text: /* jshint -W117 */
  // SDP STUFF
  function SDP(sdp) {
      this.media = sdp.split('\r\nm=');
      for (var i = 1; i < this.media.length; i++) {
          this.media[i] = 'm=' + this.media[i];
          if (i != this.media.length - 1) {
              this.media[i] += '\r\n';
          }
      }
      this.session = this.media.shift() + '\r\n';
      this.raw = this.session + this.media.join('');
  }
  
  // remove iSAC and CN from SDP
  SDP.prototype.mangle = function () {
      var i, j, mline, lines, rtpmap, newdesc;
      for (i = 0; i < this.media.length; i++) {
          lines = this.media[i].split('\r\n');
          lines.pop(); // remove empty last element
          mline = SDPUtil.parse_mline(lines.shift());
          if (mline.media != 'audio')
              continue;
          newdesc = '';
          mline.fmt.length = 0;
          for (j = 0; j < lines.length; j++) {
              if (lines[j].substr(0, 9) == 'a=rtpmap:') {
                  rtpmap = SDPUtil.parse_rtpmap(lines[j]);
                  if (rtpmap.name == 'CN' || rtpmap.name == 'ISAC')
                      continue;
                  mline.fmt.push(rtpmap.id);
                  newdesc += lines[j] + '\r\n';
              } else {
                  newdesc += lines[j] + '\r\n';
              }
          }
          this.media[i] = SDPUtil.build_mline(mline) + '\r\n';
          this.media[i] += newdesc;
      }
      this.raw = this.session + this.media.join('');
  };
  
  // remove lines matching prefix from session section
  SDP.prototype.removeSessionLines = function(prefix) {
      var self = this;
      var lines = SDPUtil.find_lines(this.session, prefix);
      lines.forEach(function(line) {
          self.session = self.session.replace(line + '\r\n', '');
      });
      this.raw = this.session + this.media.join('');
      return lines;
  }
  // remove lines matching prefix from a media section specified by mediaindex
  // TODO: non-numeric mediaindex could match mid
  SDP.prototype.removeMediaLines = function(mediaindex, prefix) {
      var self = this;
      var lines = SDPUtil.find_lines(this.media[mediaindex], prefix);
      lines.forEach(function(line) {
          self.media[mediaindex] = self.media[mediaindex].replace(line + '\r\n', '');
      });
      this.raw = this.session + this.media.join('');
      return lines;
  }
  
  // add content's to a jingle element
  SDP.prototype.toJingle = function (elem, thecreator) {
      var i, j, k, mline, ssrc, rtpmap, tmp, line, lines;
      var self = this;
      // new bundle plan
      if (SDPUtil.find_line(this.session, 'a=group:')) {
          lines = SDPUtil.find_lines(this.session, 'a=group:');
          for (i = 0; i < lines.length; i++) {
              tmp = lines[i].split(' ');
              var semantics = tmp.shift().substr(8);
              elem.c('group', {xmlns: 'urn:xmpp:jingle:apps:grouping:0', semantics:semantics});
              for (j = 0; j < tmp.length; j++) {
                  elem.c('content', {name: tmp[j]}).up();
              }
              elem.up();
          }
      }
      // old bundle plan, to be removed
      var bundle = [];
      if (SDPUtil.find_line(this.session, 'a=group:BUNDLE')) {
          bundle = SDPUtil.find_line(this.session, 'a=group:BUNDLE ').split(' ');
          bundle.shift();
      }
      for (i = 0; i < this.media.length; i++) {
          mline = SDPUtil.parse_mline(this.media[i].split('\r\n')[0]);
          if (!(mline.media == 'audio' || mline.media == 'video')) {
              continue;
          }
          if (SDPUtil.find_line(this.media[i], 'a=ssrc:')) {
              ssrc = SDPUtil.find_line(this.media[i], 'a=ssrc:').substring(7).split(' ')[0]; // take the first
          } else {
              ssrc = false;
          }
  
          elem.c('content', {creator: thecreator, name: mline.media});
          if (SDPUtil.find_line(this.media[i], 'a=mid:')) {
              // prefer identifier from a=mid if present
              var mid = SDPUtil.parse_mid(SDPUtil.find_line(this.media[i], 'a=mid:'));
              elem.attrs({ name: mid });
  
