From 4618692b5ff603d7e82d35d7f92c5bf8b5b2d822 Mon Sep 17 00:00:00 2001
From: Philipp Hancke <fippo@appear.in>
Date: Sat, 3 Feb 2018 09:52:47 +0100
Subject: [PATCH] audio: use replaceTrack for hard mute

uses replaceTrack for hard muting. This is different from soft mute, i.e.
setting track.enabled = false
---
 src/content/peerconnection/audio/index.html |  3 ++-
 src/content/peerconnection/audio/js/main.js | 25 ++++++++++++++++++++-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/content/peerconnection/audio/index.html b/src/content/peerconnection/audio/index.html
index c59acb174..dc1c5f1e6 100644
--- a/src/content/peerconnection/audio/index.html
+++ b/src/content/peerconnection/audio/index.html
@@ -56,7 +56,8 @@ <h1><a href="//webrtc.github.io/samples/" title="WebRTC samples homepage">WebRTC
         <option value="PCMU">PCMU</option>
       </select>
       <button id="callButton">Call</button>
-      <button id="hangupButton">Hang Up</button>
+      <button id="muteButton" disabled>Mute</button>
+      <button id="hangupButton" disabled>Hang Up</button>
     </div>
     <div class="graph-container" id="bitrateGraph">
       <div>Bitrate</div>
diff --git a/src/content/peerconnection/audio/js/main.js b/src/content/peerconnection/audio/js/main.js
index c3ba3447a..380afb021 100644
--- a/src/content/peerconnection/audio/js/main.js
+++ b/src/content/peerconnection/audio/js/main.js
@@ -12,11 +12,14 @@
 var audio2 = document.querySelector('audio#audio2');
 var callButton = document.querySelector('button#callButton');
 var hangupButton = document.querySelector('button#hangupButton');
+var muteButton = document.querySelector('button#muteButton');
 var codecSelector = document.querySelector('select#codec');
-hangupButton.disabled = true;
 callButton.onclick = call;
 hangupButton.onclick = hangup;
+muteButton.onclick = toggleMute;
 
+var supportsReplaceTrack = window.RTCRtpSender &&
+    'replaceTrack' in RTCRtpSender.prototype;
 var pc1;
 var pc2;
 var localStream;
@@ -126,6 +129,7 @@ function gotDescription2(desc) {
       desc.sdp = forceChosenAudioCodec(desc.sdp);
       pc1.setRemoteDescription(desc).then(
         function() {
+          muteButton.disabled = !supportsReplaceTrack;
         },
         onSetSessionDescriptionError
       );
@@ -144,10 +148,29 @@ function hangup() {
   pc1 = null;
   pc2 = null;
   hangupButton.disabled = true;
+  muteButton.disabled = true;
   callButton.disabled = false;
   codecSelector.disabled = false;
 }
 
+function toggleMute() {
+  var sender = pc1.getSenders()[0];
+  var p;
+  if (!sender.track) {
+    trace('re-adding audio track');
+    p = sender.replaceTrack(localStream.getAudioTracks()[0]);
+  } else {
+    trace('replacing audio track with null');
+    p = sender.replaceTrack(null);
+  }
+  p.then(function() {
+    console.log('replaced track');
+  })
+  .catch(function(err) {
+    console.error('during replaceTrack', err);
+  });
+}
+
 function gotRemoteStream(e) {
   if (audio2.srcObject !== e.streams[0]) {
     audio2.srcObject = e.streams[0];