snapshot of https://github.com/livekit/livekit.git @ 08c5433449c106943231037d0b892895f6e92d3b (2026-09-15)

pkg/sfu/rtpstats/rtpstats_base_lite.go

@@ -0,0 +1,557 @@
+// Copyright 2023 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rtpstats
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/livekit/protocol/livekit"
+	"github.com/livekit/protocol/logger"
+	"github.com/livekit/protocol/utils/mono"
+	"go.uber.org/zap/zapcore"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+const (
+	cGapHistogramNumBins = 101
+	cNumSequenceNumbers  = 65536
+	cFirstSnapshotID     = 1
+)
+
+// -------------------------------------------------------
+
+type RTPDeltaInfoLite struct {
+	StartTime         time.Time
+	EndTime           time.Time
+	Packets           uint32
+	Bytes             uint64
+	PacketsLost       uint32
+	PacketsOutOfOrder uint32
+	Nacks             uint32
+}
+
+func (r *RTPDeltaInfoLite) MarshalLogObject(e zapcore.ObjectEncoder) error {
+	if r == nil {
+		return nil
+	}
+
+	e.AddTime("StartTime", r.StartTime)
+	e.AddTime("EndTime", r.EndTime)
+	e.AddUint32("Packets", r.Packets)
+	e.AddUint64("Bytes", r.Bytes)
+	e.AddUint32("PacketsLost", r.PacketsLost)
+	e.AddUint32("PacketsOutOfOrder", r.PacketsOutOfOrder)
+	e.AddUint32("Nacks", r.Nacks)
+	return nil
+}
+
+// -------------------------------------------------------
+
+type snapshotLite struct {
+	isValid bool
+
+	startTime int64
+
+	extStartSN uint64
+	bytes      uint64
+
+	packetsOutOfOrder uint64
+
+	packetsLost uint64
+
+	nacks uint32
+}
+
+func (s *snapshotLite) MarshalLogObject(e zapcore.ObjectEncoder) error {
+	if s == nil {
+		return nil
+	}
+
+	e.AddBool("isValid", s.isValid)
+	e.AddTime("startTime", time.Unix(0, s.startTime))
+	e.AddUint64("extStartSN", s.extStartSN)
+	e.AddUint64("bytes", s.bytes)
+	e.AddUint64("packetsOutOfOrder", s.packetsOutOfOrder)
+	e.AddUint64("packetsLost", s.packetsLost)
+	e.AddUint32("nacks", s.nacks)
+	return nil
+}
+
+// ------------------------------------------------------------------
+
+type RTPStatsParams struct {
+	IsRTX bool
+}
+
+type rtpStatsBaseLite struct {
+	params    RTPStatsParams
+	clockRate uint32
+	logger    logger.Logger
+
+	lock sync.RWMutex
+
+	initialized bool
+
+	startTime int64
+	endTime   int64
+
+	bytes uint64
+
+	packetsOutOfOrder uint64
+
+	packetsLost uint64
+
+	gapHistogram [cGapHistogramNumBins]uint32
+
+	nacks        uint32
+	nackAcks     uint32
+	nackMisses   uint32
+	nackRepeated uint32
+
+	plis    uint32
+	lastPli int64
+
+	nextSnapshotLiteID uint32
+	snapshotLites      []snapshotLite
+}
+
+func newRTPStatsBaseLite(params RTPStatsParams) *rtpStatsBaseLite {
+	return &rtpStatsBaseLite{
+		params:             params,
+		logger:             logger.GetLogger(),
+		nextSnapshotLiteID: cFirstSnapshotID,
+		snapshotLites:      make([]snapshotLite, 2),
+	}
+}
+
+func (r *rtpStatsBaseLite) seed(from *rtpStatsBaseLite) bool {
+	if from == nil || !from.initialized || r.initialized {
+		return false
+	}
+
+	r.initialized = from.initialized
+
+	r.startTime = from.startTime
+	// do not clone endTime as a non-zero endTime indicates an ended object
+
+	r.bytes = from.bytes
+
+	r.packetsOutOfOrder = from.packetsOutOfOrder
+
+	r.packetsLost = from.packetsLost
+
+	r.gapHistogram = from.gapHistogram
+
+	r.nacks = from.nacks
+	r.nackAcks = from.nackAcks
+	r.nackMisses = from.nackMisses
+	r.nackRepeated = from.nackRepeated
+
+	r.plis = from.plis
