From b85ff8f063703c8fa6b6561d49a7dd179781a097 Mon Sep 17 00:00:00 2001
From: cnderrauber <zengjie9004@gmail.com>
Date: Mon, 4 Sep 2023 12:39:14 +0800
Subject: [PATCH 01/13] Support non-SVC AV1 track publishing (#2030)

---
 pkg/sfu/downtrack.go |  5 ++++-
 pkg/sfu/forwarder.go | 38 +++++++++++++++++++++++++-------------
 2 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/pkg/sfu/downtrack.go b/pkg/sfu/downtrack.go
index 44414d7c8..f126847bc 100644
--- a/pkg/sfu/downtrack.go
+++ b/pkg/sfu/downtrack.go
@@ -677,7 +677,10 @@ func (d *DownTrack) WriteRTP(extPkt *buffer.ExtPacket, layer int32) error {
 		return err
 	}
 
-	extensions := []pacer.ExtensionData{{ID: uint8(d.dependencyDescriptorExtID), Payload: tp.ddBytes}}
+	var extensions []pacer.ExtensionData
+	if tp.ddBytes != nil {
+		extensions = []pacer.ExtensionData{{ID: uint8(d.dependencyDescriptorExtID), Payload: tp.ddBytes}}
+	}
 	if d.playoutDelayExtID != 0 && !d.playoudDelayAcked.Load() {
 		if val := d.playoutDelayBytes.Load(); val != nil {
 			extensions = append(extensions, pacer.ExtensionData{ID: uint8(d.playoutDelayExtID), Payload: val.([]byte)})
diff --git a/pkg/sfu/forwarder.go b/pkg/sfu/forwarder.go
index 9421f238c..567465ce9 100644
--- a/pkg/sfu/forwarder.go
+++ b/pkg/sfu/forwarder.go
@@ -273,6 +273,15 @@ func (f *Forwarder) DetermineCodec(codec webrtc.RTPCodecCapability, extensions [
 	}
 	f.codec = codec
 
+	ddAvailable := func(exts []webrtc.RTPHeaderExtensionParameter) bool {
+		for _, ext := range exts {
+			if ext.URI == dd.ExtensionURI {
+				return true
+			}
+		}
+		return false
+	}
+
 	switch strings.ToLower(codec.MimeType) {
 	case "video/vp8":
 		f.codecMunger = codecmunger.NewVP8FromNull(f.codecMunger, f.logger)
@@ -289,15 +298,8 @@ func (f *Forwarder) DetermineCodec(codec webrtc.RTPCodecCapability, extensions [
 			f.vls = videolayerselector.NewSimulcast(f.logger)
 		}
 	case "video/vp9":
-		isDDAvailable := false
-	searchDone:
-		for _, ext := range extensions {
-			switch ext.URI {
-			case dd.ExtensionURI:
-				isDDAvailable = true
-				break searchDone
-			}
-		}
+		isDDAvailable := ddAvailable(extensions)
+
 		if isDDAvailable {
 			if f.vls != nil {
 				f.vls = videolayerselector.NewDependencyDescriptorFromNull(f.vls)
@@ -314,12 +316,22 @@ func (f *Forwarder) DetermineCodec(codec webrtc.RTPCodecCapability, extensions [
 		// SVC-TODO: Support for VP9 simulcast. When DD is not available, have to pick selector based on VP9 SVC or Simulcast
 	case "video/av1":
 		// DD-TODO : we only enable dd layer selector for av1/vp9 now, in the future we can enable it for vp8 too
-		if f.vls != nil {
-			f.vls = videolayerselector.NewDependencyDescriptorFromNull(f.vls)
+
+		isDDAvailable := ddAvailable(extensions)
+		if isDDAvailable {
+			if f.vls != nil {
+				f.vls = videolayerselector.NewDependencyDescriptorFromNull(f.vls)
+			} else {
+				f.vls = videolayerselector.NewDependencyDescriptor(f.logger)
+			}
 		} else {
-			f.vls = videolayerselector.NewDependencyDescriptor(f.logger)
+			if f.vls != nil {
+				f.vls = videolayerselector.NewSimulcastFromNull(f.vls)
+			} else {
+				f.vls = videolayerselector.NewSimulcast(f.logger)
+			}
 		}
-		// SVC-TODO: Support for AV1 Simulcast or just single spatial layer - won't have DD in that case
+		// SVC-TODO: Support for AV1 Simulcast
 	}
 }
 

From e922ae5f2319b6d99d9333946aa6927dd26308f3 Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Mon, 4 Sep 2023 22:01:07 +0530
Subject: [PATCH 02/13] Filter out noisy error (#2032)

---
 pkg/rtc/transport.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pkg/rtc/transport.go b/pkg/rtc/transport.go
index 47464e6b9..b671649cd 100644
--- a/pkg/rtc/transport.go
+++ b/pkg/rtc/transport.go
@@ -29,6 +29,7 @@ import (
 	"github.com/pion/interceptor/pkg/gcc"
 	"github.com/pion/interceptor/pkg/twcc"
 	"github.com/pion/rtcp"
+	"github.com/pion/sctp"
 	"github.com/pion/sdp/v3"
 	"github.com/pion/webrtc/v3"
 	"github.com/pkg/errors"
@@ -831,7 +832,9 @@ func (t *PCTransport) CreateDataChannel(label string, dci *webrtc.DataChannelIni
 	}
 
 	dcErrorHandler := func(err error) {
-		t.params.Logger.Errorw(dc.Label()+" data channel error", err)
+		if !errors.Is(err, sctp.ErrResetPacketInStateNotExist) {
+			t.params.Logger.Errorw(dc.Label()+" data channel error", err)
+		}
 	}
 
 	t.lock.Lock()

From 95edad6aab321ebaf6bac4d62ea90fe230144043 Mon Sep 17 00:00:00 2001
From: "renovate[bot]" <29139614+renovate[bot]@users.noreply.github.com>
Date: Mon, 4 Sep 2023 21:16:25 -0700
Subject: [PATCH 03/13] Update actions/checkout action to v4 (#2031)

Generated by renovateBot

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
---
 .github/workflows/buildtest.yaml | 2 +-
 .github/workflows/docker.yaml    | 2 +-
 .github/workflows/release.yaml   | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/buildtest.yaml b/.github/workflows/buildtest.yaml
index 9694df071..192750b6a 100644
--- a/.github/workflows/buildtest.yaml
+++ b/.github/workflows/buildtest.yaml
@@ -25,7 +25,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: shogo82148/actions-setup-redis@v1
         with:
           redis-version: "6.x"
diff --git a/.github/workflows/docker.yaml b/.github/workflows/docker.yaml
index e08c7f1ad..920157bfa 100644
--- a/.github/workflows/docker.yaml
+++ b/.github/workflows/docker.yaml
@@ -25,7 +25,7 @@ jobs:
   docker:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Docker meta
         id: meta
         uses: docker/metadata-action@v4
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 7e0110d0a..4da1bfecc 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -28,7 +28,7 @@ jobs:
   release:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Fetch all tags
         run: git fetch --force --tags
 

From 1590b966869e52f38c992346f95bfad5331e10ea Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Tue, 5 Sep 2023 12:00:00 +0530
Subject: [PATCH 04/13] Need to set reference layer when starting with dummy
 packets. (#2034)

Dummy packets are used at start to trigger Pion's OnTrack.
---
 pkg/sfu/buffer/rtpstats.go | 4 +---
 pkg/sfu/downtrack.go       | 7 +++++--
 pkg/sfu/forwarder.go       | 9 +++++++++
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/pkg/sfu/buffer/rtpstats.go b/pkg/sfu/buffer/rtpstats.go
index 357b50902..9bacf08f7 100644
--- a/pkg/sfu/buffer/rtpstats.go
+++ b/pkg/sfu/buffer/rtpstats.go
@@ -644,8 +644,6 @@ func (r *RTPStats) UpdateFromReceiverReport(rr rtcp.ReceptionReport) (rtt uint32
 	if extHighestSNOverridden < r.sequenceNumber.GetExtendedStart() {
 		// it is possible that the `LastSequenceNumber` in the receiver report is before the starting
 		// sequence number when dummy packets are used to trigger Pion's OnTrack path.
-		r.lastRRTime = time.Now()
-		r.lastRR = rr
 		return
 	}
 
@@ -1211,7 +1209,7 @@ func (r *RTPStats) DeltaInfo(snapshotId uint32) *RTPDeltaInfo {
 }
 
 func (r *RTPStats) DeltaInfoOverridden(snapshotId uint32) *RTPDeltaInfo {
-	if !r.params.IsReceiverReportDriven {
+	if !r.params.IsReceiverReportDriven || r.lastRRTime.IsZero() {
 		return nil
 	}
 
diff --git a/pkg/sfu/downtrack.go b/pkg/sfu/downtrack.go
index f126847bc..53e6f327e 100644
--- a/pkg/sfu/downtrack.go
+++ b/pkg/sfu/downtrack.go
@@ -1786,8 +1786,11 @@ func (d *DownTrack) sendSilentFrameOnMuteForOpus() {
 				AbsSendTimeExtID:   uint8(d.absSendTimeExtID),
 				TransportWideExtID: uint8(d.transportWideExtID),
 				WriteStream:        d.writeStream,
-				Metadata:           sendPacketMetadata{},
-				OnSent:             d.packetSent,
+				Metadata: sendPacketMetadata{
+					// although this is using empty frames, mark as padding as these are used to trigger Pion OnTrack only
+					isPadding: true,
+				},
+				OnSent: d.packetSent,
 			})
 		}
 
diff --git a/pkg/sfu/forwarder.go b/pkg/sfu/forwarder.go
index 567465ce9..b64824ca9 100644
--- a/pkg/sfu/forwarder.go
+++ b/pkg/sfu/forwarder.go
@@ -1454,6 +1454,15 @@ func (f *Forwarder) processSourceSwitch(extPkt *buffer.ExtPacket, layer int32) e
 			"referenceLayerSpatial", f.referenceLayerSpatial,
 		)
 		return nil
+	} else if f.referenceLayerSpatial == buffer.InvalidLayerSpatial {
+		f.referenceLayerSpatial = layer
+		f.logger.Debugw(
+			"catch up forwarding",
+			"sequenceNumber", extPkt.Packet.SequenceNumber,
+			"timestamp", extPkt.Packet.Timestamp,
+			"layer", layer,
+			"referenceLayerSpatial", f.referenceLayerSpatial,
+		)
 	}
 
 	logTransition := func(message string, extExpectedTS, extRefTS, extLastTS uint64, diffSeconds float64) {

