From 01bf96855dae30a951cd11e208bc8d8fb50629ab Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Mon, 23 Jun 2025 12:45:13 -0700
Subject: [PATCH] SVC with RID -> spatial layer mapping (#3754)

* SVC with RID -> spatial layer mapping

There are cases where an SVC track comes in with a RID.
As there is no RID announced in SDP, it maps to invalid layer.
Seems to happen with older browsers.

* test
---
 pkg/service/wire_gen.go           | 14 +++++++-------
 pkg/sfu/buffer/videolayerutils.go | 13 +++++++++++++
 pkg/sfu/receiver.go               |  9 +++++++++
 3 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/pkg/service/wire_gen.go b/pkg/service/wire_gen.go
index e95eb875d..9d34228ac 100644
--- a/pkg/service/wire_gen.go
+++ b/pkg/service/wire_gen.go
@@ -89,23 +89,23 @@ func InitializeServer(conf *config.Config, currentNode routing.LocalNode) (*Live
 	}
 	rtcEgressLauncher := NewEgressLauncher(egressClient, ioInfoService, objectStore)
 	topicFormatter := rpc.NewTopicFormatter()
-	v, err := rpc.NewTypedRoomClient(clientParams)
+	roomClient, err := rpc.NewTypedRoomClient(clientParams)
 	if err != nil {
 		return nil, err
 	}
-	v2, err := rpc.NewTypedParticipantClient(clientParams)
+	participantClient, err := rpc.NewTypedParticipantClient(clientParams)
 	if err != nil {
 		return nil, err
 	}
-	roomService, err := NewRoomService(limitConfig, apiConfig, router, roomAllocator, objectStore, rtcEgressLauncher, topicFormatter, v, v2)
+	roomService, err := NewRoomService(limitConfig, apiConfig, router, roomAllocator, objectStore, rtcEgressLauncher, topicFormatter, roomClient, participantClient)
 	if err != nil {
 		return nil, err
 	}
-	v3, err := rpc.NewTypedAgentDispatchInternalClient(clientParams)
+	agentDispatchInternalClient, err := rpc.NewTypedAgentDispatchInternalClient(clientParams)
 	if err != nil {
 		return nil, err
 	}
-	agentDispatchService := NewAgentDispatchService(v3, topicFormatter, roomAllocator, router)
+	agentDispatchService := NewAgentDispatchService(agentDispatchInternalClient, topicFormatter, roomAllocator, router)
 	egressService := NewEgressService(egressClient, rtcEgressLauncher, ioInfoService, roomService)
 	ingressConfig := getIngressConfig(conf)
 	ingressClient, err := rpc.NewIngressClient(clientParams)
@@ -120,11 +120,11 @@ func InitializeServer(conf *config.Config, currentNode routing.LocalNode) (*Live
 	}
 	sipService := NewSIPService(sipConfig, nodeID, messageBus, sipClient, sipStore, roomService, telemetryService)
 	rtcService := NewRTCService(conf, roomAllocator, router, telemetryService)
-	v4, err := rpc.NewTypedRTCRestParticipantClient(clientParams)
+	rtcRestParticipantClient, err := rpc.NewTypedRTCRestParticipantClient(clientParams)
 	if err != nil {
 		return nil, err
 	}
-	serviceRTCRestService, err := NewRTCRestService(conf, router, roomAllocator, clientParams, topicFormatter, v4)
+	serviceRTCRestService, err := NewRTCRestService(conf, router, roomAllocator, clientParams, topicFormatter, rtcRestParticipantClient)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/sfu/buffer/videolayerutils.go b/pkg/sfu/buffer/videolayerutils.go
index 73af99e59..1b6b3ff2e 100644
--- a/pkg/sfu/buffer/videolayerutils.go
+++ b/pkg/sfu/buffer/videolayerutils.go
@@ -351,6 +351,19 @@ func GetSpatialLayerForRid(rid string, ti *livekit.TrackInfo) int32 {
 	if len(ti.Layers) == 1 {
 		// single layer without RID
 		return 0
+	} else if len(ti.Layers) > 1 {
+		// RID present in codec, but not specified via signalling
+		// (happens with older browsers setting a rid for SVC codecs)
+		hasRid := false
+		for _, layer := range ti.Layers {
+			if layer.Rid != "" {
+				hasRid = true
+				break
+			}
+		}
+		if !hasRid {
+			return 0
+		}
 	}
 
 	return InvalidLayerSpatial
diff --git a/pkg/sfu/receiver.go b/pkg/sfu/receiver.go
index 645146ab1..f4cbd1a9b 100644
--- a/pkg/sfu/receiver.go
+++ b/pkg/sfu/receiver.go
@@ -43,6 +43,7 @@ var (
 	ErrDownTrackAlreadyExist = errors.New("DownTrack already exist")
 	ErrBufferNotFound        = errors.New("buffer not found")
 	ErrDuplicateLayer        = errors.New("duplicate layer")
+	ErrInvalidLayer          = errors.New("invalid layer")
 )
 
 // --------------------------------------
@@ -384,6 +385,14 @@ func (w *WebRTCReceiver) AddUpTrack(track TrackRemote, buff *buffer.Buffer) erro
 	if w.Kind() == webrtc.RTPCodecTypeVideo && !w.isSVC {
 		layer = buffer.GetSpatialLayerForRid(track.RID(), w.trackInfo.Load())
 	}
+	if layer < 0 {
+		w.logger.Warnw(
+			"invalid layer", nil,
+			"rid", track.RID(),
+			"trackInfo", logger.Proto(w.trackInfo.Load()),
+		)
+		return ErrInvalidLayer
+	}
 	buff.SetLogger(w.logger.WithValues("layer", layer))
 	buff.SetAudioLevelParams(audio.AudioLevelParams{
 		Config: w.audioConfig.AudioLevelConfig,