Implement activity detection.

static/protocol.js

@@ -919,29 +919,59 @@ Stream.prototype.updateStats = async function() {
     let transceivers = c.pc.getTransceivers();
     for(let i = 0; i < transceivers.length; i++) {
         let t = transceivers[i];
-        let tid = t.sender.track && t.sender.track.id;
-        if(!tid)
-            continue;
+        let stid = t.sender.track && t.sender.track.id;
+        let rtid = t.receiver.track && t.receiver.track.id;
 
-        let report;
+        let report = null;
+        if(stid) {
             try {
                 report = await t.sender.getStats();
             } catch(e) {
+            }
+        }
+
+        if(report) {
+            for(let r of report.values()) {
+                if(stid && r.type === 'outbound-rtp') {
+                    if(!('bytesSent' in r))
                         continue;
+                    if(!stats[stid])
+                        stats[stid] = {};
+                    stats[stid][r.type] = {};
+                    stats[stid][r.type].timestamp = r.timestamp;
+                    stats[stid][r.type].bytesSent = r.bytesSent;
+                    if(old[stid] && old[stid][r.type])
+                        stats[stid][r.type].rate =
+                        ((r.bytesSent - old[stid][r.type].bytesSent) * 1000 /
+                         (r.timestamp - old[stid][r.type].timestamp)) * 8;
+                }
+            }
         }
 
-        stats[tid] = {};
+        report = null;
+        if(rtid) {
+            try {
+                report = await t.receiver.getStats();
+            } catch(e) {
+                console.error(e);
+            }
+        }
 
+        if(report) {
             for(let r of report.values()) {
-            if(r.type !== 'outbound-rtp')
+                if(rtid && r.type === 'track') {
+                    if(!('totalAudioEnergy' in r))
                         continue;
-
-            stats[tid].timestamp = r.timestamp;
-            stats[tid].bytesSent = r.bytesSent;
-            if(old[tid] && old[tid].timestamp) {
-                stats[tid].rate =
-                    ((r.bytesSent - old[tid].bytesSent) * 1000 /
-                     (r.timestamp - old[tid].timestamp)) * 8;
+                    if(!stats[rtid])
+                        stats[rtid] = {};
+                    stats[rtid][r.type] = {};
+                    stats[rtid][r.type].timestamp = r.timestamp;
+                    stats[rtid][r.type].totalAudioEnergy = r.totalAudioEnergy;
+                    if(old[rtid] && old[rtid][r.type])
+                        stats[rtid][r.type].audioEnergy =
+                        (r.totalAudioEnergy - old[rtid][r.type].totalAudioEnergy) * 1000 /
+                        (r.timestamp - old[rtid][r.type].timestamp);
+                }
             }
         }
     }

static/sfu.css

@@ -610,6 +610,11 @@ h1 {
     margin-top: auto;
     margin-bottom: auto;
     position: relative;
+    border: 2px solid rgba(0,0,0,0);
+}
+
+.peer-active {
+    border: 2px solid #610a86;
 }
 
 .media {
@@ -670,6 +675,11 @@ h1 {
     margin-top: 15px;
 }
 
+.sidenav form{
+    display: block;
+    margin-top: 15px;
+}
+
 .sidenav-header h2{
     color: #fff;
     padding: 10px;

static/sfu.html

@@ -172,6 +172,10 @@
           <option value="screenshare">screen share</option>
           <option value="everything" selected>everything</option>
         </select>
+
+        <form>
+          <input id="activitybox" type="checkbox">Activity detection</input>
+        </form>
       </div>
     </div>
 

static/sfu.js

@@ -142,6 +142,9 @@ function gotDownStream(c) {
     c.onstatus = function(status) {
         setMediaStatus(c);
     }
+    c.onstats = gotDownStats;
+    if(document.getElementById('activitybox').value)
+        c.setStatsInterval(activityDetectionInterval);
 }
 
 // Store current browser viewport height in css variable
@@ -278,7 +281,23 @@ document.getElementById('requestselect').onchange = function(e) {
     serverConnection.request(this.value);
 };
 
-function displayStats(stats) {
+const activityDetectionInterval = 100;
+const activityDetectionPeriod = 700;
+const activityDetectionThreshold = 0.2;
+
+document.getElementById('activitybox').onchange = function(e) {
+    for(let id in serverConnection.down) {
+        let c = serverConnection.down[id];
+        if(this.value)
+            c.setStatsInterval(activityDetectionInterval);
+        else {
+            setActive(c, false);
+            c.setStatsInterval(0);
+        }
+    }
+}
+
+function gotUpStats(stats) {
     let c = this;
 
     let text = '';
@@ -286,16 +305,57 @@ function displayStats(stats) {
     c.pc.getSenders().forEach(s => {
         let tid = s.track && s.track.id;
         let stats = tid && c.stats[tid];
-        if(stats && stats.rate > 0) {
+        let rate = stats && stats['outbound-rtp'] && stats['outbound-rtp'].rate;
+        if(typeof rate === 'number') {
             if(text)
                 text = text + ' + ';
-            text = text + Math.round(stats.rate / 1000) + 'kbps';
+            text = text + Math.round(rate / 1000) + 'kbps';
         }
     });
 
     setLabel(c, text);
 }
 
+/**
+ * @param {Stream} c
+ * @param {boolean} value
+ */
+function setActive(c, value) {
+    let peer = document.getElementById('peer-' + c.id);
+    if(value)
+        peer.classList.add('peer-active');
+    else
+        peer.classList.remove('peer-active');
+}
+
+function gotDownStats(stats) {
+    if(!document.getElementById('activitybox').value)
+        return;
+
+    let c = this;
+
+    let maxEnergy = 0;
+
+    c.pc.getReceivers().forEach(r => {
+        let tid = r.track && r.track.id;
+        let s = tid && stats[tid];
+        let energy = s && s['track'] && s['track'].audioEnergy;
+        if(typeof energy === 'number')
+            maxEnergy = Math.max(maxEnergy, energy);
+    });
+
+    // totalAudioEnergy is defined as the integral of the square of the
+    // volume, so square the threshold.
+    if(maxEnergy > activityDetectionThreshold * activityDetectionThreshold) {
+        c.userdata.lastVoiceActivity = Date.now();
+        setActive(c, true);
+    } else {
+        let last = c.userdata.lastVoiceActivity;
+        if(!last || Date.now() - last > activityDetectionPeriod)
+            setActive(c, false);
+    }
+}
+
 function mapMediaOption(value) {
     console.assert(typeof(value) === 'string');
     switch(value) {
@@ -457,7 +517,7 @@ async function addLocalMedia(id) {
         let sender = c.pc.addTrack(t, stream);
     });
 
-    c.onstats = displayStats;
+    c.onstats = gotUpStats;
     c.setStatsInterval(2000);
     await setMedia(c, true);
     setButtonsVisibility();
@@ -486,7 +546,7 @@ async function addShareMedia(setup) {
         };
         c.labels[t.id] = 'screenshare';
     });
-    c.onstats = displayStats;
+    c.onstats = gotUpStats;
     c.setStatsInterval(2000);
     await setMedia(c, true);
     setButtonsVisibility()