From 9b9298b9270d558c9b7cca9cf7d4faf540f4be25 Mon Sep 17 00:00:00 2001
From: cnderrauber <zengjie9004@gmail.com>
Date: Wed, 6 Sep 2023 10:18:20 +0800
Subject: [PATCH 05/13] Add batch i/o to improve throughput (#2033)

* Add batch i/o to improve throughput

* remove empty line

* Solve comments

* Change rtcconfig.UDPPort to PortRange

* Fix test
---
 cmd/server/commands.go               |  5 +++--
 cmd/server/main.go                   |  3 ++-
 config-sample.yaml                   | 11 ++++++++---
 go.mod                               |  2 +-
 go.sum                               |  4 ++--
 pkg/config/config.go                 |  3 +--
 pkg/rtc/participant_internal_test.go |  1 -
 pkg/service/roommanager.go           |  2 +-
 pkg/service/server.go                |  2 +-
 test/integration_helpers.go          |  3 ++-
 10 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/cmd/server/commands.go b/cmd/server/commands.go
index 99499a50f..624af6345 100644
--- a/cmd/server/commands.go
+++ b/cmd/server/commands.go
@@ -55,8 +55,9 @@ func printPorts(c *cli.Context) error {
 	if conf.RTC.TCPPort != 0 {
 		tcpPorts = append(tcpPorts, fmt.Sprintf("%d - ICE/TCP", conf.RTC.TCPPort))
 	}
-	if conf.RTC.UDPPort != 0 {
-		udpPorts = append(udpPorts, fmt.Sprintf("%d - ICE/UDP", conf.RTC.UDPPort))
+	if conf.RTC.UDPPort.Valid() {
+		portStr, _ := conf.RTC.UDPPort.MarshalYAML()
+		udpPorts = append(udpPorts, fmt.Sprintf("%s - ICE/UDP", portStr))
 	} else {
 		udpPorts = append(udpPorts, fmt.Sprintf("%d-%d - ICE/UDP range", conf.RTC.ICEPortRangeStart, conf.RTC.ICEPortRangeEnd))
 	}
diff --git a/cmd/server/main.go b/cmd/server/main.go
index 4d37142fa..149d4cb23 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -29,6 +29,7 @@ import (
 
 	"github.com/livekit/livekit-server/pkg/rtc"
 	"github.com/livekit/livekit-server/pkg/telemetry/prometheus"
+	"github.com/livekit/mediatransportutil/pkg/rtcconfig"
 	"github.com/livekit/protocol/logger"
 
 	"github.com/livekit/livekit-server/pkg/config"
@@ -206,7 +207,7 @@ func getConfig(c *cli.Context) (*config.Config, error) {
 
 	if c.String("config") == "" && c.String("config-body") == "" && conf.Development {
 		// use single port UDP when no config is provided
-		conf.RTC.UDPPort = 7882
+		conf.RTC.UDPPort = rtcconfig.PortRange{Start: 7882}
 		conf.RTC.ICEPortRangeStart = 0
 		conf.RTC.ICEPortRangeEnd = 0
 		logger.Infow("starting in development mode")
diff --git a/config-sample.yaml b/config-sample.yaml
index c800abd16..0b44b11bf 100644
--- a/config-sample.yaml
+++ b/config-sample.yaml
@@ -43,10 +43,10 @@ rtc:
   # that maps to an external one
   use_external_ip: true
   # # when set, LiveKit will attempt to use a UDP mux so all UDP traffic goes through
-  # # a single port. This simplifies deployment, but mux will become an overhead for
-  # # highly trafficked deployments.
+  # # listed port(s). To maximize system performance, we recommend using a range of ports 
+  # # greater or equal to the number of vCPUs on the machine.
   # # port_range_start & end must not be set for this config to take effect
-  # udp_port: 7882
+  # udp_port: 7882-7892
   # # when set to true, server will use a lite ice agent, that will speed up ice connection, but
   # # might cause connect issue if server running behind NAT.
   # use_ice_lite: true
@@ -107,6 +107,11 @@ rtc:
   # # are disabled and clients don't ACK opened peer connections, only reliable, ordered delivery
   # # will be available.
   # strict_acks: true
+  # # enable batch write to merge network write system calls to reduce cpu usage. Outgoing packets
+  # # will be queued until length of queue equal to `batch_size` or time elapsed since last write exceeds `max_flush_interval`.
+  # batch_io:
+  #    batch_size: 128
+  #    max_flush_interval: 2ms
 
 # when enabled, LiveKit will expose prometheus metrics on :6789/metrics
 # prometheus_port: 6789
diff --git a/go.mod b/go.mod
index 6150a1681..b0fb0813d 100644
--- a/go.mod
+++ b/go.mod
@@ -17,7 +17,7 @@ require (
 	github.com/hashicorp/golang-lru/v2 v2.0.5
 	github.com/jxskiss/base62 v1.1.0
 	github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1
-	github.com/livekit/mediatransportutil v0.0.0-20230823131232-12f579dc9af0
+	github.com/livekit/mediatransportutil v0.0.0-20230905070227-1decac7a3c61
 	github.com/livekit/protocol v1.6.2-0.20230828184341-dfb5162c7c86
 	github.com/livekit/psrpc v0.3.3
 	github.com/mackerelio/go-osstat v0.2.4
diff --git a/go.sum b/go.sum
index 071770a9f..1b551c5ea 100644
--- a/go.sum
+++ b/go.sum
@@ -123,8 +123,8 @@ github.com/lithammer/shortuuid/v4 v4.0.0 h1:QRbbVkfgNippHOS8PXDkti4NaWeyYfcBTHtw
 github.com/lithammer/shortuuid/v4 v4.0.0/go.mod h1:Zs8puNcrvf2rV9rTH51ZLLcj7ZXqQI3lv67aw4KiB1Y=
 github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1 h1:jm09419p0lqTkDaKb5iXdynYrzB84ErPPO4LbRASk58=
 github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1/go.mod h1:Rs3MhFwutWhGwmY1VQsygw28z5bWcnEYmS1OG9OxjOQ=
-github.com/livekit/mediatransportutil v0.0.0-20230823131232-12f579dc9af0 h1:cHNvPzn6VHFcsHx8ZC9LwU/4jj22mW3LILrNg/y5A6I=
-github.com/livekit/mediatransportutil v0.0.0-20230823131232-12f579dc9af0/go.mod h1:xirUXW8xnLGmfCwUeAv/nj1VGo1OO1BmgxrYP7jK/14=
+github.com/livekit/mediatransportutil v0.0.0-20230905070227-1decac7a3c61 h1:B03f6QRPP8ESgthh4FdV6RTrW+ukEePMi4uDdAnJxKQ=
+github.com/livekit/mediatransportutil v0.0.0-20230905070227-1decac7a3c61/go.mod h1:njHoM3uTstzLF5N/FyzZ96+TYdJkgeyRbCWBWBiyS2s=
 github.com/livekit/protocol v1.6.2-0.20230828184341-dfb5162c7c86 h1:QEzGhfIOmGdRw17xIldbYzb1MTsYuVfXSqz8FTyfjWQ=
 github.com/livekit/protocol v1.6.2-0.20230828184341-dfb5162c7c86/go.mod h1:/JuO+G/btZ5gNwX2+901L6za3UvVO6DHRXHsv8kkLsU=
 github.com/livekit/psrpc v0.3.3 h1:+lltbuN39IdaynXhLLxRShgYqYsRMWeeXKzv60oqyWo=
diff --git a/pkg/config/config.go b/pkg/config/config.go
index b8dc6044e..e2f165cf8 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -308,7 +308,6 @@ var DefaultConfig = Config{
 		RTCConfig: rtcconfig.RTCConfig{
 			UseExternalIP:     false,
 			TCPPort:           7881,
-			UDPPort:           0,
 			ICEPortRangeStart: 0,
 			ICEPortRangeEnd:   0,
 			STUNServers:       []string{},
@@ -802,7 +801,7 @@ func (conf *Config) updateFromCLI(c *cli.Context, baseFlags []cli.Flag) error {
 		conf.RTC.NodeIP = c.String("node-ip")
 	}
 	if c.IsSet("udp-port") {
-		conf.RTC.UDPPort = uint32(c.Int("udp-port"))
+		conf.RTC.UDPPort = rtcconfig.PortRange{Start: (c.Int("udp-port"))}
 	}
 	if c.IsSet("bind") {
 		conf.BindAddresses = c.StringSlice("bind")
diff --git a/pkg/rtc/participant_internal_test.go b/pkg/rtc/participant_internal_test.go
index 55f773879..1454a27d6 100644
--- a/pkg/rtc/participant_internal_test.go
+++ b/pkg/rtc/participant_internal_test.go
@@ -661,7 +661,6 @@ func newParticipantForTestWithOpts(identity livekit.ParticipantIdentity, opts *p
 	}
 	conf, _ := config.NewConfig("", true, nil, nil)
 	// disable mux, it doesn't play too well with unit test
-	conf.RTC.UDPPort = 0
 	conf.RTC.TCPPort = 0
 	rtcConf, err := NewWebRTCConfig(conf)
 	if err != nil {
diff --git a/pkg/service/roommanager.go b/pkg/service/roommanager.go
index 6393e55be..9f26d1abf 100644
--- a/pkg/service/roommanager.go
+++ b/pkg/service/roommanager.go
@@ -556,7 +556,7 @@ func (r *RoomManager) rtcSessionWorker(room *rtc.Room, participant types.LocalPa
 	_ = r.refreshToken(participant)
 	tokenTicker := time.NewTicker(tokenRefreshInterval)
 	defer tokenTicker.Stop()
-	stateCheckTicker := time.NewTicker(time.Millisecond * 50)
+	stateCheckTicker := time.NewTicker(time.Millisecond * 500)
 	defer stateCheckTicker.Stop()
 	for {
 		select {
diff --git a/pkg/service/server.go b/pkg/service/server.go
index 693315994..c67555614 100644
--- a/pkg/service/server.go
+++ b/pkg/service/server.go
@@ -220,7 +220,7 @@ func (s *LivekitServer) Start() error {
 	if s.config.RTC.TCPPort != 0 {
 		values = append(values, "rtc.portTCP", s.config.RTC.TCPPort)
 	}
-	if !s.config.RTC.ForceTCP && s.config.RTC.UDPPort != 0 {
+	if !s.config.RTC.ForceTCP && s.config.RTC.UDPPort.Valid() {
 		values = append(values, "rtc.portUDP", s.config.RTC.UDPPort)
 	} else {
 		values = append(values,
diff --git a/test/integration_helpers.go b/test/integration_helpers.go
index 633c6a934..7a11b353e 100644
--- a/test/integration_helpers.go
+++ b/test/integration_helpers.go
@@ -31,6 +31,7 @@ import (
 	"github.com/livekit/livekit-server/pkg/telemetry/prometheus"
 	"github.com/livekit/livekit-server/pkg/testutils"
 	testclient "github.com/livekit/livekit-server/test/client"
+	"github.com/livekit/mediatransportutil/pkg/rtcconfig"
 	"github.com/livekit/protocol/auth"
 	"github.com/livekit/protocol/livekit"
 	"github.com/livekit/protocol/logger"
@@ -178,7 +179,7 @@ func createMultiNodeServer(nodeID string, port uint32) *service.LivekitServer {
 		panic(fmt.Sprintf("could not create config: %v", err))
 	}
 	conf.Port = port
-	conf.RTC.UDPPort = port + 1
+	conf.RTC.UDPPort = rtcconfig.PortRange{Start: int(port) + 1}
 	conf.RTC.TCPPort = port + 2
 	conf.Redis.Address = "localhost:6379"
 	conf.Keys = map[string]string{testApiKey: testApiSecret}

