javascript - WebRTC - 是否可以让浏览器代理视频从源到接收器？

Question

例如:

• 浏览器 A 正在广播视频
• 浏览器 B 是中间人
• 浏览器 C 正在接收视频

浏览器 B 充当 A 和 C 之间的中介，是否可以做这样的事情？

其次，B 是否可以既观看 A 播放的视频，又将其转发给 C？

Answer 1

当然，这很好用。 (对于 Chrome，请使用 https fiddle):

function Hop() {
  this.pc1 = new RTCPeerConnection();
  this.pc2 = new RTCPeerConnection();

  var add = (pc, can) => can && pc.addIceCandidate(can).catch(log);
  this.pc1.onicecandidate = e => add(this.pc2, e.candidate);
  this.pc2.onicecandidate = e => add(this.pc1, e.candidate);
  this.pc2.oniceconnectionstatechange = e => log(this.pc2.iceConnectionState);
};
Hop.prototype.send = function(stream) {
  this.pc1.addStream(stream);
  return Promise.all([
    new Promise(resolve => this.pc2.onaddstream = resolve),
    this.pc1.createOffer()
      .then(offer => this.pc1.setLocalDescription(offer))
      .then(() => this.pc2.setRemoteDescription(this.pc1.localDescription))
      .then(() => this.pc2.createAnswer())
      .then(answer => this.pc2.setLocalDescription(answer))
      .then(() => this.pc1.setRemoteDescription(this.pc2.localDescription))
  ])
  .then(results => results[0].stream);
};

var AtoB = new Hop(), BtoC = new Hop();

navigator.mediaDevices.getUserMedia({ video: true })
  .then(stream => AtoB.send(v1.srcObject = stream))
  .then(stream => BtoC.send(v2.srcObject = stream))
  .then(stream => v3.srcObject = stream)
  .catch(e => log(e));

var log = msg => div.innerHTML += msg + "<br>";

<video id="v1" height="120" width="160" autoplay muted></video>
<video id="v2" height="120" width="160" autoplay></video>
<video id="v3" height="120" width="160" autoplay></video><br>
<div id="div"></div>
<script src="https://webrtc.github.io/adapter/adapter-latest.js"></script>

您可以根据需要创建任意数量的跃点。