This template creates a minimal video chat between the visitors of the site. It uses the Peersockets API to set up a WebRTC video call between users. Traffic is encrypted so that only users who possess the site’s URL can read it.

(Note: this is a simple demo and won’t work with more than 2 users.)

Source

<!doctype html>
<html>
  <head>
    <link rel="icon" type="image/png" sizes="32x32" href="/thumb.png">
    <style>
      body {
        margin: 20px;
        font-family: 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
      }
      h1 {
        font-weight: 500;
      }
      #videos {
        display: grid;
        grid-template-columns: 1fr 1fr;
        grid-gap: 10px;
        margin: 10px 0;
      }
      video {
        width: 100%;
      }
    </style>
  </head>
  <body>
    <h1>Video Chat</h1>
    <button id="startButton">Start</button>
    <select id="videoSelect"></select>
    <select id="audioSelect"></select>
    <div id="videos">
      <video id="localVideo" playsinline autoplay muted></video>
      <video id="remoteVideo" playsinline autoplay></video>
    </div>
  </body>

  <script>
var peerSockets = new Set()
var topic
var localStream;
var peerConnection;
var uuid;
var videoDevice;
var audioDevice;

var peerConnectionConfig = {
  'iceServers': [
    {'urls': 'stun:stun.stunprotocol.org:3478'},
    {'urls': 'stun:stun.l.google.com:19302'},
  ]
};

async function pageReady() {
  console.log('running setup')
  uuid = createUUID();

  var peerEvents = beaker.peersockets.watch()
  peerEvents.addEventListener('join', e => {
    console.log('join', e)
    peerSockets.add(e.peerId)
  })
  peerEvents.addEventListener('leave', e => {
    console.log('leave', e)
    peerSockets.delete(e.peerId)
  })
  topic = beaker.peersockets.join('signalling')
  topic.addEventListener('message', gotMessageFromPeersocket)

  navigator.mediaDevices.getUserMedia({video: true, audio: true}).then(getUserMediaSuccess).catch(errorHandler);

  try {
    var devices = await navigator.mediaDevices.enumerateDevices()
    for (let device of devices) {
      let opt = document.createElement('option')
      opt.value = device.deviceId
      opt.textContent = device.label
      if (device.kind === 'videoinput') {
        videoSelect.append(opt)
      } else if (device.kind === 'audioinput') {
        audioSelect.append(opt)
      }
    }
    videoSelect.addEventListener('change', onChangeDevice)
    audioSelect.addEventListener('change', onChangeDevice)
  } catch (e) {
    videoSelect.remove()
    audioSelect.remove()
  }

  console.log('setup finished')
}

function onChangeDevice () {
  navigator.mediaDevices.getUserMedia({video: {deviceId: videoSelect.value}, audio: {deviceId: audioSelect.value}}).then(getUserMediaSuccess).catch(errorHandler);
}

function sendToAllPeersockets (message) {
  console.log('sent', {message})
  message = new TextEncoder('utf-8').encode(JSON.stringify(message))
  for (let peer of peerSockets) {
    topic.send(peer, message)
  }
}

function getUserMediaSuccess(stream) {
  localStream = stream;
  localVideo.srcObject = stream;
}

function start(isCaller) {
  peerConnection = new RTCPeerConnection(peerConnectionConfig);
  peerConnection.onicecandidate = gotIceCandidate;
  peerConnection.ontrack = gotRemoteStream;
  peerConnection.addStream(localStream);

  if(isCaller) {
    peerConnection.createOffer().then(createdDescription).catch(errorHandler);
  }
}
startButton.addEventListener('click', start)

function gotMessageFromPeersocket({peerId, message}) {
  console.log('received', {peerId, message})
  if(!peerConnection) start(false);

  var signal = JSON.parse(new TextDecoder().decode(message));

  // Ignore messages from ourself
  if(signal.uuid == uuid) return;

  if(signal.sdp) {
    peerConnection.setRemoteDescription(new RTCSessionDescription(signal.sdp)).then(function() {
      // Only create answers in response to offers
      if(signal.sdp.type == 'offer') {
        peerConnection.createAnswer().then(createdDescription).catch(errorHandler);
      }
    }).catch(errorHandler);
  } else if(signal.ice) {
    peerConnection.addIceCandidate(new RTCIceCandidate(signal.ice)).catch(errorHandler);
  }
}

function gotIceCandidate(event) {
  if(event.candidate != null) {
    sendToAllPeersockets({'ice': event.candidate, 'uuid': uuid});
  }
}

function createdDescription(description) {
  console.log('got description');

  peerConnection.setLocalDescription(description).then(function() {
    sendToAllPeersockets({'sdp': peerConnection.localDescription, 'uuid': uuid});
  }).catch(errorHandler);
}

function gotRemoteStream(event) {
  console.log('got remote stream');
  remoteVideo.srcObject = event.streams[0];
}

function errorHandler(error) {
  console.log(error);
}

// Taken from http://stackoverflow.com/a/105074/515584
// Strictly speaking, it's not a real UUID, but it gets the job done here
function createUUID() {
  function s4() {
    return Math.floor((1 + Math.random()) * 0x10000).toString(16).substring(1);
  }

  return s4() + s4() + '-' + s4() + '-' + s4() + '-' + s4() + '-' + s4() + s4() + s4();
}

pageReady()
  </script>
</html>
MIT License

Copyright (c) 2020 Blue Link Labs

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.