Is it possible to make a video call over websocket on the web without using WebRTC?

Question

I want to stream video (with audio) over websocket in one direction without using STUN/TURN server. Is it possible to write such a web app?

Data will flow like this:

Peer A -> Websocket Server -> Peer B

Answer 1

Yes it is possible. if you ok 0.5 s latency
streamer:

navigator.mediaDevices.getUserMedia({video:true,audio:true}).then(stream=>{
var ws,mediaRecorder;
var options = {
        mimeType: "video/webm;codecs=opus, vp8",
        bitsPerSecond:5000 //quality
        };

function handleVideo(){
  
    try{
        mediaRecorder.stop()
    }catch(e){}
    mediaRecorder=null;
    mediaRecorder = new MediaRecorder(stream,options);
    mediaRecorder.ondataavailable =function(e) {

        if(e.data&&e.data.size>0) {
            e.data.arrayBuffer().then(buffer=>{
                    ws.send(buffer)
              })
        }
    }
    mediaRecorder.start(300);
   }

   function connect(){
    ws = new WebSocket("wss://yourwebsocket.com")
    ws.binaryType = "arraybuffer"
    ws.onopen=handleVideo
    ws.onmessage=handleVideo
    ws.onclose=connect
   }
connect()

})
// so onmessage function neccessary for when someone join the socket stream again, because webm format need embl header

watcher:

var media,sourceBuffer,ws;
var video = document.getElementById('yourvideoid')

function handleStream(e){
    const buffer=e.data
    const data= new Uint8Array(buffer)
    
        if(data[0]===26&&data[1]===69&&data[2]===223){
            if(media){
            URL.revokeObjectURL(media)
            sourceBuffer=null;  
                 }
        
        media= new MediaSource();
        video.src = URL.createObjectURL(media);
        video.onloadedmetadata=function(){
            video.muted=false
            video.play()
        }
        
        media.onsourceopen=function(){
        sourceBuffer= media.addSourceBuffer("video/webm;codecs=opus, vp8");
        sourceBuffer.appendBuffer(buffer)
      }
    
        }
        
        else {
        if(!media)return;
        
            sourceBuffer.appendBuffer(buffer)
            
        }
}
function connect(){
    ws = new WebSocket("wss://yourwsserver.com")
    ws.binaryType = "arraybuffer"
    ws.onmessage=handleStream
    ws.onclose=connect
}
connect()
// we fetch data from websocket then add data to video buffer

nodejs server:

const EventEmitter = require('events');
const https = require('https');
const {Server} = require('ws'); //npm i ws

const emitter= new EventEmitter();
const app = https.createServer(options,function (req, res) {})
const wss = new Server({ server: app });


wss.on('connection', (socket,req) => {
    var isStreamer=false
    socket.fn=function(e){socket.send(e)}
    const interval= setInterval(socket.ping, 5000);
    emitter.on('data',socket.fn)
    emitter.emit('refresh','0')    

    socket.on('message', (data) => {
        isStreamer||(emitter.on('refresh',socket.fn),emitter.off('data',socket.fn),(isStreamer=true))
        emitter.emit('data',data)
    });

    socket.on('close', () => {
        clearInterval(interval)
        emitter.off('data',socket.fn)
        emitter.off('refresh',socket.fn)
        
    })
    socket.on('ping',socket.pong)
    socket.on("error", (err) => {})
});

app.listen(PORT,'0.0.0.0')

//u need to set option for https or use http instead