Move MediaTrack ToProto out of media track receiver as remote needs a (#328)

different implementation.

pkg/rtc/localparticipant.go

@@ -229,7 +229,7 @@ func (l *LocalParticipant) MediaTrackReceived(track *webrtc.TrackRemote, rtpRece
 			SubscriberConfig:    l.params.Config.Subscriber,
 		})
 
-		for ssrc,info  :=range l.params.SimTracks {
+		for ssrc, info := range l.params.SimTracks {
 			if info.Mid == mid {
 				mt.TrySetSimulcastSSRC(uint8(sfu.RidToLayer(info.Rid)), ssrc)
 			}

pkg/rtc/mediatrack.go

@@ -32,6 +32,8 @@ type MediaTrack struct {
 	numUpTracks uint32
 	buffer      *buffer.Buffer
 
+	layerSsrcs [livekit.VideoQuality_HIGH + 1]uint32
+
 	audioLevelMu sync.RWMutex
 	audioLevel   *AudioLevel
 
@@ -108,6 +110,21 @@ func (t *MediaTrack) SdpCid() string {
 	return t.params.SdpCid
 }
 
+func (t *MediaTrack) ToProto() *livekit.TrackInfo {
+	info := t.params.TrackInfo
+	info.Muted = t.IsMuted()
+	info.Simulcast = t.IsSimulcast()
+	layers := t.MediaTrackReceiver.GetVideoLayers()
+	for _, layer := range layers {
+		if int(layer.Quality) < len(t.layerSsrcs) {
+			layer.Ssrc = t.layerSsrcs[layer.Quality]
+		}
+	}
+	info.Layers = layers
+
+	return info
+}
+
 func (t *MediaTrack) publishLossPercentage() uint32 {
 	return FixedPointToPercent(uint8(atomic.LoadUint32(&t.currentUpFracLost)))
 }
@@ -221,6 +238,12 @@ func (t *MediaTrack) AddReceiver(receiver *webrtc.RTPReceiver, track *webrtc.Tra
 	})
 }
 
+func (t *MediaTrack) TrySetSimulcastSSRC(layer uint8, ssrc uint32) {
+	if int(layer) < len(t.layerSsrcs) && t.layerSsrcs[layer] == 0 {
+		t.layerSsrcs[layer] = ssrc
+	}
+}
+
 func (t *MediaTrack) GetAudioLevel() (level uint8, active bool) {
 	t.audioLevelMu.RLock()
 	defer t.audioLevelMu.RUnlock()

pkg/rtc/mediatrackreceiver.go

@@ -31,7 +31,6 @@ type MediaTrackReceiver struct {
 	lock            sync.RWMutex
 	receiver        sfu.TrackReceiver
 	layerDimensions sync.Map // livekit.VideoQuality => *livekit.VideoLayer
-	layerSsrcs      [livekit.VideoQuality_HIGH + 1]uint32
 
 	// track audio fraction lost
 	downFracLostLock  sync.Mutex
@@ -195,25 +194,6 @@ func (t *MediaTrackReceiver) AddSubscriber(sub types.Participant) error {
 	return nil
 }
 
-func (t *MediaTrackReceiver) ToProto() *livekit.TrackInfo {
-	info := t.params.TrackInfo
-	info.Muted = t.IsMuted()
-	info.Simulcast = t.IsSimulcast()
-	layers := make([]*livekit.VideoLayer, 0)
-	t.layerDimensions.Range(func(_, val interface{}) bool {
-		if layer, ok := val.(*livekit.VideoLayer); ok {
-			if int(layer.Quality) < len(t.layerSsrcs) {
-				layer.Ssrc = t.layerSsrcs[layer.Quality]
-			}
-			layers = append(layers, layer)
-		}
-		return true
-	})
-	info.Layers = layers
-
-	return info
-}
-
 func (t *MediaTrackReceiver) UpdateVideoLayers(layers []*livekit.VideoLayer) {
 	for _, layer := range layers {
 		t.layerDimensions.Store(layer.Quality, layer)
@@ -224,10 +204,16 @@ func (t *MediaTrackReceiver) UpdateVideoLayers(layers []*livekit.VideoLayer) {
 	// TODO: this might need to trigger a participant update for clients to pick up dimension change
 }
 
-func (t *MediaTrackReceiver) TrySetSimulcastSSRC(layer uint8, ssrc uint32) {
-	if int(layer) < len(t.layerSsrcs) && t.layerSsrcs[layer] == 0 {
-		t.layerSsrcs[layer] = ssrc
-	}
+func (t *MediaTrackReceiver) GetVideoLayers() []*livekit.VideoLayer {
+	layers := make([]*livekit.VideoLayer, 0)
+	t.layerDimensions.Range(func(q, val interface{}) bool {
+		if layer, ok := val.(*livekit.VideoLayer); ok {
+			layers = append(layers, layer)
+		}
+		return true
+	})
+
+	return layers
 }
 
 // GetQualityForDimension finds the closest quality to use for desired dimensions