+	r.lastPli = from.lastPli
+
+	r.nextSnapshotLiteID = from.nextSnapshotLiteID
+	r.snapshotLites = make([]snapshotLite, cap(from.snapshotLites))
+	copy(r.snapshotLites, from.snapshotLites)
+	return true
+}
+
+func (r *rtpStatsBaseLite) SetClockRate(clockRate uint32) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	r.setClockRateLocked(clockRate)
+}
+
+func (r *rtpStatsBaseLite) setClockRateLocked(clockRate uint32) {
+	r.clockRate = clockRate
+}
+
+func (r *rtpStatsBaseLite) SetLogger(logger logger.Logger) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	r.logger = logger
+}
+
+func (r *rtpStatsBaseLite) Stop() {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	r.endTime = mono.UnixNano()
+}
+
+func (r *rtpStatsBaseLite) newSnapshotLiteID(extStartSN uint64) uint32 {
+	id := r.nextSnapshotLiteID
+	r.nextSnapshotLiteID++
+
+	if cap(r.snapshotLites) < int(r.nextSnapshotLiteID-cFirstSnapshotID) {
+		snapshotLites := make([]snapshotLite, r.nextSnapshotLiteID-cFirstSnapshotID)
+		copy(snapshotLites, r.snapshotLites)
+		r.snapshotLites = snapshotLites
+	}
+
+	if r.initialized {
+		r.snapshotLites[id-cFirstSnapshotID] = initSnapshotLite(mono.UnixNano(), extStartSN)
+	}
+	return id
+}
+
+func (r *rtpStatsBaseLite) IsActive() bool {
+	r.lock.RLock()
+	defer r.lock.RUnlock()
+
+	return r.initialized && r.endTime == 0
+}
+
+func (r *rtpStatsBaseLite) UpdateNack(nackCount uint32) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	if r.endTime != 0 {
+		return
+	}
+
+	r.nacks += nackCount
+}
+
+func (r *rtpStatsBaseLite) UpdateNackProcessed(nackAckCount uint32, nackMissCount uint32, nackRepeatedCount uint32) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	if r.endTime != 0 {
+		return
+	}
+
+	r.nackAcks += nackAckCount
+	r.nackMisses += nackMissCount
+	r.nackRepeated += nackRepeatedCount
+}
+
+func (r *rtpStatsBaseLite) CheckAndUpdatePli(throttle int64, force bool) bool {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	if r.endTime != 0 || (!force && mono.UnixNano()-r.lastPli < throttle) {
+		return false
+	}
+	r.updatePliLocked(1)
+	r.updatePliTimeLocked()
+	return true
+}
+
+func (r *rtpStatsBaseLite) UpdatePliAndTime(pliCount uint32) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	if r.endTime != 0 {
+		return
+	}
+
+	r.updatePliLocked(pliCount)
+	r.updatePliTimeLocked()
+}
+
+func (r *rtpStatsBaseLite) UpdatePli(pliCount uint32) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	if r.endTime != 0 {
+		return
+	}
+
+	r.updatePliLocked(pliCount)
+}
+
+func (r *rtpStatsBaseLite) updatePliLocked(pliCount uint32) {
+	r.plis += pliCount
+}
+
+func (r *rtpStatsBaseLite) UpdatePliTime() {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	if r.endTime != 0 {
+		return
+	}
+
+	r.updatePliTimeLocked()
+}
+
+func (r *rtpStatsBaseLite) updatePliTimeLocked() {
+	r.lastPli = mono.UnixNano()
+}
+
+func (r *rtpStatsBaseLite) LastPli() int64 {
+	r.lock.RLock()
+	defer r.lock.RUnlock()
+
+	return r.lastPli
+}
+
+func (r *rtpStatsBaseLite) getPacketsSeen(extStartSN, extHighestSN uint64) uint64 {
+	packetsExpected := getPacketsExpected(extStartSN, extHighestSN)
+	if r.packetsLost > packetsExpected {
+		// should not happen
+		return 0
+	}
+
+	return packetsExpected - r.packetsLost
+}
+
+func (r *rtpStatsBaseLite) deltaInfoLite(
+	snapshotLiteID uint32,
+	extStartSN uint64,
+	extHighestSN uint64,
+) (deltaInfoLite *RTPDeltaInfoLite, loggingFields []any, err error) {
