File: source/stream-sdp.js

  1. /**
  2.  * Stores the preferred sending Peer connection streaming audio codec.
  3.  * @attribute _selectedAudioCodec
  4.  * @type String
  5.  * @default "auto"
  6.  * @private
  7.  * @for Skylink
  8.  * @since 0.5.10
  9.  */
  10. Skylink.prototype._selectedAudioCodec = 'auto';
  11.  
  12. /**
  13.  * Stores the preferred sending Peer connection streaming video codec.
  14.  * @attribute _selectedVideoCodec
  15.  * @type String
  16.  * @default "auto"
  17.  * @private
  18.  * @for Skylink
  19.  * @since 0.5.10
  20.  */
  21. Skylink.prototype._selectedVideoCodec = 'auto';
  22.  
  23. /**
  24.  * Function that modifies the SessionDescription string to enable OPUS stereo.
  25.  * @method _addSDPStereo
  26.  * @private
  27.  * @for Skylink
  28.  * @since 0.5.10
  29.  */
  30. Skylink.prototype._addSDPStereo = function(sdpLines) {
  31.   var opusRtmpLineIndex = 0;
  32.   var opusLineFound = false;
  33.   var opusPayload = 0;
  34.   var fmtpLineFound = false;
  35.  
  36.   var i, j;
  37.   var line;
  38.  
  39.   for (i = 0; i < sdpLines.length; i += 1) {
  40.     line = sdpLines[i];
  41.  
  42.     if (line.indexOf('a=rtpmap:') === 0) {
  43.       var parts = line.split(' ');
  44.  
  45.       if (parts[1].indexOf('opus/48000/') === 0) {
  46.         opusLineFound = true;
  47.         opusPayload = parts[0].split(':')[1];
  48.         opusRtmpLineIndex = i;
  49.         break;
  50.       }
  51.     }
  52.   }
  53.  
  54.   // if found
  55.   if (opusLineFound) {
  56.     log.debug([null, 'SDP', null, 'OPUS line is found. Enabling stereo']);
  57.  
  58.     // loop for fmtp payload
  59.     for (j = 0; j < sdpLines.length; j += 1) {
  60.       line = sdpLines[j];
  61.  
  62.       if (line.indexOf('a=fmtp:' + opusPayload) === 0) {
  63.         fmtpLineFound = true;
  64.         sdpLines[j] += '; stereo=1';
  65.         break;
  66.       }
  67.     }
  68.  
  69.     // if line doesn't exists for an instance firefox
  70.     if (!fmtpLineFound) {
  71.       sdpLines.splice(opusRtmpLineIndex, 0, 'a=fmtp:' + opusPayload + ' stereo=1');
  72.     }
  73.   }
  74.  
  75.   return sdpLines;
  76. };
  77.  
  78. /**
  79.  * Function that modifies the SessionDescription string to set the video resolution.
  80.  * This is not even supported in the specs, and we should re-evalute it to be removed.
  81.  * @method _setSDPVideoResolution
  82.  * @private
  83.  * @for Skylink
  84.  * @since 0.5.10
  85.  */
  86. Skylink.prototype._setSDPVideoResolution = function(sdpLines){
  87.   var video = this._streams.userMedia && this._streams.userMedia.settings.video;
  88.   var frameRate = video.frameRate || 50;
  89.   var resolution = {
  90.     width: 320,
  91.     height: 50
  92.   }; //video.resolution || {};
  93.  
  94.   var videoLineFound = false;
  95.   var videoLineIndex = 0;
  96.   var fmtpPayloads = [];
  97.  
  98.   var i, j, k;
  99.   var line;
  100.  
  101.   var sdpLineData = 'max-fr=' + frameRate +
  102.     '; max-recv-width=320' + //(resolution.width ? resolution.width : 640) +
  103.     '; max-recv-height=160'; //+ (resolution.height ? resolution.height : 480);
  104.  