From c122c20f49d3ff6cf0d3bce6cfdcc6646c6090c9 Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Wed, 6 Sep 2023 08:27:16 +0530
Subject: [PATCH 06/13] Do not re-pause a paused track. (#2037)

---
 pkg/sfu/forwarder.go                       | 10 ++++++++--
 pkg/sfu/streamallocator/streamallocator.go |  4 ++--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/pkg/sfu/forwarder.go b/pkg/sfu/forwarder.go
index b64824ca9..0b7320991 100644
--- a/pkg/sfu/forwarder.go
+++ b/pkg/sfu/forwarder.go
@@ -811,7 +811,7 @@ func (f *Forwarder) ProvisionalAllocateGetCooperativeTransition(allowOvershoot b
 	if f.provisional.muted || f.provisional.pubMuted {
 		f.provisional.allocatedLayer = buffer.InvalidLayer
 		return VideoTransition{
-			From:           f.vls.GetTarget(),
+			From:           existingTargetLayer,
 			To:             f.provisional.allocatedLayer,
 			BandwidthDelta: -getBandwidthNeeded(f.provisional.Bitrates, existingTargetLayer, f.lastAllocation.BandwidthRequested),
 		}
@@ -1300,12 +1300,18 @@ func (f *Forwarder) Pause(availableLayers []int32, brs Bitrates) VideoAllocation
 	f.lock.Lock()
 	defer f.lock.Unlock()
 
+	existingTargetLayer := f.vls.GetTarget()
+	if !existingTargetLayer.IsValid() {
+		// already paused
+		return f.lastAllocation
+	}
+
 	maxLayer := f.vls.GetMax()
 	maxSeenLayer := f.vls.GetMaxSeen()
 	optimalBandwidthNeeded := getOptimalBandwidthNeeded(f.muted, f.pubMuted, maxSeenLayer.Spatial, brs, maxLayer)
 	alloc := VideoAllocation{
 		BandwidthRequested:  0,
-		BandwidthDelta:      0 - getBandwidthNeeded(brs, f.vls.GetTarget(), f.lastAllocation.BandwidthRequested),
+		BandwidthDelta:      0 - getBandwidthNeeded(brs, existingTargetLayer, f.lastAllocation.BandwidthRequested),
 		Bitrates:            brs,
 		BandwidthNeeded:     optimalBandwidthNeeded,
 		TargetLayer:         buffer.InvalidLayer,
diff --git a/pkg/sfu/streamallocator/streamallocator.go b/pkg/sfu/streamallocator/streamallocator.go
index f9baf7e5c..91ad018cc 100644
--- a/pkg/sfu/streamallocator/streamallocator.go
+++ b/pkg/sfu/streamallocator/streamallocator.go
@@ -883,8 +883,8 @@ func (s *StreamAllocator) allocateTrack(track *Track) {
 		return
 	}
 
-	// already streaming at some layer and transition is not requesting any change, i. e. BandwidthDelta == 0
-	if transition.From.IsValid() && transition.BandwidthDelta == 0 {
+	// a no-op transition
+	if transition.From == transition.To {
 		return
 	}
 

From b38b51dad8bebfa81cb267a268d087c9fd04dd6b Mon Sep 17 00:00:00 2001
From: Trey Hakanson <treyhakanson@gmail.com>
Date: Tue, 5 Sep 2023 20:07:52 -0700
Subject: [PATCH 07/13] Integrate updated TWCC responder (#2038)

Integrates the updated TWCC responder based on `pion/interceptor` from
https://github.com/livekit/mediatransportutil/pull/25
---
 go.mod                 |  6 +++---
 go.sum                 | 10 ++++++----
 pkg/rtc/participant.go |  4 ++--
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/go.mod b/go.mod
index b0fb0813d..dc465c9d7 100644
--- a/go.mod
+++ b/go.mod
@@ -17,7 +17,7 @@ require (
 	github.com/hashicorp/golang-lru/v2 v2.0.5
 	github.com/jxskiss/base62 v1.1.0
 	github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1
-	github.com/livekit/mediatransportutil v0.0.0-20230905070227-1decac7a3c61
+	github.com/livekit/mediatransportutil v0.0.0-20230905085142-e1fcf8eae216
 	github.com/livekit/protocol v1.6.2-0.20230828184341-dfb5162c7c86
 	github.com/livekit/psrpc v0.3.3
 	github.com/mackerelio/go-osstat v0.2.4
@@ -27,7 +27,7 @@ require (
 	github.com/olekukonko/tablewriter v0.0.5
 	github.com/pion/dtls/v2 v2.2.7
 	github.com/pion/ice/v2 v2.3.11
-	github.com/pion/interceptor v0.1.17
+	github.com/pion/interceptor v0.1.18
 	github.com/pion/rtcp v1.2.10
 	github.com/pion/rtp v1.8.1
 	github.com/pion/sctp v1.8.7
@@ -97,7 +97,7 @@ require (
 	golang.org/x/crypto v0.12.0 // indirect
 	golang.org/x/mod v0.12.0 // indirect
 	golang.org/x/net v0.14.0 // indirect
-	golang.org/x/sys v0.11.0 // indirect
+	golang.org/x/sys v0.12.0 // indirect
 	golang.org/x/text v0.12.0 // indirect
 	golang.org/x/tools v0.12.1-0.20230815132531-74c255bcf846 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20230815205213-6bfd019c3878 // indirect
diff --git a/go.sum b/go.sum
index 1b551c5ea..40045977d 100644
--- a/go.sum
+++ b/go.sum
@@ -123,8 +123,8 @@ github.com/lithammer/shortuuid/v4 v4.0.0 h1:QRbbVkfgNippHOS8PXDkti4NaWeyYfcBTHtw
 github.com/lithammer/shortuuid/v4 v4.0.0/go.mod h1:Zs8puNcrvf2rV9rTH51ZLLcj7ZXqQI3lv67aw4KiB1Y=
 github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1 h1:jm09419p0lqTkDaKb5iXdynYrzB84ErPPO4LbRASk58=
 github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1/go.mod h1:Rs3MhFwutWhGwmY1VQsygw28z5bWcnEYmS1OG9OxjOQ=
-github.com/livekit/mediatransportutil v0.0.0-20230905070227-1decac7a3c61 h1:B03f6QRPP8ESgthh4FdV6RTrW+ukEePMi4uDdAnJxKQ=
-github.com/livekit/mediatransportutil v0.0.0-20230905070227-1decac7a3c61/go.mod h1:njHoM3uTstzLF5N/FyzZ96+TYdJkgeyRbCWBWBiyS2s=
+github.com/livekit/mediatransportutil v0.0.0-20230905085142-e1fcf8eae216 h1:gwGhhhx+vUXR1dZqpKBautkx7qJAXvgCdQxgluBiUqc=
+github.com/livekit/mediatransportutil v0.0.0-20230905085142-e1fcf8eae216/go.mod h1:+WIOYwiBMive5T81V8B2wdAc2zQNRjNQiJIcPxMTILY=
 github.com/livekit/protocol v1.6.2-0.20230828184341-dfb5162c7c86 h1:QEzGhfIOmGdRw17xIldbYzb1MTsYuVfXSqz8FTyfjWQ=
 github.com/livekit/protocol v1.6.2-0.20230828184341-dfb5162c7c86/go.mod h1:/JuO+G/btZ5gNwX2+901L6za3UvVO6DHRXHsv8kkLsU=
 github.com/livekit/psrpc v0.3.3 h1:+lltbuN39IdaynXhLLxRShgYqYsRMWeeXKzv60oqyWo=
@@ -188,8 +188,9 @@ github.com/pion/dtls/v2 v2.2.7/go.mod h1:8WiMkebSHFD0T+dIU+UeBaoV7kDhOW5oDCzZ7WZ
 github.com/pion/ice/v2 v2.3.10/go.mod h1:hHGCibDfmXGqukayQw979xEctASp2Pe5Oe0iDU8pRus=
 github.com/pion/ice/v2 v2.3.11 h1:rZjVmUwyT55cmN8ySMpL7rsS8KYsJERsrxJLLxpKhdw=
 github.com/pion/ice/v2 v2.3.11/go.mod h1:hPcLC3kxMa+JGRzMHqQzjoSj3xtE9F+eoncmXLlCL4E=
-github.com/pion/interceptor v0.1.17 h1:prJtgwFh/gB8zMqGZoOgJPHivOwVAp61i2aG61Du/1w=
 github.com/pion/interceptor v0.1.17/go.mod h1:SY8kpmfVBvrbUzvj2bsXz7OJt5JvmVNZ+4Kjq7FcwrI=
+github.com/pion/interceptor v0.1.18 h1:Hk26334NUQeUcJNR27YHYKT+sWNhhegQ9KFz5Nn6yMQ=
+github.com/pion/interceptor v0.1.18/go.mod h1:tpvvF4cPM6NGxFA1DUMbhabzQBxdWMATDGEUYOR9x6I=
 github.com/pion/logging v0.2.2 h1:M9+AIj/+pxNsDfAT64+MAVgJO0rsyLnoJKCqf//DoeY=
 github.com/pion/logging v0.2.2/go.mod h1:k0/tDVsRCX2Mb2ZEmTqNa7CWsQPc+YYCB7Q+5pahoms=
 github.com/pion/mdns v0.0.7/go.mod h1:4iP2UbeFhLI/vWju/bw6ZfwjJzk0z8DNValjGxR/dD8=
@@ -382,8 +383,9 @@ golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.9.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
 golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.1.0/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
diff --git a/pkg/rtc/participant.go b/pkg/rtc/participant.go
index 005ff5141..6a7ccf919 100644
--- a/pkg/rtc/participant.go
+++ b/pkg/rtc/participant.go
@@ -1713,8 +1713,8 @@ func (p *ParticipantImpl) mediaTrackReceived(track *webrtc.TrackRemote, rtpRecei
 	ssrc := uint32(track.SSRC())
 	if p.twcc == nil {
 		p.twcc = twcc.NewTransportWideCCResponder(ssrc)
-		p.twcc.OnFeedback(func(pkt rtcp.RawPacket) {
-			p.postRtcp([]rtcp.Packet{&pkt})
+		p.twcc.OnFeedback(func(pkts []rtcp.Packet) {
+			p.postRtcp(pkts)
 		})
 	}
 	p.pendingTracksLock.Unlock()