              // old BUNDLE plan, to be removed
              if (bundle.indexOf(mid) != -1) {
                  elem.c('bundle', {xmlns: 'http://estos.de/ns/bundle'}).up();
                  bundle.splice(bundle.indexOf(mid), 1);
              }
          }
          if (SDPUtil.find_line(this.media[i], 'a=rtpmap:').length) {
              elem.c('description',
                   {xmlns: 'urn:xmpp:jingle:apps:rtp:1',
                    media: mline.media });
              if (ssrc) {
                  elem.attrs({ssrc: ssrc});
              }
              for (j = 0; j < mline.fmt.length; j++) {
                  rtpmap = SDPUtil.find_line(this.media[i], 'a=rtpmap:' + mline.fmt[j]);
                  elem.c('payload-type', SDPUtil.parse_rtpmap(rtpmap));
                  // put any 'a=fmtp:' + mline.fmt[j] lines into <param name=foo value=bar/>
                  if (SDPUtil.find_line(this.media[i], 'a=fmtp:' + mline.fmt[j])) {
                      tmp = SDPUtil.parse_fmtp(SDPUtil.find_line(this.media[i], 'a=fmtp:' + mline.fmt[j]));
                      for (k = 0; k < tmp.length; k++) {
                          elem.c('parameter', tmp[k]).up();
                      }
                  }
                  this.RtcpFbToJingle(i, elem, mline.fmt[j]); // XEP-0293 -- map a=rtcp-fb
  
                  elem.up();
              }
              if (SDPUtil.find_line(this.media[i], 'a=crypto:', this.session)) {
                  elem.c('encryption', {required: 1});
                  var crypto = SDPUtil.find_lines(this.media[i], 'a=crypto:', this.session);
                  crypto.forEach(function(line) {
                      elem.c('crypto', SDPUtil.parse_crypto(line)).up();
                  });
                  elem.up(); // end of encryption
              }
  
              if (ssrc) {
                  // new style mapping
                  elem.c('source', { ssrc: ssrc, xmlns: 'urn:xmpp:jingle:apps:rtp:ssma:0' });
                  // FIXME: group by ssrc and support multiple different ssrcs
                  var ssrclines = SDPUtil.find_lines(this.media[i], 'a=ssrc:');
                  ssrclines.forEach(function(line) {
                      idx = line.indexOf(' ');
                      var linessrc = line.substr(0, idx).substr(7);
                      if (linessrc != ssrc) {
                          elem.up();
                          ssrc = linessrc;
                          elem.c('source', { ssrc: ssrc, xmlns: 'urn:xmpp:jingle:apps:rtp:ssma:0' });
                      }
                      var kv = line.substr(idx + 1);
                      elem.c('parameter');
                      if (kv.indexOf(':') == -1) {
                          elem.attrs({ name: kv });
                      } else {
                          elem.attrs({ name: kv.split(':', 2)[0] });
                          elem.attrs({ value: kv.split(':', 2)[1] });
                      }
                      elem.up();
                  });
                  elem.up();
  
                  // old proprietary mapping, to be removed at some point
                  tmp = SDPUtil.parse_ssrc(this.media[i]);
                  tmp.xmlns = 'http://estos.de/ns/ssrc';
                  tmp.ssrc = ssrc;
                  elem.c('ssrc', tmp).up(); // ssrc is part of description
              }
  
              if (SDPUtil.find_line(this.media[i], 'a=rtcp-mux')) {
                  elem.c('rtcp-mux').up();
              }
  
              // XEP-0293 -- map a=rtcp-fb:*
              this.RtcpFbToJingle(i, elem, '*');
  
