text: (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 e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
  
  },{}],2:[function(require,module,exports){
   /* eslint-env node */
  'use strict';
  
  // SDP helpers.
  var SDPUtils = {};
  
  // Generate an alphanumeric identifier for cname or mids.
  // TODO: use UUIDs instead? https://gist.github.com/jed/982883
  SDPUtils.generateIdentifier = function() {
    return Math.random().toString(36).substr(2, 10);
  };
  
  // The RTCP CNAME used by all peerconnections from the same JS.
  SDPUtils.localCName = SDPUtils.generateIdentifier();
  
  // Splits SDP into lines, dealing with both CRLF and LF.
  SDPUtils.splitLines = function(blob) {
    return blob.trim().split('\n').map(function(line) {
      return line.trim();
    });
  };
  // Splits SDP into sessionpart and mediasections. Ensures CRLF.
  SDPUtils.splitSections = function(blob) {
    var parts = blob.split('\nm=');
    return parts.map(function(part, index) {
      return (index > 0 ? 'm=' + part : part).trim() + '\r\n';
    });
  };
  
  // returns the session description.
  SDPUtils.getDescription = function(blob) {
    var sections = SDPUtils.splitSections(blob);
    return sections && sections[0];
  };
  
  // returns the individual media sections.
  SDPUtils.getMediaSections = function(blob) {
    var sections = SDPUtils.splitSections(blob);
    sections.shift();
    return sections;
  };
  
  // Returns lines that start with a certain prefix.
  SDPUtils.matchPrefix = function(blob, prefix) {
    return SDPUtils.splitLines(blob).filter(function(line) {
      return line.indexOf(prefix) === 0;
    });
  };
  
  // Parses an ICE candidate line. Sample input:
  // candidate:702786350 2 udp 41819902 8.8.8.8 60769 typ relay raddr 8.8.8.8
  // rport 55996"
  SDPUtils.parseCandidate = function(line) {
    var parts;
    // Parse both variants.
    if (line.indexOf('a=candidate:') === 0) {
      parts = line.substring(12).split(' ');
    } else {
      parts = line.substring(10).split(' ');
    }
  
    var candidate = {
      foundation: parts[0],
      component: parseInt(parts[1], 10),
      protocol: parts[2].toLowerCase(),
      priority: parseInt(parts[3], 10),
      ip: parts[4],
      port: parseInt(parts[5], 10),
      // skip parts[6] == 'typ'
      type: parts[7]
    };
  
    for (var i = 8; i < parts.length; i += 2) {
      switch (parts[i]) {
        case 'raddr':
          candidate.relatedAddress = parts[i + 1];
          break;
        case 'rport':
          candidate.relatedPort = parseInt(parts[i + 1], 10);
          break;
        case 'tcptype':
          candidate.tcpType = parts[i + 1];
          break;
        case 'ufrag':
          candidate.ufrag = parts[i + 1]; // for backward compability.
          candidate.usernameFragment = parts[i + 1];
          break;
        default: // extension handling, in particular ufrag
          candidate[parts[i]] = parts[i + 1];
          break;
      }
    }
    return candidate;
  };
  
  // Translates a candidate object into SDP candidate attribute.
  SDPUtils.writeCandidate = function(candidate) {
    var sdp = [];
    sdp.push(candidate.foundation);
    sdp.push(candidate.component);
    sdp.push(candidate.protocol.toUpperCase());
    sdp.push(candidate.priority);
    sdp.push(candidate.ip);
    sdp.push(candidate.port);
  
    var type = candidate.type;
    sdp.push('typ');
    sdp.push(type);
    if (type !== 'host' && candidate.relatedAddress &&
        candidate.relatedPort) {
      sdp.push('raddr');
      sdp.push(candidate.relatedAddress);
      sdp.push('rport');
      sdp.push(candidate.relatedPort);
    }
    if (candidate.tcpType && candidate.protocol.toLowerCase() === 'tcp') {
      sdp.push('tcptype');
      sdp.push(candidate.tcpType);
    }
    if (candidate.usernameFragment || candidate.ufrag) {
      sdp.push('ufrag');
      sdp.push(candidate.usernameFragment || candidate.ufrag);
    }
    return 'candidate:' + sdp.join(' ');
  };
  
  // Parses an ice-options line, returns an array of option tags.
  // a=ice-options:foo bar
  SDPUtils.parseIceOptions = function(line) {
    return line.substr(14).split(' ');
  }
  
  // Parses an rtpmap line, returns RTCRtpCoddecParameters. Sample input:
  // a=rtpmap:111 opus/48000/2
  SDPUtils.parseRtpMap = function(line) {
    var parts = line.substr(9).split(' ');
    var parsed = {
      payloadType: parseInt(parts.shift(), 10) // was: id
    };
  
    parts = parts[0].split('/');
  
    parsed.name = parts[0];
    parsed.clockRate = parseInt(parts[1], 10); // was: clockrate
    parsed.channels = parts.length === 3 ? parseInt(parts[2], 10) : 1;
    // legacy alias, got renamed back to channels in ORTC.
    parsed.numChannels = parsed.channels;
    return parsed;
  };
  
  // Generate an a=rtpmap line from RTCRtpCodecCapability or
  // RTCRtpCodecParameters.
  SDPUtils.writeRtpMap = function(codec) {
    var pt = codec.payloadType;
    if (codec.preferredPayloadType !== undefined) {
      pt = codec.preferredPayloadType;
    }
    var channels = codec.channels || codec.numChannels || 1;
    return 'a=rtpmap:' + pt + ' ' + codec.name + '/' + codec.clockRate +
        (channels !== 1 ? '/' + channels : '') + '\r\n';
  };
  
  // Parses an a=extmap line (headerextension from RFC 5285). Sample input:
  // a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
  // a=extmap:2/sendonly urn:ietf:params:rtp-hdrext:toffset
  SDPUtils.parseExtmap = function(line) {
    var parts = line.substr(9).split(' ');
    return {
      id: parseInt(parts[0], 10),
      direction: parts[0].indexOf('/') > 0 ? parts[0].split('/')[1] : 'sendrecv',
      uri: parts[1]
    };
  };
  
  // Generates a=extmap line from RTCRtpHeaderExtensionParameters or
  // RTCRtpHeaderExtension.
  SDPUtils.writeExtmap = function(headerExtension) {
    return 'a=extmap:' + (headerExtension.id || headerExtension.preferredId) +
        (headerExtension.direction && headerExtension.direction !== 'sendrecv'
            ? '/' + headerExtension.direction
            : '') +
        ' ' + headerExtension.uri + '\r\n';
  };
  
  // Parses an ftmp line, returns dictionary. Sample input:
  // a=fmtp:96 vbr=on;cng=on
  // Also deals with vbr=on; cng=on
  SDPUtils.parseFmtp = function(line) {
    var parsed = {};
    var kv;
    var parts = line.substr(line.indexOf(' ') + 1).split(';');
    for (var j = 0; j < parts.length; j++) {
      kv = parts[j].trim().split('=');
      parsed[kv[0].trim()] = kv[1];
    }
    return parsed;
  };
  
  // Generates an a=ftmp line from RTCRtpCodecCapability or RTCRtpCodecParameters.
  SDPUtils.writeFmtp = function(codec) {
    var line = '';
    var pt = codec.payloadType;
    if (codec.preferredPayloadType !== undefined) {
      pt = codec.preferredPayloadType;
    }
    if (codec.parameters && Object.keys(codec.parameters).length) {
      var params = [];
      Object.keys(codec.parameters).forEach(function(param) {
        if (codec.parameters[param]) {
          params.push(param + '=' + codec.parameters[param]);
        } else {
          params.push(param);
        }
      });
      line += 'a=fmtp:' + pt + ' ' + params.join(';') + '\r\n';
    }
    return line;
  };
  
  // Parses an rtcp-fb line, returns RTCPRtcpFeedback object. Sample input:
  // a=rtcp-fb:98 nack rpsi
  SDPUtils.parseRtcpFb = function(line) {
    var parts = line.substr(line.indexOf(' ') + 1).split(' ');
    return {
      type: parts.shift(),
      parameter: parts.join(' ')
    };
  };
  // Generate a=rtcp-fb lines from RTCRtpCodecCapability or RTCRtpCodecParameters.
  SDPUtils.writeRtcpFb = function(codec) {
    var lines = '';
    var pt = codec.payloadType;
    if (codec.preferredPayloadType !== undefined) {
      pt = codec.preferredPayloadType;
    }
    if (codec.rtcpFeedback && codec.rtcpFeedback.length) {
      // FIXME: special handling for trr-int?
      codec.rtcpFeedback.forEach(function(fb) {
        lines += 'a=rtcp-fb:' + pt + ' ' + fb.type +
        (fb.parameter && fb.parameter.length ? ' ' + fb.parameter : '') +
            '\r\n';
      });
    }
    return lines;
  };
  
  // Parses an RFC 5576 ssrc media attribute. Sample input:
  // a=ssrc:3735928559 cname:something
  SDPUtils.parseSsrcMedia = function(line) {
    var sp = line.indexOf(' ');
    var parts = {
      ssrc: parseInt(line.substr(7, sp - 7), 10)
    };
    var colon = line.indexOf(':', sp);
    if (colon > -1) {
      parts.attribute = line.substr(sp + 1, colon - sp - 1);
      parts.value = line.substr(colon + 1);
    } else {
      parts.attribute = line.substr(sp + 1);
    }
    return parts;
  };
  
  // Extracts the MID (RFC 5888) from a media section.
  // returns the MID or undefined if no mid line was found.
  SDPUtils.getMid = function(mediaSection) {
    var mid = SDPUtils.matchPrefix(mediaSection, 'a=mid:')[0];
    if (mid) {
      return mid.substr(6);
    }
  }
  
  SDPUtils.parseFingerprint = function(line) {
    var parts = line.substr(14).split(' ');
    return {
      algorithm: parts[0].toLowerCase(), // algorithm is case-sensitive in Edge.
      value: parts[1]
    };
  };
  
  // Extracts DTLS parameters from SDP media section or sessionpart.
  // FIXME: for consistency with other functions this should only
  //   get the fingerprint line as input. See also getIceParameters.
  SDPUtils.getDtlsParameters = function(mediaSection, sessionpart) {
    var lines = SDPUtils.matchPrefix(mediaSection + sessionpart,
        'a=fingerprint:');
    // Note: a=setup line is ignored since we use the 'auto' role.
    // Note2: 'algorithm' is not case sensitive except in Edge.
    return {
      role: 'auto',
      fingerprints: lines.map(SDPUtils.parseFingerprint)
    };
  };
  
  // Serializes DTLS parameters to SDP.
  SDPUtils.writeDtlsParameters = function(params, setupType) {
    var sdp = 'a=setup:' + setupType + '\r\n';
    params.fingerprints.forEach(function(fp) {
      sdp += 'a=fingerprint:' + fp.algorithm + ' ' + fp.value + '\r\n';
    });
    return sdp;
  };
  // Parses ICE information from SDP media section or sessionpart.
  // FIXME: for consistency with other functions this should only
  //   get the ice-ufrag and ice-pwd lines as input.
  SDPUtils.getIceParameters = function(mediaSection, sessionpart) {
    var lines = SDPUtils.splitLines(mediaSection);
    // Search in session part, too.
    lines = lines.concat(SDPUtils.splitLines(sessionpart));
    var iceParameters = {
      usernameFragment: lines.filter(function(line) {
        return line.indexOf('a=ice-ufrag:') === 0;
      })[0].substr(12),
      password: lines.filter(function(line) {
        return line.indexOf('a=ice-pwd:') === 0;
      })[0].substr(10)
    };
    return iceParameters;
  };
  
  // Serializes ICE parameters to SDP.
  SDPUtils.writeIceParameters = function(params) {
    return 'a=ice-ufrag:' + params.usernameFragment + '\r\n' +
        'a=ice-pwd:' + params.password + '\r\n';
  };
  
  // Parses the SDP media section and returns RTCRtpParameters.
  SDPUtils.parseRtpParameters = function(mediaSection) {
    var description = {
      codecs: [],
      headerExtensions: [],
      fecMechanisms: [],
      rtcp: []
    };
    var lines = SDPUtils.splitLines(mediaSection);
    var mline = lines[0].split(' ');
    for (var i = 3; i < mline.length; i++) { // find all codecs from mline[3..]
      var pt = mline[i];
      var rtpmapline = SDPUtils.matchPrefix(
          mediaSection, 'a=rtpmap:' + pt + ' ')[0];
      if (rtpmapline) {
        var codec = SDPUtils.parseRtpMap(rtpmapline);
        var fmtps = SDPUtils.matchPrefix(
            mediaSection, 'a=fmtp:' + pt + ' ');
        // Only the first a=fmtp:<pt> is considered.
        codec.parameters = fmtps.length ? SDPUtils.parseFmtp(fmtps[0]) : {};
        codec.rtcpFeedback = SDPUtils.matchPrefix(
            mediaSection, 'a=rtcp-fb:' + pt + ' ')
          .map(SDPUtils.parseRtcpFb);
        description.codecs.push(codec);
        // parse FEC mechanisms from rtpmap lines.
        switch (codec.name.toUpperCase()) {
          case 'RED':
          case 'ULPFEC':
            description.fecMechanisms.push(codec.name.toUpperCase());
            break;
          default: // only RED and ULPFEC are recognized as FEC mechanisms.
            break;
        }
      }
    }
    SDPUtils.matchPrefix(mediaSection, 'a=extmap:').forEach(function(line) {
      description.headerExtensions.push(SDPUtils.parseExtmap(line));
    });
    // FIXME: parse rtcp.
    return description;
  };
  
