github.com/webrtcHacks/adapter/issues/998#issuecomment-516921647
+  // Firefox ignores the init sendEncodings options passed to addTransceiver
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1396918
+  if (!((typeof window === 'undefined' ? 'undefined' : _typeof(window)) === 'object' && window.RTCPeerConnection)) {
+    return;
+  }
+  var origCreateAnswer = window.RTCPeerConnection.prototype.createAnswer;
+  window.RTCPeerConnection.prototype.createAnswer = function createAnswer() {
+    var _this5 = this,
+        _arguments3 = arguments;
+
+    if (this.setParametersPromises && this.setParametersPromises.length) {
+      return Promise.all(this.setParametersPromises).then(function () {
+        return origCreateAnswer.apply(_this5, _arguments3);
+      }).finally(function () {
+        _this5.setParametersPromises = [];
+      });
+    }
+    return origCreateAnswer.apply(this, arguments);
+  };
+}
+
+},{"../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, browserDetails) {
+  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;
+exports.shimAudioContext = shimAudioContext;
+
+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 _this2 = this;
+
+      for (var _len = arguments.length, streams = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+        streams[_key - 1] = arguments[_key];
+      }
+
+      if (streams) {
+        streams.forEach(function (stream) {
+          if (!_this2._localStreams) {
+            _this2._localStreams = [stream];
+          } else if (!_this2._localStreams.includes(stream)) {
+            _this2._localStreams.push(stream);
+          }
+        });
+      }
+      return _addTrack.apply(this, arguments);
+    };
+  }
+  if (!('removeStream' in window.RTCPeerConnection.prototype)) {
+    window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
+      var _this3 = 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)) {
+          _this3.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 _this4 = 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 (!_this4._remoteStreams) {
+              _this4._remoteStreams = [];
+            }
+            if (_this4._remoteStreams.includes(stream)) {
+              return;
+            }
+            _this4._remoteStreams.push(stream);
+            var event = new Event('addstream');
+            event.stream = stream;
+            _this4.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) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  // 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 OrigPeerConnection) {
+    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', { direction: 'recvonly' });
+      }
+
+      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', { direction: 'recvonly' });
+      }
+    }
+    return origCreateOffer.apply(this, arguments);
+  };
+}
+
+function shimAudioContext(window) {
+  if ((typeof window === 'undefined' ? 'undefined' : _typeof(window)) !== 'object' || window.AudioContext) {
+    return;
+  }
+  window.AudioContext = window.webkitAudioContext;
+}
+
+},{"../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) {
+        if (cb.handleEvent) {
+          cb.handleEvent(modifiedEvent);
+        } else {
+          cb(modifiedEvent);
+        }
+      }
+    };
+    this._eventMap = this._eventMap || {};
+    if (!this._eventMap[eventNameToWrap]) {
+      this._eventMap[eventNameToWrap] = new Map();
+    }
+    this._eventMap[eventNameToWrap].set(cb, wrappedCallback);
+    return nativeAddEventListener.apply(this, [nativeEventName, wrappedCallback]);
+  };
+
+  var nativeRemoveEventListener = proto.removeEventListener;
+  proto.removeEventListener = function (nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap || !this._eventMap || !this._eventMap[eventNameToWrap]) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    if (!this._eventMap[eventNameToWrap].has(cb)) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    var unwrappedCb = this._eventMap[eventNameToWrap].get(cb);
+    this._eventMap[eventNameToWrap].delete(cb);
+    if (this._eventMap[eventNameToWrap].size === 0) {
+      delete this._eventMap[eventNameToWrap];
+    }
+    if (Object.keys(this._eventMap).length === 0) {
+      delete this._eventMap;
+    }
+    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) {
+  // 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;
+  }
+
+  var navigator = window.navigator;
+
+
+  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 (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){
+/* eslint-env node */
+'use strict';
+
+// SDP helpers.
+
+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 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"
+// Input can be prefixed with a=.
+SDPUtils.parseCandidate = function (line) {
+  var parts = void 0;
+  // 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: { 1: 'rtp', 2: 'rtcp' }[parts[1]] || parts[1],
+    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 compatibility.
+        candidate.usernameFragment = parts[i + 1];
+        break;
+      default:
+        // extension handling, in particular ufrag. Don't overwrite.
+        if (candidate[parts[i]] === undefined) {
+          candidate[parts[i]] = parts[i + 1];
+        }
+        break;
+    }
+  }
+  return candidate;
+};
+
+// Translates a candidate object into SDP candidate attribute.