From 75ffb25d772440a8f64fe94836d330cb2e9cbbfd Mon Sep 17 00:00:00 2001
From: cnderrauber <zengjie9004@gmail.com>
Date: Wed, 6 Sep 2023 14:17:49 +0800
Subject: [PATCH 08/13] Parse PortRange of UDPPort from cli flag (#2039)

---
 cmd/server/main.go   | 4 ++--
 go.mod               | 2 +-
 go.sum               | 2 ++
 pkg/config/config.go | 2 +-
 4 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/cmd/server/main.go b/cmd/server/main.go
index 149d4cb23..c53f01640 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -71,9 +71,9 @@ var baseFlags = []cli.Flag{
 		Usage:   "IP address of the current node, used to advertise to clients. Automatically determined by default",
 		EnvVars: []string{"NODE_IP"},
 	},
-	&cli.IntFlag{
+	&cli.StringFlag{
 		Name:    "udp-port",
-		Usage:   "Single UDP port to use for WebRTC traffic",
+		Usage:   "UDP port(s) to use for WebRTC traffic",
 		EnvVars: []string{"UDP_PORT"},
 	},
 	&cli.StringFlag{
diff --git a/go.mod b/go.mod
index dc465c9d7..69a3398cd 100644
--- a/go.mod
+++ b/go.mod
@@ -17,7 +17,7 @@ require (
 	github.com/hashicorp/golang-lru/v2 v2.0.5
 	github.com/jxskiss/base62 v1.1.0
 	github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1
-	github.com/livekit/mediatransportutil v0.0.0-20230905085142-e1fcf8eae216
+	github.com/livekit/mediatransportutil v0.0.0-20230906055425-e81fd5f6fb3f
 	github.com/livekit/protocol v1.6.2-0.20230828184341-dfb5162c7c86
 	github.com/livekit/psrpc v0.3.3
 	github.com/mackerelio/go-osstat v0.2.4
diff --git a/go.sum b/go.sum
index 40045977d..b43ba3bb2 100644
--- a/go.sum
+++ b/go.sum
@@ -125,6 +125,8 @@ github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1 h1:jm09419p0lqTkD
 github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1/go.mod h1:Rs3MhFwutWhGwmY1VQsygw28z5bWcnEYmS1OG9OxjOQ=
 github.com/livekit/mediatransportutil v0.0.0-20230905085142-e1fcf8eae216 h1:gwGhhhx+vUXR1dZqpKBautkx7qJAXvgCdQxgluBiUqc=
 github.com/livekit/mediatransportutil v0.0.0-20230905085142-e1fcf8eae216/go.mod h1:+WIOYwiBMive5T81V8B2wdAc2zQNRjNQiJIcPxMTILY=
+github.com/livekit/mediatransportutil v0.0.0-20230906055425-e81fd5f6fb3f h1:b4ri7hQESRSzJWzXXcmANG2hJ4HTj5LM01Ekm8lnQmg=
+github.com/livekit/mediatransportutil v0.0.0-20230906055425-e81fd5f6fb3f/go.mod h1:+WIOYwiBMive5T81V8B2wdAc2zQNRjNQiJIcPxMTILY=
 github.com/livekit/protocol v1.6.2-0.20230828184341-dfb5162c7c86 h1:QEzGhfIOmGdRw17xIldbYzb1MTsYuVfXSqz8FTyfjWQ=
 github.com/livekit/protocol v1.6.2-0.20230828184341-dfb5162c7c86/go.mod h1:/JuO+G/btZ5gNwX2+901L6za3UvVO6DHRXHsv8kkLsU=
 github.com/livekit/psrpc v0.3.3 h1:+lltbuN39IdaynXhLLxRShgYqYsRMWeeXKzv60oqyWo=
diff --git a/pkg/config/config.go b/pkg/config/config.go
index e2f165cf8..1f3ab2aba 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -801,7 +801,7 @@ func (conf *Config) updateFromCLI(c *cli.Context, baseFlags []cli.Flag) error {
 		conf.RTC.NodeIP = c.String("node-ip")
 	}
 	if c.IsSet("udp-port") {
-		conf.RTC.UDPPort = rtcconfig.PortRange{Start: (c.Int("udp-port"))}
+		conf.RTC.UDPPort.UnmarshalString(c.String("udp-port"))
 	}
 	if c.IsSet("bind") {
 		conf.BindAddresses = c.StringSlice("bind")

From ce4554beb1d0a53c763e754c9b590e16ab46aff9 Mon Sep 17 00:00:00 2001
From: "renovate[bot]" <29139614+renovate[bot]@users.noreply.github.com>
Date: Tue, 5 Sep 2023 23:19:42 -0700
Subject: [PATCH 09/13] Update go deps (#1991)