  // Generates parts of the SDP media section describing the capabilities /
  // parameters.
  SDPUtils.writeRtpDescription = function(kind, caps) {
    var sdp = '';
  
    // Build the mline.
    sdp += 'm=' + kind + ' ';
    sdp += caps.codecs.length > 0 ? '9' : '0'; // reject if no codecs.
    sdp += ' UDP/TLS/RTP/SAVPF ';
    sdp += caps.codecs.map(function(codec) {
      if (codec.preferredPayloadType !== undefined) {
        return codec.preferredPayloadType;
      }
      return codec.payloadType;
    }).join(' ') + '\r\n';
  
    sdp += 'c=IN IP4 0.0.0.0\r\n';
    sdp += 'a=rtcp:9 IN IP4 0.0.0.0\r\n';
  
    // Add a=rtpmap lines for each codec. Also fmtp and rtcp-fb.
    caps.codecs.forEach(function(codec) {
      sdp += SDPUtils.writeRtpMap(codec);
      sdp += SDPUtils.writeFmtp(codec);
      sdp += SDPUtils.writeRtcpFb(codec);
    });
    var maxptime = 0;
    caps.codecs.forEach(function(codec) {
      if (codec.maxptime > maxptime) {
        maxptime = codec.maxptime;
      }
    });
    if (maxptime > 0) {
      sdp += 'a=maxptime:' + maxptime + '\r\n';
    }
    sdp += 'a=rtcp-mux\r\n';
  
    if (caps.headerExtensions) {
      caps.headerExtensions.forEach(function(extension) {
        sdp += SDPUtils.writeExtmap(extension);
      });
    }
    // FIXME: write fecMechanisms.
    return sdp;
  };
  
  // Parses the SDP media section and returns an array of
  // RTCRtpEncodingParameters.
  SDPUtils.parseRtpEncodingParameters = function(mediaSection) {
    var encodingParameters = [];
    var description = SDPUtils.parseRtpParameters(mediaSection);
    var hasRed = description.fecMechanisms.indexOf('RED') !== -1;
    var hasUlpfec = description.fecMechanisms.indexOf('ULPFEC') !== -1;
  
    // filter a=ssrc:... cname:, ignore PlanB-msid
    var ssrcs = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
    .map(function(line) {
      return SDPUtils.parseSsrcMedia(line);
    })
    .filter(function(parts) {
      return parts.attribute === 'cname';
    });
    var primarySsrc = ssrcs.length > 0 && ssrcs[0].ssrc;
    var secondarySsrc;
  
    var flows = SDPUtils.matchPrefix(mediaSection, 'a=ssrc-group:FID')
    .map(function(line) {
      var parts = line.substr(17).split(' ');
      return parts.map(function(part) {
        return parseInt(part, 10);
      });
    });
    if (flows.length > 0 && flows[0].length > 1 && flows[0][0] === primarySsrc) {
      secondarySsrc = flows[0][1];
    }
  
    description.codecs.forEach(function(codec) {
      if (codec.name.toUpperCase() === 'RTX' && codec.parameters.apt) {
        var encParam = {
          ssrc: primarySsrc,
          codecPayloadType: parseInt(codec.parameters.apt, 10),
        };
        if (primarySsrc && secondarySsrc) {
          encParam.rtx = {ssrc: secondarySsrc};
        }
        encodingParameters.push(encParam);
        if (hasRed) {
          encParam = JSON.parse(JSON.stringify(encParam));
          encParam.fec = {
            ssrc: secondarySsrc,
            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 = {};
  
    var cname;
    // Gets the first SSRC. Note that with RTX there might be multiple
    // SSRCs.
    var remoteSsrc = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
        .map(function(line) {
          return SDPUtils.parseSsrcMedia(line);
        })
        .filter(function(obj) {
          return obj.attribute === 'cname';
        })[0];
    if (remoteSsrc) {
      rtcpParameters.cname = remoteSsrc.value;
      rtcpParameters.ssrc = remoteSsrc.ssrc;
    }
  
    // Edge uses the compound attribute instead of reducedSize
    // compound is !reducedSize
    var rsize = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-rsize');
    rtcpParameters.reducedSize = rsize.length > 0;
    rtcpParameters.compound = rsize.length === 0;
  
    // parses the rtcp-mux attrіbute.
    // Note that Edge does not support unmuxed RTCP.
    var mux = SDPUtils.matchPrefix(mediaSection, 'a=rtcp-mux');
    rtcpParameters.mux = mux.length > 0;
  
    return rtcpParameters;
  };
  
  // parses either a=msid: or a=ssrc:... msid lines and returns
  // the id of the MediaStream and MediaStreamTrack.
  SDPUtils.parseMsid = function(mediaSection) {
    var parts;
    var spec = SDPUtils.matchPrefix(mediaSection, 'a=msid:');
    if (spec.length === 1) {
      parts = spec[0].substr(7).split(' ');
      return {stream: parts[0], track: parts[1]};
    }
    var planB = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
    .map(function(line) {
      return SDPUtils.parseSsrcMedia(line);
    })
    .filter(function(parts) {
      return parts.attribute === 'msid';
    });
    if (planB.length > 0) {
      parts = planB[0].value.split(' ');
      return {stream: parts[0], track: parts[1]};
    }
  };
  
  // Generate a session ID for SDP.
  // https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-20#section-5.2.1
  // recommends using a cryptographically random +ve 64-bit value
  // but right now this should be acceptable and within the right range
  SDPUtils.generateSessionId = function() {
    return Math.random().toString().substr(2, 21);
  };
  
  // Write boilder plate for start of SDP
  // sessId argument is optional - if not supplied it will
  // be generated randomly
  // sessVersion is optional and defaults to 2
  SDPUtils.writeSessionBoilerplate = function(sessId, sessVer) {
    var sessionId;
    var version = sessVer !== undefined ? sessVer : 2;
    if (sessId) {
      sessionId = sessId;
    } else {
      sessionId = SDPUtils.generateSessionId();
    }
    // FIXME: sess-id should be an NTP timestamp.
    return 'v=0\r\n' +
        'o=thisisadapterortc ' + sessionId + ' ' + version + ' IN IP4 127.0.0.1\r\n' +
        's=-\r\n' +
        't=0 0\r\n';
  };
  
  SDPUtils.writeMediaSection = function(transceiver, caps, type, stream) {
    var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);
  
    // Map ICE parameters (ufrag, pwd) to SDP.
    sdp += SDPUtils.writeIceParameters(
        transceiver.iceGatherer.getLocalParameters());
  
    // Map DTLS parameters to SDP.
    sdp += SDPUtils.writeDtlsParameters(
        transceiver.dtlsTransport.getLocalParameters(),
        type === 'offer' ? 'actpass' : 'active');
  
    sdp += 'a=mid:' + transceiver.mid + '\r\n';
  
    if (transceiver.direction) {
      sdp += 'a=' + transceiver.direction + '\r\n';
    } else if (transceiver.rtpSender && transceiver.rtpReceiver) {
      sdp += 'a=sendrecv\r\n';
    } else if (transceiver.rtpSender) {
      sdp += 'a=sendonly\r\n';
    } else if (transceiver.rtpReceiver) {
      sdp += 'a=recvonly\r\n';
    } else {
      sdp += 'a=inactive\r\n';
    }
  
    if (transceiver.rtpSender) {
      // spec.
      var msid = 'msid:' + stream.id + ' ' +
          transceiver.rtpSender.track.id + '\r\n';
      sdp += 'a=' + msid;
  
      // for Chrome.
      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
          ' ' + msid;
      if (transceiver.sendEncodingParameters[0].rtx) {
        sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
            ' ' + msid;
        sdp += 'a=ssrc-group:FID ' +
            transceiver.sendEncodingParameters[0].ssrc + ' ' +
            transceiver.sendEncodingParameters[0].rtx.ssrc +
            '\r\n';
      }
    }
    // FIXME: this should be written by writeRtpDescription.
    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
        ' cname:' + SDPUtils.localCName + '\r\n';
    if (transceiver.rtpSender && transceiver.sendEncodingParameters[0].rtx) {
      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].rtx.ssrc +
          ' cname:' + SDPUtils.localCName + '\r\n';
    }
    return sdp;
  };
  
  // Gets the direction from the mediaSection or the sessionpart.
  SDPUtils.getDirection = function(mediaSection, sessionpart) {
    // Look for sendrecv, sendonly, recvonly, inactive, default to sendrecv.
    var lines = SDPUtils.splitLines(mediaSection);
    for (var i = 0; i < lines.length; i++) {
      switch (lines[i]) {
        case 'a=sendrecv':
        case 'a=sendonly':
        case 'a=recvonly':
        case 'a=inactive':
          return lines[i].substr(2);
        default:
          // FIXME: What should happen here?
      }
    }
    if (sessionpart) {
      return SDPUtils.getDirection(sessionpart);
    }
    return 'sendrecv';
  };
  
  SDPUtils.getKind = function(mediaSection) {
    var lines = SDPUtils.splitLines(mediaSection);
    var mline = lines[0].split(' ');
    return mline[0].substr(2);
  };
  
  SDPUtils.isRejected = function(mediaSection) {
    return mediaSection.split(' ', 2)[1] === '0';
  };
  
  SDPUtils.parseMLine = function(mediaSection) {
    var lines = SDPUtils.splitLines(mediaSection);
    var parts = lines[0].substr(2).split(' ');
    return {
      kind: parts[0],
      port: parseInt(parts[1], 10),
      protocol: parts[2],
      fmt: parts.slice(3).join(' ')
    };
  };
  
  SDPUtils.parseOLine = function(mediaSection) {
    var line = SDPUtils.matchPrefix(mediaSection, 'o=')[0];
    var parts = line.substr(2).split(' ');
    return {
      username: parts[0],
      sessionId: parts[1],
      sessionVersion: parseInt(parts[2], 10),
      netType: parts[3],
      addressType: parts[4],
      address: parts[5],
    };
  }
  
  // Expose public methods.
  if (typeof module === 'object') {
    module.exports = SDPUtils;
  }
  
  },{}],3:[function(require,module,exports){
  (function (global){
  /*
   *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree.
   */
   /* eslint-env node */
  
  'use strict';
  
  var adapterFactory = require('./adapter_factory.js');
  module.exports = adapterFactory({window: global.window});
  
  }).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
  },{"./adapter_factory.js":4}],4:[function(require,module,exports){
  /*
   *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree.
   */
   /* eslint-env node */
  
  'use strict';
  
  var utils = require('./utils');
  // Shimming starts here.
  module.exports = function(dependencies, opts) {
    var window = dependencies && dependencies.window;
  
    var options = {
      shimChrome: true,
      shimFirefox: true,
      shimEdge: true,
      shimSafari: true,
    };
  
    for (var key in opts) {
      if (hasOwnProperty.call(opts, key)) {
        options[key] = opts[key];
      }
    }
  
    // Utils.
    var logging = utils.log;
    var browserDetails = utils.detectBrowser(window);
  
    // Uncomment the line below if you want logging to occur, including logging
    // for the switch statement below. Can also be turned on in the browser via
    // adapter.disableLog(false), but then logging from the switch statement below
    // will not appear.
    // require('./utils').disableLog(false);
  
    // Browser shims.
    var chromeShim = require('./chrome/chrome_shim') || null;
    var edgeShim = require('./edge/edge_shim') || null;
    var firefoxShim = require('./firefox/firefox_shim') || null;
    var safariShim = require('./safari/safari_shim') || null;
    var commonShim = require('./common_shim') || null;
  
    // Export to the adapter global object visible in the browser.
    var adapter = {
      browserDetails: browserDetails,
      commonShim: commonShim,
      extractVersion: utils.extractVersion,
      disableLog: utils.disableLog,
      disableWarnings: utils.disableWarnings
    };
  
