basic2016/hand_signaling_modify.html

<!doctype html>
<html>
<head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Hand Modify SDP</title>
</head>
<body>
  Hand Signaling 2016 Modify SDP<br />
  <button type="button" onclick="startVideo();">Start Video</button>
  <button type="button" onclick="stopVideo();">Stop Video</button>
  &nbsp;
  <button type="button" onclick="connect();">Connect</button>
  <button type="button" onclick="hangUp();">Hang Up</button> 
  <div>
    <video id="local_video" autoplay style="width: 160px; height: 120px; border: 1px solid black;"></video>
    <video id="remote_video" autoplay style="width: 160px; height: 120px; border: 1px solid black;"></video>
  </div>
  <p>SDP to set/send:&nbsp;
    <button type="button" onclick="setLocalSdpText();">Set local SDP</button><br />
    <textarea id="text_for_send_sdp" rows="5" cols="60">SDP to send</textarea>
  </p>
  <p>SDP to receive:&nbsp;
    <button type="button" onclick="onSdpText();">Receive remote SDP</button><br />
    <textarea id="text_to_receive_sdp" rows="5" cols="60"></textarea>
  </p>
</body>
<script type="text/javascript">
  let localVideo = document.getElementById('local_video');
  let remoteVideo = document.getElementById('remote_video');
  let localStream = null;
  let peerConnection = null;
  let textForSendSdp = document.getElementById('text_for_send_sdp');
  let textToReceiveSdp = document.getElementById('text_to_receive_sdp');
  let localDescriptionType = null;

  // --- prefix -----
  navigator.getUserMedia  = navigator.getUserMedia    || navigator.webkitGetUserMedia ||
                            navigator.mozGetUserMedia || navigator.msGetUserMedia;
  RTCPeerConnection = window.RTCPeerConnection || window.webkitRTCPeerConnection || window.mozRTCPeerConnection;
  RTCSessionDescription = window.RTCSessionDescription || window.webkitRTCSessionDescription || window.mozRTCSessionDescription;

  // ---------------------- media handling ----------------------- 
  // start local video
  function startVideo() {
    getDeviceStream({video: true, audio: false})
    .then(function (stream) { // success
      localStream = stream;
      playVideo(localVideo, stream);
    }).catch(function (error) { // error
      console.error('getUserMedia error:', error);
      return;
    });
  }

  // stop local video
  function stopVideo() {
    pauseVideo(localVideo);
    stopLocalStream(localStream);
  }

  function stopLocalStream(stream) {
    let tracks = stream.getTracks();
    if (! tracks) {
      console.warn('NO tracks');
      return;
    }
    
    for (let track of tracks) {
      track.stop();
    }
  }
  
  function getDeviceStream(option) {
    if ('getUserMedia' in navigator.mediaDevices) {
      console.log('navigator.mediaDevices.getUserMadia');
      return navigator.mediaDevices.getUserMedia(option);
    }
    else {
      console.log('wrap navigator.getUserMadia with Promise');
      return new Promise(function(resolve, reject){    
        navigator.getUserMedia(option,
          resolve,
          reject
        );
      });      
    }
  }

  function playVideo(element, stream) {
    if ('srcObject' in element) {
      element.srcObject = stream;
    }
    else {
      element.src = window.URL.createObjectURL(stream);
    }
    element.play();
    element.volume = 0;
  }

  function pauseVideo(element) {
    element.pause();
    if ('srcObject' in element) {
      element.srcObject = null;
    }
    else {
      if (element.src && (element.src !== '') ) {
        window.URL.revokeObjectURL(element.src);
      }
      element.src = '';
    }
  }

  // ----- hand signaling ----
  function onSdpText() {
    let text = textToReceiveSdp.value;
    if (peerConnection) {
      console.log('Received answer text...');
      let answer = new RTCSessionDescription({
        type : 'answer',
        sdp : text,
      });
      setAnswer(answer);
    }
    else {
      console.log('Received offer text...');
      let offer = new RTCSessionDescription({
        type : 'offer',
        sdp : text,
      });
      setOffer(offer);
    }
    textToReceiveSdp.value ='';
  }
 
  function sendSdp(sessionDescription) {
    console.log('---sending sdp ---');
    localDescriptionType = sessionDescription.type;
    textForSendSdp.value = sessionDescription.sdp;
    textForSendSdp.focus();
    textForSendSdp.select();
  }

  function setLocalSdpText() {
    let text = textForSendSdp.value;
    let sessionDescription = new RTCSessionDescription({
      type : localDescriptionType,
      sdp : text,
    });
    peerConnection.setLocalDescription(sessionDescription)
    .then(function() {
      console.log('setLocalDescription() success');
    })
    .catch(function(err) {
      console.error('setLocalDescription() ERROR:', err);
    });

    textForSendSdp.focus();
    textForSendSdp.select();
  }

  // ---------------------- connection handling -----------------------
  function prepareNewConnection() {
    let pc_config = {"iceServers":[]};
    let peer = new RTCPeerConnection(pc_config);