              // XEP-0294
              if (SDPUtil.find_line(this.media[i], 'a=extmap:')) {
                  lines = SDPUtil.find_lines(this.media[i], 'a=extmap:');
                  for (j = 0; j < lines.length; j++) {
                      tmp = SDPUtil.parse_extmap(lines[j]);
                      elem.c('rtp-hdrext', { xmlns: 'urn:xmpp:jingle:apps:rtp:rtp-hdrext:0',
                                      uri: tmp.uri,
                                      id: tmp.value });
                      if (tmp.hasOwnProperty('direction')) {
                          switch (tmp.direction) {
                          case 'sendonly':
                              elem.attrs({senders: 'responder'});
                              break;
                          case 'recvonly':
                              elem.attrs({senders: 'initiator'});
                              break;
                          case 'sendrecv':
                              elem.attrs({senders: 'both'});
                              break;
                          case 'inactive':
                              elem.attrs({senders: 'none'});
                              break;
                          }
                      }
                      // TODO: handle params
                      elem.up();
                  }
              }
              elem.up(); // end of description
          }
  
          // map ice-ufrag/pwd, dtls fingerprint, candidates
          this.TransportToJingle(i, elem);
  
          if (SDPUtil.find_line(this.media[i], 'a=sendrecv', this.session)) {
              elem.attrs({senders: 'both'});
          } else if (SDPUtil.find_line(this.media[i], 'a=sendonly', this.session)) {
              elem.attrs({senders: 'initiator'});
          } else if (SDPUtil.find_line(this.media[i], 'a=recvonly', this.session)) {
              elem.attrs({senders: 'responder'});
          } else if (SDPUtil.find_line(this.media[i], 'a=inactive', this.session)) {
              elem.attrs({senders: 'none'});
          }
          if (mline.port == '0') {
              // estos hack to reject an m-line
              elem.attrs({senders: 'rejected'});
          }
          elem.up(); // end of content
      }
      elem.up();
      return elem;
  };
  
  SDP.prototype.TransportToJingle = function (mediaindex, elem) {
      var i = mediaindex;
      var tmp;
      var self = this;
      elem.c('transport');
  
      // XEP-0320
      var fingerprints = SDPUtil.find_lines(this.media[mediaindex], 'a=fingerprint:', this.session);
      fingerprints.forEach(function(line) {
          tmp = SDPUtil.parse_fingerprint(line);
          tmp.xmlns = 'urn:xmpp:tmp:jingle:apps:dtls:0';
          // tmp.xmlns = 'urn:xmpp:jingle:apps:dtls:0'; -- FIXME: update receivers first
          elem.c('fingerprint').t(tmp.fingerprint);
          delete tmp.fingerprint;
          line = SDPUtil.find_line(self.media[mediaindex], 'a=setup:', self.session);
          if (line) {
              tmp.setup = line.substr(8);
          }
          elem.attrs(tmp);
          elem.up(); // end of fingerprint
      });
      tmp = SDPUtil.iceparams(this.media[mediaindex], this.session);
      if (tmp) {
          tmp.xmlns = 'urn:xmpp:jingle:transports:ice-udp:1';
          elem.attrs(tmp);
          // XEP-0176
          if (SDPUtil.find_line(this.media[mediaindex], 'a=candidate:', this.session)) { // add any a=candidate lines
              var lines = SDPUtil.find_lines(this.media[mediaindex], 'a=candidate:', this.session);
              lines.forEach(function (line) {
                  elem.c('candidate', SDPUtil.candidateToJingle(line)).up();
              });
          }
      }
      elem.up(); // end of transport
  }
  
  SDP.prototype.RtcpFbToJingle = function (mediaindex, elem, payloadtype) { // XEP-0293
      var lines = SDPUtil.find_lines(this.media[mediaindex], 'a=rtcp-fb:' + payloadtype);
      lines.forEach(function (line) {
          var tmp = SDPUtil.parse_rtcpfb(line);
          if (tmp.type == 'trr-int') {
              elem.c('rtcp-fb-trr-int', {xmlns: 'urn:xmpp:jingle:apps:rtp:rtcp-fb:0', value: tmp.params[0]});
              elem.up();
          } else {
              elem.c('rtcp-fb', {xmlns: 'urn:xmpp:jingle:apps:rtp:rtcp-fb:0', type: tmp.type});
              if (tmp.params.length > 0) {
                  elem.attrs({'subtype': tmp.params[0]});
              }
              elem.up();
          }
      });
  };
  