    // Shim browser if found.
    switch (browserDetails.browser) {
      case 'chrome':
        if (!chromeShim || !chromeShim.shimPeerConnection ||
            !options.shimChrome) {
          logging('Chrome shim is not included in this adapter release.');
          return adapter;
        }
        logging('adapter.js shimming chrome.');
        // Export to the adapter global object visible in the browser.
        adapter.browserShim = chromeShim;
        commonShim.shimCreateObjectURL(window);
  
        chromeShim.shimGetUserMedia(window);
        chromeShim.shimMediaStream(window);
        chromeShim.shimSourceObject(window);
        chromeShim.shimPeerConnection(window);
        chromeShim.shimOnTrack(window);
        chromeShim.shimAddTrackRemoveTrack(window);
        chromeShim.shimGetSendersWithDtmf(window);
        chromeShim.shimSenderReceiverGetStats(window);
  
        commonShim.shimRTCIceCandidate(window);
        commonShim.shimMaxMessageSize(window);
        commonShim.shimSendThrowTypeError(window);
        break;
      case 'firefox':
        if (!firefoxShim || !firefoxShim.shimPeerConnection ||
            !options.shimFirefox) {
          logging('Firefox shim is not included in this adapter release.');
          return adapter;
        }
        logging('adapter.js shimming firefox.');
        // Export to the adapter global object visible in the browser.
        adapter.browserShim = firefoxShim;
        commonShim.shimCreateObjectURL(window);
  
        firefoxShim.shimGetUserMedia(window);
        firefoxShim.shimSourceObject(window);
        firefoxShim.shimPeerConnection(window);
        firefoxShim.shimOnTrack(window);
        firefoxShim.shimRemoveStream(window);
        firefoxShim.shimSenderGetStats(window);
        firefoxShim.shimReceiverGetStats(window);
        firefoxShim.shimRTCDataChannel(window);
  
        commonShim.shimRTCIceCandidate(window);
        commonShim.shimMaxMessageSize(window);
        commonShim.shimSendThrowTypeError(window);
        break;
      case 'edge':
        if (!edgeShim || !edgeShim.shimPeerConnection || !options.shimEdge) {
          logging('MS edge shim is not included in this adapter release.');
          return adapter;
        }
        logging('adapter.js shimming edge.');
        // Export to the adapter global object visible in the browser.
        adapter.browserShim = edgeShim;
        commonShim.shimCreateObjectURL(window);
  
        edgeShim.shimGetUserMedia(window);
        edgeShim.shimPeerConnection(window);
        edgeShim.shimReplaceTrack(window);
  
        // the edge shim implements the full RTCIceCandidate object.
  
        commonShim.shimMaxMessageSize(window);
        commonShim.shimSendThrowTypeError(window);
        break;
      case 'safari':
        if (!safariShim || !options.shimSafari) {
          logging('Safari shim is not included in this adapter release.');
          return adapter;
        }
        logging('adapter.js shimming safari.');
        // Export to the adapter global object visible in the browser.
        adapter.browserShim = safariShim;
        commonShim.shimCreateObjectURL(window);
  
        safariShim.shimRTCIceServerUrls(window);
        safariShim.shimCallbacksAPI(window);
        safariShim.shimLocalStreamsAPI(window);
        safariShim.shimRemoteStreamsAPI(window);
        safariShim.shimTrackEventTransceiver(window);
        safariShim.shimGetUserMedia(window);
        safariShim.shimCreateOfferLegacy(window);
  
        commonShim.shimRTCIceCandidate(window);
        commonShim.shimMaxMessageSize(window);
        commonShim.shimSendThrowTypeError(window);
        break;
      default:
        logging('Unsupported browser!');
        break;
    }
  
    return adapter;
  };
  
  },{"./chrome/chrome_shim":5,"./common_shim":7,"./edge/edge_shim":1,"./firefox/firefox_shim":8,"./safari/safari_shim":10,"./utils":11}],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';
  var utils = require('../utils.js');
  var logging = utils.log;
  
  /* iterates the stats graph recursively. */
  function walkStats(stats, base, resultSet) {
    if (!base || resultSet.has(base.id)) {
      return;
    }
    resultSet.set(base.id, base);
    Object.keys(base).forEach(function(name) {
      if (name.endsWith('Id')) {
        walkStats(stats, stats.get(base[name]), resultSet);
      } else if (name.endsWith('Ids')) {
        base[name].forEach(function(id) {
          walkStats(stats, stats.get(id), resultSet);
        });
      }
    });
  }
  
  /* filter getStats for a sender/receiver track. */
  function filterStats(result, track, outbound) {
    var streamStatsType = outbound ? 'outbound-rtp' : 'inbound-rtp';
    var filteredResult = new Map();
    if (track === null) {
      return filteredResult;
    }
    var trackStats = [];
    result.forEach(function(value) {
      if (value.type === 'track' &&
          value.trackIdentifier === track.id) {
        trackStats.push(value);
      }
    });
    trackStats.forEach(function(trackStat) {
      result.forEach(function(stats) {
        if (stats.type === streamStatsType && stats.trackId === trackStat.id) {
          walkStats(result, stats, filteredResult);
        }
      });
    });
    return filteredResult;
  }
  
  module.exports = {
    shimGetUserMedia: require('./getusermedia'),
    shimMediaStream: function(window) {
      window.MediaStream = window.MediaStream || window.webkitMediaStream;
    },
  
    shimOnTrack: function(window) {
      if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
          window.RTCPeerConnection.prototype)) {
        Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
          get: function() {
            return this._ontrack;
          },
          set: function(f) {
            if (this._ontrack) {
              this.removeEventListener('track', this._ontrack);
            }
            this.addEventListener('track', this._ontrack = f);
          }
        });
        var origSetRemoteDescription =
            window.RTCPeerConnection.prototype.setRemoteDescription;
        window.RTCPeerConnection.prototype.setRemoteDescription = function() {
          var pc = this;
          if (!pc._ontrackpoly) {
            pc._ontrackpoly = function(e) {
              // onaddstream does not fire when a track is added to an existing
              // stream. But stream.onaddtrack is implemented so we use that.
              e.stream.addEventListener('addtrack', function(te) {
                var receiver;
                if (window.RTCPeerConnection.prototype.getReceivers) {
                  receiver = pc.getReceivers().find(function(r) {
                    return r.track && r.track.id === te.track.id;
                  });
                } else {
                  receiver = {track: te.track};
                }
  
                var event = new Event('track');
                event.track = te.track;
                event.receiver = receiver;
                event.transceiver = {receiver: receiver};
                event.streams = [e.stream];
                pc.dispatchEvent(event);
              });
              e.stream.getTracks().forEach(function(track) {
                var receiver;
                if (window.RTCPeerConnection.prototype.getReceivers) {
                  receiver = pc.getReceivers().find(function(r) {
                    return r.track && r.track.id === track.id;
                  });
                } else {
                  receiver = {track: track};
                }
                var event = new Event('track');
                event.track = track;
                event.receiver = receiver;
                event.transceiver = {receiver: receiver};
                event.streams = [e.stream];
                pc.dispatchEvent(event);
              });
            };
            pc.addEventListener('addstream', pc._ontrackpoly);
          }
          return origSetRemoteDescription.apply(pc, arguments);
        };
      } else if (!('RTCRtpTransceiver' in window)) {
        utils.wrapPeerConnectionEvent(window, 'track', function(e) {
          if (!e.transceiver) {
            e.transceiver = {receiver: e.receiver};
          }
          return e;
        });
      }
    },
  
    shimGetSendersWithDtmf: function(window) {
      // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
      if (typeof window === 'object' && window.RTCPeerConnection &&
          !('getSenders' in window.RTCPeerConnection.prototype) &&
          'createDTMFSender' in window.RTCPeerConnection.prototype) {
        var shimSenderWithDtmf = function(pc, track) {
          return {
            track: track,
            get dtmf() {
              if (this._dtmf === undefined) {
                if (track.kind === 'audio') {
                  this._dtmf = pc.createDTMFSender(track);
                } else {
                  this._dtmf = null;
                }
              }
              return this._dtmf;
            },
            _pc: pc
          };
        };
  
        // augment addTrack when getSenders is not available.
        if (!window.RTCPeerConnection.prototype.getSenders) {
          window.RTCPeerConnection.prototype.getSenders = function() {
            this._senders = this._senders || [];
            return this._senders.slice(); // return a copy of the internal state.
          };
          var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
          window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
            var pc = this;
            var sender = origAddTrack.apply(pc, arguments);
            if (!sender) {
              sender = shimSenderWithDtmf(pc, track);
              pc._senders.push(sender);
            }
            return sender;
          };
  
          var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
          window.RTCPeerConnection.prototype.removeTrack = function(sender) {
            var pc = this;
            origRemoveTrack.apply(pc, arguments);
            var idx = pc._senders.indexOf(sender);
            if (idx !== -1) {
              pc._senders.splice(idx, 1);
            }
          };
        }
        var origAddStream = window.RTCPeerConnection.prototype.addStream;
        window.RTCPeerConnection.prototype.addStream = function(stream) {
          var pc = this;
          pc._senders = pc._senders || [];
          origAddStream.apply(pc, [stream]);
          stream.getTracks().forEach(function(track) {
            pc._senders.push(shimSenderWithDtmf(pc, track));
          });
        };
  
        var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
        window.RTCPeerConnection.prototype.removeStream = function(stream) {
          var pc = this;
          pc._senders = pc._senders || [];
          origRemoveStream.apply(pc, [stream]);
  
          stream.getTracks().forEach(function(track) {
            var sender = pc._senders.find(function(s) {
              return s.track === track;
            });
            if (sender) {
              pc._senders.splice(pc._senders.indexOf(sender), 1); // remove sender
            }
          });
        };
      } else if (typeof window === 'object' && window.RTCPeerConnection &&
                 'getSenders' in window.RTCPeerConnection.prototype &&
                 'createDTMFSender' in window.RTCPeerConnection.prototype &&
                 window.RTCRtpSender &&
                 !('dtmf' in window.RTCRtpSender.prototype)) {
        var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
        window.RTCPeerConnection.prototype.getSenders = function() {
          var pc = this;
          var senders = origGetSenders.apply(pc, []);
          senders.forEach(function(sender) {
            sender._pc = pc;
          });
          return senders;
        };
  
        Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
          get: function() {
            if (this._dtmf === undefined) {
              if (this.track.kind === 'audio') {
                this._dtmf = this._pc.createDTMFSender(this.track);
              } else {
                this._dtmf = null;
              }
            }
            return this._dtmf;
          }
        });
      }
    },
  
    shimSenderReceiverGetStats: function(window) {
      if (!(typeof window === 'object' && window.RTCPeerConnection &&
          window.RTCRtpSender && window.RTCRtpReceiver)) {
        return;
      }
  
      // shim sender stats.
      if (!('getStats' in window.RTCRtpSender.prototype)) {
        var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
        if (origGetSenders) {
          window.RTCPeerConnection.prototype.getSenders = function() {
            var pc = this;
            var senders = origGetSenders.apply(pc, []);
            senders.forEach(function(sender) {
              sender._pc = pc;
            });
            return senders;
          };
        }
  
        var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
        if (origAddTrack) {
          window.RTCPeerConnection.prototype.addTrack = function() {
            var sender = origAddTrack.apply(this, arguments);
            sender._pc = this;
            return sender;
          };
        }
        window.RTCRtpSender.prototype.getStats = function() {
          var sender = this;
          return this._pc.getStats().then(function(result) {
            /* Note: this will include stats of all senders that
             *   send a track with the same id as sender.track as
             *   it is not possible to identify the RTCRtpSender.
             */
            return filterStats(result, sender.track, true);
          });
        };
      }
  
      // shim receiver stats.
      if (!('getStats' in window.RTCRtpReceiver.prototype)) {
        var origGetReceivers = window.RTCPeerConnection.prototype.getReceivers;
        if (origGetReceivers) {
          window.RTCPeerConnection.prototype.getReceivers = function() {
            var pc = this;
            var receivers = origGetReceivers.apply(pc, []);
            receivers.forEach(function(receiver) {
              receiver._pc = pc;
            });
            return receivers;
          };
        }
        utils.wrapPeerConnectionEvent(window, 'track', function(e) {
          e.receiver._pc = e.srcElement;
          return e;
        });
        window.RTCRtpReceiver.prototype.getStats = function() {
          var receiver = this;
          return this._pc.getStats().then(function(result) {
            return filterStats(result, receiver.track, false);
          });
        };
      }
  
      if (!('getStats' in window.RTCRtpSender.prototype &&
          'getStats' in window.RTCRtpReceiver.prototype)) {
        return;
      }
  
