Don't use JitterBuffer in SampleBuilder

The performance of the SampleBuilder is significantly worse when using
the SampleBuilder. It would be good to evaluate improving the
performance of the JitterBuffer. However for the time being we are just
going to revert.

Resolve pion#2778

Author: Sean-Der

pkg/media/samplebuilder/samplebuilder.go

@@ -8,7 +8,6 @@ import (
 	"math"
 	"time"
 
-	"github.com/pion/interceptor/pkg/jitterbuffer"
 	"github.com/pion/rtp"
 	"github.com/pion/webrtc/v4/pkg/media"
 )
@@ -17,7 +16,7 @@ import (
 type SampleBuilder struct {
 	maxLate          uint16 // how many packets to wait until we get a valid Sample
 	maxLateTimestamp uint32 // max timestamp between old and new timestamps before dropping packets
-	buffer           *jitterbuffer.JitterBuffer
+	buffer           [math.MaxUint16 + 1]*rtp.Packet
 	preparedSamples  [math.MaxUint16 + 1]*media.Sample
 
 	// Interface that allows us to take RTP packets to samples
@@ -61,7 +60,7 @@ type SampleBuilder struct {
 // The depacketizer extracts media samples from RTP packets.
 // Several depacketizers are available in package github.com/pion/rtp/codecs.
 func New(maxLate uint16, depacketizer rtp.Depacketizer, sampleRate uint32, opts ...Option) *SampleBuilder {
-	s := &SampleBuilder{maxLate: maxLate, depacketizer: depacketizer, sampleRate: sampleRate, buffer: jitterbuffer.New(jitterbuffer.WithMinimumPacketCount(1))}
+	s := &SampleBuilder{maxLate: maxLate, depacketizer: depacketizer, sampleRate: sampleRate}
 	for _, o := range opts {
 		o(s)
 	}
@@ -77,7 +76,7 @@ func (s *SampleBuilder) tooOld(location sampleSequenceLocation) bool {
 	var foundTail *rtp.Packet
 
 	for i := location.head; i != location.tail; i++ {
-		if packet, _ := s.buffer.PeekAtSequence(i); packet != nil {
+		if packet := s.buffer[i]; packet != nil {
 			foundHead = packet
 			break
 		}
@@ -88,7 +87,7 @@ func (s *SampleBuilder) tooOld(location sampleSequenceLocation) bool {
 	}
 
 	for i := location.tail - 1; i != location.head; i-- {
-		if packet, _ := s.buffer.PeekAtSequence(i); packet != nil {
+		if packet := s.buffer[i]; packet != nil {
 			foundTail = packet
 			break
 		}
@@ -106,16 +105,16 @@ func (s *SampleBuilder) fetchTimestamp(location sampleSequenceLocation) (timesta
 	if location.empty() {
 		return 0, false
 	}
-	packet, err := s.buffer.PeekAtSequence(location.head)
-	if packet == nil || err != nil {
+	packet := s.buffer[location.head]
+	if packet == nil {
 		return 0, false
 	}
 	return packet.Timestamp, true
 }
 
 func (s *SampleBuilder) releasePacket(i uint16) {
 	var p *rtp.Packet
-	p, _ = s.buffer.PopAtSequence(i)
+	p, s.buffer[i] = s.buffer[i], nil
 	if p != nil && s.packetReleaseHandler != nil {
 		s.packetReleaseHandler(p)
 	}
@@ -179,7 +178,7 @@ func (s *SampleBuilder) purgeBuffers(flush bool) {
 // Push does not copy the input. If you wish to reuse
 // this memory make sure to copy before calling Push
 func (s *SampleBuilder) Push(p *rtp.Packet) {
-	s.buffer.Push(p)
+	s.buffer[p.SequenceNumber] = p
 
 	switch s.filled.compare(p.SequenceNumber) {
 	case slCompareVoid:
@@ -221,19 +220,14 @@ func (s *SampleBuilder) buildSample(purgingBuffers bool) *media.Sample {
 
 	var consume sampleSequenceLocation
 
-	for i := s.active.head; s.active.compare(i) != slCompareAfter; i++ {
-		pkt, err := s.buffer.PeekAtSequence(i)
-		if pkt == nil || err != nil {
-			break
-		}
-
-		if s.depacketizer.IsPartitionTail(pkt.Marker, pkt.Payload) {
+	for i := s.active.head; s.buffer[i] != nil && s.active.compare(i) != slCompareAfter; i++ {
+		if s.depacketizer.IsPartitionTail(s.buffer[i].Marker, s.buffer[i].Payload) {
 			consume.head = s.active.head
 			consume.tail = i + 1
 			break
 		}
 		headTimestamp, hasData := s.fetchTimestamp(s.active)
-		if hasData && pkt.Timestamp != headTimestamp {
+		if hasData && s.buffer[i].Timestamp != headTimestamp {
 			consume.head = s.active.head
 			consume.tail = i
 			break
@@ -243,8 +237,8 @@ func (s *SampleBuilder) buildSample(purgingBuffers bool) *media.Sample {
 	if consume.empty() {
 		return nil
 	}
-	pkt, _ := s.buffer.PeekAtSequence(consume.tail)
-	if !purgingBuffers && pkt == nil {
+
+	if !purgingBuffers && s.buffer[consume.tail] == nil {
 		// wait for the next packet after this set of packets to arrive
 		// to ensure at least one post sample timestamp is known
 		// (unless we have to release right now)
@@ -256,10 +250,8 @@ func (s *SampleBuilder) buildSample(purgingBuffers bool) *media.Sample {
 