    // --- on get remote stream ---
    if ('ontrack' in peer) {
      peer.ontrack = function(event) {
        console.log('-- peer.ontrack()');
        let stream = event.streams[0];
        playVideo(remoteVideo, stream);
      };
    }
    else {
      peer.onaddstream = function(event) {
        console.log('-- peer.onaddstream()');
        let stream = event.stream;
        playVideo(remoteVideo, stream);
      };
    }

    // --- on get local ICE candidate
    peer.onicecandidate = function (evt) {
      if (evt.candidate) {
        console.log(evt.candidate);

        // Trickle ICE の場合は、ICE candidateを相手に送る
        // Vanilla ICE の場合には、何もしない
      } else {
        console.log('empty ice event');

        // Trickle ICE の場合は、何もしない
        // Vanilla ICE の場合には、ICE candidateを含んだSDPを相手に送る
        sendSdp(peer.localDescription);
      }
    };

    // --- when need to exchange SDP ---
    peer.onnegotiationneeded = function(evt) {
      console.log('-- onnegotiationneeded() ---');
    };

    // --- other events ----
    peer.onicecandidateerror = function (evt) {
      console.error('ICE candidate ERROR:', evt);
    };

    peer.onsignalingstatechange = function() {
      console.log('== signaling status=' + peer.signalingState);
    };

    peer.oniceconnectionstatechange = function() {
      console.log('== ice connection status=' + peer.iceConnectionState);
      if (peer.iceConnectionState === 'disconnected') {
        console.log('-- disconnected --');
        hangUp();
      }
    };

    peer.onicegatheringstatechange = function() {
      console.log('==***== ice gathering state=' + peer.iceGatheringState);
    };
    
    peer.onconnectionstatechange = function() {
      console.log('==***== connection state=' + peer.connectionState);
    };

    peer.onremovestream = function(event) {
      console.log('-- peer.onremovestream()');
      pauseVideo(remoteVideo);
    };
    
    
    // -- add local stream --
    if (localStream) {
      console.log('Adding local stream...');
      peer.addStream(localStream);
    }
    else {
      console.warn('no local stream, but continue.');
    }

    return peer;
  }

  function makeOffer() {
    peerConnection = prepareNewConnection();
    peerConnection.createOffer()
    .then(function (sessionDescription) {
      console.log('createOffer() succsess in promise');

      // --- modify befer setLocalDescription ---
      //return peerConnection.setLocalDescription(sessionDescription);
      sendSdp(sessionDescription);
      
    }).then(function() {
      console.log('setLocalDescription() succsess in promise');

      // -- Trickle ICE の場合は、初期SDPを相手に送る -- 
      // -- Vanilla ICE の場合には、まだSDPは送らない --
      //sendSdp(peerConnection.localDescription);
    }).catch(function(err) {
      console.error(err);
    });
  }

  function setOffer(sessionDescription) {
    if (peerConnection) {
      console.error('peerConnection alreay exist!');
    }
    peerConnection = prepareNewConnection();
    peerConnection.setRemoteDescription(sessionDescription)
    .then(function() {
      console.log('setRemoteDescription(offer) succsess in promise');
      makeAnswer();
    }).catch(function(err) {
      console.error('setRemoteDescription(offer) ERROR: ', err);
    });
  }
  
  function makeAnswer() {
    console.log('sending Answer. Creating remote session description...' );
    if (! peerConnection) {
      console.error('peerConnection NOT exist!');
      return;
    }
    
    peerConnection.createAnswer()
    .then(function (sessionDescription) {
      console.log('createAnswer() succsess in promise');

      // --- modify befer setLocalDescription ---
      //return peerConnection.setLocalDescription(sessionDescription);
      sendSdp(sessionDescription);

    }).then(function() {
      console.log('setLocalDescription() succsess in promise');

      // -- Trickle ICE の場合は、初期SDPを相手に送る -- 
      // -- Vanilla ICE の場合には、まだSDPは送らない --
      //sendSdp(peerConnection.localDescription);
    }).catch(function(err) {
      console.error(err);
    });
  }

  function setAnswer(sessionDescription) {
    if (! peerConnection) {
      console.error('peerConnection NOT exist!');
      return;
    }

    peerConnection.setRemoteDescription(sessionDescription)
    .then(function() {
      console.log('setRemoteDescription(answer) succsess in promise');
    }).catch(function(err) {
      console.error('setRemoteDescription(answer) ERROR: ', err);
    });
  }
  
  // start PeerConnection
  function connect() {
    if (! peerConnection) {
      console.log('make Offer');
      makeOffer();
    }
    else {
      console.warn('peer already exist.');
    }
  }

  // close PeerConnection
  function hangUp() {
    if (peerConnection) {
      console.log('Hang up.');
      peerConnection.close();
      peerConnection = null;
      pauseVideo(remoteVideo);
    }
    else {
      console.warn('peer NOT exist.');
    }
  }

</script>
</html>