gstreamer/subprojects/gst-examples/webrtc/check/validate/web/webrtc.js

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/* vim: set sts=4 sw=4 et :
*
* Demo Javascript app for negotiating and streaming a sendrecv webrtc stream
* with a GStreamer app. Runs only in passive mode, i.e., responds to offers
* with answers, exchanges ICE candidates, and streams.
*
* Author: Nirbheek Chauhan <nirbheek@centricular.com>
*/
// Set this to override the automatic detection in websocketServerConnect()
var ws_server;
var ws_port;
// Set this to use a specific peer id instead of a random one
var default_peer_id;
// Override with your own STUN servers if you want
var rtc_configuration = {iceServers: [{urls: "stun:stun.services.mozilla.com"},
{urls: "stun:stun.l.google.com:19302"},]};
var default_constraints = {video: true, audio: false};
var connect_attempts = 0;
var peer_connection;
var channels = []
var ws_conn;
// Promise for local stream after constraints are approved by the user
var local_stream_promise;
function getOurId() {
return Math.floor(Math.random() * (9000 - 10) + 10).toString();
}
function resetState() {
// This will call onServerClose()
ws_conn.close();
}
function handleIncomingError(error) {
setError("ERROR: " + error);
resetState();
}
function getVideoElement() {
return document.getElementById("stream");
}
function setStatus(text) {
console.log(text);
var span = document.getElementById("status")
// Don't set the status if it already contains an error
if (!span.classList.contains('error'))
span.textContent = text;
}
function setError(text) {
console.error(text);
var span = document.getElementById("status")
span.textContent = text;
span.classList.add('error');
ws_conn.send(JSON.stringify({'STATE': 'error', 'msg' : text}))
}
function resetVideo() {
// Release the webcam and mic
if (local_stream_promise)
local_stream_promise.then(stream => {
if (stream) {
stream.getTracks().forEach(function (track) { track.stop(); });
}
});
// Reset the video element and stop showing the last received frame
var videoElement = getVideoElement();
videoElement.pause();
videoElement.src = "";
videoElement.load();
}
function updateRemoteStateFromSetSDPJson(sdp) {
if (sdp.type == "offer")
ws_conn.send(JSON.stringify({'STATE': 'offer-set', 'description' : sdp}))
else if (sdp.type == "answer")
ws_conn.send(JSON.stringify({'STATE': 'answer-set', 'description' : sdp}))
else
throw new Error ("Unknown SDP type!");
}
function updateRemoteStateFromGeneratedSDPJson(sdp) {
if (sdp.type == "offer")
ws_conn.send(JSON.stringify({'STATE': 'offer-created', 'description' : sdp}))
else if (sdp.type == "answer")
ws_conn.send(JSON.stringify({'STATE': 'answer-created', 'description' : sdp}))
else
throw new Error ("Unknown SDP type!");
}
// SDP offer received from peer, set remote description and create an answer
function onIncomingSDP(sdp) {
peer_connection.setRemoteDescription(sdp).then(() => {
updateRemoteStateFromSetSDPJson(sdp)
setStatus("Set remote SDP", sdp.type);
}).catch(setError);
}
// Local description was set, send it to peer
function onLocalDescription(desc) {
updateRemoteStateFromGeneratedSDPJson(desc)
console.log("Got local description: " + JSON.stringify(desc));
peer_connection.setLocalDescription(desc).then(function() {
updateRemoteStateFromSetSDPJson(desc)
sdp = {'sdp': desc}
setStatus("Sending SDP", sdp.type);
ws_conn.send(JSON.stringify(sdp));
});
}
// ICE candidate received from peer, add it to the peer connection
function onIncomingICE(ice) {
var candidate = new RTCIceCandidate(ice);
console.log("adding candidate", candidate)
peer_connection.addIceCandidate(candidate).catch(setError);
}
function createOffer(offer) {
local_stream_promise.then((stream) => {
setStatus("Got local stream, creating offer");
peer_connection.createOffer()