+// This does not include the a= prefix!
+SDPUtils.writeCandidate = function (candidate) {
+  var sdp = [];
+  sdp.push(candidate.foundation);
+
+  var component = candidate.component;
+  if (component === 'rtp') {
+    sdp.push(1);
+  } else if (component === 'rtcp') {
+    sdp.push(2);
+  } else {
+    sdp.push(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.
+// Sample input:
+// a=ice-options:foo bar
+SDPUtils.parseIceOptions = function (line) {
+  return line.substr(14).split(' ');
+};
+
+// Parses a 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;
+};
+
+// Generates 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 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 an 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 a fmtp 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 = void 0;
+  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 a fmtp 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] !== undefined) {
+        params.push(param + '=' + codec.parameters[param]);
+      } else {
+        params.push(param);
+      }
+    });
+    line += 'a=fmtp:' + pt + ' ' + params.join(';') + '\r\n';
+  }
+  return line;
+};
+
+// Parses a 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 a 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;
+};
+
+// Parse a ssrc-group line (see RFC 5576). Sample input:
+// a=ssrc-group:semantics 12 34
+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);
+  }
+};
+
+// Parses a fingerprint line for DTLS-SRTP.
+SDPUtils.parseFingerprint = function (line) {
+  var parts = line.substr(14).split(' ');
+  return {
+    algorithm: parts[0].toLowerCase(), // algorithm is case-sensitive in Edge.
+    value: parts[1].toUpperCase() // the definition is upper-case in RFC 4572.
+  };
+};
+
+// 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 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 a=crypto lines into
+//   https://rawgit.com/aboba/edgertc/master/msortc-rs4.html#dictionary-rtcsrtpsdesparameters-members
+SDPUtils.parseCryptoLine = function (line) {
+  var parts = line.substr(9).split(' ');
+  return {
+    tag: parseInt(parts[0], 10),
+    cryptoSuite: parts[1],
+    keyParams: parts[2],
+    sessionParams: parts.slice(3)
+  };
+};
+
+SDPUtils.writeCryptoLine = function (parameters) {
+  return 'a=crypto:' + parameters.tag + ' ' + parameters.cryptoSuite + ' ' + (_typeof(parameters.keyParams) === 'object' ? SDPUtils.writeCryptoKeyParams(parameters.keyParams) : parameters.keyParams) + (parameters.sessionParams ? ' ' + parameters.sessionParams.join(' ') : '') + '\r\n';
+};
+
+// Parses the crypto key parameters into
+//   https://rawgit.com/aboba/edgertc/master/msortc-rs4.html#rtcsrtpkeyparam*
+SDPUtils.parseCryptoKeyParams = function (keyParams) {
+  if (keyParams.indexOf('inline:') !== 0) {
+    return null;
+  }
+  var parts = keyParams.substr(7).split('|');
+  return {
+    keyMethod: 'inline',
+    keySalt: parts[0],
+    lifeTime: parts[1],
+    mkiValue: parts[2] ? parts[2].split(':')[0] : undefined,
+    mkiLength: parts[2] ? parts[2].split(':')[1] : undefined
+  };
+};
+
+SDPUtils.writeCryptoKeyParams = function (keyParams) {
+  return keyParams.keyMethod + ':' + keyParams.keySalt + (keyParams.lifeTime ? '|' + keyParams.lifeTime : '') + (keyParams.mkiValue && keyParams.mkiLength ? '|' + keyParams.mkiValue + ':' + keyParams.mkiLength : '');
+};
+
+// Extracts all SDES parameters.
+SDPUtils.getCryptoParameters = function (mediaSection, sessionpart) {
+  var lines = SDPUtils.matchPrefix(mediaSection + sessionpart, 'a=crypto:');
+  return lines.map(SDPUtils.parseCryptoLine);
+};
+
+// 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 ufrag = SDPUtils.matchPrefix(mediaSection + sessionpart, 'a=ice-ufrag:')[0];
+  var pwd = SDPUtils.matchPrefix(mediaSection + sessionpart, 'a=ice-pwd:')[0];
+  if (!(ufrag && pwd)) {
+    return null;
+  }
+  return {
+    usernameFragment: ufrag.substr(12),
+    password: pwd.substr(10)
+  };
+};
+
+// Serializes ICE parameters to SDP.