  SDP.prototype.RtcpFbFromJingle = function (elem, payloadtype) { // XEP-0293
      var media = '';
      var tmp = elem.find('>rtcp-fb-trr-int[xmlns="urn:xmpp:jingle:apps:rtp:rtcp-fb:0"]');
      if (tmp.length) {
          media += 'a=rtcp-fb:' + '*' + ' ' + 'trr-int' + ' ';
          if (tmp.attr('value')) {
              media += tmp.attr('value');
          } else {
              media += '0';
          }
          media += '\r\n';
      }
      tmp = elem.find('>rtcp-fb[xmlns="urn:xmpp:jingle:apps:rtp:rtcp-fb:0"]');
      tmp.each(function () {
          media += 'a=rtcp-fb:' + payloadtype + ' ' + $(this).attr('type');
          if ($(this).attr('subtype')) {
              media += ' ' + $(this).attr('subtype');
          }
          media += '\r\n';
      });
      return media;
  };
  
  // construct an SDP from a jingle stanza
  SDP.prototype.fromJingle = function (jingle) {
      var self = this;
      this.raw = 'v=0\r\n' +
          'o=- ' + '1923518516' + ' 2 IN IP4 0.0.0.0\r\n' +// FIXME
          's=-\r\n' +
          't=0 0\r\n';
      // http://tools.ietf.org/html/draft-ietf-mmusic-sdp-bundle-negotiation-04#section-8
      if ($(jingle).find('>group[xmlns="urn:xmpp:jingle:apps:grouping:0"]').length) {
          $(jingle).find('>group[xmlns="urn:xmpp:jingle:apps:grouping:0"]').each(function (idx, group) {
              var contents = $(group).find('>content').map(function (idx, content) {
                  return content.getAttribute('name');
              }).get();
              if (contents.length > 0) {
                  self.raw += 'a=group:' + (group.getAttribute('semantics') || group.getAttribute('type')) + ' ' + contents.join(' ') + '\r\n';
              }
          });
      } else if ($(jingle).find('>group[xmlns="urn:ietf:rfc:5888"]').length) {
          // temporary namespace, not to be used. to be removed soon.
          $(jingle).find('>group[xmlns="urn:ietf:rfc:5888"]').each(function (idx, group) {
              var contents = $(group).find('>content').map(function (idx, content) {
                  return content.getAttribute('name');
              }).get();
              if (group.getAttribute('type') !== null && contents.length > 0) {
                  self.raw += 'a=group:' + group.getAttribute('type') + ' ' + contents.join(' ') + '\r\n';
              }
          });
      } else {
          // for backward compability, to be removed soon
          // assume all contents are in the same bundle group, can be improved upon later
          var bundle = $(jingle).find('>content').filter(function (idx, content) {
              //elem.c('bundle', {xmlns:'http://estos.de/ns/bundle'});
              return $(content).find('>bundle').length > 0;
          }).map(function (idx, content) {
              return content.getAttribute('name');
          }).get();
          if (bundle.length) {
              this.raw += 'a=group:BUNDLE ' + bundle.join(' ') + '\r\n';
          }
      }
  
      this.session = this.raw;
      jingle.find('>content').each(function () {
          var m = self.jingle2media($(this));
          self.media.push(m);
      });
  
      // reconstruct msid-semantic -- apparently not necessary
      /*
      var msid = SDPUtil.parse_ssrc(this.raw);
      if (msid.hasOwnProperty('mslabel')) {
          this.session += "a=msid-semantic: WMS " + msid.mslabel + "\r\n";
      }
      */
  
      this.raw = this.session + this.media.join('');
  };
  