      // shim RTCPeerConnection.getStats(track).
      var origGetStats = window.RTCPeerConnection.prototype.getStats;
      window.RTCPeerConnection.prototype.getStats = function() {
        var pc = this;
        if (arguments.length > 0 &&
            arguments[0] instanceof window.MediaStreamTrack) {
          var track = arguments[0];
          var sender;
          var receiver;
          var err;
          pc.getSenders().forEach(function(s) {
            if (s.track === track) {
              if (sender) {
                err = true;
              } else {
                sender = s;
              }
            }
          });
          pc.getReceivers().forEach(function(r) {
            if (r.track === track) {
              if (receiver) {
                err = true;
              } else {
                receiver = r;
              }
            }
            return r.track === track;
          });
          if (err || (sender && receiver)) {
            return Promise.reject(new DOMException(
              'There are more than one sender or receiver for the track.',
              'InvalidAccessError'));
          } else if (sender) {
            return sender.getStats();
          } else if (receiver) {
            return receiver.getStats();
          }
          return Promise.reject(new DOMException(
            'There is no sender or receiver for the track.',
            'InvalidAccessError'));
        }
        return origGetStats.apply(pc, arguments);
      };
    },
  
    shimSourceObject: function(window) {
      var URL = window && window.URL;
  
      if (typeof window === 'object') {
        if (window.HTMLMediaElement &&
          !('srcObject' in window.HTMLMediaElement.prototype)) {
          // Shim the srcObject property, once, when HTMLMediaElement is found.
          Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
            get: function() {
              return this._srcObject;
            },
            set: function(stream) {
              var self = this;
              // Use _srcObject as a private property for this shim
              this._srcObject = stream;
              if (this.src) {
                URL.revokeObjectURL(this.src);
              }
  
              if (!stream) {
                this.src = '';
                return undefined;
              }
              this.src = URL.createObjectURL(stream);
              // We need to recreate the blob url when a track is added or
              // removed. Doing it manually since we want to avoid a recursion.
              stream.addEventListener('addtrack', function() {
                if (self.src) {
                  URL.revokeObjectURL(self.src);
                }
                self.src = URL.createObjectURL(stream);
              });
              stream.addEventListener('removetrack', function() {
                if (self.src) {
                  URL.revokeObjectURL(self.src);
                }
                self.src = URL.createObjectURL(stream);
              });
            }
          });
        }
      }
    },
  
    shimAddTrackRemoveTrackWithNative: function(window) {
      // shim addTrack/removeTrack with native variants in order to make
      // the interactions with legacy getLocalStreams behave as in other browsers.
      // Keeps a mapping stream.id => [stream, rtpsenders...]
      window.RTCPeerConnection.prototype.getLocalStreams = function() {
        var pc = this;
        this._shimmedLocalStreams = this._shimmedLocalStreams || {};
        return Object.keys(this._shimmedLocalStreams).map(function(streamId) {
          return pc._shimmedLocalStreams[streamId][0];
        });
      };
  
      var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
      window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
        if (!stream) {
          return origAddTrack.apply(this, arguments);
        }
        this._shimmedLocalStreams = this._shimmedLocalStreams || {};
  
        var sender = origAddTrack.apply(this, arguments);
        if (!this._shimmedLocalStreams[stream.id]) {
          this._shimmedLocalStreams[stream.id] = [stream, sender];
        } else if (this._shimmedLocalStreams[stream.id].indexOf(sender) === -1) {
          this._shimmedLocalStreams[stream.id].push(sender);
        }
        return sender;
      };
  
      var origAddStream = window.RTCPeerConnection.prototype.addStream;
      window.RTCPeerConnection.prototype.addStream = function(stream) {
        var pc = this;
        this._shimmedLocalStreams = this._shimmedLocalStreams || {};
  
        stream.getTracks().forEach(function(track) {
          var alreadyExists = pc.getSenders().find(function(s) {
            return s.track === track;
          });
          if (alreadyExists) {
            throw new DOMException('Track already exists.',
                'InvalidAccessError');
          }
        });
        var existingSenders = pc.getSenders();
        origAddStream.apply(this, arguments);
        var newSenders = pc.getSenders().filter(function(newSender) {
          return existingSenders.indexOf(newSender) === -1;
        });
        this._shimmedLocalStreams[stream.id] = [stream].concat(newSenders);
      };
  
      var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
      window.RTCPeerConnection.prototype.removeStream = function(stream) {
        this._shimmedLocalStreams = this._shimmedLocalStreams || {};
        delete this._shimmedLocalStreams[stream.id];
        return origRemoveStream.apply(this, arguments);
      };
  
      var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
      window.RTCPeerConnection.prototype.removeTrack = function(sender) {
        var pc = this;
        this._shimmedLocalStreams = this._shimmedLocalStreams || {};
        if (sender) {
          Object.keys(this._shimmedLocalStreams).forEach(function(streamId) {
            var idx = pc._shimmedLocalStreams[streamId].indexOf(sender);
            if (idx !== -1) {
              pc._shimmedLocalStreams[streamId].splice(idx, 1);
            }
            if (pc._shimmedLocalStreams[streamId].length === 1) {
              delete pc._shimmedLocalStreams[streamId];
            }
          });
        }
        return origRemoveTrack.apply(this, arguments);
      };
    },
  
    shimAddTrackRemoveTrack: function(window) {
      var browserDetails = utils.detectBrowser(window);
      // shim addTrack and removeTrack.
      if (window.RTCPeerConnection.prototype.addTrack &&
          browserDetails.version >= 65) {
        return this.shimAddTrackRemoveTrackWithNative(window);
      }
  
      // also shim pc.getLocalStreams when addTrack is shimmed
      // to return the original streams.
      var origGetLocalStreams = window.RTCPeerConnection.prototype
          .getLocalStreams;
      window.RTCPeerConnection.prototype.getLocalStreams = function() {
        var pc = this;
        var nativeStreams = origGetLocalStreams.apply(this);
        pc._reverseStreams = pc._reverseStreams || {};
        return nativeStreams.map(function(stream) {
          return pc._reverseStreams[stream.id];
        });
      };
  
      var origAddStream = window.RTCPeerConnection.prototype.addStream;
      window.RTCPeerConnection.prototype.addStream = function(stream) {
        var pc = this;
        pc._streams = pc._streams || {};
        pc._reverseStreams = pc._reverseStreams || {};
  
        stream.getTracks().forEach(function(track) {
          var alreadyExists = pc.getSenders().find(function(s) {
            return s.track === track;
          });
          if (alreadyExists) {
            throw new DOMException('Track already exists.',
                'InvalidAccessError');
          }
        });
        // Add identity mapping for consistency with addTrack.
        // Unless this is being used with a stream from addTrack.
        if (!pc._reverseStreams[stream.id]) {
          var newStream = new window.MediaStream(stream.getTracks());
          pc._streams[stream.id] = newStream;
          pc._reverseStreams[newStream.id] = stream;
          stream = newStream;
        }
        origAddStream.apply(pc, [stream]);
      };
  
      var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
      window.RTCPeerConnection.prototype.removeStream = function(stream) {
        var pc = this;
        pc._streams = pc._streams || {};
        pc._reverseStreams = pc._reverseStreams || {};
  
        origRemoveStream.apply(pc, [(pc._streams[stream.id] || stream)]);
        delete pc._reverseStreams[(pc._streams[stream.id] ?
            pc._streams[stream.id].id : stream.id)];
        delete pc._streams[stream.id];
      };
  
      window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
        var pc = this;
        if (pc.signalingState === 'closed') {
          throw new DOMException(
            'The RTCPeerConnection\'s signalingState is \'closed\'.',
            'InvalidStateError');
        }
        var streams = [].slice.call(arguments, 1);
        if (streams.length !== 1 ||
            !streams[0].getTracks().find(function(t) {
              return t === track;
            })) {
          // this is not fully correct but all we can manage without
          // [[associated MediaStreams]] internal slot.
          throw new DOMException(
            'The adapter.js addTrack polyfill only supports a single ' +
            ' stream which is associated with the specified track.',
            'NotSupportedError');
        }
  
        var alreadyExists = pc.getSenders().find(function(s) {
          return s.track === track;
        });
        if (alreadyExists) {
          throw new DOMException('Track already exists.',
              'InvalidAccessError');
        }
  
        pc._streams = pc._streams || {};
        pc._reverseStreams = pc._reverseStreams || {};
        var oldStream = pc._streams[stream.id];
        if (oldStream) {
          // this is using odd Chrome behaviour, use with caution:
          // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
          // Note: we rely on the high-level addTrack/dtmf shim to
          // create the sender with a dtmf sender.
          oldStream.addTrack(track);
  
          // Trigger ONN async.
          Promise.resolve().then(function() {
            pc.dispatchEvent(new Event('negotiationneeded'));
          });
        } else {
          var newStream = new window.MediaStream([track]);
          pc._streams[stream.id] = newStream;
          pc._reverseStreams[newStream.id] = stream;
          pc.addStream(newStream);
        }
        return pc.getSenders().find(function(s) {
          return s.track === track;
        });
      };
  
      // replace the internal stream id with the external one and
      // vice versa.
      function replaceInternalStreamId(pc, description) {
        var sdp = description.sdp;
        Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
          var externalStream = pc._reverseStreams[internalId];
          var internalStream = pc._streams[externalStream.id];
          sdp = sdp.replace(new RegExp(internalStream.id, 'g'),
              externalStream.id);
        });
        return new RTCSessionDescription({
          type: description.type,
          sdp: sdp
        });
      }
      function replaceExternalStreamId(pc, description) {
        var sdp = description.sdp;
        Object.keys(pc._reverseStreams || []).forEach(function(internalId) {
          var externalStream = pc._reverseStreams[internalId];
          var internalStream = pc._streams[externalStream.id];
          sdp = sdp.replace(new RegExp(externalStream.id, 'g'),
              internalStream.id);
        });
        return new RTCSessionDescription({
          type: description.type,
          sdp: sdp
        });
      }
      ['createOffer', 'createAnswer'].forEach(function(method) {
        var nativeMethod = window.RTCPeerConnection.prototype[method];
        window.RTCPeerConnection.prototype[method] = function() {
          var pc = this;
          var args = arguments;
          var isLegacyCall = arguments.length &&
              typeof arguments[0] === 'function';
          if (isLegacyCall) {
            return nativeMethod.apply(pc, [
              function(description) {
                var desc = replaceInternalStreamId(pc, description);
                args[0].apply(null, [desc]);
              },
              function(err) {
                if (args[1]) {
                  args[1].apply(null, err);
                }
              }, arguments[2]
            ]);
          }
          return nativeMethod.apply(pc, arguments)
          .then(function(description) {
            return replaceInternalStreamId(pc, description);
          });
        };
      });
  
      var origSetLocalDescription =
          window.RTCPeerConnection.prototype.setLocalDescription;
      window.RTCPeerConnection.prototype.setLocalDescription = function() {
        var pc = this;
        if (!arguments.length || !arguments[0].type) {
          return origSetLocalDescription.apply(pc, arguments);
        }
        arguments[0] = replaceExternalStreamId(pc, arguments[0]);
        return origSetLocalDescription.apply(pc, arguments);
      };
  
      // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier
  
      var origLocalDescription = Object.getOwnPropertyDescriptor(
          window.RTCPeerConnection.prototype, 'localDescription');
      Object.defineProperty(window.RTCPeerConnection.prototype,
          'localDescription', {
            get: function() {
              var pc = this;
              var description = origLocalDescription.get.apply(this);
              if (description.type === '') {
                return description;
              }
              return replaceInternalStreamId(pc, description);
            }
          });
  
      window.RTCPeerConnection.prototype.removeTrack = function(sender) {
        var pc = this;
        if (pc.signalingState === 'closed') {
          throw new DOMException(
            'The RTCPeerConnection\'s signalingState is \'closed\'.',
            'InvalidStateError');
        }
        // We can not yet check for sender instanceof RTCRtpSender
        // since we shim RTPSender. So we check if sender._pc is set.
        if (!sender._pc) {
          throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' +
              'does not implement interface RTCRtpSender.', 'TypeError');
        }
        var isLocal = sender._pc === pc;
        if (!isLocal) {
          throw new DOMException('Sender was not created by this connection.',
              'InvalidAccessError');
        }
  
        // Search for the native stream the senders track belongs to.
        pc._streams = pc._streams || {};
        var stream;
        Object.keys(pc._streams).forEach(function(streamid) {
          var hasTrack = pc._streams[streamid].getTracks().find(function(track) {
            return sender.track === track;
          });
          if (hasTrack) {
            stream = pc._streams[streamid];
          }
        });
  
        if (stream) {
          if (stream.getTracks().length === 1) {
            // if this is the last track of the stream, remove the stream. This
            // takes care of any shimmed _senders.
            pc.removeStream(pc._reverseStreams[stream.id]);
          } else {
            // relying on the same odd chrome behaviour as above.
            stream.removeTrack(sender.track);
          }
          pc.dispatchEvent(new Event('negotiationneeded'));
        }
      };
    },
  
    shimPeerConnection: function(window) {
      var browserDetails = utils.detectBrowser(window);
  
