Set up track info properly for dummy receiver. (#4807)

In migration cases, dummy receiver trackInfo is used by relay tracks to
set up the receivers and those need the proper track info.

Also check for proper receiver when adding a migrated track.

pkg/rtc/mediatrackreceiver.go

@@ -344,7 +344,7 @@ func (t *MediaTrackReceiver) SetPotentialCodecs(codecs []webrtc.RTPCodecParamete
 		}
 		if !exist {
 			receivers = append(receivers, &simulcastReceiver{
-				TrackReceiver: NewDummyReceiver(t.ID(), string(t.PublisherID()), c, headers),
+				TrackReceiver: NewDummyReceiver(t.TrackInfo(), string(t.PublisherID()), c, headers),
 				priority:      i,
 			})
 		}

pkg/rtc/participant.go

@@ -2387,6 +2387,7 @@ func (p *ParticipantImpl) onMediaTrack(rtcTrack *webrtc.TrackRemote, rtpReceiver
 			"ssrc", track.SSRC(),
 			"rtxSsrc", track.RtxSSRC(),
 			"mime", mime.NormalizeMimeType(codec.MimeType),
+			"isNewTrack", isNewTrack,
 			"isReceiverAdded", isReceiverAdded,
 			"sdpRids", logger.StringSlice(sdpRids[:]),
 		)
@@ -3294,7 +3295,6 @@ func (p *ParticipantImpl) mediaTrackReceived(
 	rtpReceiver *webrtc.RTPReceiver,
 ) (*MediaTrack, bool, bool, buffer.VideoLayersRid) {
 	p.pendingTracksLock.Lock()
-	newTrack := false
 
 	mid := p.TransportManager.GetPublisherMid(rtpReceiver)
 	p.pubLogger.Debugw(
@@ -3318,10 +3318,13 @@ func (p *ParticipantImpl) mediaTrackReceived(
 	}
 
 	// use existing media track to handle simulcast
-	var createdAt time.Time
-	var isMigrated bool
-	var ridsFromSdp buffer.VideoLayersRid
-	var pubTime time.Duration
+	var (
+		createdAt   time.Time
+		isNewTrack  bool
+		isMigrated  bool
+		ridsFromSdp buffer.VideoLayersRid
+		pubTime     time.Duration
+	)
 	mt, ok := p.getPublishedTrackBySdpCid(track.ID()).(*MediaTrack)
 	if !ok {
 		var (
@@ -3351,7 +3354,14 @@ func (p *ParticipantImpl) mediaTrackReceived(
 				}
 			}
 			if codecFound != len(ti.Codecs) {
-				p.pubLogger.Warnw("migrated track codec mismatched", nil, "track", logger.Proto(ti), "webrtcCodec", parameters)
+				p.pubLogger.Warnw(
+					"migrated track codec mismatched", nil,
+					"trackID", ti.Sid,
+					"track", logger.Proto(ti),
+					"webrtcCodec", parameters,
+					"codecFound", codecFound,
+					"codecCount", len(ti.Codecs),
+				)
 				p.pendingTracksLock.Unlock()
 				p.IssueFullReconnect(types.ParticipantCloseReasonMigrateCodecMismatch)
 				return nil, false, false, ridsFromSdp
@@ -3375,7 +3385,7 @@ func (p *ParticipantImpl) mediaTrackReceived(
 		}
 
 		mt = p.addMediaTrack(signalCid, ti)
-		newTrack = true
+		isNewTrack = true
 	}
 
 	// a track might have been set up in migrate-in path and won't show up as a new track here,
@@ -3387,12 +3397,12 @@ func (p *ParticipantImpl) mediaTrackReceived(
 			}
 		}
 	}
-	if !newTrack {
-		newTrack = !mt.Published()
+	if !isNewTrack {
+		isNewTrack = !mt.Published()
 	}
 	mt.SetPublished(true)
 
-	if newTrack {
+	if isNewTrack {
 		// if the addTrackRequest is sent before publisher peer connection is established, then it means the client tries to publish
 		// before fully connected, in this case we only record the time when publisher peer connection is established since
 		// we want this metric to represent the time cost by publishing.
@@ -3406,7 +3416,7 @@ func (p *ParticipantImpl) mediaTrackReceived(
 