+	then, now, ok := r.getAndResetSnapshotLite(snapshotLiteID, extStartSN, extHighestSN)
+	if !ok {
+		return
+	}
+
+	startTime := then.startTime
+	endTime := now.startTime
+
+	packetsExpected := uint32(now.extStartSN - then.extStartSN)
+	if then.extStartSN > extHighestSN {
+		packetsExpected = 0
+	}
+	if packetsExpected > cNumSequenceNumbers {
+		loggingFields = []any{
+			"snapshotLiteID", snapshotLiteID,
+			"snapshotLiteNow", now,
+			"snapshotLiteThen", then,
+			"packetsExpected", packetsExpected,
+			"duration", time.Duration(endTime - startTime),
+		}
+		err = errors.New("too many packets expected in delta lite")
+		return
+	}
+	if packetsExpected == 0 {
+		deltaInfoLite = &RTPDeltaInfoLite{
+			StartTime: time.Unix(0, startTime),
+			EndTime:   time.Unix(0, endTime),
+		}
+		return
+	}
+
+	packetsLost := uint32(now.packetsLost - then.packetsLost)
+	if int32(packetsLost) < 0 {
+		packetsLost = 0
+	}
+	if packetsLost > packetsExpected {
+		loggingFields = []any{
+			"snapshotLiteID", snapshotLiteID,
+			"snapshotLiteNow", now,
+			"snapshotLiteThen", then,
+			"packetsExpected", packetsExpected,
+			"packetsLost", packetsLost,
+			"duration", time.Duration(endTime - startTime),
+		}
+		err = errors.New("unexpected number of packets lost in delta lite")
+	}
+
+	deltaInfoLite = &RTPDeltaInfoLite{
+		StartTime:         time.Unix(0, startTime),
+		EndTime:           time.Unix(0, endTime),
+		Packets:           packetsExpected,
+		Bytes:             now.bytes - then.bytes,
+		PacketsLost:       packetsLost,
+		PacketsOutOfOrder: uint32(now.packetsOutOfOrder - then.packetsOutOfOrder),
+		Nacks:             now.nacks - then.nacks,
+	}
+	return
+}
+
+func (r *rtpStatsBaseLite) marshalLogObject(e zapcore.ObjectEncoder, packetsExpected, packetsSeenMinusPadding uint64) (float64, error) {
+	if r == nil || !r.initialized || r.clockRate == 0 {
+		return 0, errors.New("not initialized")
+	}
+
+	endTime := r.endTime
+	if endTime == 0 {
+		endTime = mono.UnixNano()
+	}
+	elapsed := time.Duration(endTime - r.startTime)
+	if elapsed == 0 {
+		return 0, errors.New("no time elapsed")
+	}
+	elapsedSeconds := elapsed.Seconds()
+
+	e.AddTime("startTime", time.Unix(0, r.startTime))
+	e.AddTime("endTime", time.Unix(0, r.endTime))
+	e.AddDuration("elapsed", elapsed)
+
+	e.AddUint64("packetsExpected", packetsExpected)
+	e.AddFloat64("packetsExpectedRate", float64(packetsExpected)/elapsedSeconds)
+	e.AddUint64("packetsSeenPrimary", packetsSeenMinusPadding)
+	e.AddFloat64("packetsSeenPrimaryRate", float64(packetsSeenMinusPadding)/elapsedSeconds)
+	e.AddUint64("bytes", r.bytes)
+	e.AddFloat64("bitrate", float64(r.bytes)*8.0/elapsedSeconds)
+
+	e.AddUint64("packetsOutOfOrder", r.packetsOutOfOrder)
+
+	e.AddUint64("packetsLost", r.packetsLost)
+	e.AddFloat64("packetsLostRate", float64(r.packetsLost)/elapsedSeconds)
+	if packetsExpected != 0 {
+		e.AddFloat32("packetLostPercentage", float32(r.packetsLost)/float32(packetsExpected)*100.0)
+	}
+
+	var sb strings.Builder
+	for burst, count := range r.gapHistogram {
+		if count == 0 {
+			continue
+		}
+		if sb.Len() > 0 {
+			sb.WriteString(", ")
+		}
+		fmt.Fprintf(&sb, "%d:%d", burst+1, count)
+	}
+	if sb.Len() > 0 {
+		e.AddString("gapHistogram", "["+sb.String()+"]")
+	}
+
+	e.AddUint32("nacks", r.nacks)
+	e.AddUint32("nackAcks", r.nackAcks)
+	e.AddUint32("nackMisses", r.nackMisses)
+	e.AddUint32("nackRepeated", r.nackRepeated)