Generated by renovateBot

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
---
 go.mod | 17 +++++++++--------
 go.sum | 31 ++++++++++++++++++-------------
 2 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/go.mod b/go.mod
index 69a3398cd..c4c021f8d 100644
--- a/go.mod
+++ b/go.mod
@@ -14,7 +14,7 @@ require (
 	github.com/google/wire v0.5.0
 	github.com/gorilla/websocket v1.5.0
 	github.com/hashicorp/go-version v1.6.0
-	github.com/hashicorp/golang-lru/v2 v2.0.5
+	github.com/hashicorp/golang-lru/v2 v2.0.6
 	github.com/jxskiss/base62 v1.1.0
 	github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1
 	github.com/livekit/mediatransportutil v0.0.0-20230906055425-e81fd5f6fb3f
@@ -38,15 +38,15 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.16.0
 	github.com/redis/go-redis/v9 v9.1.0
-	github.com/rs/cors v1.9.0
+	github.com/rs/cors v1.10.0
 	github.com/stretchr/testify v1.8.4
 	github.com/thoas/go-funk v0.9.3
 	github.com/twitchtv/twirp v8.1.3+incompatible
-	github.com/ua-parser/uap-go v0.0.0-20230823192112-f8d2018c34f3
+	github.com/ua-parser/uap-go v0.0.0-20230823213814-f77b3e91e9dc
 	github.com/urfave/cli/v2 v2.25.7
 	github.com/urfave/negroni/v3 v3.0.0
 	go.uber.org/atomic v1.11.0
-	golang.org/x/exp v0.0.0-20230817173708-d852ddb80c63
+	golang.org/x/exp v0.0.0-20230905200255-921286631fa9
 	golang.org/x/sync v0.3.0
 	google.golang.org/protobuf v1.31.0
 	gopkg.in/yaml.v3 v3.0.1
@@ -68,6 +68,7 @@ require (
 	github.com/google/uuid v1.3.1 // indirect
 	github.com/hashicorp/go-cleanhttp v0.5.2 // indirect
 	github.com/hashicorp/go-retryablehttp v0.7.4 // indirect
+	github.com/hashicorp/golang-lru v0.5.4 // indirect
 	github.com/josharian/native v1.1.0 // indirect
 	github.com/klauspost/compress v1.16.7 // indirect
 	github.com/klauspost/cpuid/v2 v2.0.9 // indirect
@@ -94,12 +95,12 @@ require (
 	github.com/zeebo/xxh3 v1.0.2 // indirect
 	go.uber.org/multierr v1.10.0 // indirect
 	go.uber.org/zap v1.25.0 // indirect
-	golang.org/x/crypto v0.12.0 // indirect
+	golang.org/x/crypto v0.13.0 // indirect
 	golang.org/x/mod v0.12.0 // indirect
-	golang.org/x/net v0.14.0 // indirect
+	golang.org/x/net v0.15.0 // indirect
 	golang.org/x/sys v0.12.0 // indirect
-	golang.org/x/text v0.12.0 // indirect
-	golang.org/x/tools v0.12.1-0.20230815132531-74c255bcf846 // indirect
+	golang.org/x/text v0.13.0 // indirect
+	golang.org/x/tools v0.13.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20230815205213-6bfd019c3878 // indirect
 	google.golang.org/grpc v1.57.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
diff --git a/go.sum b/go.sum
index b43ba3bb2..b9c1c5afd 100644
--- a/go.sum
+++ b/go.sum
@@ -88,8 +88,10 @@ github.com/hashicorp/go-retryablehttp v0.7.4 h1:ZQgVdpTdAL7WpMIwLzCfbalOcSUdkDZn
 github.com/hashicorp/go-retryablehttp v0.7.4/go.mod h1:Jy/gPYAdjqffZ/yFGCFV2doI5wjtH1ewM9u8iYVjtX8=
 github.com/hashicorp/go-version v1.6.0 h1:feTTfFNnjP967rlCxM/I9g701jU+RN74YKx2mOkIeek=
 github.com/hashicorp/go-version v1.6.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
-github.com/hashicorp/golang-lru/v2 v2.0.5 h1:wW7h1TG88eUIJ2i69gaE3uNVtEPIagzhGvHgwfx2Vm4=
-github.com/hashicorp/golang-lru/v2 v2.0.5/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
+github.com/hashicorp/golang-lru v0.5.4 h1:YDjusn29QI/Das2iO9M0BHnIbxPeyuCHsjMW+lJfyTc=
+github.com/hashicorp/golang-lru v0.5.4/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
+github.com/hashicorp/golang-lru/v2 v2.0.6 h1:3xi/Cafd1NaoEnS/yDssIiuVeDVywU0QdFGl3aQaQHM=
+github.com/hashicorp/golang-lru/v2 v2.0.6/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/josharian/native v0.0.0-20200817173448-b6b71def0850/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
 github.com/josharian/native v1.0.0/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
@@ -244,8 +246,8 @@ github.com/redis/go-redis/v9 v9.1.0 h1:137FnGdk+EQdCbye1FW+qOEcY5S+SpY9T0Niuqvtf
 github.com/redis/go-redis/v9 v9.1.0/go.mod h1:urWj3He21Dj5k4TK1y59xH8Uj6ATueP8AH1cY3lZl4c=
 github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
-github.com/rs/cors v1.9.0 h1:l9HGsTsHJcvW14Nk7J9KFz8bzeAWXn3CG6bgt7LsrAE=
-github.com/rs/cors v1.9.0/go.mod h1:XyqrcTp5zjWr1wsJ8PIRZssZ8b/WMcMf71DJnit4EMU=
+github.com/rs/cors v1.10.0 h1:62NOS1h+r8p1mW6FM0FSB0exioXLhd/sh15KpjWBZ+8=
+github.com/rs/cors v1.10.0/go.mod h1:XyqrcTp5zjWr1wsJ8PIRZssZ8b/WMcMf71DJnit4EMU=
 github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/sclevine/agouti v3.0.0+incompatible/go.mod h1:b4WX9W9L1sfQKXeJf1mUTLZKJ48R1S7H23Ji7oFO5Bw=
@@ -268,8 +270,8 @@ github.com/thoas/go-funk v0.9.3 h1:7+nAEx3kn5ZJcnDm2Bh23N2yOtweO14bi//dvRtgLpw=
 github.com/thoas/go-funk v0.9.3/go.mod h1:+IWnUfUmFO1+WVYQWQtIJHeRRdaIyyYglZN7xzUPe4Q=
 github.com/twitchtv/twirp v8.1.3+incompatible h1:+F4TdErPgSUbMZMwp13Q/KgDVuI7HJXP61mNV3/7iuU=
 github.com/twitchtv/twirp v8.1.3+incompatible/go.mod h1:RRJoFSAmTEh2weEqWtpPE3vFK5YBhA6bqp2l1kfCC5A=
-github.com/ua-parser/uap-go v0.0.0-20230823192112-f8d2018c34f3 h1:YsXCA7ZdgFMgwDpNpYj4y2WPRVrOVVDAkQlFc477T54=
-github.com/ua-parser/uap-go v0.0.0-20230823192112-f8d2018c34f3/go.mod h1:OBcG9bn7sHtXgarhUEb3OfCnNsgtGnkVf41ilSZ3K3E=
+github.com/ua-parser/uap-go v0.0.0-20230823213814-f77b3e91e9dc h1:iT5lwxf894PiMq7cnMMQg/7VOD1pxmu//gQuHWAFy4s=
+github.com/ua-parser/uap-go v0.0.0-20230823213814-f77b3e91e9dc/go.mod h1:BUbeWZiieNxAuuADTBNb3/aeje6on3DhU3rpWsQSB1E=
 github.com/urfave/cli/v2 v2.25.7 h1:VAzn5oq403l5pHjc4OhD54+XGO9cdKVL/7lDjF+iKUs=
 github.com/urfave/cli/v2 v2.25.7/go.mod h1:8qnjx1vcq5s2/wpsqoZFndg2CE5tNFyrTvS6SinrnYQ=
 github.com/urfave/negroni/v3 v3.0.0 h1:Vo8CeZfu1lFR9gW8GnAb6dOGCJyijfil9j/jKKc/JhU=
@@ -296,10 +298,11 @@ golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5y
 golang.org/x/crypto v0.8.0/go.mod h1:mRqEX+O9/h5TFCrQhkgjo2yKi0yYA+9ecGkdQoHrywE=
 golang.org/x/crypto v0.10.0/go.mod h1:o4eNf7Ede1fv+hwOwZsTHl9EsPFO6q6ZvYR8vYfY45I=
 golang.org/x/crypto v0.11.0/go.mod h1:xgJhtzW8F9jGdVFWZESrid1U1bjeNy4zgy5cRr/CIio=
-golang.org/x/crypto v0.12.0 h1:tFM/ta59kqch6LlvYnPa0yx5a83cL2nHflFhYKvv9Yk=
 golang.org/x/crypto v0.12.0/go.mod h1:NF0Gs7EO5K4qLn+Ylc+fih8BSTeIjAP05siRnAh98yw=
-golang.org/x/exp v0.0.0-20230817173708-d852ddb80c63 h1:m64FZMko/V45gv0bNmrNYoDEq8U5YUhetc9cBWKS1TQ=
-golang.org/x/exp v0.0.0-20230817173708-d852ddb80c63/go.mod h1:0v4NqG35kSWCMzLaMeX+IQrlSnVE/bqGSyC2cz/9Le8=
+golang.org/x/crypto v0.13.0 h1:mvySKfSWJ+UKUii46M40LOvyWfN0s2U+46/jDd0e6Ck=
+golang.org/x/crypto v0.13.0/go.mod h1:y6Z2r+Rw4iayiXXAIxJIDAJ1zMW4yaTpebo8fPOliYc=
+golang.org/x/exp v0.0.0-20230905200255-921286631fa9 h1:GoHiUyI/Tp2nVkLI2mCxVkOjsbSXD66ic0XW0js0R9g=
+golang.org/x/exp v0.0.0-20230905200255-921286631fa9/go.mod h1:S2oDrQGGwySpoQPVqRShND87VCbxmc6bL1Yd2oYrm6k=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
@@ -333,8 +336,9 @@ golang.org/x/net v0.9.0/go.mod h1:d48xBJpPfHeWQsugry2m+kC02ZBRGRgulfHnEXEuWns=
 golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
 golang.org/x/net v0.11.0/go.mod h1:2L/ixqYpgIVXmeoSA/4Lu7BzTG4KIyPIryS4IsOd1oQ=
 golang.org/x/net v0.13.0/go.mod h1:zEVYFnQC7m/vmpQFELhcD1EWkZlX69l4oqgmer6hfKA=
-golang.org/x/net v0.14.0 h1:BONx9s002vGdD9umnlX1Po8vOZmrgH34qlHcD1MfK14=
 golang.org/x/net v0.14.0/go.mod h1:PpSgVXXLK0OxS0F31C1/tv6XNguvCrnXIDrFMspZIUI=
+golang.org/x/net v0.15.0 h1:ugBLEUaxABaB5AJqW9enI0ACdci2RUd4eP51NTBvuJ8=
+golang.org/x/net v0.15.0/go.mod h1:idbUs1IY1+zTqbi8yxTbhexhEEk5ur9LInksu6HrEpk=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -410,8 +414,9 @@ golang.org/x/text v0.8.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/text v0.10.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/text v0.11.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
-golang.org/x/text v0.12.0 h1:k+n5B8goJNdU7hSvEtMUz3d1Q6D/XW4COJSJR6fN0mc=
 golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
+golang.org/x/text v0.13.0 h1:ablQoSUd0tRdKxZewP80B+BaqeKJuVhuRxj/dkrun3k=
+golang.org/x/text v0.13.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/time v0.3.0 h1:rg5rLMjNzMS1RkNLzCG38eapWhnYLFYXDXj2gOlr8j4=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190422233926-fe54fb35175b/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
@@ -419,8 +424,8 @@ golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtn
 golang.org/x/tools v0.0.0-20201224043029-2b0845dc783e/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
-golang.org/x/tools v0.12.1-0.20230815132531-74c255bcf846 h1:Vve/L0v7CXXuxUmaMGIEK/dEeq7uiqb5qBgQrZzIE7E=
-golang.org/x/tools v0.12.1-0.20230815132531-74c255bcf846/go.mod h1:Sc0INKfu04TlqNoRA1hgpFZbhYXHPr4V5DzpSBTPqQM=
+golang.org/x/tools v0.13.0 h1:Iey4qkscZuv0VvIt8E0neZjtPVQFSc870HQ448QgEmQ=
+golang.org/x/tools v0.13.0/go.mod h1:HvlwmtVNQAhOuCjW7xxvovg8wbNq7LwfXh/k7wXUl58=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

From 0fffaf32825dae53d46f9d6dddf29d8d53c46960 Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Thu, 7 Sep 2023 13:25:09 +0530
Subject: [PATCH 10/13] Some small optimisations (#2042)

* WIP commit

* WIP commit

* WIP commit

* Revert unintended delete
---
 pkg/sfu/downtrack.go |  23 +++++----
 pkg/sfu/forwarder.go |   6 +--
 pkg/sfu/rtpmunger.go | 108 ++++++++++++++++++++++++-------------------
 3 files changed, 77 insertions(+), 60 deletions(-)

diff --git a/pkg/sfu/downtrack.go b/pkg/sfu/downtrack.go
index 53e6f327e..d48b98460 100644
--- a/pkg/sfu/downtrack.go
+++ b/pkg/sfu/downtrack.go
@@ -237,6 +237,7 @@ type DownTrack struct {
 	isClosed             atomic.Bool
 	connected            atomic.Bool
 	bindAndConnectedOnce atomic.Bool
+	writable             atomic.Bool
 
 	rtpStats *buffer.RTPStats
 
@@ -420,7 +421,7 @@ func (d *DownTrack) Bind(t webrtc.TrackLocalContext) (webrtc.RTPCodecParameters,
 	d.forwarder.DetermineCodec(d.codec, d.params.Receiver.HeaderExtensions())
 
 	d.params.Logger.Debugw("downtrack bound")
-	d.onBindAndConnected()
+	d.onBindAndConnectedChange()
 
 	return codec, nil
 }
@@ -429,6 +430,7 @@ func (d *DownTrack) Bind(t webrtc.TrackLocalContext) (webrtc.RTPCodecParameters,
 // because a track has been stopped.
 func (d *DownTrack) Unbind(_ webrtc.TrackLocalContext) error {
 	d.bound.Store(false)
+	d.onBindAndConnectedChange()
 	return nil
 }
 
@@ -600,7 +602,7 @@ func (d *DownTrack) keyFrameRequester(generation uint32, layer int32) {
 			return
 		}
 
-		if d.connected.Load() {
+		if d.writable.Load() {
 			d.params.Logger.Debugw("sending PLI for layer lock", "generation", generation, "layer", layer)
 			d.params.Receiver.SendPLI(layer, false)
 			d.rtpStats.UpdateLayerLockPliAndTime(1)
@@ -608,7 +610,7 @@ func (d *DownTrack) keyFrameRequester(generation uint32, layer int32) {
 
 		<-ticker.C
 
-		if generation != d.keyFrameRequestGeneration.Load() || !d.bound.Load() {
+		if generation != d.keyFrameRequestGeneration.Load() || !d.writable.Load() {
 			return
 		}
 	}
@@ -643,7 +645,7 @@ func (d *DownTrack) maxLayerNotifierWorker() {
 
