webrtc - 私のwebRTC実装はonaddstreamを決して呼び出しません

Question

WebRTC を簡素化するhttps://github.com/HenrikJoreteg/RTCPeerConnectionを使用していますが、それでも動作しません。WebRTC ピア接続 (offer、answer、ice) は確立されますが、onaddstream は呼び出されません。

(次のコードを使用する同じ html で 2 つのブラウザー タブを開き、start 関数を実行してビデオを取得し、peer を実行して接続を開始してコードを実行します。)

このコードのバグを指摘してくれる人はいますか?

var local_stream;
var localvid = document.getElementById('localvid');
var remotevid = document.getElementById('remotevid');
var servers= {iceServers: [{"url": "stun:stun.l.google.com:19302"}]};
var constraints = {optional: [{"DtlsSrtpKeyAgreement": true}]};
var peerConn = new PeerConnection(servers,constraints);

function start(){
  navigator.getUserMedia || 
    (navigator.getUserMedia = navigator.getUserMedia || navigator.mozGetUserMedia ||
               navigator.webkitGetUserMedia || navigator.msGetUserMedia);
  if (navigator.getUserMedia) {
    navigator.getUserMedia({
            video: true, 
            audio: false
          }, onSuccess, function(){});
  } else {
        alert('getUserMedia is not supported in this browser.');
  }
}
function onSuccess(stream){
  localvid.src = window.webkitURL.createObjectURL(stream);
  local_stream = stream;
  localvid.autoplay = true;
}

function peer(){
  peerConn.addStream(local_stream);
  peerConn.offer({ mandatory: { OfferToReceiveAudio:false, OfferToReceiveVideo: true} },
      function( err, offer){
        if(!err){
          console.log("Creating an offer...");
          socket.emit('offer',offer);
        }
      }
      );
}

peerConn.on('ice', function(candidate){
  if(candidate){
    console.log("Sending ice...");console.log(candidate);
    socket.emit('ice',candidate);
  }else { console.log("End of candidates.");}
}); 

peerConn.on('streamAdded',function(stream){
  console.log("Adding stream..");
  remotevid.src = window.webkitURL.createObjectURL(stream);
  remotevid.autoplay = true;
});


socket.on('offer',function(offer){
  peerConn.answer(offer,function (err,answer){
    if(!err){
      console.log("Creating the answer...");console.log(answer);
      socket.emit('answer',answer);
    }
  });
});

socket.on('answer', function(answer){
  console.log("Got the answer...");
  peerConn.handleAnswer(answer);
});

socket.on('ice', function (candidate){
  console.log("Processing ice...");
  peerConn.processIce(candidate);
  console.log(candidate);
});