Layer 0 and non-simulacst tracks also can be fully unsubscribed. (#308)

pkg/rtc/mediatrack.go

@@ -366,8 +366,10 @@ func (t *MediaTrack) NumUpTracks() (uint32, uint32) {
 	numExpected := atomic.LoadUint32(&t.numUpTracks)
 
 	t.maxQualityLock.RLock()
-	// LK-TODO: take into account t.allSubscribersMuted when turning off layer 0 also
-	maxSubscribed := uint32(SpatialLayerForQuality(t.maxSubscribedQuality) + 1)
+	maxSubscribed := uint32(0)
+	if !t.allSubscribersMuted {
+		maxSubscribed = uint32(SpatialLayerForQuality(t.maxSubscribedQuality) + 1)
+	}
 	t.maxQualityLock.RUnlock()
 	if maxSubscribed < numExpected {
 		numExpected = maxSubscribed
@@ -818,7 +820,7 @@ func (t *MediaTrack) OnSubscribedMaxQualityChange(f func(trackID livekit.TrackID
 }
 
 func (t *MediaTrack) NotifySubscriberMute(subscriberID livekit.ParticipantID) {
-	if !t.IsSimulcast() {
+	if t.Kind() != livekit.TrackType_VIDEO {
 		return
 	}
 
@@ -836,7 +838,7 @@ func (t *MediaTrack) NotifySubscriberMute(subscriberID livekit.ParticipantID) {
 }
 
 func (t *MediaTrack) NotifySubscriberMaxQuality(subscriberID livekit.ParticipantID, quality livekit.VideoQuality) {
-	if !t.IsSimulcast() {
+	if t.Kind() != livekit.TrackType_VIDEO {
 		return
 	}
 
@@ -878,7 +880,7 @@ func (t *MediaTrack) stopMaxQualityTimer() {
 }
 
 func (t *MediaTrack) updateQualityChange() {
-	if t.IsMuted() || !t.IsSimulcast() {
+	if t.Kind() != livekit.TrackType_VIDEO || t.IsMuted() {
 		return
 	}
 
@@ -902,19 +904,12 @@ func (t *MediaTrack) updateQualityChange() {
 	if allSubscribersMuted {
 		if !t.allSubscribersMuted {
 			notifyMaxExpected = true
+			maxExpectedSpatialLayer = sfu.InvalidLayerSpatial
+
 			t.allSubscribersMuted = true
 
-			// LK-TODO: do not set this when turning off LOW also below
-			t.maxSubscribedQuality = livekit.VideoQuality_LOW
-			maxExpectedSpatialLayer = SpatialLayerForQuality(t.maxSubscribedQuality)
-
 			subscribedQualities = []*livekit.SubscribedQuality{
-				// LK-TODO-START
-				// Restarting layers and subscribers getting video involves several things in the path
-				// which adds up to a few seconds of latency on re-subscription. Do not turn off the
-				// base layer till there is a good design to reduce re-subscription delays
-				// LK-TODO-END
-				{Quality: livekit.VideoQuality_LOW, Enabled: true},
+				{Quality: livekit.VideoQuality_LOW, Enabled: false},
 				{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
 				{Quality: livekit.VideoQuality_HIGH, Enabled: false},
 			}
@@ -923,8 +918,9 @@ func (t *MediaTrack) updateQualityChange() {
 		t.allSubscribersMuted = false
 		if maxSubscribedQuality != t.maxSubscribedQuality {
 			notifyMaxExpected = true
+			maxExpectedSpatialLayer = SpatialLayerForQuality(maxSubscribedQuality)
+
 			t.maxSubscribedQuality = maxSubscribedQuality
-			maxExpectedSpatialLayer = SpatialLayerForQuality(t.maxSubscribedQuality)
 
 			subscribedQualities = append(subscribedQualities, &livekit.SubscribedQuality{Quality: livekit.VideoQuality_LOW, Enabled: true})
 

pkg/rtc/mediatrack_test.go

@@ -125,7 +125,6 @@ func TestSubscribedMaxQuality(t *testing.T) {
 				},
 			},
 		}})
-		mt.simulcasted.TrySet(true)
 
 		mt.NotifySubscriberMaxQuality("s1", livekit.VideoQuality_HIGH)
 
@@ -138,11 +137,10 @@ func TestSubscribedMaxQuality(t *testing.T) {
 		})
 
 		// mute all subscribers
-		// LK-TODO: layer 0 is not disabled
 		mt.NotifySubscriberMute("s1")
 
 		expectedSubscribedQualities := []*livekit.SubscribedQuality{
-			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_LOW, Enabled: true},
+			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_LOW, Enabled: false},
 			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
 			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_HIGH, Enabled: false},
 		}
@@ -174,7 +172,6 @@ func TestSubscribedMaxQuality(t *testing.T) {
 				},
 			},
 		}})
-		mt.simulcasted.TrySet(true)
 
 		actualTrackID := ""
 		actualSubscribedQualities := []*livekit.SubscribedQuality{}
@@ -218,19 +215,7 @@ func TestSubscribedMaxQuality(t *testing.T) {
 		require.Equal(t, "v1", actualTrackID)
 		require.EqualValues(t, expectedSubscribedQualities, actualSubscribedQualities)
 
-		// muting one should still produce LOW
-		mt.NotifySubscriberMute("s1")
-
-		expectedSubscribedQualities = []*livekit.SubscribedQuality{
-			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_LOW, Enabled: true},
-			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
-			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_HIGH, Enabled: false},
-		}
-		require.Equal(t, "v1", actualTrackID)
-		require.EqualValues(t, expectedSubscribedQualities, actualSubscribedQualities)
-
-		// muting "s2" should disable all qualities
-		// LK-TODO: layer 0 is not disabled
+		// muting "s2" only should not disable all qualities
 		mt.NotifySubscriberMute("s2")
 
 		expectedSubscribedQualities = []*livekit.SubscribedQuality{
@@ -240,5 +225,16 @@ func TestSubscribedMaxQuality(t *testing.T) {
 		}
 		require.Equal(t, "v1", actualTrackID)
 		require.EqualValues(t, expectedSubscribedQualities, actualSubscribedQualities)
+
+		// muting "s1" also should disable all qualities
+		mt.NotifySubscriberMute("s1")
+
+		expectedSubscribedQualities = []*livekit.SubscribedQuality{
+			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_LOW, Enabled: false},
+			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_MEDIUM, Enabled: false},
+			&livekit.SubscribedQuality{Quality: livekit.VideoQuality_HIGH, Enabled: false},
+		}
+		require.Equal(t, "v1", actualTrackID)
+		require.EqualValues(t, expectedSubscribedQualities, actualSubscribedQualities)
 	})
 }

pkg/sfu/forwarder.go

@@ -137,14 +137,17 @@ func (v VideoLayers) GreaterThan(v2 VideoLayers) bool {
 }
 
 const (
+	InvalidLayerSpatial  = int32(-1)
+	InvalidLayerTemporal = int32(-1)
+
 	DefaultMaxLayerSpatial  = int32(2)
 	DefaultMaxLayerTemporal = int32(3)
 )
 
 var (
 	InvalidLayers = VideoLayers{
-		spatial:  -1,
-		temporal: -1,
+		spatial:  InvalidLayerSpatial,
+		temporal: InvalidLayerTemporal,
 	}
 
 	DefaultMaxLayers = VideoLayers{