Add WithRTPTimestamp to set initial RTP timestamp

Move to the new RTP API newPacketizerWithOptions, add WithRTPTimestamp
To make it possible to set the initial RTP timestamp for the track.

Author: JoeTurki

track_local_static.go

@@ -33,6 +33,7 @@ type TrackLocalStaticRTP struct {
 	codec             RTPCodecCapability
 	payloader         func(RTPCodecCapability) (rtp.Payloader, error)
 	id, rid, streamID string
+	rtpTimestamp      *uint32
 }
 
 // NewTrackLocalStaticRTP returns a TrackLocalStaticRTP.
@@ -69,6 +70,13 @@ func WithPayloader(h func(RTPCodecCapability) (rtp.Payloader, error)) func(*Trac
 	}
 }
 
+// WithRTPTimestamp set the initial RTP timestamp for the track.
+func WithRTPTimestamp(timestamp uint32) func(*TrackLocalStaticRTP) {
+	return func(s *TrackLocalStaticRTP) {
+		s.rtpTimestamp = &timestamp
+	}
+}
+
 // Bind is called by the PeerConnection after negotiation is complete
 // This asserts that the code requested is supported by the remote peer.
 // If so it sets up all the state (SSRC and PayloadType) to have a call.
@@ -282,14 +290,21 @@ func (s *TrackLocalStaticSample) Bind(t TrackLocalContext) (RTPCodecParameters,
 	}
 
 	s.sequencer = rtp.NewRandomSequencer()
-	s.packetizer = rtp.NewPacketizer(
+
+	options := []rtp.PacketizerOption{}
+
+	if s.rtpTrack.rtpTimestamp != nil {
+		options = append(options, rtp.WithTimestamp(*s.rtpTrack.rtpTimestamp))
+	}
+
+	s.packetizer = rtp.NewPacketizerWithOptions(
 		outboundMTU,
-		0, // Value is handled when writing
-		0, // Value is handled when writing
 		payloader,
 		s.sequencer,
 		codec.ClockRate,
+		options...,
 	)
+
 	s.clockRate = float64(codec.RTPCodecCapability.ClockRate)
 
 	return codec, nil

track_local_static_test.go

@@ -425,3 +425,44 @@ func Test_TrackLocalStatic_Payloader(t *testing.T) {
 
 	closePairNow(t, offerer, answerer)
 }
+
+func Test_TrackLocalStatic_Timestamp(t *testing.T) {
+	lim := test.TimeOut(time.Second * 30)
+	defer lim.Stop()
+
+	report := test.CheckRoutines(t)
+	defer report()
+
+	initialTimestamp := uint32(12345)
+	track, err := NewTrackLocalStaticSample(
+		RTPCodecCapability{MimeType: MimeTypeVP8},
+		"video",
+		"pion",
+		WithRTPTimestamp(initialTimestamp),
+	)
+	assert.NoError(t, err)
+
+	pcOffer, pcAnswer, err := newPair()
+	assert.NoError(t, err)
+
+	_, err = pcOffer.AddTrack(track)
+	assert.NoError(t, err)
+
+	onTrackFired, onTrackFiredFunc := context.WithCancel(context.Background())
+	pcAnswer.OnTrack(func(trackRemote *TrackRemote, _ *RTPReceiver) {
+		pkt, _, err := trackRemote.ReadRTP()
+		assert.NoError(t, err)
+		assert.GreaterOrEqual(t, pkt.Timestamp, initialTimestamp)
+		// Allow for ~10 dropped packets
+		assert.LessOrEqual(t, pkt.Timestamp, initialTimestamp+30000)
+
+		onTrackFiredFunc()
+	})
+
+	assert.NoError(t, signalPair(pcOffer, pcAnswer))
+
+	sendVideoUntilDone(t, onTrackFired.Done(), []*TrackLocalStaticSample{track})
+
+	<-onTrackFired.Done()
+	closePairNow(t, pcOffer, pcAnswer)
+}