src/content/peerconnection/bandwidth/js/main.js

/*
 *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree.
 */
/* global TimelineDataSeries, TimelineGraphView */

'use strict';

var remoteVideo = document.querySelector('video#remoteVideo');
var localVideo = document.querySelector('video#localVideo');
var callButton = document.querySelector('button#callButton');
var hangupButton = document.querySelector('button#hangupButton');
var bandwidthSelector = document.querySelector('select#bandwidth');
hangupButton.disabled = true;
callButton.onclick = call;
hangupButton.onclick = hangup;

var pc1;
var pc2;
var localStream;

var bitrateGraph;
var bitrateSeries;

var packetGraph;
var packetSeries;

var lastResult;

var offerOptions = {
  offerToReceiveAudio: 0,
  offerToReceiveVideo: 1
};

function gotStream(stream) {
  hangupButton.disabled = false;
  trace('Received local stream');
  localStream = stream;
  localVideo.srcObject = stream;
  pc1.addStream(localStream);
  trace('Adding Local Stream to peer connection');

  pc1.createOffer(
    offerOptions
  ).then(
    gotDescription1,
    onCreateSessionDescriptionError
  );

  bitrateSeries = new TimelineDataSeries();
  bitrateGraph = new TimelineGraphView('bitrateGraph', 'bitrateCanvas');
  bitrateGraph.updateEndDate();

  packetSeries = new TimelineDataSeries();
  packetGraph = new TimelineGraphView('packetGraph', 'packetCanvas');
  packetGraph.updateEndDate();
}

function onCreateSessionDescriptionError(error) {
  trace('Failed to create session description: ' + error.toString());
}

function call() {
  callButton.disabled = true;
  bandwidthSelector.disabled = false;
  trace('Starting call');
  var servers = null;
  var pcConstraints = {
    'optional': []
  };
  pc1 = new RTCPeerConnection(servers, pcConstraints);
  trace('Created local peer connection object pc1');
  pc1.onicecandidate = iceCallback1;
  pc2 = new RTCPeerConnection(servers, pcConstraints);
  trace('Created remote peer connection object pc2');
  pc2.onicecandidate = iceCallback2;
  pc2.onaddstream = gotRemoteStream;
  trace('Requesting local stream');
  navigator.mediaDevices.getUserMedia({
    video: true
  })
  .then(gotStream)
  .catch(function(e) {
    alert('getUserMedia() error: ' + e.name);
  });
}

function gotDescription1(desc) {
  trace('Offer from pc1 \n' + desc.sdp);
  pc1.setLocalDescription(desc).then(
    function() {
      pc2.setRemoteDescription(desc).then(
        function() {
          pc2.createAnswer().then(
            gotDescription2,
            onCreateSessionDescriptionError
          );
        },
        onSetSessionDescriptionError
      );
    },
    onSetSessionDescriptionError
  );
}

function gotDescription2(desc) {
  pc2.setLocalDescription(desc).then(
    function() {
      trace('Answer from pc2 \n' + desc.sdp);
      // insert b=AS after c= line.
      desc.sdp = desc.sdp.replace(/c=IN IP4 (.*)\r\n/,
          'c=IN IP4 $(1)\r\nb=AS:512\r\n');
      pc1.setRemoteDescription(desc).then(
        function() {
        },
        onSetSessionDescriptionError
      );
    },
    onSetSessionDescriptionError
  );
}

function hangup() {
  trace('Ending call');
  localStream.getTracks().forEach(function(track) {
    track.stop();
  });
  pc1.close();
  pc2.close();
  pc1 = null;
  pc2 = null;
  hangupButton.disabled = true;
  callButton.disabled = false;
  bandwidthSelector.disabled = true;
}

function gotRemoteStream(e) {
  remoteVideo.srcObject = e.stream;
  trace('Received remote stream');
}

function iceCallback1(event) {
  if (event.candidate) {
    pc2.addIceCandidate(
      new RTCIceCandidate(event.candidate)
    ).then(
      onAddIceCandidateSuccess,
      onAddIceCandidateError
    );
    trace('Local ICE candidate: \n' + event.candidate.candidate);
  }
}

function iceCallback2(event) {
  if (event.candidate) {
    pc1.addIceCandidate(
      new RTCIceCandidate(event.candidate)
    ).then(
      onAddIceCandidateSuccess,
      onAddIceCandidateError
    );
    trace('Remote ICE candidate: \n ' + event.candidate.candidate);
  }
}

function onAddIceCandidateSuccess() {
  trace('AddIceCandidate success.');
}

function onAddIceCandidateError(error) {
  trace('Failed to add ICE Candidate: ' + error.toString());
}

function onSetSessionDescriptionError(error) {
  trace('Failed to set session description: ' + error.toString());
}

// renegotiate bandwidth on the fly.
bandwidthSelector.onchange = function() {
  bandwidthSelector.disabled = true;
  var bandwidth = bandwidthSelector.options[bandwidthSelector.selectedIndex]
      .value;
  pc1.setLocalDescription(pc1.localDescription)
  .then(function() {
    var desc = pc1.remoteDescription;
    desc.sdp = desc.sdp.replace(/b=AS:(.*)\r\n/, 'b=AS:' + bandwidth + '\r\n');
    return pc1.setRemoteDescription(desc);
  })
  .then(function() {
    bandwidthSelector.disabled = false;
  })
  .catch(onSetSessionDescriptionError);
};

// query getStats every second
window.setInterval(function() {
  if (!window.pc1) {
    return;
  }
  window.pc1.getStats(null).then(function(res) {
    Object.keys(res).forEach(function(key) {
      var report = res[key];
      var bytes;
      var packets;
      var now = report.timestamp;
      if ((report.type === 'outboundrtp') ||
          (report.type === 'outbound-rtp') ||
          (report.type === 'ssrc' && report.bytesSent)) {
        bytes = report.bytesSent;
        packets = report.packetsSent;
        if (lastResult && lastResult[report.id]) {
          // calculate bitrate
          var bitrate = 8 * (bytes - lastResult[report.id].bytesSent) /
              (now - lastResult[report.id].timestamp);

          // append to chart
          bitrateSeries.addPoint(now, bitrate);
          bitrateGraph.setDataSeries([bitrateSeries]);
          bitrateGraph.updateEndDate();

          // calculate number of packets and append to chart
          packetSeries.addPoint(now, packets -
              lastResult[report.id].packetsSent);
          packetGraph.setDataSeries([packetSeries]);
          packetGraph.updateEndDate();
        }
      }
    });
    lastResult = res;
  });
}, 1000);