 // WriteRTP writes an RTP Packet to the DownTrack
 func (d *DownTrack) WriteRTP(extPkt *buffer.ExtPacket, layer int32) error {
-	if !d.bound.Load() || !d.connected.Load() {
+	if !d.writable.Load() {
 		return nil
 	}
 
@@ -720,6 +722,10 @@ func (d *DownTrack) WriteRTP(extPkt *buffer.ExtPacket, layer int32) error {
 // WritePaddingRTP tries to write as many padding only RTP packets as necessary
 // to satisfy given size to the DownTrack
 func (d *DownTrack) WritePaddingRTP(bytesToSend int, paddingOnMute bool, forceMarker bool) int {
+	if !d.writable.Load() {
+		return 0
+	}
+
 	if !d.rtpStats.IsActive() && !paddingOnMute {
 		return 0
 	}
@@ -1224,8 +1230,8 @@ func (d *DownTrack) CreateSenderReport() *rtcp.SenderReport {
 func (d *DownTrack) writeBlankFrameRTP(duration float32, generation uint32) chan struct{} {
 	done := make(chan struct{})
 	go func() {
-		// don't send if nothing has been sent
-		if !d.rtpStats.IsActive() {
+		// don't send if not writable OR nothing has been sent
+		if !d.writable.Load() || !d.rtpStats.IsActive() {
 			close(done)
 			return
 		}
@@ -1492,7 +1498,7 @@ func (d *DownTrack) handleRTCP(bytes []byte) {
 
 func (d *DownTrack) SetConnected() {
 	if !d.connected.Swap(true) {
-		d.onBindAndConnected()
+		d.onBindAndConnectedChange()
 	}
 }
 
@@ -1710,7 +1716,7 @@ func (d *DownTrack) GetAndResetBytesSent() (uint32, uint32) {
 	return d.bytesSent.Swap(0), d.bytesRetransmitted.Swap(0)
 }
 
-func (d *DownTrack) onBindAndConnected() {
+func (d *DownTrack) onBindAndConnectedChange() {
 	if d.connected.Load() && d.bound.Load() && !d.bindAndConnectedOnce.Swap(true) {
 		if d.kind == webrtc.RTPCodecTypeVideo {
 			_, layer := d.forwarder.CheckSync()
@@ -1723,6 +1729,7 @@ func (d *DownTrack) onBindAndConnected() {
 			go d.sendPaddingOnMute()
 		}
 	}
+	d.writable.Store(d.connected.Load() && d.bound.Load())
 }
 
 func (d *DownTrack) sendPaddingOnMute() {
diff --git a/pkg/sfu/forwarder.go b/pkg/sfu/forwarder.go
index 0b7320991..49c56bc2f 100644
--- a/pkg/sfu/forwarder.go
+++ b/pkg/sfu/forwarder.go
@@ -1622,9 +1622,6 @@ func (f *Forwarder) processSourceSwitch(extPkt *buffer.ExtPacket, layer int32) e
 
 // should be called with lock held
 func (f *Forwarder) getTranslationParamsCommon(extPkt *buffer.ExtPacket, layer int32, tp *TranslationParams) (*TranslationParams, error) {
-	if tp == nil {
-		tp = &TranslationParams{}
-	}
 	if f.lastSSRC != extPkt.Packet.SSRC {
 		if err := f.processSourceSwitch(extPkt, layer); err != nil {
 			tp.shouldDrop = true
@@ -1649,7 +1646,7 @@ func (f *Forwarder) getTranslationParamsCommon(extPkt *buffer.ExtPacket, layer i
 
 // should be called with lock held
 func (f *Forwarder) getTranslationParamsAudio(extPkt *buffer.ExtPacket, layer int32) (*TranslationParams, error) {
-	return f.getTranslationParamsCommon(extPkt, layer, nil)
+	return f.getTranslationParamsCommon(extPkt, layer, &TranslationParams{})
 }
 
 // should be called with lock held
@@ -1661,7 +1658,6 @@ func (f *Forwarder) getTranslationParamsVideo(extPkt *buffer.ExtPacket, layer in
 	}
 
 	tp := &TranslationParams{}
-
 	if !f.vls.GetTarget().IsValid() {
 		// stream is paused by streamallocator
 		tp.shouldDrop = true
diff --git a/pkg/sfu/rtpmunger.go b/pkg/sfu/rtpmunger.go
index c0ce6ae6a..8176cfe81 100644
--- a/pkg/sfu/rtpmunger.go
+++ b/pkg/sfu/rtpmunger.go
@@ -72,9 +72,12 @@ type RTPMunger struct {
 
 	extLastSN       uint64
 	extSecondLastSN uint64
-	extLastTS       uint64
-	tsOffset        uint64
-	lastMarker      bool
+	snOffset        uint64
+
+	extLastTS uint64
+	tsOffset  uint64
+
+	lastMarker bool
 
 	extRtxGateSn      uint64
 	isInRtxGateRegion bool
@@ -88,12 +91,11 @@ func NewRTPMunger(logger logger.Logger) *RTPMunger {
 }
 
 func (r *RTPMunger) DebugInfo() map[string]interface{} {
-	snOffset, _ := r.snRangeMap.GetValue(r.extHighestIncomingSN + 1)
 	return map[string]interface{}{
 		"ExtHighestIncomingSN": r.extHighestIncomingSN,
 		"ExtLastSN":            r.extLastSN,
 		"ExtSecondLastSN":      r.extSecondLastSN,
-		"SNOffset":             snOffset,
+		"SNOffset":             r.snOffset,
 		"ExtLastTS":            r.extLastTS,
 		"TSOffset":             r.tsOffset,
 		"LastMarker":           r.lastMarker,
@@ -116,14 +118,20 @@ func (r *RTPMunger) SeedLast(state RTPMungerState) {
 
 func (r *RTPMunger) SetLastSnTs(extPkt *buffer.ExtPacket) {
 	r.extHighestIncomingSN = extPkt.ExtSequenceNumber - 1
+
 	r.extLastSN = extPkt.ExtSequenceNumber
 	r.extSecondLastSN = r.extLastSN - 1
+	r.updateSnOffset()
+
 	r.extLastTS = extPkt.ExtTimestamp
 }
 
 func (r *RTPMunger) UpdateSnTsOffsets(extPkt *buffer.ExtPacket, snAdjust uint64, tsAdjust uint64) {
 	r.extHighestIncomingSN = extPkt.ExtSequenceNumber - 1
+
 	r.snRangeMap.ClearAndResetValue(extPkt.ExtSequenceNumber - r.extLastSN - snAdjust)
+	r.updateSnOffset()
+
 	r.tsOffset = extPkt.ExtTimestamp - r.extLastTS - tsAdjust
 }
 
@@ -148,16 +156,42 @@ func (r *RTPMunger) PacketDropped(extPkt *buffer.ExtPacket) {
 	}
 
 	r.extLastSN = r.extSecondLastSN
+	r.updateSnOffset()
 }
 
 func (r *RTPMunger) UpdateAndGetSnTs(extPkt *buffer.ExtPacket) (*TranslationParamsRTP, error) {
 	diff := int64(extPkt.ExtSequenceNumber - r.extHighestIncomingSN)
+	if (diff == 1 && len(extPkt.Packet.Payload) != 0) || diff > 1 {
+		// in-order - either contiguous packet with payload OR packet following a gap, may or may not have payload
+		r.extHighestIncomingSN = extPkt.ExtSequenceNumber
+
+		ordering := SequenceNumberOrderingContiguous
+		if diff > 1 {
+			ordering = SequenceNumberOrderingGap
+		}
+
+		extMungedSN := extPkt.ExtSequenceNumber - r.snOffset
+		extMungedTS := extPkt.ExtTimestamp - r.tsOffset
+
+		r.extSecondLastSN = r.extLastSN
+		r.extLastSN = extMungedSN
+		r.extLastTS = extMungedTS
+		r.lastMarker = extPkt.Packet.Marker
+
+		if extPkt.KeyFrame {
+			r.extRtxGateSn = extMungedSN
+			r.isInRtxGateRegion = true
+		}
+
+		if r.isInRtxGateRegion && (extMungedSN-r.extRtxGateSn) > RtxGateWindow {
+			r.isInRtxGateRegion = false
+		}
 
-	// can get duplicate packet due to FEC
-	if diff == 0 {
 		return &TranslationParamsRTP{
-			snOrdering: SequenceNumberOrderingDuplicate,
-		}, ErrDuplicatePacket
+			snOrdering:     ordering,
+			sequenceNumber: uint16(extMungedSN),
+			timestamp:      uint32(extMungedTS),
+		}, nil
 	}
 
 	if diff < 0 {
@@ -176,53 +210,25 @@ func (r *RTPMunger) UpdateAndGetSnTs(extPkt *buffer.ExtPacket) (*TranslationPara
 		}, nil
 	}
 
-	ordering := SequenceNumberOrderingContiguous
-	if diff > 1 {
-		ordering = SequenceNumberOrderingGap
-	}
-
-	r.extHighestIncomingSN = extPkt.ExtSequenceNumber
-
 	// if padding only packet, can be dropped and sequence number adjusted, if contiguous
-	if diff == 1 && len(extPkt.Packet.Payload) == 0 {
+	if diff == 1 {
+		r.extHighestIncomingSN = extPkt.ExtSequenceNumber
+
 		if err := r.snRangeMap.ExcludeRange(r.extHighestIncomingSN, r.extHighestIncomingSN+1); err != nil {
 			r.logger.Errorw("could not exclude range", err, "sn", r.extHighestIncomingSN)
 		}
+
+		r.updateSnOffset()
+
 		return &TranslationParamsRTP{
-			snOrdering: ordering,
+			snOrdering: SequenceNumberOrderingContiguous,
 		}, ErrPaddingOnlyPacket
 	}
 
-	snOffset, err := r.snRangeMap.GetValue(extPkt.ExtSequenceNumber)
-	if err != nil {
-		r.logger.Errorw("could not get sequence number adjustment", err, "sn", extPkt.ExtSequenceNumber, "payloadSize", len(extPkt.Packet.Payload))
-		return &TranslationParamsRTP{
-			snOrdering: ordering,
-		}, ErrSequenceNumberOffsetNotFound
-	}
-
-	extMungedSN := extPkt.ExtSequenceNumber - snOffset
-	extMungedTS := extPkt.ExtTimestamp - r.tsOffset
-
-	r.extSecondLastSN = r.extLastSN
-	r.extLastSN = extMungedSN
-	r.extLastTS = extMungedTS
-	r.lastMarker = extPkt.Packet.Marker
-
-	if extPkt.KeyFrame {
-		r.extRtxGateSn = extMungedSN
-		r.isInRtxGateRegion = true
-	}
-
-	if r.isInRtxGateRegion && (extMungedSN-r.extRtxGateSn) > RtxGateWindow {
-		r.isInRtxGateRegion = false
-	}
-
+	// can get duplicate packet due to FEC
 	return &TranslationParamsRTP{
-		snOrdering:     ordering,
-		sequenceNumber: uint16(extMungedSN),
-		timestamp:      uint32(extMungedTS),
-	}, nil
+		snOrdering: SequenceNumberOrderingDuplicate,
+	}, ErrDuplicatePacket
 }
 
 func (r *RTPMunger) FilterRTX(nacks []uint16) []uint16 {
@@ -297,3 +303,11 @@ func (r *RTPMunger) UpdateAndGetPaddingSnTs(num int, clockRate uint32, frameRate
 func (r *RTPMunger) IsOnFrameBoundary() bool {
 	return r.lastMarker
 }
+
+func (r *RTPMunger) updateSnOffset() {
+	snOffset, err := r.snRangeMap.GetValue(r.extHighestIncomingSN + 1)
+	if err != nil {
+		r.logger.Errorw("could not get SN offset", err)
+	}
+	r.snOffset = snOffset
+}

From 6c947194871d938718c5b19da67915f46daf8b27 Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Thu, 7 Sep 2023 14:59:22 +0530
Subject: [PATCH 11/13] Cache extended highest. (#2043)

* Cache extended highest.

