route original timestamps without converting to durations (#3839)

This improves timestamp precision.

internal/formatprocessor/ac3.go

@@ -1,24 +1,33 @@
 package formatprocessor
 
 import (
+	"crypto/rand"
 	"errors"
 	"fmt"
 	"time"
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpac3"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
 )
 
+func randUint32() (uint32, error) {
+	var b [4]byte
+	_, err := rand.Read(b[:])
+	if err != nil {
+		return 0, err
+	}
+	return uint32(b[0])<<24 | uint32(b[1])<<16 | uint32(b[2])<<8 | uint32(b[3]), nil
+}
+
 type formatProcessorAC3 struct {
 	udpMaxPayloadSize int
 	format            *format.AC3
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpac3.Encoder
 	decoder           *rtpac3.Decoder
+	randomStart       uint32
 }
 
 func newAC3(
@@ -37,10 +46,7 @@ func newAC3(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -65,9 +71,8 @@ func (t *formatProcessorAC3) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -76,7 +81,7 @@ func (t *formatProcessorAC3) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 func (t *formatProcessorAC3) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.AC3{

internal/formatprocessor/av1.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpav1"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
@@ -23,9 +22,9 @@ var (
 type formatProcessorAV1 struct {
 	udpMaxPayloadSize int
 	format            *format.AV1
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpav1.Encoder
 	decoder           *rtpav1.Decoder
+	randomStart       uint32
 }
 
 func newAV1(
@@ -44,10 +43,7 @@ func newAV1(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -73,9 +69,8 @@ func (t *formatProcessorAV1) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -84,7 +79,7 @@ func (t *formatProcessorAV1) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 func (t *formatProcessorAV1) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.AV1{

internal/formatprocessor/g711.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtplpcm"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
@@ -15,9 +14,9 @@ import (
 type formatProcessorG711 struct {
 	udpMaxPayloadSize int
 	format            *format.G711
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtplpcm.Encoder
 	decoder           *rtplpcm.Decoder
+	randomStart       uint32
 }
 
 func newG711(
@@ -36,10 +35,7 @@ func newG711(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -67,9 +63,8 @@ func (t *formatProcessorG711) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -78,7 +73,7 @@ func (t *formatProcessorG711) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 func (t *formatProcessorG711) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.G711{

internal/formatprocessor/generic.go

@@ -35,7 +35,7 @@ func (t *formatProcessorGeneric) ProcessUnit(_ unit.Unit) error {
 func (t *formatProcessorGeneric) ProcessRTPPacket(
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	_ bool,
 ) (unit.Unit, error) {
 	u := &unit.Generic{

internal/formatprocessor/h264.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtph264"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/bluenviron/mediacommon/pkg/codecs/h264"
 	"github.com/pion/rtp"
 
@@ -85,9 +84,9 @@ func rtpH264ExtractParams(payload []byte) ([]byte, []byte) {
 type formatProcessorH264 struct {
 	udpMaxPayloadSize int
 	format            *format.H264
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtph264.Encoder
 	decoder           *rtph264.Decoder
+	randomStart       uint32
 }
 
 func newH264(
@@ -106,10 +105,7 @@ func newH264(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -246,9 +242,8 @@ func (t *formatProcessorH264) ProcessUnit(uu unit.Unit) error {
 		}
 		u.RTPPackets = pkts
 
-		ts := t.timeEncoder.Encode(u.PTS)
 		for _, pkt := range u.RTPPackets {
-			pkt.Timestamp += ts
+			pkt.Timestamp += t.randomStart + uint32(u.PTS)
 		}
 	}
 
@@ -258,7 +253,7 @@ func (t *formatProcessorH264) ProcessUnit(uu unit.Unit) error {
 func (t *formatProcessorH264) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.H264{

internal/formatprocessor/h265.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtph265"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/bluenviron/mediacommon/pkg/codecs/h265"
 	"github.com/pion/rtp"
 
@@ -105,9 +104,9 @@ func rtpH265ExtractParams(payload []byte) ([]byte, []byte, []byte) {
 type formatProcessorH265 struct {
 	udpMaxPayloadSize int
 	format            *format.H265
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtph265.Encoder
 	decoder           *rtph265.Decoder
+	randomStart       uint32
 }
 
 func newH265(
@@ -126,10 +125,7 @@ func newH265(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -278,9 +274,8 @@ func (t *formatProcessorH265) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 		}
 		u.RTPPackets = pkts
 
-		ts := t.timeEncoder.Encode(u.PTS)
 		for _, pkt := range u.RTPPackets {
-			pkt.Timestamp += ts
+			pkt.Timestamp += t.randomStart + uint32(u.PTS)
 		}
 	}
 
