Skip padding packet for simulcast probe

Skip padding packet for simulcast probe Fix rtx attributes panic for nil map
pion · Feb 2, 2024 · 519c332 · 519c332
1 parent c259e89
commit 519c332
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Showing 3 changed files with 15 additions and 3 deletions.
diff --git a/peerconnection.go b/peerconnection.go
@@ -1588,7 +1588,7 @@ func (pc *PeerConnection) handleIncomingSSRC(rtpStream io.Reader, ssrc SSRC) err
 	}
 
 	var mid, rid, rsid string
-	payloadType, err := handleUnknownRTPPacket(b[:i], uint8(midExtensionID), uint8(streamIDExtensionID), uint8(repairStreamIDExtensionID), &mid, &rid, &rsid)
+	payloadType, paddingOnly, err := handleUnknownRTPPacket(b[:i], uint8(midExtensionID), uint8(streamIDExtensionID), uint8(repairStreamIDExtensionID), &mid, &rid, &rsid)
 	if err != nil {
 		return err
 	}
@@ -1606,12 +1606,17 @@ func (pc *PeerConnection) handleIncomingSSRC(rtpStream io.Reader, ssrc SSRC) err
 
 	for readCount := 0; readCount <= simulcastProbeCount; readCount++ {
 		if mid == "" || (rid == "" && rsid == "") {
+			// skip padding only packets for probing
+			if paddingOnly {
+				readCount--
+			}
+
 			i, _, err := interceptor.Read(b, nil)
 			if err != nil {
 				return err
 			}
 
-			if _, err = handleUnknownRTPPacket(b[:i], uint8(midExtensionID), uint8(streamIDExtensionID), uint8(repairStreamIDExtensionID), &mid, &rid, &rsid); err != nil {
+			if _, paddingOnly, err = handleUnknownRTPPacket(b[:i], uint8(midExtensionID), uint8(streamIDExtensionID), uint8(repairStreamIDExtensionID), &mid, &rid, &rsid); err != nil {
 				return err
 			}
 

diff --git a/rtpreceiver.go b/rtpreceiver.go
@@ -463,6 +463,9 @@ func (r *RTPReceiver) receiveForRtx(ssrc SSRC, rsid string, streamInfo *intercep
 				continue
 			}
 
+			if attributes == nil {
+				attributes = make(interceptor.Attributes)
+			}
 			attributes.Set(AttributeRtxPayloadType, b[1]&0x7F)
 			attributes.Set(AttributeRtxSequenceNumber, binary.BigEndian.Uint16(b[2:4]))
 			attributes.Set(AttributeRtxSsrc, binary.BigEndian.Uint32(b[8:12]))

diff --git a/rtptransceiver.go b/rtptransceiver.go
@@ -266,7 +266,7 @@ func satisfyTypeAndDirection(remoteKind RTPCodecType, remoteDirection RTPTransce
 
 // handleUnknownRTPPacket consumes a single RTP Packet and returns information that is helpful
 // for demuxing and handling an unknown SSRC (usually for Simulcast)
-func handleUnknownRTPPacket(buf []byte, midExtensionID, streamIDExtensionID, repairStreamIDExtensionID uint8, mid, rid, rsid *string) (payloadType PayloadType, err error) {
+func handleUnknownRTPPacket(buf []byte, midExtensionID, streamIDExtensionID, repairStreamIDExtensionID uint8, mid, rid, rsid *string) (payloadType PayloadType, paddingOnly bool, err error) {
 	rp := &rtp.Packet{}
 	if err = rp.Unmarshal(buf); err != nil {
 		return
@@ -289,5 +289,9 @@ func handleUnknownRTPPacket(buf []byte, midExtensionID, streamIDExtensionID, rep
 		*rsid = string(payload)
 	}
 
+	if rp.Padding && len(rp.Payload) == 0 {
+		paddingOnly = true
+	}
+
 	return
 }