 	_, isReceiverAdded := mt.AddReceiver(rtpReceiver, track, mid)
 
-	if newTrack {
+	if isNewTrack {
 		go func() {
 			// TODO: remove this after we know where the high delay is coming from
 			if pubTime > 3*time.Second {
@@ -3437,11 +3447,12 @@ func (p *ParticipantImpl) mediaTrackReceived(
 				p.GetClientInfo().GetSdk(),
 				p.Kind(),
 			)
+
 			p.handleTrackPublished(mt, isMigrated, false)
 		}()
 	}
 
-	return mt, newTrack, isReceiverAdded, ridsFromSdp
+	return mt, isNewTrack, isReceiverAdded, ridsFromSdp
 }
 
 func (p *ParticipantImpl) addMigratedTrack(cid string, ti *livekit.TrackInfo) *MediaTrack {
@@ -3456,6 +3467,31 @@ func (p *ParticipantImpl) addMigratedTrack(cid string, ti *livekit.TrackInfo) *M
 		return nil
 	}
 
+	// check if the migrated track has correct codec
+	if len(ti.Codecs) > 0 {
+		parameters := rtpReceiver.GetParameters()
+		var codecFound int
+		for _, c := range ti.Codecs {
+			for _, nc := range parameters.Codecs {
+				if mime.IsMimeTypeStringEqual(nc.MimeType, c.MimeType) {
+					codecFound++
+					break
+				}
+			}
+		}
+		if codecFound != len(ti.Codecs) {
+			p.pubLogger.Warnw(
+				"migrated track codec mismatched", nil,
+				"trackID", ti.Sid,
+				"track", logger.Proto(ti),
+				"webrtcCodec", parameters,
+				"codecFound", codecFound,
+				"codecCount", len(ti.Codecs),
+			)
+			return nil
+		}
+	}
+
 	mt := p.addMediaTrack(cid, ti)
 	mt.SetMigrated(true)
 

pkg/rtc/wrappedreceiver.go

@@ -184,7 +184,7 @@ func (r *WrappedReceiver) AddOnReady(f func()) {
 
 type DummyReceiver struct {
 	receiver         atomic.Value
-	trackID          livekit.TrackID
+	trackInfo        *livekit.TrackInfo
 	streamId         string
 	codec            webrtc.RTPCodecParameters
 	headerExtensions []webrtc.RTPHeaderExtensionParameter
@@ -201,9 +201,14 @@ type DummyReceiver struct {
 	redReceiver, primaryReceiver *DummyRedReceiver
 }
 
-func NewDummyReceiver(trackID livekit.TrackID, streamId string, codec webrtc.RTPCodecParameters, headerExtensions []webrtc.RTPHeaderExtensionParameter) *DummyReceiver {
+func NewDummyReceiver(
+	trackInfo *livekit.TrackInfo,
+	streamId string,
+	codec webrtc.RTPCodecParameters,
+	headerExtensions []webrtc.RTPHeaderExtensionParameter,
+) *DummyReceiver {
 	return &DummyReceiver{
-		trackID:          trackID,
+		trackInfo:        trackInfo,
 		streamId:         streamId,
 		codec:            codec,
 		headerExtensions: headerExtensions,
@@ -262,7 +267,7 @@ func (d *DummyReceiver) Upgrade(receiver sfu.TrackReceiver) {
 }
 
 func (d *DummyReceiver) TrackID() livekit.TrackID {
-	return d.trackID
+	return livekit.TrackID(d.trackInfo.Sid)
 }
 
 func (d *DummyReceiver) StreamID() string {
@@ -391,7 +396,7 @@ func (d *DummyReceiver) TrackInfo() *livekit.TrackInfo {
 	if receiver := d.getReceiver(); receiver != nil {
 		return receiver.TrackInfo()
 	}
-	return nil
+	return d.trackInfo
 }
 
 func (d *DummyReceiver) UpdateTrackInfo(ti *livekit.TrackInfo) {