Add E2E RID Simulcast test

Relates to #1345

peerconnection_media_test.go

@@ -386,6 +386,20 @@ func (u *undeclaredSsrcLoggerFactory) NewLogger(subsystem string) logging.Levele
 	return &undeclaredSsrcLogger{u.unhandledSimulcastError}
 }
 
+// Filter SSRC lines
+func filterSsrc(offer *SessionDescription) (filteredSDP string) {
+	scanner := bufio.NewScanner(strings.NewReader(offer.SDP))
+	for scanner.Scan() {
+		l := scanner.Text()
+		if strings.HasPrefix(l, "a=ssrc") {
+			continue
+		}
+
+		filteredSDP += l + "\n"
+	}
+	return
+}
+
 // If a SessionDescription has a single media section and no SSRC
 // assume that it is meant to handle all RTP packets
 func TestUndeclaredSSRC(t *testing.T) {
@@ -395,20 +409,6 @@ func TestUndeclaredSSRC(t *testing.T) {
 	report := test.CheckRoutines(t)
 	defer report()
 
-	// Filter SSRC lines
-	filterSsrc := func(offer *SessionDescription) (filteredSDP string) {
-		scanner := bufio.NewScanner(strings.NewReader(offer.SDP))
-		for scanner.Scan() {
-			l := scanner.Text()
-			if strings.HasPrefix(l, "a=ssrc") {
-				continue
-			}
-
-			filteredSDP += l + "\n"
-		}
-		return
-	}
-
 	t.Run("No SSRC", func(t *testing.T) {
 		pcOffer, pcAnswer, err := newPair()
 		assert.NoError(t, err)
@@ -1091,3 +1091,107 @@ func TestPeerConnection_RaceReplaceTrack(t *testing.T) {
 
 	assert.NoError(t, pc.Close())
 }
+
+func TestPeerConnection_Simulcast(t *testing.T) {
+	lim := test.TimeOut(time.Second * 30)
+	defer lim.Stop()
+
+	report := test.CheckRoutines(t)
+	defer report()
+
+	// Enable Extension Headers needed for Simulcast
+	m := &MediaEngine{}
+	if err := m.RegisterDefaultCodecs(); err != nil {
+		panic(err)
+	}
+	for _, extension := range []string{
+		"urn:ietf:params:rtp-hdrext:sdes:mid",
+		"urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id",
+		"urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id",
+	} {
+		if err := m.RegisterHeaderExtension(RTPHeaderExtensionCapability{URI: extension}, RTPCodecTypeVideo); err != nil {
+			panic(err)
+		}
+	}
+
+	t.Run("RID Based", func(t *testing.T) {
+		rids := []string{"a", "b", "c"}
+
+		pcOffer, pcAnswer, err := NewAPI(WithMediaEngine(m)).newPair(Configuration{})
+		assert.NoError(t, err)
+
+		vp8Writer, err := NewTrackLocalStaticRTP(RTPCodecCapability{MimeType: MimeTypeVP8}, "video", "pion2")
+		assert.NoError(t, err)
+
+		_, err = pcOffer.AddTrack(vp8Writer)
+		assert.NoError(t, err)
+
+		var ridMapLock sync.RWMutex
+		ridMap := map[string]int{}
+		pcAnswer.OnTrack(func(trackRemote *TrackRemote, r *RTPReceiver) {
+			ridMapLock.Lock()
+			defer ridMapLock.Unlock()
+			ridMap[trackRemote.RID()] = ridMap[trackRemote.RID()] + 1
+		})
+
+		offer, err := pcOffer.CreateOffer(nil)
+		assert.NoError(t, err)
+
+		offerGatheringComplete := GatheringCompletePromise(pcOffer)
+		assert.NoError(t, pcOffer.SetLocalDescription(offer))
+		<-offerGatheringComplete
+
+		offer.SDP = filterSsrc(pcOffer.LocalDescription())
+		for _, rid := range rids {
+			offer.SDP += "a=" + sdpAttributeRid + ":" + rid + " send\r\n"
+		}
+		offer.SDP += "a=simulcast:send " + strings.Join(rids, ";") + "\r\n"
+
+		assert.NoError(t, pcAnswer.SetRemoteDescription(offer))
+
+		answer, err := pcAnswer.CreateAnswer(nil)
+		assert.NoError(t, err)
+
+		answerGatheringComplete := GatheringCompletePromise(pcAnswer)
+		assert.NoError(t, pcAnswer.SetLocalDescription(answer))
+		<-answerGatheringComplete
+
+		assert.NoError(t, pcOffer.SetRemoteDescription(*pcAnswer.LocalDescription()))
+
+		func() {
+			for sequenceNumber := uint16(0); ; sequenceNumber++ {
+				time.Sleep(20 * time.Millisecond)
+
+				for ssrc, rid := range rids {
+					header := &rtp.Header{
+						Version:        2,
+						SSRC:           uint32(ssrc),
+						SequenceNumber: sequenceNumber,
+						PayloadType:    96,
+					}
+					assert.NoError(t, header.SetExtension(1, []byte("0")))
+					assert.NoError(t, header.SetExtension(2, []byte(rid)))
+
+					_, err = vp8Writer.bindings[0].writeStream.WriteRTP(header, []byte{0x00})
+					assert.NoError(t, err)
+				}
+
+				ridMapLock.Lock()
+				ridCount := len(ridMap)
+				ridMapLock.Unlock()
+				if ridCount == 3 {
+					return
+				}
+			}
+		}()
+
+		ridMapLock.Lock()
+		defer ridMapLock.Unlock()
+
+		for _, rid := range rids {
+			assert.Equal(t, ridMap[rid], 1)
+		}
+		assert.Equal(t, len(ridMap), 3)
+		closePairNow(t, pcOffer, pcAnswer)
+	})
+}