  // translate a jingle content element into an an SDP media part
  SDP.prototype.jingle2media = function (content) {
      var media = '',
          desc = content.find('description'),
          ssrc = desc.attr('ssrc'),
          self = this,
          tmp;
  
      tmp = { media: desc.attr('media') };
      tmp.port = '1';
      if (content.attr('senders') == 'rejected') {
          // estos hack to reject an m-line.
          tmp.port = '0';
      }
      if (content.find('>transport>fingerprint').length || desc.find('encryption').length) {
          tmp.proto = 'RTP/SAVPF';
      } else {
          tmp.proto = 'RTP/AVPF';
      }
      tmp.fmt = desc.find('payload-type').map(function () { return this.getAttribute('id'); }).get();
      media += SDPUtil.build_mline(tmp) + '\r\n';
      media += 'c=IN IP4 0.0.0.0\r\n';
      media += 'a=rtcp:1 IN IP4 0.0.0.0\r\n';
      tmp = content.find('>transport[xmlns="urn:xmpp:jingle:transports:ice-udp:1"]');
      if (tmp.length) {
          if (tmp.attr('ufrag')) {
              media += SDPUtil.build_iceufrag(tmp.attr('ufrag')) + '\r\n';
          }
          if (tmp.attr('pwd')) {
              media += SDPUtil.build_icepwd(tmp.attr('pwd')) + '\r\n';
          }
          tmp.find('>fingerprint').each(function () {
              // FIXME: check namespace at some point
              media += 'a=fingerprint:' + this.getAttribute('hash');
              media += ' ' + $(this).text();
              media += '\r\n';
              if (this.getAttribute('setup')) {
                  media += 'a=setup:' + this.getAttribute('setup') + '\r\n';
              }
          });
      }
      switch (content.attr('senders')) {
      case 'initiator':
          media += 'a=sendonly\r\n';
          break;
      case 'responder':
          media += 'a=recvonly\r\n';
          break;
      case 'none':
          media += 'a=inactive\r\n';
          break;
      case 'both':
          media += 'a=sendrecv\r\n';
          break;
      }
      media += 'a=mid:' + content.attr('name') + '\r\n';
  
      // <description><rtcp-mux/></description>
      // see http://code.google.com/p/libjingle/issues/detail?id=309 -- no spec though
      // and http://mail.jabber.org/pipermail/jingle/2011-December/001761.html
      if (desc.find('rtcp-mux').length) {
          media += 'a=rtcp-mux\r\n';
      }
  
      if (desc.find('encryption').length) {
          desc.find('encryption>crypto').each(function () {
              media += 'a=crypto:' + this.getAttribute('tag');
              media += ' ' + this.getAttribute('crypto-suite');
              media += ' ' + this.getAttribute('key-params');
              if (this.getAttribute('session-params')) {
                  media += ' ' + this.getAttribute('session-params');
              }
              media += '\r\n';
          });
      }
      desc.find('payload-type').each(function () {
          media += SDPUtil.build_rtpmap(this) + '\r\n';
          if ($(this).find('>parameter').length) {
              media += 'a=fmtp:' + this.getAttribute('id') + ' ';
              media += $(this).find('parameter').map(function () { return (this.getAttribute('name') ? (this.getAttribute('name') + '=') : '') + this.getAttribute('value'); }).get().join(';');
              media += '\r\n';
          }
          // xep-0293
          media += self.RtcpFbFromJingle($(this), this.getAttribute('id'));
      });
  
      // xep-0293
      media += self.RtcpFbFromJingle(desc, '*');
  
