Update timestamp processing for MPEG-TS

pkg/mpegts/consumer.go

@@ -114,3 +114,10 @@ func (c *Consumer) Stop() error {
 	_ = c.SuperConsumer.Close()
 	return c.wr.Close()
 }
+
+func TimestampFromRTP(rtp *rtp.Packet, codec *core.Codec) {
+	if codec.ClockRate == ClockRate {
+		return
+	}
+	rtp.Timestamp = uint32(float64(rtp.Timestamp) / float64(codec.ClockRate) * ClockRate)
+}

pkg/mpegts/demuxer.go

@@ -197,7 +197,7 @@ func (d *Demuxer) readPES(pid uint16, start bool) *rtp.Packet {
 		_ = d.readBit()   // Original or Copy
 
 		pts := d.readBit() // PTS indicator
-		_ = d.readBit()    // DTS indicator
+		dts := d.readBit() // DTS indicator
 		_ = d.readBit()    // ESCR flag
 		_ = d.readBit()    // ES rate flag
 		_ = d.readBit()    // DSM trick mode flag
@@ -213,8 +213,12 @@ func (d *Demuxer) readPES(pid uint16, start bool) *rtp.Packet {
 			packetSize -= uint16(3 + headerSize)
 		}
 
-		if pts != 0 {
-			pes.PTS = d.readTime()
+		if dts != 0 {
+			d.skip(5) // skip PTSorDTS
+			pes.PTSorDTS = d.readTime()
+			headerSize -= 10
+		} else if pts != 0 {
+			pes.PTSorDTS = d.readTime()
 			headerSize -= 5
 		}
 
@@ -301,7 +305,8 @@ func (d *Demuxer) setSize(size byte) {
 
 const (
 	PacketSize = 188
-	SyncByte   = 0x47 // Uppercase G
+	SyncByte   = 0x47  // Uppercase G
+	ClockRate  = 90000 // fixed clock rate for PTS/DTS of any type
 )
 
 // https://en.wikipedia.org/wiki/Program-specific_information#Elementary_stream_types
@@ -320,9 +325,9 @@ type PES struct {
 	StreamType byte   // from PMT table
 	Sequence   uint16 // manual
 	Timestamp  uint32 // manual
-	PTS        uint32 // from PTS extra header, always 90000Hz
-	Payload    []byte // from PTS body
-	Size       int    // from PTS header, can be 0
+	PTSorDTS   uint32 // from extra header, always 90000Hz
+	Payload    []byte // from PES body
+	Size       int    // from PES header, can be 0
 
 	wr *bits.Writer
 }
@@ -343,7 +348,7 @@ func (p *PES) GetPacket() (pkt *rtp.Packet) {
 		pkt = &rtp.Packet{
 			Header: rtp.Header{
 				PayloadType: p.StreamType,
-				Timestamp:   p.PTS, // PTS is ok, because 90000Hz
+				Timestamp:   p.PTSorDTS,
 			},
 			Payload: annexb.EncodeToAVCC(p.Payload, false),
 		}
@@ -356,12 +361,13 @@ func (p *PES) GetPacket() (pkt *rtp.Packet) {
 				Version:        2,
 				PayloadType:    p.StreamType,
 				SequenceNumber: p.Sequence,
-				Timestamp:      p.Timestamp,
+				Timestamp:      p.PTSorDTS,
+				//Timestamp:      p.Timestamp,
 			},
 			Payload: aac.ADTStoRTP(p.Payload),
 		}
 
-		p.Timestamp += aac.RTPTimeSize(pkt.Payload) // update next timestamp!
+		//p.Timestamp += aac.RTPTimeSize(pkt.Payload) // update next timestamp!
 
 	case StreamTypePCMATapo:
 		p.Sequence++
@@ -371,12 +377,13 @@ func (p *PES) GetPacket() (pkt *rtp.Packet) {
 				Version:        2,
 				PayloadType:    p.StreamType,
 				SequenceNumber: p.Sequence,
-				Timestamp:      p.Timestamp,
+				Timestamp:      p.PTSorDTS,
+				//Timestamp:      p.Timestamp,
 			},
 			Payload: p.Payload,
 		}
 
-		p.Timestamp += uint32(len(p.Payload)) // update next timestamp!
+		//p.Timestamp += uint32(len(p.Payload)) // update next timestamp!
 	}
 
 	p.Payload = nil

pkg/mpegts/muxer.go

@@ -51,9 +51,9 @@ func (m *Muxer) GetPayload(pid uint16, timestamp uint32, payload []byte) []byte
 	}
 
 	if pes.Timestamp != 0 {
-		pes.PTS += timestamp - pes.Timestamp
+		pes.PTSorDTS += timestamp - pes.Timestamp
 	}
-	//log.Print(pid, pes.PTS, timestamp, pes.Timestamp)
+	//log.Print(pid, pes.PTSorDTS, timestamp, pes.Timestamp)
 	pes.Timestamp = timestamp
 
 	// min header size (3 byte) + adv header size (PES)
@@ -74,7 +74,7 @@ func (m *Muxer) GetPayload(pid uint16, timestamp uint32, payload []byte) []byte
 	b[7] = 0x80 // PTS indicator
 	b[8] = 5    // PES header length
 
-	WriteTime(b[9:], pes.PTS)
+	WriteTime(b[9:], pes.PTSorDTS)
 
 	pes.Payload = append(b, payload...)
 	pes.Size = 1 // set PUSI in first PES

pkg/mpegts/producer.go

@@ -9,6 +9,7 @@ import (
 	"github.com/AlexxIT/go2rtc/pkg/core"
 	"github.com/AlexxIT/go2rtc/pkg/h264"
 	"github.com/AlexxIT/go2rtc/pkg/h265"
+	"github.com/pion/rtp"
 )
 
 type Producer struct {
@@ -43,6 +44,7 @@ func (c *Producer) Start() error {
 
 		for _, receiver := range c.Receivers {
 			if receiver.ID == pkt.PayloadType {
+				TimestampToRTP(pkt, receiver.Codec)
 				receiver.WriteRTP(pkt)
 				break
 			}
@@ -135,3 +137,10 @@ func StreamType(codec *core.Codec) uint8 {
 	}
 	return 0
 }
+
+func TimestampToRTP(rtp *rtp.Packet, codec *core.Codec) {
+	if codec.ClockRate == ClockRate {
+		return
+	}
+	rtp.Timestamp = uint32(float64(rtp.Timestamp) * float64(codec.ClockRate) / ClockRate)
+}

pkg/tapo/client.go

@@ -191,6 +191,7 @@ func (c *Client) Handle() error {
 
 			for _, receiver := range c.receivers {
 				if receiver.ID == pkt.PayloadType {
+					mpegts.TimestampToRTP(pkt, receiver.Codec)
 					receiver.WriteRTP(pkt)
 					break
 				}