Adds talk muted detection.

Fires event only once when the user is muted, if he unmutes and then mutes back again a new event will be fired if local talking is detected.

modules/talkmuted/TalkMutedDetection.js

@@ -0,0 +1,58 @@
+var JitsiTrackEvents = require('../../JitsiTrackEvents');
+
+/**
+ * Creates TalkMutedDetection
+ * @param callback the callback to call when detected local user is talking
+ * while its microphone is muted.
+ * @constructor
+ */
+function TalkMutedDetection(callback) {
+    this.callback = callback;
+
+    // we track firing the event, in order to avoid sending too many events
+    this.eventFired = false;
+}
+
+/**
+ * Receives audio level events for all send/receive streams.
+ * @param ssrc the ssrc of the stream
+ * @param level the current audio level
+ * @param isLocal whether this is local or remote stream (sent or received)
+ */
+TalkMutedDetection.prototype.audioLevelListener =
+    function (ssrc, level, isLocal) {
+        // we are interested only in local audio stream
+        // and if event is not already sent
+        if (!isLocal || !this.audioTrack || this.eventFired)
+            return;
+
+        if (this.audioTrack.isMuted() && level > 0.02) {
+            this.eventFired = true;
+            this.callback();
+        }
+    };
+
+/**
+ * Mute changed for a track.
+ * @param track the track which mute state has changed.
+ */
+TalkMutedDetection.prototype.muteChanged = function (track) {
+    if (!track.isLocal() || !track.isAudioTrack())
+        return;
+
+    if (track.isMuted())
+        this.eventFired = false;
+};
+
+/**
+ * Adds local tracks. We are interested only in the audio one.
+ * @param track
+ */
+TalkMutedDetection.prototype.addTrack = function(track){
+    if (!track.isAudioTrack())
+        return;
+
+    this.audioTrack = track;
+};
+
+module.exports = TalkMutedDetection;