fix(buffer): fix nack request (#336)

Author: OrlandoCo

pkg/buffer/buffer.go

@@ -255,3 +255,7 @@ func (b *Buffer) onTransportWideCC(fn func(sn uint16, timeNS int64, marker bool)
 func (b *Buffer) onFeedback(fn func(fb []rtcp.Packet)) {
 	b.feedbackCB = fn
 }
+
+func (b *Buffer) onNack(fn func(fb *rtcp.TransportLayerNack)) {
+	b.pktQueue.onLost = fn
+}

pkg/buffer/interceptor.go

@@ -4,6 +4,8 @@ import (
 	"sync"
 	"sync/atomic"
 
+	log "github.com/pion/ion-log"
+
 	"github.com/pion/interceptor"
 	"github.com/pion/rtcp"
 	"github.com/pion/rtp"
@@ -84,7 +86,9 @@ func (i *Interceptor) BindRTCPReader(reader interceptor.RTCPReader) interceptor.
 
 func (i *Interceptor) BindRTCPWriter(writer interceptor.RTCPWriter) interceptor.RTCPWriter {
 	i.twcc.onFeedback = func(pkts []rtcp.Packet) {
-		writer.Write(pkts, nil)
+		if _, err := writer.Write(pkts, nil); err != nil {
+			log.Errorf("Writing buffer twcc rtcp err: %v", err)
+		}
 	}
 	i.rtcpWriter.Store(writer)
 	return writer
@@ -127,12 +131,21 @@ func (i *Interceptor) newBuffer(info *interceptor.StreamInfo) *Buffer {
 	buffer := NewBuffer(info, Options{})
 	buffer.onFeedback(func(pkts []rtcp.Packet) {
 		if p, ok := i.rtcpWriter.Load().(interceptor.RTCPWriter); ok {
-			p.Write(pkts, nil)
+			if _, err := p.Write(pkts, nil); err != nil {
+				log.Errorf("Writing buffer rtcp err: %v", err)
+			}
 		}
 	})
 	buffer.onTransportWideCC(func(sn uint16, timeNS int64, marker bool) {
 		i.twcc.push(sn, timeNS, marker)
 	})
+	buffer.onNack(func(fb *rtcp.TransportLayerNack) {
+		if p, ok := i.rtcpWriter.Load().(interceptor.RTCPWriter); ok {
+			if _, err := p.Write([]rtcp.Packet{fb}, nil); err != nil {
+				log.Errorf("Writing buffer rtcp err: %v", err)
+			}
+		}
+	})
 	i.Lock()
 	i.buffers = append(i.buffers, buffer)
 	i.twcc.mSSRC = info.SSRC

pkg/sfu/nack.go

@@ -27,9 +27,9 @@ func newNACKList() *nackList {
 	}
 }
 
-func (n *nackList) getNACKSeqNo(seqno []uint16) []uint16 {
+func (n *nackList) getNACKSeqNo(seqNo []uint16) []uint16 {
 	packets := make([]uint16, 0, 17)
-	for _, sn := range seqno {
+	for _, sn := range seqNo {
 		if nack, ok := n.nacks[sn]; !ok {
 			n.nacks[sn] = n.ll.PushBack(NACK{sn, time.Now().UnixNano()})
 			packets = append(packets, sn)

pkg/sfu/subscriber.go

@@ -2,6 +2,7 @@ package sfu
 
 import (
 	"io"
+	"math"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -173,6 +174,7 @@ func (s *Subscriber) Close() error {
 func (s *Subscriber) downTracksReports() {
 	for {
 		time.Sleep(5 * time.Second)
+
 		var r []rtcp.Packet
 		var sd []rtcp.SourceDescriptionChunk
 		s.RLock()
@@ -210,14 +212,24 @@ func (s *Subscriber) downTracksReports() {
 			}
 		}
 		s.RUnlock()
-		if len(r) > 0 {
+		i := math.Ceil(float64(len(sd)) / float64(20))
+		j := 0
+		for i > 0 {
+			if i > 1 {
+				sd = sd[j*20 : (j+1)*20-1]
+			} else {
+				sd = sd[j*20 : cap(sd)]
+			}
 			r = append(r, &rtcp.SourceDescription{Chunks: sd})
 			if err := s.pc.WriteRTCP(r); err != nil {
 				if err == io.EOF || err == io.ErrClosedPipe {
 					return
 				}
 				log.Errorf("Sending downtrack reports err: %v", err)
 			}
+			r = r[:0]
+			i--
+			j++
 		}
 	}
 }