+
+	e.AddUint32("plis", r.plis)
+	e.AddTime("lastPli", time.Unix(0, r.lastPli))
+	return elapsedSeconds, nil
+}
+
+func (r *rtpStatsBaseLite) toProto(packetsExpected, packetsSeenMinusPadding, packetsLost uint64) *livekit.RTPStats {
+	if r.startTime == 0 || r.clockRate == 0 {
+		return nil
+	}
+
+	endTime := r.endTime
+	if endTime == 0 {
+		endTime = mono.UnixNano()
+	}
+	elapsed := time.Duration(endTime - r.startTime).Seconds()
+	if elapsed == 0.0 {
+		return nil
+	}
+
+	packetRate := float64(packetsSeenMinusPadding) / elapsed
+	bitrate := float64(r.bytes) * 8.0 / elapsed
+
+	packetLostRate := float64(packetsLost) / elapsed
+	packetLostPercentage := float32(0)
+	if packetsExpected != 0 {
+		packetLostPercentage = float32(packetsLost) / float32(packetsExpected) * 100.0
+	}
+
+	p := &livekit.RTPStats{
+		StartTime:            timestamppb.New(time.Unix(0, r.startTime)),
+		EndTime:              timestamppb.New(time.Unix(0, endTime)),
+		Duration:             elapsed,
+		Packets:              uint32(packetsSeenMinusPadding),
+		PacketRate:           packetRate,
+		Bytes:                r.bytes,
+		Bitrate:              bitrate,
+		PacketsLost:          uint32(packetsLost),
+		PacketLossRate:       packetLostRate,
+		PacketLossPercentage: packetLostPercentage,
+		PacketsOutOfOrder:    uint32(r.packetsOutOfOrder),
+		Nacks:                r.nacks,
+		NackAcks:             r.nackAcks,
+		NackMisses:           r.nackMisses,
+		NackRepeated:         r.nackRepeated,
+		Plis:                 r.plis,
+		LastPli:              timestamppb.New(time.Unix(0, r.lastPli)),
+	}
+
+	for i := range len(r.gapHistogram) {
+		if r.gapHistogram[i] == 0 {
+			continue
+		}
+		if p.GapHistogram == nil {
+			p.GapHistogram = make(map[int32]uint32, len(r.gapHistogram))
+		}
+		p.GapHistogram[int32(i+1)] = r.gapHistogram[i]
+	}
+
+	return p
+}
+
+func (r *rtpStatsBaseLite) getAndResetSnapshotLite(snapshotLiteID uint32, extStartSN uint64, extHighestSN uint64) (snapshotLite, snapshotLite, bool) {
+	if !r.initialized {
+		return snapshotLite{}, snapshotLite{}, false
+	}
+
+	idx := snapshotLiteID - cFirstSnapshotID
+	then := r.snapshotLites[idx]
+	if !then.isValid {
+		then = initSnapshotLite(r.startTime, extStartSN)
+		r.snapshotLites[idx] = then
+	}
+
+	// snapshot now
+	now := r.getSnapshotLite(mono.UnixNano(), extHighestSN+1)
+	r.snapshotLites[idx] = now
+	return then, now, true
+}
+
+func (r *rtpStatsBaseLite) updateGapHistogram(gap int) {
+	if gap < 2 {
+		return
+	}
+
+	missing := gap - 1
+	if missing > len(r.gapHistogram) {
+		r.gapHistogram[len(r.gapHistogram)-1]++
+	} else {
+		r.gapHistogram[missing-1]++
+	}
+}
+
+func (r *rtpStatsBaseLite) getSnapshotLite(startTime int64, extStartSN uint64) snapshotLite {
+	return snapshotLite{
+		isValid:           true,
+		startTime:         startTime,
+		extStartSN:        extStartSN,
+		bytes:             r.bytes,
+		packetsOutOfOrder: r.packetsOutOfOrder,
+		packetsLost:       r.packetsLost,
+		nacks:             r.nacks,
+	}
+}
+
+// ----------------------------------
+
+func initSnapshotLite(startTime int64, extStartSN uint64) snapshotLite {
+	return snapshotLite{
+		isValid:    true,
+		startTime:  startTime,
+		extStartSN: extStartSN,
+	}
+}
+
+func getPacketsExpected(extStartSN, extHighestSN uint64) uint64 {
+	return extHighestSN - extStartSN + 1
+}
+
+func shouldLog(count int) bool {
+	return count < 20 || count%200 == 0
