Update main.go

machinery/src/webrtc/main.go

@@ -16,6 +16,9 @@ import (
 	"github.com/kerberos-io/agent/machinery/src/packets"
 
 	mqtt "github.com/eclipse/paho.mqtt.golang"
+	"github.com/pion/interceptor"
+	"github.com/pion/interceptor/pkg/intervalpli"
+	"github.com/pion/webrtc/v4"
 	pionWebRTC "github.com/pion/webrtc/v4"
 	pionMedia "github.com/pion/webrtc/v4/pkg/media"
 )
@@ -81,6 +84,19 @@ func RegisterCandidates(key string, candidate models.ReceiveHDCandidatesPayload)
 	CandidatesMutex.Unlock()
 }
 
+func RegisterDefaultInterceptors(mediaEngine *pionWebRTC.MediaEngine, interceptorRegistry *interceptor.Registry) error {
+	if err := pionWebRTC.ConfigureNack(mediaEngine, interceptorRegistry); err != nil {
+		return err
+	}
+	if err := pionWebRTC.ConfigureRTCPReports(interceptorRegistry); err != nil {
+		return err
+	}
+	if err := pionWebRTC.ConfigureSimulcastExtensionHeaders(mediaEngine); err != nil {
+		return err
+	}
+	return nil
+}
+
 func InitializeWebRTCConnection(configuration *models.Configuration, communication *models.Communication, mqttClient mqtt.Client, videoTrack *pionWebRTC.TrackLocalStaticSample, audioTrack *pionWebRTC.TrackLocalStaticSample, handshake models.RequestHDStreamPayload) {
 
 	config := configuration.Config
@@ -114,7 +130,31 @@ func InitializeWebRTCConnection(configuration *models.Configuration, communicati
 			log.Log.Error("webrtc.main.InitializeWebRTCConnection(): something went wrong registering codecs for media engine: " + err.Error())
 		}
 
-		api := pionWebRTC.NewAPI(pionWebRTC.WithMediaEngine(mediaEngine))
+		// Create a InterceptorRegistry. This is the user configurable RTP/RTCP Pipeline.
+		// This provides NACKs, RTCP Reports and other features. If you use `webrtc.NewPeerConnection`
+		// this is enabled by default. If you are manually managing You MUST create a InterceptorRegistry
+		// for each PeerConnection.
+		interceptorRegistry := &interceptor.Registry{}
+
+		// Use the default set of Interceptors
+		if err := webrtc.RegisterDefaultInterceptors(mediaEngine, interceptorRegistry); err != nil {
+			panic(err)
+		}
+
+		// Register a intervalpli factory
+		// This interceptor sends a PLI every 3 seconds. A PLI causes a video keyframe to be generated by the sender.
+		// This makes our video seekable and more error resilent, but at a cost of lower picture quality and higher bitrates
+		// A real world application should process incoming RTCP packets from viewers and forward them to senders
+		intervalPliFactory, err := intervalpli.NewReceiverInterceptor()
+		if err != nil {
+			panic(err)
+		}
+		interceptorRegistry.Add(intervalPliFactory)
+
+		api := pionWebRTC.NewAPI(
+			pionWebRTC.WithMediaEngine(mediaEngine),
+			pionWebRTC.WithInterceptorRegistry(interceptorRegistry),
+		)
 
 		policy := pionWebRTC.ICETransportPolicyAll
 		if config.ForceTurn == "true" {
@@ -139,13 +179,36 @@ func InitializeWebRTCConnection(configuration *models.Configuration, communicati
 
 		if err == nil && peerConnection != nil {
 
-			if _, err = peerConnection.AddTrack(videoTrack); err != nil {
+			var videoSender *pionWebRTC.RTPSender = nil
+			if videoSender, err = peerConnection.AddTrack(videoTrack); err != nil {
 				log.Log.Error("webrtc.main.InitializeWebRTCConnection(): something went wrong while adding video track: " + err.Error())
 			}
+			// Read incoming RTCP packets
+			// Before these packets are returned they are processed by interceptors. For things
+			// like NACK this needs to be called.
+			go func() {
+				rtcpBuf := make([]byte, 1500)
+				for {
+					if _, _, rtcpErr := videoSender.Read(rtcpBuf); rtcpErr != nil {
+						return
+					}
+				}
+			}()
 
-			if _, err = peerConnection.AddTrack(audioTrack); err != nil {
+			var audioSender *pionWebRTC.RTPSender = nil
+			if audioSender, err = peerConnection.AddTrack(audioTrack); err != nil {
 				log.Log.Error("webrtc.main.InitializeWebRTCConnection(): something went wrong while adding audio track: " + err.Error())
-			}
+			} // Read incoming RTCP packets
+			// Before these packets are returned they are processed by interceptors. For things
+			// like NACK this needs to be called.
+			go func() {
+				rtcpBuf := make([]byte, 1500)
+				for {
+					if _, _, rtcpErr := audioSender.Read(rtcpBuf); rtcpErr != nil {
+						return
+					}
+				}
+			}()
 
 			peerConnection.OnConnectionStateChange(func(connectionState pionWebRTC.PeerConnectionState) {
 				if connectionState == pionWebRTC.PeerConnectionStateDisconnected || connectionState == pionWebRTC.PeerConnectionStateClosed {