Do not pause rid in SDP (#4129)

pkg/rtc/transport.go

@@ -328,6 +328,9 @@ func newPeerConnection(params TransportParams, onBandwidthEstimator func(estimat
 
 	se := params.Config.SettingEngine
 	se.DisableMediaEngineCopy(true)
+	// simulcast layer disable/enable signalled via signalling channel,
+	// so disable rid pause in SDP
+	se.SetIgnoreRidPauseForRecv(true)
 
 	// Change elliptic curve to improve connectivity
 	// https://github.com/pion/dtls/pull/474
@@ -2033,6 +2036,7 @@ func (t *PCTransport) preparePC(previousAnswer webrtc.SessionDescription) error
 	//
 	se := webrtc.SettingEngine{}
 	_ = se.SetAnsweringDTLSRole(lksdp.ExtractDTLSRole(parsed))
+	se.SetIgnoreRidPauseForRecv(true)
 	api := webrtc.NewAPI(
 		webrtc.WithSettingEngine(se),
 		webrtc.WithMediaEngine(t.me),

pkg/sfu/buffer/buffer.go

@@ -335,7 +335,7 @@ func (b *Buffer) Bind(params webrtc.RTPParameters, codec webrtc.RTPCodecCapabili
 	}
 
 	if len(b.pPackets) != 0 {
-		b.logger.Debugw("releasing queued packets on bind")
+		b.logger.Debugw("releasing queued packets on bind", "count", len(b.pPackets))
 	}
 	for _, pp := range b.pPackets {
 		b.calc(pp.packet, nil, pp.arrivalTime, false, true)