  105.   for (i = 0; i < sdpLines.length; i += 1) {
  106.     line = sdpLines[i];
  107.  
  108.     if (line.indexOf('a=video') === 0 || line.indexOf('m=video') === 0) {
  109.       videoLineFound = true;
  110.       videoLineIndex = i;
  111.       fmtpPayloads = line.split(' ');
  112.       fmtpPayloads.splice(0, 3);
  113.       break;
  114.     }
  115.   }
  116.  
  117.   if (videoLineFound) {
  118.     // loop for every video codec
  119.     // ignore if not vp8 or h264
  120.     for (j = 0; j < fmtpPayloads.length; j += 1) {
  121.       var payload = fmtpPayloads[j];
  122.       var rtpmapLineIndex = 0;
  123.       var fmtpLineIndex = 0;
  124.       var fmtpLineFound = false;
  125.       var ignore = false;
  126.  
  127.       for (k = 0; k < sdpLines.length; k += 1) {
  128.        line = sdpLines[k];
  129.  
  130.         if (line.indexOf('a=rtpmap:' + payload) === 0) {
  131.           // for non h264 or vp8 codec, ignore. these are experimental codecs
  132.           // that may not exists afterwards
  133.           if (!(line.indexOf('VP8') > 0 || line.indexOf('H264') > 0)) {
  134.             ignore = true;
  135.             break;
  136.           }
  137.           rtpmapLineIndex = k;
  138.         }
  139.  
  140.         if (line.indexOf('a=fmtp:' + payload) === 0) {
  141.           fmtpLineFound = true;
  142.           fmtpLineIndex = k;
  143.         }
  144.       }
  145.  
  146.       if (ignore) {
  147.         continue;
  148.       }
  149.  
  150.       if (fmtpLineFound) {
  151.         sdpLines[fmtpLineIndex] += ';' + sdpLineData;
  152.  
  153.       } else {
  154.         sdpLines.splice(rtpmapLineIndex + 1, 0, 'a=fmtp:' + payload + ' ' + sdpLineData);
  155.       }
  156.     }
  157.  
  158.     log.debug([null, 'SDP', null, 'Setting video resolution (broken)']);
  159.   }
  160.   return sdpLines;
  161. };
  162.  
  163. /**
  164.  * Function that modifies the SessionDescription string to set the sending bandwidth.
  165.  * Setting this may not necessarily work in Firefox.
  166.  * @method _setSDPBitrate
  167.  * @private
  168.  * @for Skylink
  169.  * @since 0.5.10
  170.  */
  171. Skylink.prototype._setSDPBitrate = function(sdpLines, settings) {
  172.   // Find if user has audioStream
  173.   var bandwidth = this._streamsBandwidthSettings;
  174.  
  175.   // Prevent setting of bandwidth audio if not configured
  176.   if (typeof bandwidth.audio === 'number' && bandwidth.audio > 0) {
  177.     var hasSetAudio = false;
  178.  
  179.     for (var i = 0; i < sdpLines.length; i += 1) {
  180.       // set the audio bandwidth
  181.       if (sdpLines[i].indexOf('m=audio') === 0) {
  182.       //if (sdpLines[i].indexOf('a=audio') === 0 || sdpLines[i].indexOf('m=audio') === 0) {
  183.         sdpLines.splice(i + 1, 0, window.webrtcDetectedBrowser === 'firefox' ?
  184.           'b=TIAS:' + (bandwidth.audio * 1024) : 'b=AS:' + bandwidth.audio);
  185.  
  186.         log.info([null, 'SDP', null, 'Setting maximum sending audio bandwidth bitrate @(index:' + i + ') -> '], bandwidth.audio);
  187.         hasSetAudio = true;
  188.         break;
  189.       }
  190.     }
  191.  