      // The RTCPeerConnection object.
      if (!window.RTCPeerConnection && window.webkitRTCPeerConnection) {
        window.RTCPeerConnection = function(pcConfig, pcConstraints) {
          // Translate iceTransportPolicy to iceTransports,
          // see https://code.google.com/p/webrtc/issues/detail?id=4869
          // this was fixed in M56 along with unprefixing RTCPeerConnection.
          logging('PeerConnection');
          if (pcConfig && pcConfig.iceTransportPolicy) {
            pcConfig.iceTransports = pcConfig.iceTransportPolicy;
          }
  
          return new window.webkitRTCPeerConnection(pcConfig, pcConstraints);
        };
        window.RTCPeerConnection.prototype =
            window.webkitRTCPeerConnection.prototype;
        // wrap static methods. Currently just generateCertificate.
        if (window.webkitRTCPeerConnection.generateCertificate) {
          Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
            get: function() {
              return window.webkitRTCPeerConnection.generateCertificate;
            }
          });
        }
      } else {
        // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
        var OrigPeerConnection = window.RTCPeerConnection;
        window.RTCPeerConnection = function(pcConfig, pcConstraints) {
          if (pcConfig && pcConfig.iceServers) {
            var newIceServers = [];
            for (var i = 0; i < pcConfig.iceServers.length; i++) {
              var server = pcConfig.iceServers[i];
              if (!server.hasOwnProperty('urls') &&
                  server.hasOwnProperty('url')) {
                utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
                server = JSON.parse(JSON.stringify(server));
                server.urls = server.url;
                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.
        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
          get: function() {
            return OrigPeerConnection.generateCertificate;
          }
        });
      }
  
      var origGetStats = window.RTCPeerConnection.prototype.getStats;
      window.RTCPeerConnection.prototype.getStats = function(selector,
          successCallback, errorCallback) {
        var pc = this;
        var args = arguments;
  
        // If selector is a function then we are in the old style stats so just
        // pass back the original getStats format to avoid breaking old users.
        if (arguments.length > 0 && typeof selector === 'function') {
          return origGetStats.apply(this, arguments);
        }
  
        // When spec-style getStats is supported, return those when called with
        // either no arguments or the selector argument is null.
        if (origGetStats.length === 0 && (arguments.length === 0 ||
            typeof arguments[0] !== 'function')) {
          return origGetStats.apply(this, []);
        }
  
        var fixChromeStats_ = function(response) {
          var standardReport = {};
          var reports = response.result();
          reports.forEach(function(report) {
            var standardStats = {
              id: report.id,
              timestamp: report.timestamp,
              type: {
                localcandidate: 'local-candidate',
                remotecandidate: 'remote-candidate'
              }[report.type] || report.type
            };
            report.names().forEach(function(name) {
              standardStats[name] = report.stat(name);
            });
            standardReport[standardStats.id] = standardStats;
          });
  
          return standardReport;
        };
  
        // shim getStats with maplike support
        var makeMapStats = function(stats) {
          return new Map(Object.keys(stats).map(function(key) {
            return [key, stats[key]];
          }));
        };
  
        if (arguments.length >= 2) {
          var successCallbackWrapper_ = function(response) {
            args[1](makeMapStats(fixChromeStats_(response)));
          };
  
          return origGetStats.apply(this, [successCallbackWrapper_,
            arguments[0]]);
        }
  
        // promise-support
        return new Promise(function(resolve, reject) {
          origGetStats.apply(pc, [
            function(response) {
              resolve(makeMapStats(fixChromeStats_(response)));
            }, reject]);
        }).then(successCallback, errorCallback);
      };
  
      // add promise support -- natively available in Chrome 51
      if (browserDetails.version < 51) {
        ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
            .forEach(function(method) {
              var nativeMethod = window.RTCPeerConnection.prototype[method];
              window.RTCPeerConnection.prototype[method] = function() {
                var args = arguments;
                var pc = this;
                var promise = new Promise(function(resolve, reject) {
                  nativeMethod.apply(pc, [args[0], resolve, reject]);
                });
                if (args.length < 2) {
                  return promise;
                }
                return promise.then(function() {
                  args[1].apply(null, []);
                },
                function(err) {
                  if (args.length >= 3) {
                    args[2].apply(null, [err]);
                  }
                });
              };
            });
      }
  
      // promise support for createOffer and createAnswer. Available (without
      // bugs) since M52: crbug/619289
      if (browserDetails.version < 52) {
        ['createOffer', 'createAnswer'].forEach(function(method) {
          var nativeMethod = window.RTCPeerConnection.prototype[method];
          window.RTCPeerConnection.prototype[method] = function() {
            var pc = this;
            if (arguments.length < 1 || (arguments.length === 1 &&
                typeof arguments[0] === 'object')) {
              var opts = arguments.length === 1 ? arguments[0] : undefined;
              return new Promise(function(resolve, reject) {
                nativeMethod.apply(pc, [resolve, reject, opts]);
              });
            }
            return nativeMethod.apply(this, arguments);
          };
        });
      }
  
      // shim implicit creation of RTCSessionDescription/RTCIceCandidate
      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
          .forEach(function(method) {
            var nativeMethod = window.RTCPeerConnection.prototype[method];
            window.RTCPeerConnection.prototype[method] = function() {
              arguments[0] = new ((method === 'addIceCandidate') ?
                  window.RTCIceCandidate :
                  window.RTCSessionDescription)(arguments[0]);
              return nativeMethod.apply(this, arguments);
            };
          });
  
      // support for addIceCandidate(null or undefined)
      var nativeAddIceCandidate =
          window.RTCPeerConnection.prototype.addIceCandidate;
      window.RTCPeerConnection.prototype.addIceCandidate = function() {
        if (!arguments[0]) {
          if (arguments[1]) {
            arguments[1].apply(null);
          }
          return Promise.resolve();
        }
        return nativeAddIceCandidate.apply(this, arguments);
      };
    }
  };
  
  },{"../utils.js":11,"./getusermedia":6}],6:[function(require,module,exports){
  /*
   *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree.
   */
   /* eslint-env node */
  'use strict';
  var utils = require('../utils.js');
  var logging = utils.log;
  
  // Expose public methods.
  module.exports = function(window) {
    var browserDetails = utils.detectBrowser(window);
    var navigator = window && window.navigator;
  
    var constraintsToChrome_ = function(c) {
      if (typeof c !== 'object' || c.mandatory || c.optional) {
        return c;
      }
      var cc = {};
      Object.keys(c).forEach(function(key) {
        if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
          return;
        }
        var r = (typeof c[key] === 'object') ? c[key] : {ideal: c[key]};
        if (r.exact !== undefined && typeof r.exact === 'number') {
          r.min = r.max = r.exact;
        }
        var oldname_ = function(prefix, name) {
          if (prefix) {
            return prefix + name.charAt(0).toUpperCase() + name.slice(1);
          }
          return (name === 'deviceId') ? 'sourceId' : name;
        };
        if (r.ideal !== undefined) {
          cc.optional = cc.optional || [];
          var oc = {};
          if (typeof r.ideal === 'number') {
            oc[oldname_('min', key)] = r.ideal;
            cc.optional.push(oc);
            oc = {};
            oc[oldname_('max', key)] = r.ideal;
            cc.optional.push(oc);
          } else {
            oc[oldname_('', key)] = r.ideal;
            cc.optional.push(oc);
          }
        }
        if (r.exact !== undefined && typeof r.exact !== 'number') {
          cc.mandatory = cc.mandatory || {};
          cc.mandatory[oldname_('', key)] = r.exact;
        } else {
          ['min', 'max'].forEach(function(mix) {
            if (r[mix] !== undefined) {
              cc.mandatory = cc.mandatory || {};
              cc.mandatory[oldname_(mix, key)] = r[mix];
            }
          });
        }
      });
      if (c.advanced) {
        cc.optional = (cc.optional || []).concat(c.advanced);
      }
      return cc;
    };
  
    var shimConstraints_ = function(constraints, func) {
      if (browserDetails.version >= 61) {
        return func(constraints);
      }
      constraints = JSON.parse(JSON.stringify(constraints));
      if (constraints && typeof constraints.audio === 'object') {
        var remap = function(obj, a, b) {
          if (a in obj && !(b in obj)) {
            obj[b] = obj[a];
            delete obj[a];
          }
        };
        constraints = JSON.parse(JSON.stringify(constraints));
        remap(constraints.audio, 'autoGainControl', 'googAutoGainControl');
        remap(constraints.audio, 'noiseSuppression', 'googNoiseSuppression');
        constraints.audio = constraintsToChrome_(constraints.audio);
      }
      if (constraints && typeof constraints.video === 'object') {
        // Shim facingMode for mobile & surface pro.
        var face = constraints.video.facingMode;
        face = face && ((typeof face === 'object') ? face : {ideal: face});
        var getSupportedFacingModeLies = browserDetails.version < 66;
  
        if ((face && (face.exact === 'user' || face.exact === 'environment' ||
                      face.ideal === 'user' || face.ideal === 'environment')) &&
            !(navigator.mediaDevices.getSupportedConstraints &&
              navigator.mediaDevices.getSupportedConstraints().facingMode &&
              !getSupportedFacingModeLies)) {
          delete constraints.video.facingMode;
          var matches;
          if (face.exact === 'environment' || face.ideal === 'environment') {
            matches = ['back', 'rear'];
          } else if (face.exact === 'user' || face.ideal === 'user') {
            matches = ['front'];
          }
          if (matches) {
            // Look for matches in label, or use last cam for back (typical).
            return navigator.mediaDevices.enumerateDevices()
            .then(function(devices) {
              devices = devices.filter(function(d) {
                return d.kind === 'videoinput';
              });
              var dev = devices.find(function(d) {
                return matches.some(function(match) {
                  return d.label.toLowerCase().indexOf(match) !== -1;
                });
              });
              if (!dev && devices.length && matches.indexOf('back') !== -1) {
                dev = devices[devices.length - 1]; // more likely the back cam
              }
              if (dev) {
                constraints.video.deviceId = face.exact ? {exact: dev.deviceId} :
                                                          {ideal: dev.deviceId};
              }
              constraints.video = constraintsToChrome_(constraints.video);
              logging('chrome: ' + JSON.stringify(constraints));
              return func(constraints);
            });
          }
        }
        constraints.video = constraintsToChrome_(constraints.video);
      }
      logging('chrome: ' + JSON.stringify(constraints));
      return func(constraints);
    };
  
    var shimError_ = function(e) {
      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.constraintName,
        toString: function() {
          return this.name + (this.message && ': ') + this.message;
        }
      };
    };
  
    var getUserMedia_ = function(constraints, onSuccess, onError) {
      shimConstraints_(constraints, function(c) {
        navigator.webkitGetUserMedia(c, onSuccess, function(e) {
          if (onError) {
            onError(shimError_(e));
          }
        });
      });
    };
  
    navigator.getUserMedia = getUserMedia_;
  
    // Returns the result of getUserMedia as a Promise.
    var getUserMediaPromise_ = function(constraints) {
      return new Promise(function(resolve, reject) {
        navigator.getUserMedia(constraints, resolve, reject);
      });
    };
  
    if (!navigator.mediaDevices) {
      navigator.mediaDevices = {
        getUserMedia: getUserMediaPromise_,
        enumerateDevices: function() {
          return new Promise(function(resolve) {
            var kinds = {audio: 'audioinput', video: 'videoinput'};
            return window.MediaStreamTrack.getSources(function(devices) {
              resolve(devices.map(function(device) {
                return {label: device.label,
                  kind: kinds[device.kind],
                  deviceId: device.id,
                  groupId: ''};
              }));
            });
          });
        },
        getSupportedConstraints: function() {
          return {
            deviceId: true, echoCancellation: true, facingMode: true,
            frameRate: true, height: true, width: true
          };
        }
      };
    }
  
    // A shim for getUserMedia method on the mediaDevices object.
    // TODO(KaptenJansson) remove once implemented in Chrome stable.
    if (!navigator.mediaDevices.getUserMedia) {
      navigator.mediaDevices.getUserMedia = function(constraints) {
        return getUserMediaPromise_(constraints);
      };
    } else {
      // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
      // function which returns a Promise, it does not accept spec-style
      // constraints.
      var origGetUserMedia = navigator.mediaDevices.getUserMedia.
          bind(navigator.mediaDevices);
      navigator.mediaDevices.getUserMedia = function(cs) {
        return shimConstraints_(cs, function(c) {
          return origGetUserMedia(c).then(function(stream) {
            if (c.audio && !stream.getAudioTracks().length ||
                c.video && !stream.getVideoTracks().length) {
              stream.getTracks().forEach(function(track) {
                track.stop();
              });
              throw new DOMException('', 'NotFoundError');
            }
            return stream;
          }, function(e) {
            return Promise.reject(shimError_(e));
          });
        });
      };
    }
  
    // Dummy devicechange event methods.
    // TODO(KaptenJansson) remove once implemented in Chrome stable.
    if (typeof navigator.mediaDevices.addEventListener === 'undefined') {
      navigator.mediaDevices.addEventListener = function() {
        logging('Dummy mediaDevices.addEventListener called.');
      };
    }
    if (typeof navigator.mediaDevices.removeEventListener === 'undefined') {
      navigator.mediaDevices.removeEventListener = function() {
        logging('Dummy mediaDevices.removeEventListener called.');
      };
    }
  };
  
