Merge pull request #769 from jitsi/ttfm

Adds analytics event and console log for TTFM (time to first media).

conference.js

@@ -628,6 +628,12 @@ export default {
     sendFeedback (overallFeedback, detailedFeedback) {
         return room.sendFeedback (overallFeedback, detailedFeedback);
     },
+    /**
+     * Returns the connection times stored in the library.
+     */
+    getConnectionTimes () {
+        return this._room.getConnectionTimes();
+    },
     // used by torture currently
     isJoined () {
         return this._room

modules/UI/videolayout/SmallVideo.js

@@ -167,6 +167,17 @@ SmallVideo.createStreamElement = function (stream) {
         console.log("(TIME) Render " + type + ":\t",
                     now);
         AnalyticsAdapter.sendEvent('render.' + type, now);
+
+        // Time to first media, a number that can be used for comparision of
+        // time fot rendering media. It can be used for the first and
+        // the rest participants. It subtracts the period of waiting for the
+        // second participant to join (time between join and first
+        // session initiate).
+        var ttfm = now - APP.connectionTimes["document.ready"]
+            - (APP.conference.getConnectionTimes()["session.initiate"]
+                - APP.conference.getConnectionTimes()["muc.joined"]);
+        console.log("(TIME) TTFM " + type + ":\t", ttfm);
+        AnalyticsAdapter.sendEvent('ttfm.' + type, ttfm);
     };
     return element;
 };