+}
+
+// ----------------------------------

pkg/sfu/rtpstats/rtpstats_receiver_lite.go

@@ -0,0 +1,179 @@
+// Copyright 2023 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rtpstats
+
+import (
+	"go.uber.org/zap/zapcore"
+
+	"github.com/livekit/mediatransportutil/pkg/utils"
+	"github.com/livekit/protocol/livekit"
+	"github.com/livekit/protocol/utils/mono"
+)
+
+type RTPFlowStateLite struct {
+	IsNotHandled bool
+
+	LossStartInclusive uint64
+	LossEndExclusive   uint64
+
+	ExtSequenceNumber uint64
+}
+
+func (r *RTPFlowStateLite) MarshalLogObject(e zapcore.ObjectEncoder) error {
+	if r == nil {
+		return nil
+	}
+
+	e.AddBool("IsNotHandled", r.IsNotHandled)
+	e.AddUint64("LossStartInclusive", r.LossStartInclusive)
+	e.AddUint64("LossEndExclusive", r.LossEndExclusive)
+	e.AddUint64("ExtSequenceNumber", r.ExtSequenceNumber)
+	return nil
+}
+
+// ---------------------------------------------------------------------
+
+type RTPStatsReceiverLite struct {
+	*rtpStatsBaseLite
+
+	sequenceNumber *utils.WrapAround[uint16, uint64]
+}
+
+func NewRTPStatsReceiverLite(params RTPStatsParams) *RTPStatsReceiverLite {
+	return &RTPStatsReceiverLite{
+		rtpStatsBaseLite: newRTPStatsBaseLite(params),
+		sequenceNumber:   utils.NewWrapAround[uint16, uint64](utils.WrapAroundParams{IsRestartAllowed: false}),
+	}
+}
+
+func (r *RTPStatsReceiverLite) NewSnapshotLiteId() uint32 {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	return r.newSnapshotLiteID(r.sequenceNumber.GetExtendedHighest())
+}
+
+func (r *RTPStatsReceiverLite) Update(packetTime int64, packetSize int, sequenceNumber uint16) (flowStateLite RTPFlowStateLite) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	if r.endTime != 0 {
+		flowStateLite.IsNotHandled = true
+		return
+	}
+
+	var resSN utils.WrapAroundUpdateResult[uint64]
+	if !r.initialized {
+		r.initialized = true
+
+		r.startTime = mono.UnixNano()
+
+		resSN = r.sequenceNumber.Update(sequenceNumber)
+
+		// initialize lite snapshots if any
+		for i := uint32(0); i < r.nextSnapshotLiteID-cFirstSnapshotID; i++ {
+			r.snapshotLites[i] = initSnapshotLite(r.startTime, r.sequenceNumber.GetExtendedStart())
+		}
+
+		r.logger.Debugw(
+			"rtp receiver lite stream start",
+			"rtpStats", lockedRTPStatsReceiverLiteLogEncoder{r},
+		)
+	} else {
+		resSN = r.sequenceNumber.Update(sequenceNumber)
+		if resSN.IsUnhandled {
+			flowStateLite.IsNotHandled = true
+			return
+		}
+	}
+
+	gapSN := int64(resSN.ExtendedVal - resSN.PreExtendedHighest)
+	if gapSN <= 0 { // duplicate OR out-of-order
+		r.packetsOutOfOrder++ // counting duplicate as out-of-order
+		if gapSN != 0 && r.packetsLost > 0 {
+			r.packetsLost--
+		}
+	} else { // in-order
+		r.updateGapHistogram(int(gapSN))
+		r.packetsLost += uint64(gapSN - 1)
+
+		flowStateLite.LossStartInclusive = resSN.PreExtendedHighest + 1
+		flowStateLite.LossEndExclusive = resSN.ExtendedVal
+	}
+	flowStateLite.ExtSequenceNumber = resSN.ExtendedVal
+	r.bytes += uint64(packetSize)
+	return
+}
+
+func (r *RTPStatsReceiverLite) DeltaInfoLite(snapshotLiteID uint32) *RTPDeltaInfoLite {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	deltaInfoLite, loggingFields, err := r.deltaInfoLite(
+		snapshotLiteID,
+		r.sequenceNumber.GetExtendedStart(),
+		r.sequenceNumber.GetExtendedHighest(),
+	)
+	if err != nil {
+		r.logger.Infow(err.Error(), append(loggingFields, "rtpStats", lockedRTPStatsReceiverLiteLogEncoder{r})...)