 	// scan for any packet after the current and use that time stamp as the diff point
 	for i := consume.tail; i < s.active.tail; i++ {
-		pkt, _ = s.buffer.PeekAtSequence(i)
-
-		if pkt != nil {
-			afterTimestamp = pkt.Timestamp
+		if s.buffer[i] != nil {
+			afterTimestamp = s.buffer[i].Timestamp
 			break
 		}
 	}
@@ -269,11 +261,10 @@ func (s *SampleBuilder) buildSample(purgingBuffers bool) *media.Sample {
 
 	// prior to decoding all the packets, check if this packet
 	// would end being disposed anyway
-	pkt, err := s.buffer.PeekAtSequence(consume.head)
-	if err == nil && !s.depacketizer.IsPartitionHead(pkt.Payload) {
+	if !s.depacketizer.IsPartitionHead(s.buffer[consume.head].Payload) {
 		isPadding := false
 		for i := consume.head; i != consume.tail; i++ {
-			if s.lastSampleTimestamp != nil && *s.lastSampleTimestamp == pkt.Timestamp && len(pkt.Payload) == 0 {
+			if s.lastSampleTimestamp != nil && *s.lastSampleTimestamp == s.buffer[i].Timestamp && len(s.buffer[i].Payload) == 0 {
 				isPadding = true
 			}
 		}
@@ -291,22 +282,16 @@ func (s *SampleBuilder) buildSample(purgingBuffers bool) *media.Sample {
 	var metadata interface{}
 	var rtpHeaders []*rtp.Header
 	for i := consume.head; i != consume.tail; i++ {
-		pkt, err := s.buffer.PeekAtSequence(i)
-		if err != nil {
-			return nil
-		}
-		p, err := s.depacketizer.Unmarshal(pkt.Payload)
+		p, err := s.depacketizer.Unmarshal(s.buffer[i].Payload)
 		if err != nil {
 			return nil
 		}
 		if i == consume.head && s.packetHeadHandler != nil {
 			metadata = s.packetHeadHandler(s.depacketizer)
 		}
 		if s.returnRTPHeaders {
-			if packet, _ := s.buffer.PeekAtSequence(i); packet != nil {
-				h := pkt.Header.Clone()
-				rtpHeaders = append(rtpHeaders, &h)
-			}
+			h := s.buffer[i].Header.Clone()
+			rtpHeaders = append(rtpHeaders, &h)
 		}
 
 		data = append(data, p...)
@@ -404,11 +389,3 @@ func WithRTPHeaders(enable bool) Option {
 		o.returnRTPHeaders = enable
 	}
 }
-
-// WithJitterBufferMinimumLength sets the minimum number of packets which must first
-// be received before starting any playback
-func WithJitterBufferMinimumLength(length uint16) Option {
-	return func(o *SampleBuilder) {
-		o.buffer = jitterbuffer.New(jitterbuffer.WithMinimumPacketCount(length))
-	}
-}

pkg/media/samplebuilder/samplebuilder_test.go

@@ -396,18 +396,14 @@ func TestSampleBuilderCleanReference(t *testing.T) {
 			s.Push(pkt5)
 
 			for i := 0; i < 3; i++ {
-				pkt, err := s.buffer.PeekAtSequence(uint16((i + int(seqStart)) % 0x10000))
-
-				if pkt != nil || err == nil {
+				if s.buffer[(i+int(seqStart))%0x10000] != nil {
 					t.Errorf("Old packet (%d) is not unreferenced (maxLate: 10, pushed: 12)", i)
 				}
 			}
-			pkt, err := s.buffer.PeekAtSequence(uint16((14 + int(seqStart)) % 0x10000))
-			if pkt != pkt4 || err != nil {
+			if s.buffer[(14+int(seqStart))%0x10000] != pkt4 {
 				t.Error("New packet must be referenced after jump")
 			}
-			pkt, err = s.buffer.PeekAtSequence(uint16((12 + int(seqStart)) % 0x10000))
-			if pkt != pkt5 || err != nil {
+			if s.buffer[(12+int(seqStart))%0x10000] != pkt5 {
 				t.Error("New packet must be referenced after jump")
 			}
 		})