Prevents calculating extended highest on every update to populate
PreExtendedHighest in the result.

* remove incorrect comment
---
 pkg/sfu/utils/wraparound.go | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/pkg/sfu/utils/wraparound.go b/pkg/sfu/utils/wraparound.go
index 5dd2b1e93..1b5502c62 100644
--- a/pkg/sfu/utils/wraparound.go
+++ b/pkg/sfu/utils/wraparound.go
@@ -29,10 +29,11 @@ type extendedNumber interface {
 type WrapAround[T number, ET extendedNumber] struct {
 	fullRange ET
 
-	initialized bool
-	start       T
-	highest     T
-	cycles      ET
+	initialized     bool
+	start           T
+	highest         T
+	cycles          ET
+	extendedHighest ET
 }
 
 func NewWrapAround[T number, ET extendedNumber]() *WrapAround[T, ET] {
@@ -47,6 +48,7 @@ func (w *WrapAround[T, ET]) Seed(from *WrapAround[T, ET]) {
 	w.start = from.start
 	w.highest = from.highest
 	w.cycles = from.cycles
+	w.updateExtendedHighest()
 }
 
 type WrapAroundUpdateResult[ET extendedNumber] struct {
@@ -63,15 +65,16 @@ func (w *WrapAround[T, ET]) Update(val T) (result WrapAroundUpdateResult[ET]) {
 
 		w.start = val
 		w.highest = val
+		w.updateExtendedHighest()
 		w.initialized = true
 		return
 	}
 
-	result.PreExtendedHighest = w.GetExtendedHighest()
+	result.PreExtendedHighest = w.extendedHighest
 
 	gap := val - w.highest
-	if gap == 0 || gap > T(w.fullRange>>1) {
-		// duplicate OR out-of-order
+	if gap > T(w.fullRange>>1) {
+		// out-of-order
 		result.IsRestart, result.PreExtendedStart, result.ExtendedVal = w.maybeAdjustStart(val)
 		return
 	}
@@ -82,13 +85,15 @@ func (w *WrapAround[T, ET]) Update(val T) (result WrapAroundUpdateResult[ET]) {
 	}
 	w.highest = val
 
-	result.ExtendedVal = w.getExtendedHighest(w.cycles, val)
+	w.updateExtendedHighest()
+	result.ExtendedVal = w.extendedHighest
 	return
 }
 
 func (w *WrapAround[T, ET]) RollbackRestart(ev ET) {
 	if w.isWrapBack(w.start, T(ev)) {
 		w.cycles -= w.fullRange
+		w.updateExtendedHighest()
 	}
 	w.start = T(ev)
 }
@@ -96,6 +101,7 @@ func (w *WrapAround[T, ET]) RollbackRestart(ev ET) {
 func (w *WrapAround[T, ET]) ResetHighest(ev ET) {
 	w.highest = T(ev)
 	w.cycles = ev & ^(w.fullRange - 1)
+	w.updateExtendedHighest()
 }
 
 func (w *WrapAround[T, ET]) GetStart() T {
@@ -111,7 +117,11 @@ func (w *WrapAround[T, ET]) GetHighest() T {
 }
 
 func (w *WrapAround[T, ET]) GetExtendedHighest() ET {
-	return w.getExtendedHighest(w.cycles, w.highest)
+	return w.extendedHighest
+}
+
+func (w *WrapAround[T, ET]) updateExtendedHighest() {
+	w.extendedHighest = getExtendedHighest(w.cycles, w.highest)
 }
 
 func (w *WrapAround[T, ET]) maybeAdjustStart(val T) (isRestart bool, preExtendedStart ET, extendedVal ET) {
@@ -125,7 +135,7 @@ func (w *WrapAround[T, ET]) maybeAdjustStart(val T) (isRestart bool, preExtended
 		if w.isWrapBack(val, w.highest) {
 			cycles -= w.fullRange
 		}
-		extendedVal = w.getExtendedHighest(cycles, val)
+		extendedVal = getExtendedHighest(cycles, val)
 		return
 	}
 
@@ -136,6 +146,7 @@ func (w *WrapAround[T, ET]) maybeAdjustStart(val T) (isRestart bool, preExtended
 
 		if w.isWrapBack(val, w.highest) {
 			w.cycles = w.fullRange
+			w.updateExtendedHighest()
 			cycles = 0
 		}
 		w.start = val
@@ -144,7 +155,7 @@ func (w *WrapAround[T, ET]) maybeAdjustStart(val T) (isRestart bool, preExtended
 			cycles -= w.fullRange
 		}
 	}
-	extendedVal = w.getExtendedHighest(cycles, val)
+	extendedVal = getExtendedHighest(cycles, val)
 	return
 }
 
@@ -152,6 +163,8 @@ func (w *WrapAround[T, ET]) isWrapBack(earlier T, later T) bool {
 	return ET(later) < (w.fullRange>>1) && ET(earlier) >= (w.fullRange>>1)
 }
 
-func (w *WrapAround[T, ET]) getExtendedHighest(cycles ET, val T) ET {
+// ------------------------------------
+
+func getExtendedHighest[T number, ET extendedNumber](cycles ET, val T) ET {
 	return cycles + ET(val)
 }

From 3babb432c6fd94a07d6d67384c694184565850ba Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Thu, 7 Sep 2023 15:58:42 +0530
Subject: [PATCH 12/13] Missed an SN offset update in the previous round
 (#2044)

---
 pkg/sfu/rtpmunger.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pkg/sfu/rtpmunger.go b/pkg/sfu/rtpmunger.go
index 8176cfe81..1d902aaf3 100644
--- a/pkg/sfu/rtpmunger.go
+++ b/pkg/sfu/rtpmunger.go
@@ -289,6 +289,7 @@ func (r *RTPMunger) UpdateAndGetPaddingSnTs(num int, clockRate uint32, frameRate
 	r.extSecondLastSN = extLastSN - 1
 	r.extLastSN = extLastSN
 	r.snRangeMap.DecValue(uint64(num))
+	r.updateSnOffset()
 
 	r.tsOffset -= extLastTS - r.extLastTS
 	r.extLastTS = extLastTS

From b95670f56b1bfe40136629121b09659c22f80775 Mon Sep 17 00:00:00 2001
From: Raja Subramanian <raja.gobi@tutanota.com>
Date: Thu, 7 Sep 2023 22:22:00 +0530
Subject: [PATCH 13/13] Removing one snapshot in down track. (#2047)

Profiling showed updating jitter going through the snapshot maps.
With the reduction of one, there should only be one snapshot
and hopefully that should gain some cycles back.
---
 pkg/sfu/buffer/rtpstats.go                   |  2 +-
 pkg/sfu/connectionquality/connectionstats.go | 49 +++++++++-----------
 pkg/sfu/downtrack.go                         | 36 +++++---------
 3 files changed, 35 insertions(+), 52 deletions(-)

diff --git a/pkg/sfu/buffer/rtpstats.go b/pkg/sfu/buffer/rtpstats.go
index 9bacf08f7..1f0f2694e 100644
--- a/pkg/sfu/buffer/rtpstats.go
+++ b/pkg/sfu/buffer/rtpstats.go
@@ -705,7 +705,7 @@ func (r *RTPStats) UpdateFromReceiverReport(rr rtcp.ReceptionReport) (rtt uint32
 	return
 }
 
-func (r *RTPStats) LastReceiverReport() time.Time {
+func (r *RTPStats) LastReceiverReportTime() time.Time {
 	r.lock.RLock()
 	defer r.lock.RUnlock()
 
diff --git a/pkg/sfu/connectionquality/connectionstats.go b/pkg/sfu/connectionquality/connectionstats.go
index 565eccabb..641290fa8 100644
--- a/pkg/sfu/connectionquality/connectionstats.go
+++ b/pkg/sfu/connectionquality/connectionstats.go
@@ -42,6 +42,7 @@ type ConnectionStatsParams struct {
 	GetDeltaStats             func() map[uint32]*buffer.StreamStatsWithLayers
 	GetDeltaStatsOverridden   func() map[uint32]*buffer.StreamStatsWithLayers
 	GetLastReceiverReportTime func() time.Time
+	GetTotalPacketsSent       func() uint64
 	Logger                    logger.Logger
 }
 
@@ -54,6 +55,7 @@ type ConnectionStats struct {
 	onStatsUpdate func(cs *ConnectionStats, stat *livekit.AnalyticsStat)
 
 	lock               sync.RWMutex
+	packetsSent        uint64
 	streamingStartedAt time.Time
 
 	scorer *qualityScorer
@@ -213,13 +215,11 @@ func (cs *ConnectionStats) updateScoreWithAggregate(agg *buffer.RTPDeltaInfo, at
 }
 
 func (cs *ConnectionStats) updateScoreFromReceiverReport(at time.Time) (float32, map[uint32]*buffer.StreamStatsWithLayers) {
-	if cs.params.GetDeltaStatsOverridden == nil || cs.params.GetLastReceiverReportTime == nil {
+	if cs.params.GetDeltaStatsOverridden == nil || cs.params.GetLastReceiverReportTime == nil || cs.params.GetTotalPacketsSent == nil {
 		return MinMOS, nil
 	}
 
