Revert "Add currentDirection to RTPTransceiver"

This reverts commit 045df4c4bf.

peerconnection.go

@@ -991,7 +991,6 @@ func (pc *PeerConnection) SetLocalDescription(desc SessionDescription) error {
 	weAnswer := desc.Type == SDPTypeAnswer
 	remoteDesc := pc.RemoteDescription()
 	if weAnswer && remoteDesc != nil {
-		_ = setRTPTransceiverCurrentDirection(&desc, currentTransceivers, false)
 		if err := pc.startRTPSenders(currentTransceivers); err != nil {
 			return err
 		}
@@ -1151,7 +1150,6 @@ func (pc *PeerConnection) SetRemoteDescription(desc SessionDescription) error {
 
 	if isRenegotation {
 		if weOffer {
-			_ = setRTPTransceiverCurrentDirection(&desc, currentTransceivers, true)
 			if err = pc.startRTPSenders(currentTransceivers); err != nil {
 				return err
 			}
@@ -1181,7 +1179,6 @@ func (pc *PeerConnection) SetRemoteDescription(desc SessionDescription) error {
 	// Start the networking in a new routine since it will block until
 	// the connection is actually established.
 	if weOffer {
-		_ = setRTPTransceiverCurrentDirection(&desc, currentTransceivers, true)
 		if err := pc.startRTPSenders(currentTransceivers); err != nil {
 			return err
 		}
@@ -1240,51 +1237,6 @@ func (pc *PeerConnection) startReceiver(incoming trackDetails, receiver *RTPRece
 	}
 }
 
-func setRTPTransceiverCurrentDirection(answer *SessionDescription, currentTransceivers []*RTPTransceiver, weOffer bool) error {
-	currentTransceivers = append([]*RTPTransceiver{}, currentTransceivers...)
-	for _, media := range answer.parsed.MediaDescriptions {
-		midValue := getMidValue(media)
-		if midValue == "" {
-			return errPeerConnRemoteDescriptionWithoutMidValue
-		}
-
-		if media.MediaName.Media == mediaSectionApplication {
-			continue
-		}
-
-		var t *RTPTransceiver
-		t, currentTransceivers = findByMid(midValue, currentTransceivers)
-
-		if t == nil {
-			return fmt.Errorf("%w: %q", errPeerConnTranscieverMidNil, midValue)
-		}
-
-		direction := getPeerDirection(media)
-		if direction == RTPTransceiverDirection(Unknown) {
-			continue
-		}
-
-		// reverse direction if it was a remote answer
-		if weOffer {
-			switch direction {
-			case RTPTransceiverDirectionSendonly:
-				direction = RTPTransceiverDirectionRecvonly
-			case RTPTransceiverDirectionRecvonly:
-				// Pion will answer recvonly with a offer recvonly transceiver, so we should
-				// not change the direction to sendonly if we are the offerer, otherwise this
-				// tranceiver can't be reuse for AddTrack
-				if t.Direction() != RTPTransceiverDirectionRecvonly {
-					direction = RTPTransceiverDirectionSendonly
-				}
-			default:
-			}
-		}
-
-		t.setCurrentDirection(direction)
-	}
-	return nil
-}
-
 func runIfNewReceiver(
 	incomingTrack trackDetails,
 	transceivers []*RTPTransceiver,
@@ -1771,13 +1723,7 @@ func (pc *PeerConnection) AddTrack(track TrackLocal) (*RTPSender, error) {
 	pc.mu.Lock()
 	defer pc.mu.Unlock()
 	for _, t := range pc.rtpTransceivers {
-		currentDirection := t.getCurrentDirection()
-		// According to https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-addtrack, if the
-		// transceiver can be reused only if it's currentDirection never be sendrecv or sendonly.
-		// But that will cause sdp inflate. So we only check currentDirection's current value,
-		// that's worked for all browsers.
-		if !t.stopped && t.kind == track.Kind() && t.Sender() == nil &&
-			!(currentDirection == RTPTransceiverDirectionSendrecv || currentDirection == RTPTransceiverDirectionSendonly) {
+		if !t.stopped && t.kind == track.Kind() && t.Sender() == nil {
 			sender, err := pc.api.NewRTPSender(track, pc.dtlsTransport)
 			if err == nil {
 				err = t.SetSender(sender, track)

peerconnection_renegotiation_test.go

@@ -129,14 +129,14 @@ func TestPeerConnection_Renegotiation_AddRecvonlyTransceiver(t *testing.T) {
 				pcOffer.OnTrack(func(track *TrackRemote, r *RTPReceiver) {
 					onTrackFiredFunc()
 				})
-				assert.NoError(t, signalPair(pcAnswer, pcOffer))
 			} else {
 				pcAnswer.OnTrack(func(track *TrackRemote, r *RTPReceiver) {
 					onTrackFiredFunc()
 				})
-				assert.NoError(t, signalPair(pcOffer, pcAnswer))
 			}
 
+			assert.NoError(t, signalPair(pcOffer, pcAnswer))
+
 			sendVideoUntilDone(onTrackFired.Done(), t, []*TrackLocalStaticSample{localTrack})
 
 			closePairNow(t, pcOffer, pcAnswer)
@@ -381,7 +381,6 @@ func TestPeerConnection_Transceiver_Mid(t *testing.T) {
 
 	offer, err = pcOffer.CreateOffer(nil)
 	assert.NoError(t, err)
-	assert.NoError(t, pcOffer.SetLocalDescription(offer))
 
 	assert.Equal(t, len(offer.parsed.MediaDescriptions), 2)
 
@@ -393,11 +392,6 @@ func TestPeerConnection_Transceiver_Mid(t *testing.T) {
 	pcOffer.ops.Done()
 	pcAnswer.ops.Done()
 
