Update the BitrateController any time the active speaker changes (#1114)

Fixes an issue where we wouldn't forward the proper streams in last-n due to the BitrateController not getting the needed notifications of active speaker ordering changes.

Co-authored-by: Boris Grozev <boris@jitsi.org>

Author: bbaldino

src/main/java/org/jitsi/videobridge/Conference.java

@@ -447,6 +447,8 @@ void dominantSpeakerChanged()
             getVideobridge().getStatistics().totalDominantSpeakerChanges.increment();
         }
 
+        speechActivityEndpointsChanged(speechActivity.getEndpointIds());
+
         if (dominantSpeaker != null)
         {
             broadcastMessage(
@@ -1068,11 +1070,10 @@ public void setLastKnownFocus(Jid jid)
     /**
      * Notifies this instance that the list of ordered endpoints has changed
      */
-    void speechActivityEndpointsChanged()
+    void speechActivityEndpointsChanged(List<String> newEndpointIds)
     {
-        List<String> endpoints = speechActivity.getEndpointIds();
         endpointsCache.forEach(
-                e ->  e.speechActivityEndpointsChanged(endpoints));
+                e ->  e.speechActivityEndpointsChanged(newEndpointIds));
     }
 
     /**

src/main/java/org/jitsi/videobridge/ConferenceSpeechActivity.java

@@ -418,6 +418,7 @@ public void endpointsChanged()
         {
             final boolean finalDominantSpeakerChanged = dominantSpeakerChanged;
             final boolean finalEndpointsChanged = endpointsListChanged;
+            final List<String> finalNewEndpointIds = getEndpointIds();
             TaskPools.IO_POOL.submit(() -> {
                 final Conference conference = this.conference;
                 if (conference == null)
@@ -428,9 +429,10 @@ public void endpointsChanged()
                 {
                     conference.dominantSpeakerChanged();
                 }
-                if (finalEndpointsChanged)
+                // Dominant speaker changed implies that the list changed.
+                if (finalEndpointsChanged && !finalDominantSpeakerChanged)
                 {
-                    conference.speechActivityEndpointsChanged();
+                    conference.speechActivityEndpointsChanged(finalNewEndpointIds);
                 }
 
             });

src/main/java/org/jitsi/videobridge/cc/BitrateController.java

@@ -922,6 +922,14 @@ private TrackBitrateAllocation[] prioritize(
             // of the conference.
             adjustedLastN = Math.min(lastN, conferenceEndpoints.size() - 1);
         }
+        if (logger.isDebugEnabled())
+        {
+            logger.debug("Prioritizing endpoints, adjusted last-n: " + adjustedLastN +
+                ", sorted endpoint list: " +
+                conferenceEndpoints.stream().map(AbstractEndpoint::getID).collect(Collectors.joining(", ")) +
+                ". Selected endpoints: " + String.join(", ", selectedEndpointIds) +
+                ". Pinned endpoints: " + String.join(", ", pinnedEndpointIds));
+        }
 
         int endpointPriority = 0;
 
@@ -935,6 +943,8 @@ private TrackBitrateAllocation[] prioritize(
                     || sourceEndpoint.getID().equals(destinationEndpoint.getID())
                     || !selectedEndpointIds.contains(sourceEndpoint.getID()))
             {
+                logger.trace(() -> "Endpoint " + sourceEndpoint.getID() + " is expired, is this destination, or " +
+                    "is not selected; ignoring");
                 continue;
             }
 
@@ -954,6 +964,7 @@ private TrackBitrateAllocation[] prioritize(
                             true /* selected */,
                             maxRxFrameHeightPx));
                 }
+                logger.trace(() -> "Adding selected endpoint " + sourceEndpoint.getID() + " to allocations");
 
                 endpointPriority++;
             }
@@ -972,6 +983,8 @@ private TrackBitrateAllocation[] prioritize(
                     || sourceEndpoint.getID().equals(destinationEndpoint.getID())
                     || !pinnedEndpointIds.contains(sourceEndpoint.getID()))
                 {
+                    logger.trace(() -> "Endpoint " + sourceEndpoint.getID() + " is expired, is this destination, or " +
+                        "is not pinned; ignoring");
                     continue;
                 }
 
@@ -991,6 +1004,7 @@ endpointPriority, new TrackBitrateAllocation(
                                 maxRxFrameHeightPx));
                     }
 
+                    logger.trace(() -> "Adding pinned endpoint " + sourceEndpoint.getID() + " to allocations");
                     endpointPriority++;
                 }
 
@@ -1025,6 +1039,7 @@ endpointPriority, new TrackBitrateAllocation(
                                 maxRxFrameHeightPx));
                     }
 
+                    logger.trace(() -> "Adding endpoint " + sourceEndpoint.getID() + " to allocations");
                     endpointPriority++;
                 }
             }