-	cs.lock.RLock()
-	streamingStartedAt := cs.streamingStartedAt
-	cs.lock.RUnlock()
+	streamingStartedAt := cs.updateStreamingStart(at)
 	if streamingStartedAt.IsZero() {
 		// not streaming, just return current score
 		mos, _ := cs.scorer.GetMOSAndQuality()
@@ -260,6 +260,11 @@ func (cs *ConnectionStats) updateScoreFromReceiverReport(at time.Time) (float32,
 }
 
 func (cs *ConnectionStats) updateScoreAt(at time.Time) (float32, map[uint32]*buffer.StreamStatsWithLayers) {
+	if cs.params.GetDeltaStatsOverridden != nil {
+		// receiver report based quality scoring, use stats from receiver report for scoring
+		return cs.updateScoreFromReceiverReport(at)
+	}
+
 	if cs.params.GetDeltaStats == nil {
 		return MinMOS, nil
 	}
@@ -275,33 +280,25 @@ func (cs *ConnectionStats) updateScoreAt(at time.Time) (float32, map[uint32]*buf
 		deltaInfoList = append(deltaInfoList, s.RTPStats)
 	}
 	agg := buffer.AggregateRTPDeltaInfo(deltaInfoList)
-	if agg != nil && agg.Packets > 0 {
-		// not very accurate as streaming could have started part way in the window, but don't need accurate time
-		cs.maybeSetStreamingStart(agg.StartTime)
-	} else {
-		cs.clearStreamingStart()
-	}
-
-	if cs.params.GetDeltaStatsOverridden != nil {
-		// receiver report based quality scoring, use stats from receiver report for scoring
-		return cs.updateScoreFromReceiverReport(at)
-	}
-
 	return cs.updateScoreWithAggregate(agg, at), streams
 }
 
-func (cs *ConnectionStats) maybeSetStreamingStart(at time.Time) {
+func (cs *ConnectionStats) updateStreamingStart(at time.Time) time.Time {
 	cs.lock.Lock()
-	if cs.streamingStartedAt.IsZero() {
-		cs.streamingStartedAt = at
-	}
-	cs.lock.Unlock()
-}
+	defer cs.lock.Unlock()
 
-func (cs *ConnectionStats) clearStreamingStart() {
-	cs.lock.Lock()
-	cs.streamingStartedAt = time.Time{}
-	cs.lock.Unlock()
+	packetsSent := cs.params.GetTotalPacketsSent()
+	if packetsSent > cs.packetsSent {
+		if cs.streamingStartedAt.IsZero() {
+			// the start could be anywhere after last update, but using `at` as this is not required to be accurate
+			cs.streamingStartedAt = at
+		}
+	} else {
+		cs.streamingStartedAt = time.Time{}
+	}
+	cs.packetsSent = packetsSent
+
+	return cs.streamingStartedAt
 }
 
 func (cs *ConnectionStats) getStat() {
diff --git a/pkg/sfu/downtrack.go b/pkg/sfu/downtrack.go
index d48b98460..6216fa0d8 100644
--- a/pkg/sfu/downtrack.go
+++ b/pkg/sfu/downtrack.go
@@ -129,14 +129,13 @@ var (
 
 type DownTrackState struct {
 	RTPStats                       *buffer.RTPStats
-	DeltaStatsSnapshotId           uint32
 	DeltaStatsOverriddenSnapshotId uint32
 	ForwarderState                 ForwarderState
 }
 
 func (d DownTrackState) String() string {
-	return fmt.Sprintf("DownTrackState{rtpStats: %s, delta: %d, deltaOverridden: %d, forwarder: %s}",
-		d.RTPStats.ToString(), d.DeltaStatsSnapshotId, d.DeltaStatsOverriddenSnapshotId, d.ForwarderState.String())
+	return fmt.Sprintf("DownTrackState{rtpStats: %s, deltaOverridden: %d, forwarder: %s}",
+		d.RTPStats.ToString(), d.DeltaStatsOverriddenSnapshotId, d.ForwarderState.String())
 }
 
 // -------------------------------------------------------------------
@@ -248,7 +247,6 @@ type DownTrack struct {
 	blankFramesGeneration atomic.Uint32
 
 	connectionStats                *connectionquality.ConnectionStats
-	deltaStatsSnapshotId           uint32
 	deltaStatsOverriddenSnapshotId uint32
 
 	isNACKThrottled atomic.Bool
@@ -310,15 +308,14 @@ func NewDownTrack(params DowntrackParams) (*DownTrack, error) {
 		IsReceiverReportDriven: true,
 		Logger:                 params.Logger,
 	})
-	d.deltaStatsSnapshotId = d.rtpStats.NewSnapshotId()
 	d.deltaStatsOverriddenSnapshotId = d.rtpStats.NewSnapshotId()
 
 	d.connectionStats = connectionquality.NewConnectionStats(connectionquality.ConnectionStatsParams{
 		MimeType:                  codecs[0].MimeType, // LK-TODO have to notify on codec change
 		IsFECEnabled:              strings.EqualFold(codecs[0].MimeType, webrtc.MimeTypeOpus) && strings.Contains(strings.ToLower(codecs[0].SDPFmtpLine), "fec"),
-		GetDeltaStats:             d.getDeltaStats,
 		GetDeltaStatsOverridden:   d.getDeltaStatsOverridden,
-		GetLastReceiverReportTime: func() time.Time { return d.rtpStats.LastReceiverReport() },
+		GetLastReceiverReportTime: func() time.Time { return d.rtpStats.LastReceiverReportTime() },
+		GetTotalPacketsSent:       func() uint64 { return d.rtpStats.GetTotalPacketsPrimary() },
 		Logger:                    params.Logger.WithValues("direction", "down"),
 	})
 	d.connectionStats.OnStatsUpdate(func(_cs *connectionquality.ConnectionStats, stat *livekit.AnalyticsStat) {
@@ -328,7 +325,6 @@ func NewDownTrack(params DowntrackParams) (*DownTrack, error) {
 	})
 
 	// set initial playout delay to minimum value
-
 	if d.params.PlayoutDelayLimit.GetEnabled() && d.params.PlayoutDelayLimit.GetMin() > 0 {
 		delay := rtpextension.PlayoutDelayFromValue(
 			uint16(d.params.PlayoutDelayLimit.GetMin()),
@@ -730,13 +726,11 @@ func (d *DownTrack) WritePaddingRTP(bytesToSend int, paddingOnMute bool, forceMa
 		return 0
 	}
 
-	// LK-TODO-START
 	// Ideally should look at header extensions negotiated for
 	// track and decide if padding can be sent. But, browsers behave
 	// in unexpected ways when using audio for bandwidth estimation and
 	// padding is mainly used to probe for excess available bandwidth.
 	// So, to be safe, limit to video tracks
-	// LK-TODO-END
 	if d.kind == webrtc.RTPCodecTypeAudio {
 		return 0
 	}
@@ -750,6 +744,12 @@ func (d *DownTrack) WritePaddingRTP(bytesToSend int, paddingOnMute bool, forceMa
 		return 0
 	}
 
+	// Hold sending padding packets till first RTCP-RR is received for this RTP stream.
+	// That is definitive proof that the remote side knows about this RTP stream.
+	if d.rtpStats.LastReceiverReportTime().IsZero() && !paddingOnMute {
+		return 0
+	}
+
 	// RTP padding maximum is 255 bytes. Break it up.
 	// Use 20 byte as estimate of RTP header size (12 byte header + 8 byte extension)
 	num := (bytesToSend + RTPPaddingMaxPayloadSize + RTPPaddingEstimatedHeaderSize - 1) / (RTPPaddingMaxPayloadSize + RTPPaddingEstimatedHeaderSize)
@@ -762,16 +762,8 @@ func (d *DownTrack) WritePaddingRTP(bytesToSend int, paddingOnMute bool, forceMa
 		return 0
 	}
 
-	// LK-TODO Look at load balancing a la sfu.Receiver to spread across available CPUs
 	bytesSent := 0
 	for i := 0; i < len(snts); i++ {
-		// LK-TODO-START
-		// Hold sending padding packets till first RTCP-RR is received for this RTP stream.
-		// That is definitive proof that the remote side knows about this RTP stream.
-		// The packet count check at the beginning of this function gates sending padding
-		// on as yet unstarted streams which is a reasonable check.
-		// LK-TODO-END
-
 		hdr := rtp.Header{
 			Version:        2,
 			Padding:        true,
@@ -812,7 +804,7 @@ func (d *DownTrack) WritePaddingRTP(bytesToSend int, paddingOnMute bool, forceMa
 		bytesSent += hdr.MarshalSize() + len(payload)
 	}
 
-	// STREAM_ALLOCATOR-TODO: change this to pull this counter from stream allocator so that counter can be update in pacer callback
+	// STREAM_ALLOCATOR-TODO: change this to pull this counter from stream allocator so that counter can be updated in pacer callback
 	return bytesSent
 }
 
@@ -979,7 +971,6 @@ func (d *DownTrack) MaxLayer() buffer.VideoLayer {
 func (d *DownTrack) GetState() DownTrackState {
 	dts := DownTrackState{
 		RTPStats:                       d.rtpStats,
-		DeltaStatsSnapshotId:           d.deltaStatsSnapshotId,
 		DeltaStatsOverriddenSnapshotId: d.deltaStatsOverriddenSnapshotId,
 		ForwarderState:                 d.forwarder.GetState(),
 	}
@@ -988,7 +979,6 @@ func (d *DownTrack) GetState() DownTrackState {
 
 func (d *DownTrack) SeedState(state DownTrackState) {
 	d.rtpStats.Seed(state.RTPStats)
-	d.deltaStatsSnapshotId = state.DeltaStatsSnapshotId
 	d.deltaStatsOverriddenSnapshotId = state.DeltaStatsOverriddenSnapshotId
 	d.forwarder.SeedState(state.ForwarderState)
 }
@@ -1698,10 +1688,6 @@ func (d *DownTrack) deltaStats(ds *buffer.RTPDeltaInfo) map[uint32]*buffer.Strea
 	return streamStats
 }
 
-func (d *DownTrack) getDeltaStats() map[uint32]*buffer.StreamStatsWithLayers {
-	return d.deltaStats(d.rtpStats.DeltaInfo(d.deltaStatsSnapshotId))
-}
-
 func (d *DownTrack) getDeltaStatsOverridden() map[uint32]*buffer.StreamStatsWithLayers {
 	return d.deltaStats(d.rtpStats.DeltaInfoOverridden(d.deltaStatsOverriddenSnapshotId))
 }