ConfigureFlexFEC03 helper and fec example

interceptor.go

@@ -10,6 +10,7 @@ import (
 	"sync/atomic"
 
 	"github.com/pion/interceptor"
+	"github.com/pion/interceptor/pkg/flexfec"
 	"github.com/pion/interceptor/pkg/nack"
 	"github.com/pion/interceptor/pkg/report"
 	"github.com/pion/interceptor/pkg/rfc8888"
@@ -160,6 +161,41 @@ func ConfigureSimulcastExtensionHeaders(mediaEngine *MediaEngine) error {
 	)
 }
 
+// ConfigureFlexFEC03 registers flexfec-03 codec with provided payloadType in mediaEngine
+// and adds corresponding interceptor to the registry.
+// Note that this function should be called before any other interceptor that modifies RTP packets
+// (i.e. TWCCHeaderExtensionSender) is added to the registry, so that packets generated by flexfec
+// interceptor are not modified.
+func ConfigureFlexFEC03(
+	payloadType PayloadType,
+	mediaEngine *MediaEngine,
+	interceptorRegistry *interceptor.Registry,
+	options ...flexfec.FecOption,
+) error {
+	codecFEC := RTPCodecParameters{
+		RTPCodecCapability: RTPCodecCapability{
+			MimeType:     MimeTypeFlexFEC03,
+			ClockRate:    90000,
+			SDPFmtpLine:  "repair-window=10000000",
+			RTCPFeedback: nil,
+		},
+		PayloadType: payloadType,
+	}
+
+	if err := mediaEngine.RegisterCodec(codecFEC, RTPCodecTypeVideo); err != nil {
+		return err
+	}
+
+	generator, err := flexfec.NewFecInterceptor(options...)
+	if err != nil {
+		return err
+	}
+
+	interceptorRegistry.Add(generator)
+
+	return nil
+}
+
 type interceptorToTrackLocalWriter struct{ interceptor atomic.Value } // interceptor.RTPWriter }
 
 func (i *interceptorToTrackLocalWriter) WriteRTP(header *rtp.Header, payload []byte) (int, error) {