-	assert.NoError(t, pcAnswer.SetRemoteDescription(offer))
-	answer, err = pcAnswer.CreateAnswer(nil)
-	assert.NoError(t, err)
-	assert.NoError(t, pcOffer.SetRemoteDescription(answer))
-
 	track3, err := NewTrackLocalStaticSample(RTPCodecCapability{MimeType: MimeTypeVP8}, "video", "pion3")
 	require.NoError(t, err)
 
@@ -475,12 +469,12 @@ func TestPeerConnection_Renegotiation_CodecChange(t *testing.T) {
 
 	require.NoError(t, pcOffer.RemoveTrack(sender1))
 
+	sender2, err := pcOffer.AddTrack(track2)
+	require.NoError(t, err)
+
 	require.NoError(t, signalPair(pcOffer, pcAnswer))
 	<-tracksClosed
 
-	sender2, err := pcOffer.AddTrack(track2)
-	require.NoError(t, err)
-	require.NoError(t, signalPair(pcOffer, pcAnswer))
 	transceivers = pcOffer.GetTransceivers()
 	require.Equal(t, 1, len(transceivers))
 	require.Equal(t, "0", transceivers[0].Mid())
@@ -1153,47 +1147,6 @@ func TestPeerConnection_Renegotiation_Simulcast(t *testing.T) {
 	})
 }
 
-func TestPeerConnection_Regegotiation_ReuseTransceiver(t *testing.T) {
-	lim := test.TimeOut(time.Second * 30)
-	defer lim.Stop()
-
-	report := test.CheckRoutines(t)
-	defer report()
-
-	pcOffer, pcAnswer, err := newPair()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	vp8Track, err := NewTrackLocalStaticSample(RTPCodecCapability{MimeType: MimeTypeVP8}, "foo", "bar")
-	assert.NoError(t, err)
-	sender, err := pcOffer.AddTrack(vp8Track)
-	assert.NoError(t, err)
-	assert.NoError(t, signalPair(pcOffer, pcAnswer))
-
-	assert.Equal(t, len(pcOffer.GetTransceivers()), 1)
-	assert.Equal(t, pcOffer.GetTransceivers()[0].getCurrentDirection(), RTPTransceiverDirectionSendonly)
-	assert.NoError(t, pcOffer.RemoveTrack(sender))
-	assert.Equal(t, pcOffer.GetTransceivers()[0].getCurrentDirection(), RTPTransceiverDirectionSendonly)
-
-	// should not reuse tranceiver
-	vp8Track2, err := NewTrackLocalStaticSample(RTPCodecCapability{MimeType: MimeTypeVP8}, "foo", "bar")
-	assert.NoError(t, err)
-	sender2, err := pcOffer.AddTrack(vp8Track2)
-	assert.NoError(t, err)
-	assert.Equal(t, len(pcOffer.GetTransceivers()), 2)
-	assert.NoError(t, signalPair(pcOffer, pcAnswer))
-	assert.True(t, sender2.rtpTransceiver == pcOffer.GetTransceivers()[1])
-
-	// should reuse first transceiver
-	sender, err = pcOffer.AddTrack(vp8Track)
-	assert.NoError(t, err)
-	assert.Equal(t, len(pcOffer.GetTransceivers()), 2)
-	assert.True(t, sender.rtpTransceiver == pcOffer.GetTransceivers()[0])
-
-	closePairNow(t, pcOffer, pcAnswer)
-}
-
 func TestPeerConnection_Renegotiation_MidConflict(t *testing.T) {
 	lim := test.TimeOut(time.Second * 30)
 	defer lim.Stop()

rtptransceiver.go

@@ -13,11 +13,10 @@ import (
 
 // RTPTransceiver represents a combination of an RTPSender and an RTPReceiver that share a common mid.
 type RTPTransceiver struct {
-	mid              atomic.Value // string
-	sender           atomic.Value // *RTPSender
-	receiver         atomic.Value // *RTPReceiver
-	direction        atomic.Value // RTPTransceiverDirection
-	currentDirection atomic.Value // RTPTransceiverDirection
+	mid       atomic.Value // string
+	sender    atomic.Value // *RTPSender
+	receiver  atomic.Value // *RTPReceiver
+	direction atomic.Value // RTPTransceiverDirection
 
 	codecs []RTPCodecParameters // User provided codecs via SetCodecPreferences
 
@@ -39,7 +38,6 @@ func newRTPTransceiver(
 	t.setReceiver(receiver)
 	t.setSender(sender)
 	t.setDirection(direction)
-	t.setCurrentDirection(RTPTransceiverDirection(Unknown))
 	return t
 }
 
@@ -162,7 +160,6 @@ func (t *RTPTransceiver) Stop() error {
 	}
 
 	t.setDirection(RTPTransceiverDirectionInactive)
-	t.setCurrentDirection(RTPTransceiverDirectionInactive)
 	return nil
 }
 
@@ -182,17 +179,6 @@ func (t *RTPTransceiver) setDirection(d RTPTransceiverDirection) {
 	t.direction.Store(d)
 }
 
-func (t *RTPTransceiver) setCurrentDirection(d RTPTransceiverDirection) {
-	t.currentDirection.Store(d)
-}
-
-func (t *RTPTransceiver) getCurrentDirection() RTPTransceiverDirection {
-	if v, ok := t.currentDirection.Load().(RTPTransceiverDirection); ok {
-		return v
-	}
-	return RTPTransceiverDirection(Unknown)
-}
-
 func (t *RTPTransceiver) setSendingTrack(track TrackLocal) error {
 	if err := t.Sender().ReplaceTrack(track); err != nil {
 		return err