+SDPUtils.writeIceParameters = function (params) {
+  var sdp = 'a=ice-ufrag:' + params.usernameFragment + '\r\n' + 'a=ice-pwd:' + params.password + '\r\n';
+  if (params.iceLite) {
+    sdp += 'a=ice-lite\r\n';
+  }
+  return sdp;
+};
+
+// 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';
+  }
+
+  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 = void 0;
+
+  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 that with RTX there might be multiple
+  // SSRCs.
+  var remoteSsrc = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:').map(function (line) {
+    return SDPUtils.parseSsrcMedia(line);
+  }).filter(function (obj) {
+    return obj.attribute === 'cname';
+  })[0];
+  if (remoteSsrc) {
+    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;
+};
+
+SDPUtils.writeRtcpParameters = function (rtcpParameters) {
+  var sdp = '';
+  if (rtcpParameters.reducedSize) {
+    sdp += 'a=rtcp-rsize\r\n';
+  }
+  if (rtcpParameters.mux) {
+    sdp += 'a=rtcp-mux\r\n';
+  }
+  if (rtcpParameters.ssrc !== undefined && rtcpParameters.cname) {
+    sdp += 'a=ssrc:' + rtcpParameters.ssrc + ' cname:' + rtcpParameters.cname + '\r\n';
+  }
+  return sdp;
+};
+
+// parses either a=msid: or a=ssrc:... msid lines and returns
+// the id of the MediaStream and MediaStreamTrack.
+SDPUtils.parseMsid = function (mediaSection) {
+  var parts = void 0;
+  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] };
+  }
+};
+
+// SCTP
+// parses draft-ietf-mmusic-sctp-sdp-26 first and falls back
+// to draft-ietf-mmusic-sctp-sdp-05
+SDPUtils.parseSctpDescription = function (mediaSection) {
+  var mline = SDPUtils.parseMLine(mediaSection);
+  var maxSizeLine = SDPUtils.matchPrefix(mediaSection, 'a=max-message-size:');
+  var maxMessageSize = void 0;
+  if (maxSizeLine.length > 0) {
+    maxMessageSize = parseInt(maxSizeLine[0].substr(19), 10);
+  }
+  if (isNaN(maxMessageSize)) {
+    maxMessageSize = 65536;
+  }
+  var sctpPort = SDPUtils.matchPrefix(mediaSection, 'a=sctp-port:');
+  if (sctpPort.length > 0) {
+    return {
+      port: parseInt(sctpPort[0].substr(12), 10),
+      protocol: mline.fmt,
+      maxMessageSize: maxMessageSize
+    };
+  }
+  var sctpMapLines = SDPUtils.matchPrefix(mediaSection, 'a=sctpmap:');
+  if (sctpMapLines.length > 0) {
+    var parts = sctpMapLines[0].substr(10).split(' ');
+    return {
+      port: parseInt(parts[0], 10),
+      protocol: parts[1],
+      maxMessageSize: maxMessageSize
+    };
+  }
+};
+
+// SCTP
+// outputs the draft-ietf-mmusic-sctp-sdp-26 version that all browsers
+// support by now receiving in this format, unless we originally parsed
+// as the draft-ietf-mmusic-sctp-sdp-05 format (indicated by the m-line
+// protocol of DTLS/SCTP -- without UDP/ or TCP/)
+SDPUtils.writeSctpDescription = function (media, sctp) {
+  var output = [];
+  if (media.protocol !== 'DTLS/SCTP') {
+    output = ['m=' + media.kind + ' 9 ' + media.protocol + ' ' + sctp.protocol + '\r\n', 'c=IN IP4 0.0.0.0\r\n', 'a=sctp-port:' + sctp.port + '\r\n'];
+  } else {
+    output = ['m=' + media.kind + ' 9 ' + media.protocol + ' ' + sctp.port + '\r\n', 'c=IN IP4 0.0.0.0\r\n', 'a=sctpmap:' + sctp.port + ' ' + sctp.protocol + ' 65535\r\n'];
+  }
+  if (sctp.maxMessageSize !== undefined) {
+    output.push('a=max-message-size:' + sctp.maxMessageSize + '\r\n');
+  }
+  return output.join('');
+};
+
+// 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 boiler 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 = void 0;
+  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';
+};
+
+// 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 === 'undefined' ? 'undefined' : _typeof(module)) === 'object') {
+  module.exports = SDPUtils;
+}
+},{}]},{},[1])(1)
+});