.then(onLocalDescription).catch(setError);
}).catch(setError)
}
function createAnswer(offer) {
local_stream_promise.then((stream) => {
setStatus("Got local stream, creating answer");
peer_connection.createAnswer()
.then(onLocalDescription).catch(setError);
}).catch(setError)
}
function handleOptions(options) {
console.log ('received options', options);
if (options.bundlePolicy != null) {
rtc_configuration['bundlePolicy'] = options.bundlePolicy;
}
}
function onServerMessage(event) {
console.log("Received " + event.data);
switch (event.data) {
case "HELLO":
setStatus("Registered with server, waiting for call");
return;
default:
if (event.data.startsWith("ERROR")) {
handleIncomingError(event.data);
return;
}
// Handle incoming JSON SDP and ICE messages
try {
msg = JSON.parse(event.data);
} catch (e) {
if (e instanceof SyntaxError) {
handleIncomingError("Error parsing incoming JSON: " + event.data);
} else {
handleIncomingError("Unknown error parsing response: " + event.data);
}
return;
}
if (msg.SET_TITLE != null) {
// some debugging for tests that hang around
document.title = msg['SET_TITLE']
return;
} else if (msg.OPTIONS != null) {
handleOptions(msg.OPTIONS);
return;
}
// Incoming JSON signals the beginning of a call
if (!peer_connection)
createCall();
if (msg.sdp != null) {
onIncomingSDP(msg.sdp);
} else if (msg.ice != null) {
onIncomingICE(msg.ice);
} else if (msg.CREATE_OFFER != null) {
createOffer(msg.CREATE_OFFER)
} else if (msg.CREATE_ANSWER != null) {
createAnswer(msg.CREATE_ANSWER)
} else if (msg.DATA_CREATE != null) {
addDataChannel(msg.DATA_CREATE.id)
} else if (msg.DATA_CLOSE != null) {
closeDataChannel(msg.DATA_CLOSE.id)
} else if (msg.DATA_SEND_MSG != null) {
sendDataChannelMessage(msg.DATA_SEND_MSG)
} else {
handleIncomingError("Unknown incoming JSON: " + msg);
}
}
}
function onServerClose(event) {
setStatus('Disconnected from server');
resetVideo();
if (peer_connection) {
peer_connection.close();
peer_connection = null;
}
channels = []
// Reset after a second
window.setTimeout(websocketServerConnect, 1000);
}
function onServerError(event) {
setError("Unable to connect to server, did you add an exception for the certificate?")
// Retry after 3 seconds
window.setTimeout(websocketServerConnect, 3000);
}
function getLocalStream() {
var constraints;
constraints = default_constraints;
console.log(JSON.stringify(constraints));
// Add local stream
if (navigator.mediaDevices.getUserMedia) {
return navigator.mediaDevices.getUserMedia(constraints);
} else {
errorUserMediaHandler();
}
}
function websocketServerConnect() {
connect_attempts++;
if (connect_attempts > 3) {
setError("Too many connection attempts, aborting. Refresh page to try again");
return;
}
// Clear errors in the status span
var span = document.getElementById("status");
span.classList.remove('error');
span.textContent = '';
// Fetch the peer id to use
var url = new URL(window.location.href);
peer_id = url.searchParams.get("id");
peer_id = peer_id || default_peer_id || getOurId();
ws_port = ws_port || url.searchParams.get("port");
ws_port = ws_port || '8443';
ws_server = ws_server || url.searchParams.get("server");
if (window.location.protocol.startsWith ("file")) {
ws_server = ws_server || "127.0.0.1";
} else if (window.location.protocol.startsWith ("http")) {
ws_server = ws_server || window.location.hostname;
} else {
throw new Error ("Don't know how to connect to the signalling server with uri" + window.location);
}
var ws_url = 'wss://' + ws_server + ':' + ws_port
setStatus("Connecting to server " + ws_url);
ws_conn = new WebSocket(ws_url);
/* When connected, immediately register with the server */
ws_conn.addEventListener('open', (event) => {
document.getElementById("peer-id").textContent = peer_id;
ws_conn.send('HELLO ' + peer_id);