  },{"../utils.js":11}],7:[function(require,module,exports){
  /*
   *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree.
   */
   /* eslint-env node */
  'use strict';
  
  var SDPUtils = require('sdp');
  var utils = require('./utils');
  
  module.exports = {
    shimRTCIceCandidate: function(window) {
      // foundation is arbitrarily chosen as an indicator for full support for
      // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
      if (!window.RTCIceCandidate || (window.RTCIceCandidate && 'foundation' in
          window.RTCIceCandidate.prototype)) {
        return;
      }
  
      var NativeRTCIceCandidate = window.RTCIceCandidate;
      window.RTCIceCandidate = function(args) {
        // Remove the a= which shouldn't be part of the candidate string.
        if (typeof args === 'object' && args.candidate &&
            args.candidate.indexOf('a=') === 0) {
          args = JSON.parse(JSON.stringify(args));
          args.candidate = args.candidate.substr(2);
        }
  
        if (args.candidate && args.candidate.length) {
          // Augment the native candidate with the parsed fields.
          var nativeCandidate = new NativeRTCIceCandidate(args);
          var parsedCandidate = SDPUtils.parseCandidate(args.candidate);
          var augmentedCandidate = Object.assign(nativeCandidate,
              parsedCandidate);
  
          // Add a serializer that does not serialize the extra attributes.
          augmentedCandidate.toJSON = function() {
            return {
              candidate: augmentedCandidate.candidate,
              sdpMid: augmentedCandidate.sdpMid,
              sdpMLineIndex: augmentedCandidate.sdpMLineIndex,
              usernameFragment: augmentedCandidate.usernameFragment,
            };
          };
          return augmentedCandidate;
        }
        return new NativeRTCIceCandidate(args);
      };
      window.RTCIceCandidate.prototype = NativeRTCIceCandidate.prototype;
  
      // Hook up the augmented candidate in onicecandidate and
      // addEventListener('icecandidate', ...)
      utils.wrapPeerConnectionEvent(window, 'icecandidate', function(e) {
        if (e.candidate) {
          Object.defineProperty(e, 'candidate', {
            value: new window.RTCIceCandidate(e.candidate),
            writable: 'false'
          });
        }
        return e;
      });
    },
  
    // shimCreateObjectURL must be called before shimSourceObject to avoid loop.
  
    shimCreateObjectURL: function(window) {
      var URL = window && window.URL;
  
      if (!(typeof window === 'object' && window.HTMLMediaElement &&
            'srcObject' in window.HTMLMediaElement.prototype &&
          URL.createObjectURL && URL.revokeObjectURL)) {
        // Only shim CreateObjectURL using srcObject if srcObject exists.
        return undefined;
      }
  
      var nativeCreateObjectURL = URL.createObjectURL.bind(URL);
      var nativeRevokeObjectURL = URL.revokeObjectURL.bind(URL);
      var streams = new Map(), newId = 0;
  
      URL.createObjectURL = function(stream) {
        if ('getTracks' in stream) {
          var url = 'polyblob:' + (++newId);
          streams.set(url, stream);
          utils.deprecated('URL.createObjectURL(stream)',
              'elem.srcObject = stream');
          return url;
        }
        return nativeCreateObjectURL(stream);
      };
      URL.revokeObjectURL = function(url) {
        nativeRevokeObjectURL(url);
        streams.delete(url);
      };
  
      var dsc = Object.getOwnPropertyDescriptor(window.HTMLMediaElement.prototype,
                                                'src');
      Object.defineProperty(window.HTMLMediaElement.prototype, 'src', {
        get: function() {
          return dsc.get.apply(this);
        },
        set: function(url) {
          this.srcObject = streams.get(url) || null;
          return dsc.set.apply(this, [url]);
        }
      });
  
      var nativeSetAttribute = window.HTMLMediaElement.prototype.setAttribute;
      window.HTMLMediaElement.prototype.setAttribute = function() {
        if (arguments.length === 2 &&
            ('' + arguments[0]).toLowerCase() === 'src') {
          this.srcObject = streams.get(arguments[1]) || null;
        }
        return nativeSetAttribute.apply(this, arguments);
      };
    },
  
    shimMaxMessageSize: function(window) {
      if (window.RTCSctpTransport || !window.RTCPeerConnection) {
        return;
      }
      var browserDetails = utils.detectBrowser(window);
  
      if (!('sctp' in window.RTCPeerConnection.prototype)) {
        Object.defineProperty(window.RTCPeerConnection.prototype, 'sctp', {
          get: function() {
            return typeof this._sctp === 'undefined' ? null : this._sctp;
          }
        });
      }
  
      var sctpInDescription = function(description) {
        var sections = SDPUtils.splitSections(description.sdp);
        sections.shift();
        return sections.some(function(mediaSection) {
          var mLine = SDPUtils.parseMLine(mediaSection);
          return mLine && mLine.kind === 'application'
              && mLine.protocol.indexOf('SCTP') !== -1;
        });
      };
  
      var getRemoteFirefoxVersion = function(description) {
        // TODO: Is there a better solution for detecting Firefox?
        var match = description.sdp.match(/mozilla...THIS_IS_SDPARTA-(\d+)/);
        if (match === null || match.length < 2) {
          return -1;
        }
        var version = parseInt(match[1], 10);
        // Test for NaN (yes, this is ugly)
        return version !== version ? -1 : version;
      };
  
      var getCanSendMaxMessageSize = function(remoteIsFirefox) {
        // Every implementation we know can send at least 64 KiB.
        // Note: Although Chrome is technically able to send up to 256 KiB, the
        //       data does not reach the other peer reliably.
        //       See: https://bugs.chromium.org/p/webrtc/issues/detail?id=8419
        var canSendMaxMessageSize = 65536;
        if (browserDetails.browser === 'firefox') {
          if (browserDetails.version < 57) {
            if (remoteIsFirefox === -1) {
              // FF < 57 will send in 16 KiB chunks using the deprecated PPID
              // fragmentation.
              canSendMaxMessageSize = 16384;
            } else {
              // However, other FF (and RAWRTC) can reassemble PPID-fragmented
              // messages. Thus, supporting ~2 GiB when sending.
              canSendMaxMessageSize = 2147483637;
            }
          } else if (browserDetails.version < 60) {
            // Currently, all FF >= 57 will reset the remote maximum message size
            // to the default value when a data channel is created at a later
            // stage. :(
            // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
            canSendMaxMessageSize =
              browserDetails.version === 57 ? 65535 : 65536;
          } else {
            // FF >= 60 supports sending ~2 GiB
            canSendMaxMessageSize = 2147483637;
          }
        }
        return canSendMaxMessageSize;
      };
  
      var getMaxMessageSize = function(description, remoteIsFirefox) {
        // Note: 65536 bytes is the default value from the SDP spec. Also,
        //       every implementation we know supports receiving 65536 bytes.
        var maxMessageSize = 65536;
  
        // FF 57 has a slightly incorrect default remote max message size, so
        // we need to adjust it here to avoid a failure when sending.
        // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1425697
        if (browserDetails.browser === 'firefox'
             && browserDetails.version === 57) {
          maxMessageSize = 65535;
        }
  
        var match = SDPUtils.matchPrefix(description.sdp, 'a=max-message-size:');
        if (match.length > 0) {
          maxMessageSize = parseInt(match[0].substr(19), 10);
        } else if (browserDetails.browser === 'firefox' &&
                    remoteIsFirefox !== -1) {
          // If the maximum message size is not present in the remote SDP and
          // both local and remote are Firefox, the remote peer can receive
          // ~2 GiB.
          maxMessageSize = 2147483637;
        }
        return maxMessageSize;
      };
  
      var origSetRemoteDescription =
          window.RTCPeerConnection.prototype.setRemoteDescription;
      window.RTCPeerConnection.prototype.setRemoteDescription = function() {
        var pc = this;
        pc._sctp = null;
  
        if (sctpInDescription(arguments[0])) {
          // Check if the remote is FF.
          var isFirefox = getRemoteFirefoxVersion(arguments[0]);
  
          // Get the maximum message size the local peer is capable of sending
          var canSendMMS = getCanSendMaxMessageSize(isFirefox);
  
          // Get the maximum message size of the remote peer.
          var remoteMMS = getMaxMessageSize(arguments[0], isFirefox);
  
          // Determine final maximum message size
          var maxMessageSize;
          if (canSendMMS === 0 && remoteMMS === 0) {
            maxMessageSize = Number.POSITIVE_INFINITY;
          } else if (canSendMMS === 0 || remoteMMS === 0) {
            maxMessageSize = Math.max(canSendMMS, remoteMMS);
          } else {
            maxMessageSize = Math.min(canSendMMS, remoteMMS);
          }
  
          // Create a dummy RTCSctpTransport object and the 'maxMessageSize'
          // attribute.
          var sctp = {};
          Object.defineProperty(sctp, 'maxMessageSize', {
            get: function() {
              return maxMessageSize;
            }
          });
          pc._sctp = sctp;
        }
  
        return origSetRemoteDescription.apply(pc, arguments);
      };
    },
  
    shimSendThrowTypeError: function(window) {
      if (!(window.RTCPeerConnection &&
          'createDataChannel' in window.RTCPeerConnection.prototype)) {
        return;
      }
  
      // Note: Although Firefox >= 57 has a native implementation, the maximum
      //       message size can be reset for all data channels at a later stage.
      //       See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
  
      function wrapDcSend(dc, pc) {
        var origDataChannelSend = dc.send;
        dc.send = function() {
          var data = arguments[0];
          var length = data.length || data.size || data.byteLength;
          if (dc.readyState === 'open' &&
              pc.sctp && length > pc.sctp.maxMessageSize) {
            throw new TypeError('Message too large (can send a maximum of ' +
              pc.sctp.maxMessageSize + ' bytes)');
          }
          return origDataChannelSend.apply(dc, arguments);
        };
      }
      var origCreateDataChannel =
        window.RTCPeerConnection.prototype.createDataChannel;
      window.RTCPeerConnection.prototype.createDataChannel = function() {
        var pc = this;
        var dataChannel = origCreateDataChannel.apply(pc, arguments);
        wrapDcSend(dataChannel, pc);
        return dataChannel;
      };
      utils.wrapPeerConnectionEvent(window, 'datachannel', function(e) {
        wrapDcSend(e.channel, e.target);
        return e;
      });
    }
  };
  
  },{"./utils":11,"sdp":2}],8:[function(require,module,exports){
  /*
   *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree.
   */
   /* eslint-env node */
  'use strict';
  
  var utils = require('../utils');
  
  module.exports = {
    shimGetUserMedia: require('./getusermedia'),
    shimOnTrack: function(window) {
      if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
          window.RTCPeerConnection.prototype)) {
        Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
          get: function() {
            return this._ontrack;
          },
          set: function(f) {
            if (this._ontrack) {
              this.removeEventListener('track', this._ontrack);
              this.removeEventListener('addstream', this._ontrackpoly);
            }
            this.addEventListener('track', this._ontrack = f);
            this.addEventListener('addstream', this._ontrackpoly = function(e) {
              e.stream.getTracks().forEach(function(track) {
                var event = new Event('track');
                event.track = track;
                event.receiver = {track: track};
                event.transceiver = {receiver: event.receiver};
                event.streams = [e.stream];
                this.dispatchEvent(event);
              }.bind(this));
            }.bind(this));
          }
        });
      }
      if (typeof window === 'object' && window.RTCTrackEvent &&
          ('receiver' in window.RTCTrackEvent.prototype) &&
          !('transceiver' in window.RTCTrackEvent.prototype)) {
        Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
          get: function() {
            return {receiver: this.receiver};
          }
        });
      }
    },
  
    shimSourceObject: function(window) {
      // Firefox has supported mozSrcObject since FF22, unprefixed in 42.
      if (typeof window === 'object') {
        if (window.HTMLMediaElement &&
          !('srcObject' in window.HTMLMediaElement.prototype)) {
          // Shim the srcObject property, once, when HTMLMediaElement is found.
          Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
            get: function() {
              return this.mozSrcObject;
            },
            set: function(stream) {
              this.mozSrcObject = stream;
            }
          });
        }
      }
    },
  
    shimPeerConnection: function(window) {
      var browserDetails = utils.detectBrowser(window);
  
      if (typeof window !== 'object' || !(window.RTCPeerConnection ||
          window.mozRTCPeerConnection)) {
        return; // probably media.peerconnection.enabled=false in about:config
      }
      // The RTCPeerConnection object.
      if (!window.RTCPeerConnection) {
        window.RTCPeerConnection = function(pcConfig, pcConstraints) {
          if (browserDetails.version < 38) {
            // .urls is not supported in FF < 38.
            // create RTCIceServers with a single url.
            if (pcConfig && pcConfig.iceServers) {
              var newIceServers = [];
              for (var i = 0; i < pcConfig.iceServers.length; i++) {
                var server = pcConfig.iceServers[i];
                if (server.hasOwnProperty('urls')) {
                  for (var j = 0; j < server.urls.length; j++) {
                    var newServer = {
                      url: server.urls[j]
                    };
                    if (server.urls[j].indexOf('turn') === 0) {
                      newServer.username = server.username;
                      newServer.credential = server.credential;
                    }
                    newIceServers.push(newServer);
                  }
                } else {
                  newIceServers.push(pcConfig.iceServers[i]);
                }
              }
              pcConfig.iceServers = newIceServers;
            }
          }
          return new window.mozRTCPeerConnection(pcConfig, pcConstraints);
        };
        window.RTCPeerConnection.prototype =
            window.mozRTCPeerConnection.prototype;
  