      // xep-0294
      tmp = desc.find('>rtp-hdrext[xmlns="urn:xmpp:jingle:apps:rtp:rtp-hdrext:0"]');
      tmp.each(function () {
          media += 'a=extmap:' + this.getAttribute('id') + ' ' + this.getAttribute('uri') + '\r\n';
      });
  
      content.find('>transport[xmlns="urn:xmpp:jingle:transports:ice-udp:1"]>candidate').each(function () {
          media += SDPUtil.candidateFromJingle(this);
      });
  
      tmp = content.find('description>source[xmlns="urn:xmpp:jingle:apps:rtp:ssma:0"]');
      tmp.each(function () {
          var ssrc = this.getAttribute('ssrc');
          $(this).find('>parameter').each(function () {
              media += 'a=ssrc:' + ssrc + ' ' + this.getAttribute('name');
              if (this.getAttribute('value') && this.getAttribute('value').length)
                  media += ':' + this.getAttribute('value');
              media += '\r\n';
          });
      });
  
      if (tmp.length === 0) {
          // fallback to proprietary mapping of a=ssrc lines
          tmp = content.find('description>ssrc[xmlns="http://estos.de/ns/ssrc"]');
          if (tmp.length) {
              media += 'a=ssrc:' + ssrc + ' cname:' + tmp.attr('cname') + '\r\n';
              media += 'a=ssrc:' + ssrc + ' msid:' + tmp.attr('msid') + '\r\n';
              media += 'a=ssrc:' + ssrc + ' mslabel:' + tmp.attr('mslabel') + '\r\n';
              media += 'a=ssrc:' + ssrc + ' label:' + tmp.attr('label') + '\r\n';
          }
      }
      return media;
  };
  