+	}
+
+	return deltaInfoLite
+}
+
+func (r *RTPStatsReceiverLite) MarshalLogObject(e zapcore.ObjectEncoder) error {
+	if r == nil {
+		return nil
+	}
+
+	r.lock.RLock()
+	defer r.lock.RUnlock()
+
+	return lockedRTPStatsReceiverLiteLogEncoder{r}.MarshalLogObject(e)
+}
+
+func (r *RTPStatsReceiverLite) ToProto() *livekit.RTPStats {
+	r.lock.RLock()
+	defer r.lock.RUnlock()
+
+	return r.rtpStatsBaseLite.toProto(r.sequenceNumber.GetExtendedStart(), r.sequenceNumber.GetExtendedHighest(), r.packetsLost)
+}
+
+// ----------------------------------
+
+type lockedRTPStatsReceiverLiteLogEncoder struct {
+	*RTPStatsReceiverLite
+}
+
+func (r lockedRTPStatsReceiverLiteLogEncoder) MarshalLogObject(e zapcore.ObjectEncoder) error {
+	if r.RTPStatsReceiverLite == nil {
+		return nil
+	}
+
+	extStartSN, extHighestSN := r.sequenceNumber.GetExtendedStart(), r.sequenceNumber.GetExtendedHighest()
+	if _, err := r.rtpStatsBaseLite.marshalLogObject(
+		e,
+		getPacketsExpected(extStartSN, extHighestSN),
+		getPacketsExpected(extStartSN, extHighestSN),
+	); err != nil {
+		return err
+	}
+
+	e.AddUint64("extStartSN", r.sequenceNumber.GetExtendedStart())
+	e.AddUint64("extHighestSN", r.sequenceNumber.GetExtendedHighest())
+	return nil
+}
+
+// ----------------------------------

pkg/sfu/rtpstats/rtpstats_sender_lite.go

@@ -0,0 +1,121 @@
+// Copyright 2023 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rtpstats
+
+import (
+	"github.com/livekit/protocol/livekit"
+	"github.com/livekit/protocol/utils/mono"
+	"go.uber.org/zap/zapcore"
+)
+
+type RTPStatsSenderLite struct {
+	*rtpStatsBaseLite
+
+	extStartSN   uint64
+	extHighestSN uint64
+}
+
+func NewRTPStatsSenderLite(params RTPStatsParams) *RTPStatsSenderLite {
+	return &RTPStatsSenderLite{
+		rtpStatsBaseLite: newRTPStatsBaseLite(params),
+	}
+}
+
+func (r *RTPStatsSenderLite) Update(packetTime int64, packetSize int, extSequenceNumber uint64) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
+	if r.endTime != 0 {
+		return
+	}
+
+	if !r.initialized {
+		r.initialized = true
+
+		r.startTime = mono.UnixNano()
+
+		r.extStartSN = extSequenceNumber
+		r.extHighestSN = extSequenceNumber - 1
+
+		r.logger.Debugw(
+			"rtp sender lite stream start",
+			"rtpStats", lockedRTPStatsSenderLiteLogEncoder{r},
+		)
+	}
+
+	gapSN := int64(extSequenceNumber - r.extHighestSN)
+	if gapSN <= 0 { // duplicate OR out-of-order
+		r.packetsOutOfOrder++ // counting duplicate as out-of-order
+		r.packetsLost--
+	} else { // in-order
+		r.updateGapHistogram(int(gapSN))
+		r.packetsLost += uint64(gapSN - 1)
+
+		r.extHighestSN = extSequenceNumber
+	}
+
+	r.bytes += uint64(packetSize)
+}
+
+func (r *RTPStatsSenderLite) MarshalLogObject(e zapcore.ObjectEncoder) error {
+	if r == nil {
+		return nil
+	}
+
+	r.lock.RLock()
+	defer r.lock.RUnlock()
+
+	return lockedRTPStatsSenderLiteLogEncoder{r}.MarshalLogObject(e)
+}
+
+func (r *RTPStatsSenderLite) ToProto() *livekit.RTPStats {
+	r.lock.RLock()
+	defer r.lock.RUnlock()
+
+	return r.rtpStatsBaseLite.toProto(r.extStartSN, r.extHighestSN, r.packetsLost)
+}
+
+func (r *RTPStatsSenderLite) ExtHighestSequenceNumber() uint64 {
+	r.lock.RLock()
+	defer r.lock.RUnlock()
+
+	return r.extHighestSN
+}
+
+// -------------------------------------------------------------------
+
+type lockedRTPStatsSenderLiteLogEncoder struct {
+	*RTPStatsSenderLite
+}
+
+func (r lockedRTPStatsSenderLiteLogEncoder) MarshalLogObject(e zapcore.ObjectEncoder) error {
+	if r.RTPStatsSenderLite == nil {
+		return nil
+	}
+
+	if _, err := r.rtpStatsBaseLite.marshalLogObject(
+		e,
+		getPacketsExpected(r.extStartSN, r.extHighestSN),
+		getPacketsExpected(r.extStartSN, r.extHighestSN),
+	); err != nil {
+		return err
+	}
+
+	e.AddUint64("extStartSN", r.extStartSN)
+	e.AddUint64("extHighestSN", r.extHighestSN)
+	return nil
+}
+
+// -------------------------------------------------------------------

pkg/sfu/rtpstats/rtpstats_test.go

@@ -0,0 +1,286 @@
+// Copyright 2023 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rtpstats
+
+import (
+	"math/rand"