        // wrap static methods. Currently just generateCertificate.
        if (window.mozRTCPeerConnection.generateCertificate) {
          Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
            get: function() {
              return window.mozRTCPeerConnection.generateCertificate;
            }
          });
        }
  
        window.RTCSessionDescription = window.mozRTCSessionDescription;
        window.RTCIceCandidate = window.mozRTCIceCandidate;
      }
  
      // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
          .forEach(function(method) {
            var nativeMethod = window.RTCPeerConnection.prototype[method];
            window.RTCPeerConnection.prototype[method] = function() {
              arguments[0] = new ((method === 'addIceCandidate') ?
                  window.RTCIceCandidate :
                  window.RTCSessionDescription)(arguments[0]);
              return nativeMethod.apply(this, arguments);
            };
          });
  
      // support for addIceCandidate(null or undefined)
      var nativeAddIceCandidate =
          window.RTCPeerConnection.prototype.addIceCandidate;
      window.RTCPeerConnection.prototype.addIceCandidate = function() {
        if (!arguments[0]) {
          if (arguments[1]) {
            arguments[1].apply(null);
          }
          return Promise.resolve();
        }
        return nativeAddIceCandidate.apply(this, arguments);
      };
  
      // shim getStats with maplike support
      var makeMapStats = function(stats) {
        var map = new Map();
        Object.keys(stats).forEach(function(key) {
          map.set(key, stats[key]);
          map[key] = stats[key];
        });
        return map;
      };
  
      var modernStatsTypes = {
        inboundrtp: 'inbound-rtp',
        outboundrtp: 'outbound-rtp',
        candidatepair: 'candidate-pair',
        localcandidate: 'local-candidate',
        remotecandidate: 'remote-candidate'
      };
  
      var nativeGetStats = window.RTCPeerConnection.prototype.getStats;
      window.RTCPeerConnection.prototype.getStats = function(
        selector,
        onSucc,
        onErr
      ) {
        return nativeGetStats.apply(this, [selector || null])
          .then(function(stats) {
            if (browserDetails.version < 48) {
              stats = makeMapStats(stats);
            }
            if (browserDetails.version < 53 && !onSucc) {
              // Shim only promise getStats with spec-hyphens in type names
              // Leave callback version alone; misc old uses of forEach before Map
              try {
                stats.forEach(function(stat) {
                  stat.type = modernStatsTypes[stat.type] || stat.type;
                });
              } catch (e) {
                if (e.name !== 'TypeError') {
                  throw e;
                }
                // Avoid TypeError: "type" is read-only, in old versions. 34-43ish
                stats.forEach(function(stat, i) {
                  stats.set(i, Object.assign({}, stat, {
                    type: modernStatsTypes[stat.type] || stat.type
                  }));
                });
              }
            }
            return stats;
          })
          .then(onSucc, onErr);
      };
    },
  
    shimSenderGetStats: function(window) {
      if (!(typeof window === 'object' && window.RTCPeerConnection &&
          window.RTCRtpSender)) {
        return;
      }
      if (window.RTCRtpSender && 'getStats' in window.RTCRtpSender.prototype) {
        return;
      }
      var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
      if (origGetSenders) {
        window.RTCPeerConnection.prototype.getSenders = function() {
          var pc = this;
          var senders = origGetSenders.apply(pc, []);
          senders.forEach(function(sender) {
            sender._pc = pc;
          });
          return senders;
        };
      }
  
      var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
      if (origAddTrack) {
        window.RTCPeerConnection.prototype.addTrack = function() {
          var sender = origAddTrack.apply(this, arguments);
          sender._pc = this;
          return sender;
        };
      }
      window.RTCRtpSender.prototype.getStats = function() {
        return this.track ? this._pc.getStats(this.track) :
            Promise.resolve(new Map());
      };
    },
  
    shimReceiverGetStats: function(window) {
      if (!(typeof window === 'object' && window.RTCPeerConnection &&
          window.RTCRtpSender)) {
        return;
      }
      if (window.RTCRtpSender && 'getStats' in window.RTCRtpReceiver.prototype) {
        return;
      }
      var origGetReceivers = window.RTCPeerConnection.prototype.getReceivers;
      if (origGetReceivers) {
        window.RTCPeerConnection.prototype.getReceivers = function() {
          var pc = this;
          var receivers = origGetReceivers.apply(pc, []);
          receivers.forEach(function(receiver) {
            receiver._pc = pc;
          });
          return receivers;
        };
      }
      utils.wrapPeerConnectionEvent(window, 'track', function(e) {
        e.receiver._pc = e.srcElement;
        return e;
      });
      window.RTCRtpReceiver.prototype.getStats = function() {
        return this._pc.getStats(this.track);
      };
    },
  
    shimRemoveStream: function(window) {
      if (!window.RTCPeerConnection ||
          'removeStream' in window.RTCPeerConnection.prototype) {
        return;
      }
      window.RTCPeerConnection.prototype.removeStream = function(stream) {
        var pc = this;
        utils.deprecated('removeStream', 'removeTrack');
        this.getSenders().forEach(function(sender) {
          if (sender.track && stream.getTracks().indexOf(sender.track) !== -1) {
            pc.removeTrack(sender);
          }
        });
      };
    },
  
    shimRTCDataChannel: function(window) {
      // rename DataChannel to RTCDataChannel (native fix in FF60):
      // https://bugzilla.mozilla.org/show_bug.cgi?id=1173851
      if (window.DataChannel && !window.RTCDataChannel) {
        window.RTCDataChannel = window.DataChannel;
      }
    },
  };
  
  },{"../utils":11,"./getusermedia":9}],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';
  
  var utils = require('../utils');
  var logging = utils.log;
  
  // Expose public methods.
  module.exports = function(window) {
    var browserDetails = utils.detectBrowser(window);
    var navigator = window && window.navigator;
    var MediaStreamTrack = window && window.MediaStreamTrack;
  
    var shimError_ = function(e) {
      return {
        name: {
          InternalError: 'NotReadableError',
          NotSupportedError: 'TypeError',
          PermissionDeniedError: 'NotAllowedError',
          SecurityError: 'NotAllowedError'
        }[e.name] || e.name,
        message: {
          'The operation is insecure.': 'The request is not allowed by the ' +
          'user agent or the platform in the current context.'
        }[e.message] || e.message,
        constraint: e.constraint,
        toString: function() {
          return this.name + (this.message && ': ') + this.message;
        }
      };
    };
  
    // getUserMedia constraints shim.
    var getUserMedia_ = function(constraints, onSuccess, onError) {
      var constraintsToFF37_ = function(c) {
        if (typeof c !== 'object' || c.require) {
          return c;
        }
        var require = [];
        Object.keys(c).forEach(function(key) {
          if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
            return;
          }
          var r = c[key] = (typeof c[key] === 'object') ?
              c[key] : {ideal: c[key]};
          if (r.min !== undefined ||
              r.max !== undefined || r.exact !== undefined) {
            require.push(key);
          }
          if (r.exact !== undefined) {
            if (typeof r.exact === 'number') {
              r. min = r.max = r.exact;
            } else {
              c[key] = r.exact;
            }
            delete r.exact;
          }
          if (r.ideal !== undefined) {
            c.advanced = c.advanced || [];
            var oc = {};
            if (typeof r.ideal === 'number') {
              oc[key] = {min: r.ideal, max: r.ideal};
            } else {
              oc[key] = r.ideal;
            }
            c.advanced.push(oc);
            delete r.ideal;
            if (!Object.keys(r).length) {
              delete c[key];
            }
          }
        });
        if (require.length) {
          c.require = require;
        }
        return c;
      };
      constraints = JSON.parse(JSON.stringify(constraints));
      if (browserDetails.version < 38) {
        logging('spec: ' + JSON.stringify(constraints));
        if (constraints.audio) {
          constraints.audio = constraintsToFF37_(constraints.audio);
        }
        if (constraints.video) {
          constraints.video = constraintsToFF37_(constraints.video);
        }
        logging('ff37: ' + JSON.stringify(constraints));
      }
      return navigator.mozGetUserMedia(constraints, onSuccess, function(e) {
        onError(shimError_(e));
      });
    };
  
    // Returns the result of getUserMedia as a Promise.
    var getUserMediaPromise_ = function(constraints) {
      return new Promise(function(resolve, reject) {
        getUserMedia_(constraints, resolve, reject);
      });
    };
  
    // Shim for mediaDevices on older versions.
    if (!navigator.mediaDevices) {
      navigator.mediaDevices = {getUserMedia: getUserMediaPromise_,
        addEventListener: function() { },
        removeEventListener: function() { }
      };
    }
    navigator.mediaDevices.enumerateDevices =
        navigator.mediaDevices.enumerateDevices || function() {
          return new Promise(function(resolve) {
            var infos = [
              {kind: 'audioinput', deviceId: 'default', label: '', groupId: ''},
              {kind: 'videoinput', deviceId: 'default', label: '', groupId: ''}
            ];
            resolve(infos);
          });
        };
  
    if (browserDetails.version < 41) {
      // Work around http://bugzil.la/1169665
      var orgEnumerateDevices =
          navigator.mediaDevices.enumerateDevices.bind(navigator.mediaDevices);
      navigator.mediaDevices.enumerateDevices = function() {
        return orgEnumerateDevices().then(undefined, function(e) {
          if (e.name === 'NotFoundError') {
            return [];
          }
          throw e;
        });
      };
    }
    if (browserDetails.version < 49) {
      var origGetUserMedia = navigator.mediaDevices.getUserMedia.
          bind(navigator.mediaDevices);
      navigator.mediaDevices.getUserMedia = function(c) {
        return origGetUserMedia(c).then(function(stream) {
          // Work around https://bugzil.la/802326
          if (c.audio && !stream.getAudioTracks().length ||
              c.video && !stream.getVideoTracks().length) {
            stream.getTracks().forEach(function(track) {
              track.stop();
            });
            throw new DOMException('The object can not be found here.',
                                   'NotFoundError');
          }
          return stream;
        }, function(e) {
          return Promise.reject(shimError_(e));
        });
      };
    }
    if (!(browserDetails.version > 55 &&
        'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
      var remap = function(obj, a, b) {
        if (a in obj && !(b in obj)) {
          obj[b] = obj[a];
          delete obj[a];
        }
      };
  
      var nativeGetUserMedia = navigator.mediaDevices.getUserMedia.
          bind(navigator.mediaDevices);
      navigator.mediaDevices.getUserMedia = function(c) {
        if (typeof c === 'object' && typeof c.audio === 'object') {
          c = JSON.parse(JSON.stringify(c));
          remap(c.audio, 'autoGainControl', 'mozAutoGainControl');
          remap(c.audio, 'noiseSuppression', 'mozNoiseSuppression');
        }
        return nativeGetUserMedia(c);
      };
  
      if (MediaStreamTrack && MediaStreamTrack.prototype.getSettings) {
        var nativeGetSettings = MediaStreamTrack.prototype.getSettings;
        MediaStreamTrack.prototype.getSettings = function() {
          var obj = nativeGetSettings.apply(this, arguments);
          remap(obj, 'mozAutoGainControl', 'autoGainControl');
          remap(obj, 'mozNoiseSuppression', 'noiseSuppression');
          return obj;
        };
      }
  
      if (MediaStreamTrack && MediaStreamTrack.prototype.applyConstraints) {
        var nativeApplyConstraints = MediaStreamTrack.prototype.applyConstraints;
        MediaStreamTrack.prototype.applyConstraints = function(c) {
          if (this.kind === 'audio' && typeof c === 'object') {
            c = JSON.parse(JSON.stringify(c));
            remap(c, 'autoGainControl', 'mozAutoGainControl');
            remap(c, 'noiseSuppression', 'mozNoiseSuppression');
          }
          return nativeApplyConstraints.apply(this, [c]);
        };
      }
    }
    navigator.getUserMedia = function(constraints, onSuccess, onError) {
      if (browserDetails.version < 44) {
        return getUserMedia_(constraints, onSuccess, onError);
      }
      // Replace Firefox 44+'s deprecation warning with unprefixed version.
      utils.deprecated('navigator.getUserMedia',
          'navigator.mediaDevices.getUserMedia');
      navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
    };
  };
  