@@ -290,7 +285,7 @@ func (t *formatProcessorH265) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 func (t *formatProcessorH265) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.H265{

internal/formatprocessor/lpcm.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtplpcm"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
@@ -15,9 +14,9 @@ import (
 type formatProcessorLPCM struct {
 	udpMaxPayloadSize int
 	format            *format.LPCM
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtplpcm.Encoder
 	decoder           *rtplpcm.Decoder
+	randomStart       uint32
 }
 
 func newLPCM(
@@ -36,10 +35,7 @@ func newLPCM(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -67,9 +63,8 @@ func (t *formatProcessorLPCM) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -78,7 +73,7 @@ func (t *formatProcessorLPCM) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 func (t *formatProcessorLPCM) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.LPCM{

internal/formatprocessor/mjpeg.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpmjpeg"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
@@ -16,9 +15,9 @@ import (
 type formatProcessorMJPEG struct {
 	udpMaxPayloadSize int
 	format            *format.MJPEG
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpmjpeg.Encoder
 	decoder           *rtpmjpeg.Decoder
+	randomStart       uint32
 }
 
 func newMJPEG(
@@ -37,10 +36,7 @@ func newMJPEG(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -66,9 +62,8 @@ func (t *formatProcessorMJPEG) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -77,7 +72,7 @@ func (t *formatProcessorMJPEG) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 func (t *formatProcessorMJPEG) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.MJPEG{

internal/formatprocessor/mpeg1_audio.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpmpeg1audio"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
@@ -16,9 +15,9 @@ import (
 type formatProcessorMPEG1Audio struct {
 	udpMaxPayloadSize int
 	format            *format.MPEG1Audio
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpmpeg1audio.Encoder
 	decoder           *rtpmpeg1audio.Decoder
+	randomStart       uint32
 }
 
 func newMPEG1Audio(
@@ -37,10 +36,7 @@ func newMPEG1Audio(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -65,9 +61,8 @@ func (t *formatProcessorMPEG1Audio) ProcessUnit(uu unit.Unit) error { //nolint:d
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -76,7 +71,7 @@ func (t *formatProcessorMPEG1Audio) ProcessUnit(uu unit.Unit) error { //nolint:d
 func (t *formatProcessorMPEG1Audio) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.MPEG1Audio{

internal/formatprocessor/mpeg1_video.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpmpeg1video"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
@@ -25,9 +24,9 @@ var (
 type formatProcessorMPEG1Video struct {
 	udpMaxPayloadSize int
 	format            *format.MPEG1Video
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpmpeg1video.Encoder
 	decoder           *rtpmpeg1video.Decoder
+	randomStart       uint32
 }
 
 func newMPEG1Video(
@@ -46,10 +45,7 @@ func newMPEG1Video(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -75,9 +71,8 @@ func (t *formatProcessorMPEG1Video) ProcessUnit(uu unit.Unit) error { //nolint:d
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -86,7 +81,7 @@ func (t *formatProcessorMPEG1Video) ProcessUnit(uu unit.Unit) error { //nolint:d
 func (t *formatProcessorMPEG1Video) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.MPEG1Video{

internal/formatprocessor/mpeg4_audio.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpmpeg4audio"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
@@ -16,9 +15,9 @@ import (
 type formatProcessorMPEG4Audio struct {
 	udpMaxPayloadSize int
 	format            *format.MPEG4Audio
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpmpeg4audio.Encoder
 	decoder           *rtpmpeg4audio.Decoder
+	randomStart       uint32
 }
 
 func newMPEG4Audio(
@@ -37,10 +36,7 @@ func newMPEG4Audio(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -69,9 +65,8 @@ func (t *formatProcessorMPEG4Audio) ProcessUnit(uu unit.Unit) error { //nolint:d
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -80,7 +75,7 @@ func (t *formatProcessorMPEG4Audio) ProcessUnit(uu unit.Unit) error { //nolint:d
 func (t *formatProcessorMPEG4Audio) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.MPEG4Audio{

internal/formatprocessor/mpeg4_video.go

@@ -8,7 +8,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpmpeg4video"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/bluenviron/mediacommon/pkg/codecs/mpeg4video"
 	"github.com/pion/rtp"
 
@@ -30,9 +29,9 @@ var (
 type formatProcessorMPEG4Video struct {
 	udpMaxPayloadSize int
 	format            *format.MPEG4Video
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpmpeg4video.Encoder
 	decoder           *rtpmpeg4video.Decoder
+	randomStart       uint32
 }
 
 func newMPEG4Video(
@@ -51,10 +50,7 @@ func newMPEG4Video(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -115,9 +111,8 @@ func (t *formatProcessorMPEG4Video) ProcessUnit(uu unit.Unit) error { //nolint:d
 			return err
 		}
 