  192.     if (!hasSetAudio) {
  193.       log.warn([null, 'SDP', null, 'Not setting maximum sending audio bandwidth bitrate as m=audio line is not found']);
  194.     }
  195.   } else {
  196.     log.warn([null, 'SDP', null, 'Not setting maximum sending audio bandwidth bitrate and leaving to browser\'s defaults']);
  197.   }
  198.  
  199.   // Prevent setting of bandwidth video if not configured
  200.   if (typeof bandwidth.video === 'number' && bandwidth.video > 0) {
  201.     var hasSetVideo = false;
  202.  
  203.     for (var j = 0; j < sdpLines.length; j += 1) {
  204.       // set the video bandwidth
  205.       if (sdpLines[j].indexOf('m=video') === 0) {
  206.       //if (sdpLines[j].indexOf('a=video') === 0 || sdpLines[j].indexOf('m=video') === 0) {
  207.         sdpLines.splice(j + 1, 0, window.webrtcDetectedBrowser === 'firefox' ?
  208.           'b=TIAS:' + (bandwidth.video * 1024) : 'b=AS:' + bandwidth.video);
  209.  
  210.         log.info([null, 'SDP', null, 'Setting maximum sending video bandwidth bitrate @(index:' + j + ') -> '], bandwidth.video);
  211.         hasSetVideo = true;
  212.         break;
  213.       }
  214.     }
  215.  
  216.     if (!hasSetVideo) {
  217.       log.warn([null, 'SDP', null, 'Not setting maximum sending video bandwidth bitrate as m=video line is not found']);
  218.     }
  219.   } else {
  220.     log.warn([null, 'SDP', null, 'Not setting maximum sending video bandwidth bitrate and leaving to browser\'s defaults']);
  221.   }
  222.  
  223.   // Prevent setting of bandwidth data if not configured
  224.   if (typeof bandwidth.data === 'number' && bandwidth.data > 0) {
  225.     var hasSetData = false;
  226.  
  227.     for (var k = 0; k < sdpLines.length; k += 1) {
  228.       // set the data bandwidth
  229.       if (sdpLines[k].indexOf('m=application') === 0) {
  230.       //if (sdpLines[k].indexOf('a=application') === 0 || sdpLines[k].indexOf('m=application') === 0) {
  231.         sdpLines.splice(k + 1, 0, window.webrtcDetectedBrowser === 'firefox' ?
  232.           'b=TIAS:' + (bandwidth.data * 1024) : 'b=AS:' + bandwidth.data);
  233.  
  234.         log.info([null, 'SDP', null, 'Setting maximum sending data bandwidth bitrate @(index:' + k + ') -> '], bandwidth.data);
  235.         hasSetData = true;
  236.         break;
  237.       }
  238.     }
  239.  
  240.     if (!hasSetData) {
  241.       log.warn([null, 'SDP', null, 'Not setting maximum sending data bandwidth bitrate as m=application line is not found']);
  242.     }
  243.   } else {
  244.     log.warn([null, 'SDP', null, 'Not setting maximum sending data bandwidth bitrate and leaving to browser\'s defaults']);
  245.   }
  246.  
  247.   return sdpLines;
  248. };
  249.  
  250. /**
  251.  * Function that modifies the SessionDescription string to set the preferred sending video codec.
  252.  * @method _setSDPVideoCodec
  253.  * @private
  254.  * @for Skylink
  255.  * @since 0.5.2
  256.  */
  257. Skylink.prototype._setSDPVideoCodec = function(sdpLines) {
  258.   log.log('Setting video codec', this._selectedVideoCodec);
  259.   var codecFound = false;
  260.   var payload = 0;
  261.  
  262.   var i, j;
  263.   var line;
  264.  
  265.   for (i = 0; i < sdpLines.length; i += 1) {
  266.     line = sdpLines[i];
  267.  
  268.     if (line.indexOf('a=rtpmap:') === 0) {
  269.       if (line.indexOf(this._selectedVideoCodec) > 0) {
  270.         codecFound = true;
  271.         payload = line.split(':')[1].split(' ')[0];
  272.         break;
  273.       }
  274.     }
  275.   }
  276.  
