limit to receive only

pkg/rtc/participant_sdp.go

@@ -179,6 +179,10 @@ func (p *ParticipantImpl) populateMid(parsedOffer *sdp.SessionDescription) {
 				continue
 			}
 
+			if p.TransportManager.GetPublisherRTPTransceiverDirection(mid) != webrtc.RTPTransceiverDirectionRecvonly {
+				continue
+			}
+
 			p.pendingTracksLock.Lock()
 			signalCid, ti, migrated := p.getPendingTrackByTrackTypeWithoutMid(trackType)
 			if migrated || ti == nil || signalCid == "" {

pkg/rtc/transport.go

@@ -1160,6 +1160,16 @@ func (t *PCTransport) GetRTPReceiver(mid string) *webrtc.RTPReceiver {
 	return nil
 }
 
+func (t *PCTransport) GetRTPTransceiverDirection(mid string) webrtc.RTPTransceiverDirection {
+	for _, tr := range t.pc.GetTransceivers() {
+		if tr.Mid() == mid {
+			return tr.Direction()
+		}
+	}
+
+	return webrtc.RTPTransceiverDirectionUnknown
+}
+
 func (t *PCTransport) CreateDataChannel(label string, dci *webrtc.DataChannelInit) error {
 	dc, err := t.pc.CreateDataChannel(label, dci)
 	if err != nil {

pkg/rtc/transportmanager.go

@@ -248,6 +248,14 @@ func (t *TransportManager) GetPublisherRTPReceiver(mid string) *webrtc.RTPReceiv
 	}
 }
 
+func (t *TransportManager) GetPublisherRTPTransceiverDirection(mid string) webrtc.RTPTransceiverDirection {
+	if t.params.SinglePeerConnection {
+		return t.subscriber.GetRTPTransceiverDirection(mid)
+	} else {
+		return t.publisher.GetRTPTransceiverDirection(mid)
+	}
+}
+
 func (t *TransportManager) WritePublisherRTCP(pkts []rtcp.Packet) error {
 	if t.params.SinglePeerConnection {
 		return t.subscriber.WriteRTCP(pkts)