Simplify RTCP forwarding

Signed-off-by: Šimon Brandner <[email protected]>

Author: SimonBrandner

src/publisher.go

@@ -127,31 +127,40 @@ func (p *Publisher) Matches(trackDescription event.SFUTrackDescription) bool {
 
 func (p *Publisher) WriteRTCP(packets []rtcp.Packet) {
 	packetsToSend := []rtcp.Packet{}
+	readSSRC := uint32(p.Track.SSRC())
 
 	for _, packet := range packets {
-		// Since we sometimes spam the sender with PLIs, make sure we don't send
-		// them way too often
-		if _, ok := packet.(*rtcp.PictureLossIndication); ok {
+		switch typedPacket := packet.(type) {
+		// We mung the packets here, so that the SSRCs match what the
+		// receiver expects:
+		// The media SSRC is the SSRC of the media about which the packet is
+		// reporting; therefore, we mung it to be the SSRC of the publishing
+		// participant's track. Without this, it would be SSRC of the SFU's
+		// track which isn't right
+		case *rtcp.PictureLossIndication:
+			// Since we sometimes spam the sender with PLIs, make sure we don't send
+			// them way too often
 			if time.Now().UnixNano()-p.lastPLI.Load() < minimalPLIInterval.Nanoseconds() {
 				continue
 			}
-
 			p.lastPLI.Store(time.Now().UnixNano())
+
+			typedPacket.MediaSSRC = readSSRC
+			packetsToSend = append(packetsToSend, typedPacket)
+		case *rtcp.FullIntraRequest:
+			typedPacket.MediaSSRC = readSSRC
+			packetsToSend = append(packetsToSend, typedPacket)
 		}
 
 		packetsToSend = append(packetsToSend, packet)
 	}
 
-	if len(packetsToSend) < 1 {
-		return
-	}
-
-	if err := p.Call.PeerConnection.WriteRTCP(packetsToSend); err != nil {
-		if errors.Is(err, io.ErrClosedPipe) {
-			return
+	if len(packetsToSend) != 1 {
+		if err := p.Call.PeerConnection.WriteRTCP(packetsToSend); err != nil {
+			if !errors.Is(err, io.ErrClosedPipe) {
+				p.logger.WithError(err).Warn("failed to write RTCP on track")
+			}
 		}
-
-		p.logger.WithError(err).Warn("failed to write RTCP on track")
 	}
 }
 

src/subscriber.go

@@ -21,7 +21,6 @@ import (
 	"io"
 	"sync"
 
-	"github.com/pion/rtcp"
 	"github.com/pion/webrtc/v3"
 	"github.com/sirupsen/logrus"
 )
@@ -125,28 +124,6 @@ func (s *Subscriber) forwardRTCP() {
 			s.logger.WithError(err).Warn("failed to read RTCP on track")
 		}
 
-		packetsToForward := []rtcp.Packet{}
-		readSSRC := uint32(s.publisher.Track.SSRC())
-
-		for _, packet := range packets {
-			switch typedPacket := packet.(type) {
-			// We mung the packets here, so that the SSRCs match what the
-			// receiver expects:
-			// The media SSRC is the SSRC of the media about which the packet is
-			// reporting; therefore, we mung it to be the SSRC of the publishing
-			// participant's track. Without this, it would be SSRC of the SFU's
-			// track which isn't right
-			case *rtcp.PictureLossIndication:
-				typedPacket.MediaSSRC = readSSRC
-				packetsToForward = append(packetsToForward, typedPacket)
-			case *rtcp.FullIntraRequest:
-				typedPacket.MediaSSRC = readSSRC
-				packetsToForward = append(packetsToForward, typedPacket)
-			}
-		}
-
-		if len(packetsToForward) != 0 {
-			s.publisher.WriteRTCP(packetsToForward)
-		}
+		s.publisher.WriteRTCP(packets)
 	}
 }