  },{"../utils":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';
  var utils = require('../utils');
  
  module.exports = {
    shimLocalStreamsAPI: function(window) {
      if (typeof window !== 'object' || !window.RTCPeerConnection) {
        return;
      }
      if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
        window.RTCPeerConnection.prototype.getLocalStreams = function() {
          if (!this._localStreams) {
            this._localStreams = [];
          }
          return this._localStreams;
        };
      }
      if (!('getStreamById' in window.RTCPeerConnection.prototype)) {
        window.RTCPeerConnection.prototype.getStreamById = function(id) {
          var result = null;
          if (this._localStreams) {
            this._localStreams.forEach(function(stream) {
              if (stream.id === id) {
                result = stream;
              }
            });
          }
          if (this._remoteStreams) {
            this._remoteStreams.forEach(function(stream) {
              if (stream.id === id) {
                result = stream;
              }
            });
          }
          return result;
        };
      }
      if (!('addStream' in window.RTCPeerConnection.prototype)) {
        var _addTrack = window.RTCPeerConnection.prototype.addTrack;
        window.RTCPeerConnection.prototype.addStream = function(stream) {
          if (!this._localStreams) {
            this._localStreams = [];
          }
          if (this._localStreams.indexOf(stream) === -1) {
            this._localStreams.push(stream);
          }
          var pc = this;
          stream.getTracks().forEach(function(track) {
            _addTrack.call(pc, track, stream);
          });
        };
  
        window.RTCPeerConnection.prototype.addTrack = function(track, stream) {
          if (stream) {
            if (!this._localStreams) {
              this._localStreams = [stream];
            } else if (this._localStreams.indexOf(stream) === -1) {
              this._localStreams.push(stream);
            }
          }
          return _addTrack.call(this, track, stream);
        };
      }
      if (!('removeStream' in window.RTCPeerConnection.prototype)) {
        window.RTCPeerConnection.prototype.removeStream = function(stream) {
          if (!this._localStreams) {
            this._localStreams = [];
          }
          var index = this._localStreams.indexOf(stream);
          if (index === -1) {
            return;
          }
          this._localStreams.splice(index, 1);
          var pc = this;
          var tracks = stream.getTracks();
          this.getSenders().forEach(function(sender) {
            if (tracks.indexOf(sender.track) !== -1) {
              pc.removeTrack(sender);
            }
          });
        };
      }
    },
    shimRemoteStreamsAPI: function(window) {
      if (typeof window !== 'object' || !window.RTCPeerConnection) {
        return;
      }
      if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
        window.RTCPeerConnection.prototype.getRemoteStreams = function() {
          return this._remoteStreams ? this._remoteStreams : [];
        };
      }
      if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
        Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
          get: function() {
            return this._onaddstream;
          },
          set: function(f) {
            var pc = 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 (!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);
              });
            });
          }
        });
      }
    },
    shimCallbacksAPI: function(window) {
      if (typeof window !== 'object' || !window.RTCPeerConnection) {
        return;
      }
      var prototype = window.RTCPeerConnection.prototype;
      var createOffer = prototype.createOffer;
      var createAnswer = prototype.createAnswer;
      var setLocalDescription = prototype.setLocalDescription;
      var setRemoteDescription = prototype.setRemoteDescription;
      var addIceCandidate = prototype.addIceCandidate;
  
      prototype.createOffer = function(successCallback, failureCallback) {
        var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
        var promise = createOffer.apply(this, [options]);
        if (!failureCallback) {
          return promise;
        }
        promise.then(successCallback, failureCallback);
        return Promise.resolve();
      };
  
      prototype.createAnswer = function(successCallback, failureCallback) {
        var options = (arguments.length >= 2) ? arguments[2] : arguments[0];
        var promise = createAnswer.apply(this, [options]);
        if (!failureCallback) {
          return promise;
        }
        promise.then(successCallback, failureCallback);
        return Promise.resolve();
      };
  
      var withCallback = function(description, successCallback, failureCallback) {
        var promise = setLocalDescription.apply(this, [description]);
        if (!failureCallback) {
          return promise;
        }
        promise.then(successCallback, failureCallback);
        return Promise.resolve();
      };
      prototype.setLocalDescription = withCallback;
  
      withCallback = function(description, successCallback, failureCallback) {
        var promise = setRemoteDescription.apply(this, [description]);
        if (!failureCallback) {
          return promise;
        }
        promise.then(successCallback, failureCallback);
        return Promise.resolve();
      };
      prototype.setRemoteDescription = withCallback;
  
      withCallback = function(candidate, successCallback, failureCallback) {
        var promise = addIceCandidate.apply(this, [candidate]);
        if (!failureCallback) {
          return promise;
        }
        promise.then(successCallback, failureCallback);
        return Promise.resolve();
      };
      prototype.addIceCandidate = withCallback;
    },
    shimGetUserMedia: function(window) {
      var navigator = window && window.navigator;
  
      if (!navigator.getUserMedia) {
        if (navigator.webkitGetUserMedia) {
          navigator.getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
        } else if (navigator.mediaDevices &&
            navigator.mediaDevices.getUserMedia) {
          navigator.getUserMedia = function(constraints, cb, errcb) {
            navigator.mediaDevices.getUserMedia(constraints)
            .then(cb, errcb);
          }.bind(navigator);
        }
      }
    },
    shimRTCIceServerUrls: function(window) {
      // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
      var OrigPeerConnection = window.RTCPeerConnection;
      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
        if (pcConfig && pcConfig.iceServers) {
          var newIceServers = [];
          for (var i = 0; i < pcConfig.iceServers.length; i++) {
            var server = pcConfig.iceServers[i];
            if (!server.hasOwnProperty('urls') &&
                server.hasOwnProperty('url')) {
              utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
              server = JSON.parse(JSON.stringify(server));
              server.urls = server.url;
              delete server.url;
              newIceServers.push(server);
            } else {
              newIceServers.push(pcConfig.iceServers[i]);
            }
          }
          pcConfig.iceServers = newIceServers;
        }
        return new OrigPeerConnection(pcConfig, pcConstraints);
      };
      window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
      // wrap static methods. Currently just generateCertificate.
      if ('generateCertificate' in window.RTCPeerConnection) {
        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
          get: function() {
            return OrigPeerConnection.generateCertificate;
          }
        });
      }
    },
    shimTrackEventTransceiver: function(window) {
      // Add event.transceiver member over deprecated event.receiver
      if (typeof window === 'object' && window.RTCPeerConnection &&
          ('receiver' in window.RTCTrackEvent.prototype) &&
          // can't check 'transceiver' in window.RTCTrackEvent.prototype, as it is
          // defined for some reason even when window.RTCTransceiver is not.
          !window.RTCTransceiver) {
        Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
          get: function() {
            return {receiver: this.receiver};
          }
        });
      }
    },
  
    shimCreateOfferLegacy: function(window) {
      var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
      window.RTCPeerConnection.prototype.createOffer = function(offerOptions) {
        var pc = this;
        if (offerOptions) {
          if (typeof offerOptions.offerToReceiveAudio !== 'undefined') {
            // support bit values
            offerOptions.offerToReceiveAudio = !!offerOptions.offerToReceiveAudio;
          }
          var audioTransceiver = pc.getTransceivers().find(function(transceiver) {
            return transceiver.sender.track &&
                transceiver.sender.track.kind === 'audio';
          });
          if (offerOptions.offerToReceiveAudio === false && audioTransceiver) {
            if (audioTransceiver.direction === 'sendrecv') {
              if (audioTransceiver.setDirection) {
                audioTransceiver.setDirection('sendonly');
              } else {
                audioTransceiver.direction = 'sendonly';
              }
            } else if (audioTransceiver.direction === 'recvonly') {
              if (audioTransceiver.setDirection) {
                audioTransceiver.setDirection('inactive');
              } else {
                audioTransceiver.direction = 'inactive';
              }
            }
          } else if (offerOptions.offerToReceiveAudio === true &&
              !audioTransceiver) {
            pc.addTransceiver('audio');
          }
  
  
          if (typeof offerOptions.offerToReceiveAudio !== 'undefined') {
            // support bit values
            offerOptions.offerToReceiveVideo = !!offerOptions.offerToReceiveVideo;
          }
          var videoTransceiver = pc.getTransceivers().find(function(transceiver) {
            return transceiver.sender.track &&
                transceiver.sender.track.kind === 'video';
          });
          if (offerOptions.offerToReceiveVideo === false && videoTransceiver) {
            if (videoTransceiver.direction === 'sendrecv') {
              videoTransceiver.setDirection('sendonly');
            } else if (videoTransceiver.direction === 'recvonly') {
              videoTransceiver.setDirection('inactive');
            }
          } else if (offerOptions.offerToReceiveVideo === true &&
              !videoTransceiver) {
            pc.addTransceiver('video');
          }
        }
        return origCreateOffer.apply(pc, arguments);
      };
    }
  };
  
  },{"../utils":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';
  
  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.
  function wrapPeerConnectionEvent(window, eventNameToWrap, wrapper) {
    if (!window.RTCPeerConnection) {
      return;
    }
    var proto = window.RTCPeerConnection.prototype;
    var nativeAddEventListener = proto.addEventListener;
    proto.addEventListener = function(nativeEventName, cb) {
      if (nativeEventName !== eventNameToWrap) {
        return nativeAddEventListener.apply(this, arguments);
      }
      var wrappedCallback = function(e) {
        cb(wrapper(e));
      };
      this._eventMap = this._eventMap || {};
      this._eventMap[cb] = wrappedCallback;
      return nativeAddEventListener.apply(this, [nativeEventName,
        wrappedCallback]);
    };
  
    var nativeRemoveEventListener = proto.removeEventListener;
    proto.removeEventListener = function(nativeEventName, cb) {
      if (nativeEventName !== eventNameToWrap || !this._eventMap
          || !this._eventMap[cb]) {
        return nativeRemoveEventListener.apply(this, arguments);
      }
      var unwrappedCb = this._eventMap[cb];
      delete this._eventMap[cb];
      return nativeRemoveEventListener.apply(this, [nativeEventName,
        unwrappedCb]);
    };
  
    Object.defineProperty(proto, 'on' + eventNameToWrap, {
      get: function() {
        return this['_on' + eventNameToWrap];
      },
      set: function(cb) {
        if (this['_on' + eventNameToWrap]) {
          this.removeEventListener(eventNameToWrap,
              this['_on' + eventNameToWrap]);
          delete this['_on' + eventNameToWrap];
        }
        if (cb) {
          this.addEventListener(eventNameToWrap,
              this['_on' + eventNameToWrap] = cb);
        }
      },
      enumerable: true,
      configurable: true
    });
  }
  
  // Utility methods.
  module.exports = {
    extractVersion: extractVersion,
    wrapPeerConnectionEvent: wrapPeerConnectionEvent,
    disableLog: function(bool) {
      if (typeof bool !== 'boolean') {
        return new Error('Argument type: ' + typeof bool +
            '. Please use a boolean.');
      }
      logDisabled_ = bool;
      return (bool) ? 'adapter.js logging disabled' :
          'adapter.js logging enabled';
    },
  
    /**
     * Disable or enable deprecation warnings
     * @param {!boolean} bool set to true to disable warnings.
     */
    disableWarnings: function(bool) {
      if (typeof bool !== 'boolean') {
        return new Error('Argument type: ' + typeof bool +
            '. Please use a boolean.');
      }
      deprecationWarnings_ = !bool;
      return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
    },
  
    log: function() {
      if (typeof window === 'object') {
        if (logDisabled_) {
          return;
        }
        if (typeof console !== 'undefined' && typeof console.log === 'function') {
          console.log.apply(console, arguments);
        }
      }
    },
  
    /**
     * Shows a deprecation warning suggesting the modern and spec-compatible API.
     */
    deprecated: function(oldMethod, newMethod) {
      if (!deprecationWarnings_) {
        return;
      }
      console.warn(oldMethod + ' is deprecated, please use ' + newMethod +
          ' instead.');
    },
  
    /**
     * Browser detector.
     *
     * @return {object} result containing browser and version
     *     properties.
     */
    detectBrowser: function(window) {
      var navigator = window && window.navigator;
  
      // Returned result object.
      var result = {};
      result.browser = null;
      result.version = null;
  
      // Fail early if it's not a browser
      if (typeof window === 'undefined' || !window.navigator) {
        result.browser = 'Not a browser.';
        return result;
      }
  
      if (navigator.mozGetUserMedia) { // Firefox.
        result.browser = 'firefox';
        result.version = extractVersion(navigator.userAgent,
            /Firefox\/(\d+)\./, 1);
      } else if (navigator.webkitGetUserMedia) {
        // Chrome, Chromium, Webview, Opera.
        // Version matches Chrome/WebRTC version.
        result.browser = 'chrome';
        result.version = extractVersion(navigator.userAgent,
            /Chrom(e|ium)\/(\d+)\./, 2);
      } else if (navigator.mediaDevices &&
          navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) { // Edge.
        result.browser = 'edge';
        result.version = extractVersion(navigator.userAgent,
            /Edge\/(\d+).(\d+)$/, 2);
      } else if (window.RTCPeerConnection &&
          navigator.userAgent.match(/AppleWebKit\/(\d+)\./)) { // Safari.
        result.browser = 'safari';
        result.version = extractVersion(navigator.userAgent,
            /AppleWebKit\/(\d+)\./, 1);
      } else { // Default fallthrough: not supported.
        result.browser = 'Not a supported browser.';
        return result;
      }
  
      return result;
    }
  };
  
  },{}]},{},[3])(3)
  });
  