fix: webrtc拉流丢包没有重传问题

rtc/rtc_sink.go

@@ -7,6 +7,7 @@ import (
 	"github.com/lkmio/lkm/stream"
 	"github.com/pion/webrtc/v3"
 	"github.com/pion/webrtc/v3/pkg/media"
+	"io"
 	"time"
 )
 
@@ -72,12 +73,27 @@ func (s *Sink) StartStreaming(transStream stream.TransStream) error {
 		remoteTrack, err = webrtc.NewTrackLocalStaticSample(webrtc.RTPCodecCapability{MimeType: mimeType}, id, "pion")
 		if err != nil {
 			return err
-		} else if _, err := connection.AddTransceiverFromTrack(remoteTrack, webrtc.RTPTransceiverInit{Direction: webrtc.RTPTransceiverDirectionSendonly}); err != nil {
-			return err
-		} else if _, err = connection.AddTrack(remoteTrack); err != nil {
+		}
+
+		transceiver, err := connection.AddTransceiverFromTrack(remoteTrack, webrtc.RTPTransceiverInit{Direction: webrtc.RTPTransceiverDirectionSendonly})
+		if err != nil {
 			return err
 		}
 
+		// pion需要在外部读取rtcp包,才会处理nack包丢包重传. https://github.com/pion/interceptor/blob/e1874104865b23ba465ecc505f959daf156cc2a5/pkg/nack/responder_interceptor.go#L82
+		go func() {
+			for {
+				_, _, err := transceiver.Sender().ReadRTCP()
+				if err == nil {
+					continue
+				} else if io.EOF == err || io.ErrClosedPipe == err {
+					break
+				} else {
+					println(err.Error())
+				}
+			}
+		}()
+
 		s.tracks[index] = remoteTrack
 	}