  277.   if (codecFound) {
  278.     for (j = 0; j < sdpLines.length; j += 1) {
  279.       line = sdpLines[j];
  280.  
  281.       if (line.indexOf('m=video') === 0 || line.indexOf('a=video') === 0) {
  282.         var parts = line.split(' ');
  283.         var payloads = line.split(' ');
  284.         payloads.splice(0, 3);
  285.  
  286.         var selectedPayloadIndex = payloads.indexOf(payload);
  287.  
  288.         if (selectedPayloadIndex === -1) {
  289.           payloads.splice(0, 0, payload);
  290.         } else {
  291.           var first = payloads[0];
  292.           payloads[0] = payload;
  293.           payloads[selectedPayloadIndex] = first;
  294.         }
  295.         sdpLines[j] = parts[0] + ' ' + parts[1] + ' ' + parts[2] + ' ' + payloads.join(' ');
  296.         break;
  297.       }
  298.     }
  299.   }
  300.   return sdpLines;
  301. };
  302.  
  303. /**
  304.  * Function that modifies the SessionDescription string to set the preferred sending audio codec.
  305.  * @method _setSDPAudioCodec
  306.  * @private
  307.  * @for Skylink
  308.  * @since 0.5.2
  309.  */
  310. Skylink.prototype._setSDPAudioCodec = function(sdpLines) {
  311.   log.log('Setting audio codec', this._selectedAudioCodec);
  312.   var codecFound = false;
  313.   var payload = 0;
  314.  
  315.   var i, j;
  316.   var line;
  317.  
  318.   for (i = 0; i < sdpLines.length; i += 1) {
  319.     line = sdpLines[i];
  320.  
  321.     if (line.indexOf('a=rtpmap:') === 0) {
  322.       if (line.indexOf(this._selectedAudioCodec) > 0) {
  323.         codecFound = true;
  324.         payload = line.split(':')[1].split(' ')[0];
  325.       }
  326.     }
  327.   }
  328.  
  329.   if (codecFound) {
  330.     for (j = 0; j < sdpLines.length; j += 1) {
  331.       line = sdpLines[j];
  332.  
  333.       if (line.indexOf('m=audio') === 0 || line.indexOf('a=audio') === 0) {
  334.         var parts = line.split(' ');
  335.         var payloads = line.split(' ');
  336.         payloads.splice(0, 3);
  337.  
  338.         var selectedPayloadIndex = payloads.indexOf(payload);
  339.  
  340.         if (selectedPayloadIndex === -1) {
  341.           payloads.splice(0, 0, payload);
  342.         } else {
  343.           var first = payloads[0];
  344.           payloads[0] = payload;
  345.           payloads[selectedPayloadIndex] = first;
  346.         }
  347.         sdpLines[j] = parts[0] + ' ' + parts[1] + ' ' + parts[2] + ' ' + payloads.join(' ');
  348.         break;
  349.       }
  350.     }
  351.   }
  352.   return sdpLines;
  353. };
  354.  
  355. /**
  356.  * Function that modifies the SessionDescription string to remove the experimental H264 Firefox flag
  357.  *   that is breaking connections.
  358.  * To evaluate removal of this change once we roll out H264 codec interop.
  359.  * @method _removeSDPFirefoxH264Pref
  360.  * @private
  361.  * @for Skylink
  362.  * @since 0.5.2
  363.  */
  364. Skylink.prototype._removeSDPFirefoxH264Pref = function(sdpLines) {
  365.   var invalidLineIndex = sdpLines.indexOf(
  366.     'a=fmtp:0 profile-level-id=0x42e00c;packetization-mode=1');
  367.   if (invalidLineIndex > -1) {
  368.     log.debug([null, 'SDP', null, 'Firefox H264 invalid pref found:'], invalidLineIndex);
  369.     sdpLines.splice(invalidLineIndex, 1);
  370.   }
  371.   return sdpLines;
  372. };
  373.  