  SDPUtil = {
      iceparams: function (mediadesc, sessiondesc) {
          var data = null;
          if (SDPUtil.find_line(mediadesc, 'a=ice-ufrag:', sessiondesc) &&
              SDPUtil.find_line(mediadesc, 'a=ice-pwd:', sessiondesc)) {
              data = {
                  ufrag: SDPUtil.parse_iceufrag(SDPUtil.find_line(mediadesc, 'a=ice-ufrag:', sessiondesc)),
                  pwd: SDPUtil.parse_icepwd(SDPUtil.find_line(mediadesc, 'a=ice-pwd:', sessiondesc))
              };
          }
          return data;
      },
      parse_iceufrag: function (line) {
          return line.substring(12);
      },
      build_iceufrag: function (frag) {
          return 'a=ice-ufrag:' + frag;
      },
      parse_icepwd: function (line) {
          return line.substring(10);
      },
      build_icepwd: function (pwd) {
          return 'a=ice-pwd:' + pwd;
      },
      parse_mid: function (line) {
          return line.substring(6);
      },
      parse_mline: function (line) {
          var parts = line.substring(2).split(' '),
          data = {};
          data.media = parts.shift();
          data.port = parts.shift();
          data.proto = parts.shift();
          if (parts[parts.length - 1] === '') { // trailing whitespace
              parts.pop();
          }
          data.fmt = parts;
          return data;
      },
      build_mline: function (mline) {
          return 'm=' + mline.media + ' ' + mline.port + ' ' + mline.proto + ' ' + mline.fmt.join(' ');
      },
      parse_rtpmap: function (line) {
          var parts = line.substring(9).split(' '),
              data = {};
          data.id = parts.shift();
          parts = parts[0].split('/');
          data.name = parts.shift();
          data.clockrate = parts.shift();
          data.channels = parts.length ? parts.shift() : '1';
          return data;
      },
      build_rtpmap: function (el) {
          var line = 'a=rtpmap:' + el.getAttribute('id') + ' ' + el.getAttribute('name') + '/' + el.getAttribute('clockrate');
          if (el.getAttribute('channels') && el.getAttribute('channels') != '1') {
              line += '/' + el.getAttribute('channels');
          }
          return line;
      },
      parse_crypto: function (line) {
          var parts = line.substring(9).split(' '),
          data = {};
          data.tag = parts.shift();
          data['crypto-suite'] = parts.shift();
          data['key-params'] = parts.shift();
          if (parts.length) {
              data['session-params'] = parts.join(' ');
          }
          return data;
      },
      parse_fingerprint: function (line) { // RFC 4572
          var parts = line.substring(14).split(' '),
          data = {};
          data.hash = parts.shift();
          data.fingerprint = parts.shift();
          // TODO assert that fingerprint satisfies 2UHEX *(":" 2UHEX) ?
          return data;
      },
      parse_fmtp: function (line) {
          var parts = line.split(' '),
              i, key, value,
              data = [];
          parts.shift();
          parts = parts.join(' ').split(';');
          for (i = 0; i < parts.length; i++) {
              key = parts[i].split('=')[0];
              while (key.length && key[0] == ' ') {
                  key = key.substring(1);
              }
              value = parts[i].split('=')[1];
              if (key && value) {
                  data.push({name: key, value: value});
              } else if (key) {
                  // rfc 4733 (DTMF) style stuff
                  data.push({name: '', value: key});
              }
          }
          return data;
      },
      parse_icecandidate: function (line) {
          var candidate = {},
              elems = line.split(' ');
          candidate.foundation = elems[0].substring(12);
          candidate.component = elems[1];
          candidate.protocol = elems[2].toLowerCase();
          candidate.priority = elems[3];
          candidate.ip = elems[4];
          candidate.port = elems[5];
          // elems[6] => "typ"
          candidate.type = elems[7];
          candidate.generation = 0; // default value, may be overwritten below
          for (var i = 8; i < elems.length; i += 2) {
              switch (elems[i]) {
              case 'raddr':
                  candidate['rel-addr'] = elems[i + 1];
                  break;
              case 'rport':
                  candidate['rel-port'] = elems[i + 1];
                  break;
              case 'generation':
                  candidate.generation = elems[i + 1];
                  break;
              default: // TODO
                  console.log('parse_icecandidate not translating "' + elems[i] + '" = "' + elems[i + 1] + '"');
              }
          }
          candidate.network = '1';
          candidate.id = Math.random().toString(36).substr(2, 10); // not applicable to SDP -- FIXME: should be unique, not just random
          return candidate;
      },
      build_icecandidate: function (cand) {
          var line = ['a=candidate:' + cand.foundation, cand.component, cand.protocol, cand.priority, cand.ip, cand.port, 'typ', cand.type].join(' ');
          line += ' ';
          switch (cand.type) {
          case 'srflx':
          case 'prflx':
          case 'relay':
              if (cand.hasOwnAttribute('rel-addr') && cand.hasOwnAttribute('rel-port')) {
                  line += 'raddr';
                  line += ' ';
                  line += cand['rel-addr'];
                  line += ' ';
                  line += 'rport';
                  line += ' ';
                  line += cand['rel-port'];
                  line += ' ';
              }
              break;
          }
          line += 'generation';
          line += ' ';
          line += cand.hasOwnAttribute('generation') ? cand.generation : '0';
          return line;
      },
      parse_ssrc: function (desc) {
          // proprietary mapping of a=ssrc lines
