function setupVariables(){
getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
RTCPeerConnection = webkitRTCPeerConnection;
servers =['stun:stun.l.google.com:19302'];
}
setupVariables();
function connect() {
connectButton.disabled = true;
disconnectButton.disabled = false;
connectToSignalServer();
getUserMedia({audio:false, video:false}, showStream, handleError);
}
function connectToSignalServer(){
socket = io.connect('http://192.168.5.103:2013');
socket.on('incomingCall', function(message){
createAnswer(message);
});
socket.on('receiveAnswer', function(message){
elaborateAnswer(message);
});
socket.on('receiveIce', function(message){
receiveIce(message);
});
}
function showStream(stream){
myVideo.src = window.URL.createObjectURL(stream);
localStream = stream;
callButton.disabled = false;
setupPeerConnection();
}
function setupPeerConnection(stream){
peerConnection = new RTCPeerConnection(servers);
peerConnection.onicecandidate = gotIceCandidate;
peerConnection.addStream(localStream);
peerConnection.onaddstream = showRemoteStream;
}
function callOther() {
callButton.disabled = true;
peerConnection.createOffer(gotLocalDescriptionOnCall,handleError);
}
function gotLocalDescriptionOnCall(offer) {
peerConnection.setLocalDescription(offer);
socket.emit('callRequest', JSON.stringify({'sdp': offer}));
};
function createAnswer(message){
var signal = JSON.parse(message);
peerConnection.setRemoteDescription(new RTCSessionDescription(signal.sdp), function() {
peerConnection.createAnswer(gotLocalDescriptionOnAnswer);
});
}
function gotLocalDescriptionOnAnswer(answer) {
peerConnection.setLocalDescription(answer);
socket.emit('sendAnswer', JSON.stringify({'sdp': answer}));
};
function elaborateAnswer(answer){
var signal = JSON.parse(answer);
peerConnection.setRemoteDescription(new RTCSessionDescription(signal.sdp));
}
function gotIceCandidate(event) {
if(event.candidate != null) {
socket.emit('sendIce',JSON.stringify({'ice': event.candidate}));
}
}
function receiveIce(message){
var signal = JSON.parse(message);
peerConnection.addIceCandidate(new RTCIceCandidate(signal.ice));
}
function showRemoteStream(event){
otherVideo.src = window.URL.createObjectURL(event.stream);
}
function toggleSharing = function(){
localStream.getVideoTracks()[0].enabled = !(localStream.getVideoTracks()[0].enabled);
localStream.getAudioTracks()[0].enabled = !(localStream.getAudioTracks()[0].enabled);
}
Server
Per l’implementazione del web-server abbiamo utilizzato Node.Js con la configurazione qui sotto riportata.
Salvare la configurazione in un file con nome server.js, e nello stesso folder salvare il file index.html.
Lanciare il terminale, portarsi nella directory contenente i files ed eseguire “node server.js”.
var static = require('node-static');
var https = require('http');
var file = new(static.Server)();
var app = http.createServer(function (req, res) {
file.serve(req, res);
});
A questo punto è sufficiente aprire Chrome e richiamare l’indirizzo http://localhost:2003.
Utilizzando lo stesso browser aprire un’altra tab e richiamare lo stesso indirizzo.