-		ts := t.timeEncoder.Encode(u.PTS)
 		for _, pkt := range u.RTPPackets {
-			pkt.Timestamp += ts
+			pkt.Timestamp += t.randomStart + uint32(u.PTS)
 		}
 
 		u.RTPPackets = pkts
@@ -129,7 +124,7 @@ func (t *formatProcessorMPEG4Video) ProcessUnit(uu unit.Unit) error { //nolint:d
 func (t *formatProcessorMPEG4Video) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.MPEG4Video{

internal/formatprocessor/opus.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpsimpleaudio"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/bluenviron/mediacommon/pkg/codecs/opus"
 	"github.com/pion/rtp"
 
@@ -16,9 +15,9 @@ import (
 type formatProcessorOpus struct {
 	udpMaxPayloadSize int
 	format            *format.Opus
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpsimpleaudio.Encoder
 	decoder           *rtpsimpleaudio.Decoder
+	randomStart       uint32
 }
 
 func newOpus(
@@ -37,10 +36,7 @@ func newOpus(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -69,11 +65,10 @@ func (t *formatProcessorOpus) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 			return err
 		}
 
-		ts := t.timeEncoder.Encode(pts)
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(pts)
 
 		rtpPackets = append(rtpPackets, pkt)
-		pts += opus.PacketDuration(packet)
+		pts += int64(opus.PacketDuration(packet)) * int64(t.format.ClockRate()) / int64(time.Second)
 	}
 
 	u.RTPPackets = rtpPackets
@@ -84,7 +79,7 @@ func (t *formatProcessorOpus) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 func (t *formatProcessorOpus) ProcessRTPPacket(
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.Opus{

internal/formatprocessor/processor.go

@@ -19,7 +19,7 @@ type Processor interface {
 	ProcessRTPPacket(
 		pkt *rtp.Packet,
 		ntp time.Time,
-		pts time.Duration,
+		pts int64,
 		hasNonRTSPReaders bool,
 	) (unit.Unit, error)
 }

internal/formatprocessor/vp8.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpvp8"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
@@ -16,9 +15,9 @@ import (
 type formatProcessorVP8 struct {
 	udpMaxPayloadSize int
 	format            *format.VP8
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpvp8.Encoder
 	decoder           *rtpvp8.Decoder
+	randomStart       uint32
 }
 
 func newVP8(
@@ -37,10 +36,7 @@ func newVP8(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -66,9 +62,8 @@ func (t *formatProcessorVP8) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -77,7 +72,7 @@ func (t *formatProcessorVP8) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 func (t *formatProcessorVP8) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.VP8{

internal/formatprocessor/vp9.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4/pkg/format"
 	"github.com/bluenviron/gortsplib/v4/pkg/format/rtpvp9"
-	"github.com/bluenviron/gortsplib/v4/pkg/rtptime"
 	"github.com/pion/rtp"
 
 	"github.com/bluenviron/mediamtx/internal/unit"
@@ -16,9 +15,9 @@ import (
 type formatProcessorVP9 struct {
 	udpMaxPayloadSize int
 	format            *format.VP9
-	timeEncoder       *rtptime.Encoder
 	encoder           *rtpvp9.Encoder
 	decoder           *rtpvp9.Decoder
+	randomStart       uint32
 }
 
 func newVP9(
@@ -37,10 +36,7 @@ func newVP9(
 			return nil, err
 		}
 
-		t.timeEncoder = &rtptime.Encoder{
-			ClockRate: forma.ClockRate(),
-		}
-		err = t.timeEncoder.Initialize()
+		t.randomStart, err = randUint32()
 		if err != nil {
 			return nil, err
 		}
@@ -66,9 +62,8 @@ func (t *formatProcessorVP9) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 	}
 	u.RTPPackets = pkts
 
-	ts := t.timeEncoder.Encode(u.PTS)
 	for _, pkt := range u.RTPPackets {
-		pkt.Timestamp += ts
+		pkt.Timestamp += t.randomStart + uint32(u.PTS)
 	}
 
 	return nil
@@ -77,7 +72,7 @@ func (t *formatProcessorVP9) ProcessUnit(uu unit.Unit) error { //nolint:dupl
 func (t *formatProcessorVP9) ProcessRTPPacket( //nolint:dupl
 	pkt *rtp.Packet,
 	ntp time.Time,
-	pts time.Duration,
+	pts int64,
 	hasNonRTSPReaders bool,
 ) (unit.Unit, error) {
 	u := &unit.VP9{