video_stream_server.js

#!/usr/bin/env node

var net = require('net');
var ws = require('ws');
var cameras = require('./devices').cameras;
var log = require('./utils').log;

var PI_STREAM_PORT = 8000,
    STREAM_MAGIC_BYTES = 'jsmp'; // Must be 4 bytes

var width = 320,
    height = 240;

var servers = Object.keys(cameras).reduce(function(out, key) {
  var cam = cameras[key];
  out[cam.device] = createWebSocketServer({ port: cam.port });
  return out;
}, {});

function createWebSocketServer(opts) {
  var socketServer = new ws.Server({port: opts.port});
  socketServer.on('connection', function onConnection(socket) {
    // Send magic bytes and video size to the newly connected socket
    // struct { char magic[4]; unsigned short width, height; }
    var streamHeader = new Buffer(8);
    streamHeader.write(STREAM_MAGIC_BYTES);
    streamHeader.writeUInt16BE(width, 4);
    streamHeader.writeUInt16BE(height, 6);
    socket.send(streamHeader, {binary: true});
  });

  socketServer.broadcast = function(data, o) {
    for(var i in this.clients) {
      if (this.clients[i].readyState === 1) {
        this.clients[i].send(data, o);
      }    
    }
  };
  return socketServer;
}

// Server to accept incoming MPEG Stream
var streamServer = net.createServer(function(socket) {
  this.piSockets = {};
  var that = this;
  socket.on('data', function onData(chunk) {
      if (!socket.nameSet) {
        chunk = chunk.toString('utf8').split('~');
        socket.name = chunk[0];
        if (chunk.length > 1) {
          that.piSockets[socket.name] = socket;
          socket.nameSet = true;
          log('New Pi id: ' + socket.name);
          chunk.shift();
          chunk = chunk.join();
        } else {
          return;
        }
      }
      try {
        servers[socket.name].broadcast(chunk, {binary: true});
      }
      catch (e) {
        log(e);
      }
  });
  socket.on('close', function onClose() {
    log('SOCKET CLOSE - video socket closed -> ' + socket.name);
    socket.destroy();
  });
  socket.on('error', function() {
    log('ERROR - video socket error with -> ' + socket.name);
    socket.destroy();
  })
});
streamServer.listen(PI_STREAM_PORT, function() {
  console.log('Video server listening on port:', PI_STREAM_PORT);
  console.log('------------------------------------')
});