+	"testing"
+	"time"
+
+	"github.com/pion/rtp"
+	"github.com/stretchr/testify/require"
+)
+
+func getPacket(sn uint16, ts uint32, payloadSize int) *rtp.Packet {
+	return &rtp.Packet{
+		Header: rtp.Header{
+			SequenceNumber: sn,
+			Timestamp:      ts,
+		},
+		Payload: make([]byte, payloadSize),
+	}
+}
+
+func Test_RTPStatsReceiver_Update(t *testing.T) {
+	clockRate := uint32(90000)
+	r := NewRTPStatsReceiver(RTPStatsParams{})
+	r.SetClockRate(clockRate)
+
+	sequenceNumber := uint16(rand.Float64() * float64(1<<16))
+	timestamp := uint32(rand.Float64() * float64(1<<32))
+	packet := getPacket(sequenceNumber, timestamp, 1000)
+	flowState := r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		0,
+	)
+	require.True(t, r.initialized)
+	require.Equal(t, sequenceNumber, r.sequenceNumber.GetHighest())
+	require.Equal(t, sequenceNumber, uint16(r.sequenceNumber.GetExtendedHighest()))
+	require.Equal(t, timestamp, r.timestamp.GetHighest())
+	require.Equal(t, timestamp, uint32(r.timestamp.GetExtendedHighest()))
+
+	// in-order, no loss
+	sequenceNumber++
+	timestamp += 3000
+	packet = getPacket(sequenceNumber, timestamp, 1000)
+	flowState = r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		0,
+	)
+	require.Equal(t, sequenceNumber, r.sequenceNumber.GetHighest())
+	require.Equal(t, sequenceNumber, uint16(r.sequenceNumber.GetExtendedHighest()))
+	require.Equal(t, timestamp, r.timestamp.GetHighest())
+	require.Equal(t, timestamp, uint32(r.timestamp.GetExtendedHighest()))
+
+	// out-of-order, would cause a restart which is disallowed
+	packet = getPacket(sequenceNumber-10, timestamp-30000, 1000)
+	flowState = r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		0,
+	)
+	require.Equal(t, RTPFlowUnhandledReasonPreStartTimestamp, flowState.UnhandledReason)
+	require.Equal(t, sequenceNumber, r.sequenceNumber.GetHighest())
+	require.Equal(t, sequenceNumber, uint16(r.sequenceNumber.GetExtendedHighest()))
+	require.Equal(t, timestamp, r.timestamp.GetHighest())
+	require.Equal(t, timestamp, uint32(r.timestamp.GetExtendedHighest()))
+	require.Equal(t, uint64(0), r.packetsOutOfOrder)
+	require.Equal(t, uint64(0), r.packetsDuplicate)
+
+	// duplicate of the above out-of-order packet, but would not be handled as it causes a restart
+	packet = getPacket(sequenceNumber-10, timestamp-30000, 1000)
+	flowState = r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		0,
+	)
+	require.Equal(t, RTPFlowUnhandledReasonPreStartTimestamp, flowState.UnhandledReason)
+	require.Equal(t, sequenceNumber, r.sequenceNumber.GetHighest())
+	require.Equal(t, sequenceNumber, uint16(r.sequenceNumber.GetExtendedHighest()))
+	require.Equal(t, timestamp, r.timestamp.GetHighest())
+	require.Equal(t, timestamp, uint32(r.timestamp.GetExtendedHighest()))
+	require.Equal(t, uint64(0), r.packetsOutOfOrder)
+	require.Equal(t, uint64(0), r.packetsDuplicate)
+
+	// loss
+	sequenceNumber += 10
+	timestamp += 30000
+	packet = getPacket(sequenceNumber, timestamp, 1000)
+	flowState = r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		0,
+	)
+	require.Equal(t, uint64(sequenceNumber-9), flowState.LossStartInclusive)
+	require.Equal(t, uint64(sequenceNumber), flowState.LossEndExclusive)
+	require.Equal(t, uint64(9), r.packetsLost)
+
+	// out-of-order should decrement number of lost packets
+	packet = getPacket(sequenceNumber-6, timestamp-18000, 1000)
+	flowState = r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		0,
+	)
+	require.Equal(t, sequenceNumber, r.sequenceNumber.GetHighest())
+	require.Equal(t, sequenceNumber, uint16(r.sequenceNumber.GetExtendedHighest()))
+	require.Equal(t, timestamp, r.timestamp.GetHighest())
+	require.Equal(t, timestamp, uint32(r.timestamp.GetExtendedHighest()))
+	require.Equal(t, uint64(1), r.packetsOutOfOrder)
+	require.Equal(t, uint64(0), r.packetsDuplicate)
+	require.Equal(t, uint64(8), r.packetsLost)
+
+	// test sequence number history
+	// with a gap
+	sequenceNumber += 2
+	timestamp += 6000
+	packet = getPacket(sequenceNumber, timestamp, 1000)
+	flowState = r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		0,
