How can I stream audio using Socket.io in real time?

user_2340215 0
Viewed 12974

I am currently using socket.io to create a chat application in HTML and JS. I am able to communication between two computers easily sending written messages. My problem is that I am not able to figure out how to send real-time voice recorded in one computer to the other. I am using "navigator.getUserMedia" to record audio from the microphone and it works great, but I can not send it to through Socket.io to another computer.

I know that I can start recording, then stop and finally send the result, but it is not what I need, what I need is real-time streaming.

This is the code for the server:

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var path = require('path');
var users = [];

app.get('/', function(req, res){
res.sendFile(__dirname + '/index.html');
});

io.on('connection', function(socket){

socket.on('add user', function(user_id){
    users.push(user_id);
});

socket.on('chat message', function(msg){
    io.emit('chat message', msg);
});
socket.on('voice sent', function(msg){
    io.emit('voice received', msg);
});
});

http.listen(3000, function(){
  console.log('listening on *:3000');
});

And this is client js:

$(function () {
    var socket = io();
    var user_id = Math.random();

    socket.emit('add user', user_id);

    $('form').submit(function(){
      socket.emit('chat message', {"message": $('#m').val(), "user": user_id});
      $('#m').val('');
      return false;
    });
    socket.on('chat message', function(msg){
      if(msg.user == user_id){
        $('#messages').append($('<li class="mine">').text(msg.message));
      }
      else{
        $('#messages').append($('<li>').text(msg.message));
      }

    });

    socket.on('voice received', function(msg){
      var audio = document.querySelector('audio'); 
      audio.src = window.URL.createObjectURL(stream);
    });

    navigator.getUserMedia = navigator.getUserMedia ||
                     navigator.webkitGetUserMedia ||
                     navigator.mozGetUserMedia;
    if (navigator.getUserMedia) {
       console.log('getUserMedia supported.');
       navigator.getUserMedia ({audio: true}, successCallback, errorCallback);
    } else {
       console.log('getUserMedia not supported on your browser!');
    }

    function successCallback(stream){
       socket.emit('voice sent', stream);
    }

    function errorCallback(error) {
      console.error('An error occurred: [CODE ' + error.code + ']');
    }
  });

I hope somebody can help me. Thanks

socket.io node.js audio streaming javascript
3 Answers

I tried to do so , after a while i done it so :

export default {
  data() {
    return {
      audioCtx: new AudioContext(), // for get stream from mic and send via socket
      audioC: new AudioContext(), // for receive data from socket and translate and play 
    }
  },
  created() {
    navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia

    if (navigator.getUserMedia) {
      console.log('getUserMedia supported.')

      navigator.getUserMedia(
        { audio: true },
        stream => {
          const source = this.audioCtx.createMediaStreamSource(stream)
          const processor = this.audioCtx.createScriptProcessor(2048, 1, 1)

          source.connect(processor)
          processor.connect(this.audioCtx.destination)

          processor.onaudioprocess = e => {
            this.$store.state.mic.Emit('Voice', e.inputBuffer.getChannelData(0))
          }

          this.$store.state.mic.On('Voice', msg => {
            const fbu = new Float32Array(Object.values(JSON.parse(msg)))
            const audioBuffer = this.audioC.createBuffer(1, 2048, this.audioC.sampleRate)

            audioBuffer.getChannelData(0).set(fbu)

            const sourceNode = new AudioBufferSourceNode(this.audioC, { buffer: audioBuffer })

            sourceNode.connect(this.audioC.destination)
            sourceNode.start(0)
          })

          this.audioC.resume()
        },
        err => console.error(err)
      )
    }
  }
}

and the server just sends every thing it got to all except sender client but still there is problem , due to different AudioBufferSourceNode the call quality is not good , it's separated and chopped.

user_102487410

in this block of code

    socket.on('voice received', function(msg){
      var audio = document.querySelector('audio'); 
      audio.src = window.URL.createObjectURL(stream);
    });

stream is defined nowhere .... i think this could solve your problem

    socket.on('voice received', function(msg){
      var audio = document.querySelector('audio'); 
      audio.src = window.URL.createObjectURL(msg);
    });
user_150836160
user_197698000
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