setStatus("Registering with server");
});
ws_conn.addEventListener('error', onServerError);
ws_conn.addEventListener('message', onServerMessage);
ws_conn.addEventListener('close', onServerClose);
}
function onRemoteStreamAdded(event) {
videoTracks = event.stream.getVideoTracks();
audioTracks = event.stream.getAudioTracks();
if (videoTracks.length > 0) {
console.log('Incoming stream: ' + videoTracks.length + ' video tracks and ' + audioTracks.length + ' audio tracks');
getVideoElement().srcObject = event.stream;
} else {
handleIncomingError('Stream with unknown tracks added, resetting');
}
}
function errorUserMediaHandler() {
setError("Browser doesn't support getUserMedia!");
}
const handleDataChannelMessageReceived = (event) =>{
console.log("dataChannel.OnMessage:", event, event.data.type);
setStatus("Received data channel message");
ws_conn.send(JSON.stringify({'DATA-MSG' : event.data, 'id' : event.target.label}));
};
const handleDataChannelOpen = (event) =>{
console.log("dataChannel.OnOpen", event);
ws_conn.send(JSON.stringify({'DATA-STATE' : 'open', 'id' : event.target.label}));
};
const handleDataChannelError = (error) =>{
console.log("dataChannel.OnError:", error);
ws_conn.send(JSON.stringify({'DATA-STATE' : error, 'id' : event.target.label}));
};
const handleDataChannelClose = (event) =>{
console.log("dataChannel.OnClose", event);
ws_conn.send(JSON.stringify({'DATA-STATE' : 'closed', 'id' : event.target.label}));
};
function onDataChannel(event) {
setStatus("Data channel created");
let channel = event.channel;
console.log('adding remote data channel with label', channel.label)
ws_conn.send(JSON.stringify({'DATA-NEW' : {'id' : channel.label, 'location' : 'remote'}}));
channel.onopen = handleDataChannelOpen;
channel.onmessage = handleDataChannelMessageReceived;
channel.onerror = handleDataChannelError;
channel.onclose = handleDataChannelClose;
channels.push(channel)
}
function addDataChannel(label) {
channel = peer_connection.createDataChannel(label, null);
console.log('adding local data channel with label', label)
ws_conn.send(JSON.stringify({'DATA-NEW' : {'id' : label, 'location' : 'local'}}));
channel.onopen = handleDataChannelOpen;
channel.onmessage = handleDataChannelMessageReceived;
channel.onerror = handleDataChannelError;
channel.onclose = handleDataChannelClose;
channels.push(channel)
}
function find_channel(label) {
console.log('find', label, 'in', channels)
for (var c in channels) {
if (channels[c].label === label) {
console.log('found', label, c)
return channels[c];
}
}
return null;
}
function closeDataChannel(label) {
channel = find_channel (label)
console.log('closing data channel with label', label)
channel.close()
}
function sendDataChannelMessage(msg) {
channel = find_channel (msg.id)
console.log('sending on data channel', msg.id, 'message', msg.msg)
channel.send(msg.msg)
}
function createCall() {
// Reset connection attempts because we connected successfully
connect_attempts = 0;
console.log('Creating RTCPeerConnection with configuration', rtc_configuration);
peer_connection = new RTCPeerConnection(rtc_configuration);
peer_connection.ondatachannel = onDataChannel;
peer_connection.onaddstream = onRemoteStreamAdded;
/* Send our video/audio to the other peer */
local_stream_promise = getLocalStream().then((stream) => {
console.log('Adding local stream');
peer_connection.addStream(stream);
return stream;
}).catch(setError);
peer_connection.onicecandidate = (event) => {
// We have a candidate, send it to the remote party with the
// same uuid
if (event.candidate == null) {
console.log("ICE Candidate was null, done");
return;
}
console.log("generated ICE Candidate", event.candidate);
ws_conn.send(JSON.stringify({'ice': event.candidate}));
};
setStatus("Created peer connection for call, waiting for SDP");
}