+	)
+	require.Equal(t, uint64(sequenceNumber-1), flowState.LossStartInclusive)
+	require.Equal(t, uint64(sequenceNumber), flowState.LossEndExclusive)
+	require.Equal(t, uint64(9), r.packetsLost)
+	require.False(t, r.history.IsSet(uint64(sequenceNumber)-1))
+
+	// out-of-order
+	sequenceNumber--
+	timestamp -= 3000
+	packet = getPacket(sequenceNumber, timestamp, 999)
+	flowState = r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		0,
+	)
+	require.Equal(t, uint64(8), r.packetsLost)
+	require.Equal(t, uint64(2), r.packetsOutOfOrder)
+	require.True(t, r.history.IsSet(uint64(sequenceNumber)))
+
+	// padding only
+	sequenceNumber += 2
+	timestamp += 3000
+	packet = getPacket(sequenceNumber, timestamp, 0)
+	flowState = r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		25,
+	)
+	require.Equal(t, uint64(8), r.packetsLost)
+	require.Equal(t, uint64(2), r.packetsOutOfOrder)
+	require.True(t, r.history.IsSet(uint64(sequenceNumber)))
+	require.True(t, r.history.IsSet(uint64(sequenceNumber)-1))
+	require.True(t, r.history.IsSet(uint64(sequenceNumber)-2))
+
+	// old packet, but simulating increasing sequence number after roll over
+	packet = getPacket(sequenceNumber+400, timestamp-6000, 300)
+	flowState = r.Update(
+		time.Now().UnixNano(),
+		packet.Header.SequenceNumber,
+		packet.Header.Timestamp,
+		packet.Header.Marker,
+		packet.Header.MarshalSize(),
+		len(packet.Payload),
+		0,
+	)
+	require.Equal(t, RTPFlowUnhandledReasonOldSequenceNumber, flowState.UnhandledReason)
+	require.Equal(t, sequenceNumber, r.sequenceNumber.GetHighest())
+	require.Equal(t, sequenceNumber, uint16(r.sequenceNumber.GetExtendedHighest()))
+	require.Equal(t, timestamp, r.timestamp.GetHighest())
+	require.Equal(t, timestamp, uint32(r.timestamp.GetExtendedHighest()))
+
+	r.Stop()
+}
+
+func Test_RTPStatsReceiver_Restart(t *testing.T) {
+	clockRate := uint32(90000)
+	r := NewRTPStatsReceiver(RTPStatsParams{})
+	r.SetClockRate(clockRate)
+
+	// should not restart till there are at least threshold packets
+	require.False(t, r.maybeRestart(10, 20, 1000))
+	require.False(t, r.maybeRestart(11, 20, 1000))
+	require.False(t, r.maybeRestart(13, 20, 1000))
+	require.False(t, r.maybeRestart(14, 20, 1000))
+	// although adding 5th packet should have enough packets for a check,
+	// still should not restart as there is a sequence number gap between 11 and 13
+	require.False(t, r.maybeRestart(15, 20, 1000))
+	require.False(t, r.maybeRestart(16, 19, 1000))
+	// has enough packets, but still cannot restart because timestamps are not increasing
+	require.False(t, r.maybeRestart(17, 21, 1000))
+	require.False(t, r.maybeRestart(18, 21, 1000))
+	require.False(t, r.maybeRestart(19, 21, 1000))
+	// can restart as there are enough packets with proper sequencing
+	require.True(t, r.maybeRestart(20, 21, 1000))
+	require.Equal(t, restartThreshold, r.restartPacketsN)
+
+	r.resetRestart()
+	require.Zero(t, r.restartPacketsN)
+
+	r.Stop()
+}
+
+func Test_RTPStatsSender_getIntervalStats(t *testing.T) {
+	t.Run("packetsNotFoundMetadata should match lost packets", func(t *testing.T) {
+		r := NewRTPStatsSender(RTPStatsParams{}, 1024)
+		stats := r.getIntervalStats(0, 10000, 10000)
+		require.EqualValues(t, 8977, stats.packetsNotFoundMetadata)
+	})
+}
+
+func BenchmarkRTPStatsReceiver_Update(b *testing.B) {
+	const clockRate = 90000
+	const hdrSize = 12
+	const payloadSize = 1200
+	const paddingSize = 0
+	const tsIncrement = 3000 // ~33ms at 90kHz
+
+	r := NewRTPStatsReceiver(RTPStatsParams{})
+	r.SetClockRate(clockRate)
+
+	// initialize before running benchmark loop
+	packetTime := time.Now().UnixNano()
+	sn := uint16(0)
+	ts := uint32(0)
+	r.Update(packetTime, sn, ts, false, hdrSize, payloadSize, paddingSize)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		sn++
+		ts += tsIncrement
+		packetTime += 33 * int64(time.Millisecond) // ~30fps
+		marker := (i+1)%100 == 0                   // marker every 100 packets
+		r.Update(packetTime, sn, ts, marker, hdrSize, payloadSize, paddingSize)
+	}
+}