          // TODO: see "Jingle RTP Source Description" by Juberti and P. Thatcher on google docs
          // and parse according to that
          var lines = desc.split('\r\n'),
              data = {};
          for (var i = 0; i < lines.length; i++) {
              if (lines[i].substring(0, 7) == 'a=ssrc:') {
                  var idx = lines[i].indexOf(' ');
                  data[lines[i].substr(idx + 1).split(':', 2)[0]] = lines[i].substr(idx + 1).split(':', 2)[1];
              }
          }
          return data;
      },
      parse_rtcpfb: function (line) {
          var parts = line.substr(10).split(' ');
          var data = {};
          data.pt = parts.shift();
          data.type = parts.shift();
          data.params = parts;
          return data;
      },
      parse_extmap: function (line) {
          var parts = line.substr(9).split(' ');
          var data = {};
          data.value = parts.shift();
          if (data.value.indexOf('/') != -1) {
              data.direction = data.value.substr(data.value.indexOf('/') + 1);
              data.value = data.value.substr(0, data.value.indexOf('/'));
          } else {
              data.direction = 'both';
          }
          data.uri = parts.shift();
          data.params = parts;
          return data;
      },
      find_line: function (haystack, needle, sessionpart) {
          var lines = haystack.split('\r\n');
          for (var i = 0; i < lines.length; i++) {
              if (lines[i].substring(0, needle.length) == needle) {
                  return lines[i];
              }
          }
          if (!sessionpart) {
              return false;
          }
          // search session part
          lines = sessionpart.split('\r\n');
          for (var j = 0; j < lines.length; j++) {
              if (lines[j].substring(0, needle.length) == needle) {
                  return lines[j];
              }
          }
          return false;
      },
      find_lines: function (haystack, needle, sessionpart) {
          var lines = haystack.split('\r\n'),
              needles = [];
          for (var i = 0; i < lines.length; i++) {
              if (lines[i].substring(0, needle.length) == needle)
                  needles.push(lines[i]);
          }
          if (needles.length || !sessionpart) {
              return needles;
          }
          // search session part
          lines = sessionpart.split('\r\n');
          for (var j = 0; j < lines.length; j++) {
              if (lines[j].substring(0, needle.length) == needle) {
                  needles.push(lines[j]);
              }
          }
          return needles;
      },
      candidateToJingle: function (line) {
          // a=candidate:2979166662 1 udp 2113937151 192.168.2.100 57698 typ host generation 0
          //      <candidate component=... foundation=... generation=... id=... ip=... network=... port=... priority=... protocol=... type=.../>
          if (line.substring(0, 12) != 'a=candidate:') {
              console.log('parseCandidate called with a line that is not a candidate line');
              console.log(line);
              return null;
          }
          if (line.substring(line.length - 2) == '\r\n') // chomp it
              line = line.substring(0, line.length - 2);
          var candidate = {},
              elems = line.split(' '),
              i;
          if (elems[6] != 'typ') {
              console.log('did not find typ in the right place');
              console.log(line);
              return null;
          }
          candidate.foundation = elems[0].substring(12);
          candidate.component = elems[1];
          candidate.protocol = elems[2].toLowerCase();
          candidate.priority = elems[3];
          candidate.ip = elems[4];
          candidate.port = elems[5];
          // elems[6] => "typ"
          candidate.type = elems[7];
          for (i = 8; i < elems.length; i += 2) {
              switch (elems[i]) {
              case 'raddr':
                  candidate['rel-addr'] = elems[i + 1];
                  break;
              case 'rport':
                  candidate['rel-port'] = elems[i + 1];
                  break;
              case 'generation':
                  candidate.generation = elems[i + 1];
                  break;
              default: // TODO
                  console.log('not translating "' + elems[i] + '" = "' + elems[i + 1] + '"');
              }
          }
          candidate.network = '1';
          candidate.id = Math.random().toString(36).substr(2, 10); // not applicable to SDP -- FIXME: should be unique, not just random
          return candidate;
      },
      candidateFromJingle: function (cand) {
          var line = 'a=candidate:';
          line += cand.getAttribute('foundation');
          line += ' ';
          line += cand.getAttribute('component');
          line += ' ';
          line += cand.getAttribute('protocol'); //.toUpperCase(); // chrome M23 doesn't like this
          line += ' ';
          line += cand.getAttribute('priority');
          line += ' ';
          line += cand.getAttribute('ip');
          line += ' ';
          line += cand.getAttribute('port');
          line += ' ';
          line += 'typ';
          line += ' ' + cand.getAttribute('type');
          line += ' ';
          switch (cand.getAttribute('type')) {
          case 'srflx':
          case 'prflx':
          case 'relay':
              if (cand.getAttribute('rel-addr') && cand.getAttribute('rel-port')) {
                  line += 'raddr';
                  line += ' ';
                  line += cand.getAttribute('rel-addr');
                  line += ' ';
                  line += 'rport';
                  line += ' ';
                  line += cand.getAttribute('rel-port');
                  line += ' ';
              }
              break;
          }
          line += 'generation';
          line += ' ';
          line += cand.getAttribute('generation') || '0';
          return line + '\r\n';
      }
  };
  