  374. /**
  375.  * Function that modifies the SessionDescription string to set with the correct MediaStream ID and
  376.  *   MediaStreamTrack IDs that is not provided from Firefox connection to Chromium connection.
  377.  * @method _addSDPSsrcFirefoxAnswer
  378.  * @private
  379.  * @for Skylink
  380.  * @since 0.6.6
  381.  */
  382. Skylink.prototype._addSDPSsrcFirefoxAnswer = function (targetMid, sdp) {
  383.   var self = this;
  384.   var agent = self.getPeerInfo(targetMid).agent;
  385.  
  386.   var pc = self._peerConnections[targetMid];
  387.  
  388.   if (!pc) {
  389.     log.error([targetMid, 'RTCSessionDesription', 'answer', 'Peer connection object ' +
  390.       'not found. Unable to parse answer session description for peer']);
  391.     return;
  392.   }
  393.  
  394.   var updatedSdp = sdp;
  395.  
  396.   // for this case, this is because firefox uses Unified Plan and Chrome uses
  397.   // Plan B. we have to remodify this a bit to let the non-ff detect as new mediastream
  398.   // as chrome/opera/safari detects it as default due to missing ssrc specified as used in plan B.
  399.   if (window.webrtcDetectedBrowser === 'firefox' && agent.name !== 'firefox' &&
  400.     //pc.remoteDescription.sdp.indexOf('a=msid-semantic: WMS *') === -1 &&
  401.     updatedSdp.indexOf('a=msid-semantic:WMS *') > 0) {
  402.     // start parsing
  403.     var sdpLines = updatedSdp.split('\r\n');
  404.     var streamId = '';
  405.     var replaceSSRCSemantic = -1;
  406.     var i;
  407.     var trackId = '';
  408.  
  409.     var parseTracksSSRC = function (track) {
  410.       for (i = 0, trackId = ''; i < sdpLines.length; i++) {
  411.         if (!!trackId) {
  412.           if (sdpLines[i].indexOf('a=ssrc:') === 0) {
  413.             var ssrcId = sdpLines[i].split(':')[1].split(' ')[0];
  414.             sdpLines.splice(i+1, 0, 'a=ssrc:' + ssrcId +  ' msid:' + streamId + ' ' + trackId,
  415.               'a=ssrc:' + ssrcId + ' mslabel:default',
  416.               'a=ssrc:' + ssrcId + ' label:' + trackId);
  417.             break;
  418.           } else if (sdpLines[i].indexOf('a=mid:') === 0) {
  419.             break;
  420.           }
  421.         } else if (sdpLines[i].indexOf('a=msid:') === 0) {
  422.           if (i > 0 && sdpLines[i-1].indexOf('a=mid:' + track) === 0) {
  423.             var parts = sdpLines[i].split(':')[1].split(' ');
  424.  
  425.             streamId = parts[0];
  426.             trackId = parts[1];
  427.             replaceSSRCSemantic = true;
  428.           }
  429.         }
  430.       }
  431.     };
  432.  
  433.     parseTracksSSRC('video');
  434.     parseTracksSSRC('audio');
  435.  
  436.     /*if (replaceSSRCSemantic) {
  437.       for (i = 0; i < sdpLines.length; i++) {
  438.         if (sdpLines[i].indexOf('a=msid-semantic:WMS ') === 0) {
  439.           var parts = sdpLines[i].split(' ');
  440.           parts[parts.length - 1] = streamId;
  441.           sdpLines[i] = parts.join(' ');
  442.           break;
  443.         }
  444.       }
  445.  
  446.     }*/
  447.     updatedSdp = sdpLines.join('\r\n');
  448.  
  449.     log.debug([targetMid, 'RTCSessionDesription', 'answer', 'Parsed remote description from firefox'], sdpLines);
  450.   }
  451.  
  452.   return updatedSdp;
  453. };
  454.