server: support setupping tracks with arbitrary interleaved IDs (#47)

client_publish_test.go

@@ -131,7 +131,7 @@ func TestClientPublishSerial(t *testing.T) {
 					f.Payload = make([]byte, 2048)
 					err = f.Read(bconn.Reader)
 					require.NoError(t, err)
-					require.Equal(t, StreamTypeRTP, f.StreamType)
+					require.Equal(t, 0, f.Channel)
 					require.Equal(t, []byte{0x01, 0x02, 0x03, 0x04}, f.Payload)
 				}
 
@@ -143,8 +143,7 @@ func TestClientPublishSerial(t *testing.T) {
 					})
 				} else {
 					err = base.InterleavedFrame{
-						TrackID:    0,
+						Channel: 1,
-						StreamType: StreamTypeRTCP,
 						Payload: []byte{0x05, 0x06, 0x07, 0x08},
 					}.Write(bconn.Writer)
 					require.NoError(t, err)
@@ -735,7 +734,7 @@ func TestClientPublishAutomaticProtocol(t *testing.T) {
 		f.Payload = make([]byte, 2048)
 		err = f.Read(bconn.Reader)
 		require.NoError(t, err)
-		require.Equal(t, StreamTypeRTP, f.StreamType)
+		require.Equal(t, 0, f.Channel)
 		require.Equal(t, []byte{0x01, 0x02, 0x03, 0x04}, f.Payload)
 
 		req, err = readRequest(bconn.Reader)
@@ -841,13 +840,13 @@ func TestClientPublishRTCPReport(t *testing.T) {
 		f.Payload = make([]byte, 2048)
 		err = f.Read(bconn.Reader)
 		require.NoError(t, err)
-		require.Equal(t, StreamTypeRTP, f.StreamType)
+		require.Equal(t, 0, f.Channel)
 		rr.ProcessFrame(time.Now(), StreamTypeRTP, f.Payload)
 
 		f.Payload = make([]byte, 2048)
 		err = f.Read(bconn.Reader)
 		require.NoError(t, err)
-		require.Equal(t, StreamTypeRTCP, f.StreamType)
+		require.Equal(t, 1, f.Channel)
 		pkt, err := rtcp.Unmarshal(f.Payload)
 		require.NoError(t, err)
 		sr, ok := pkt[0].(*rtcp.SenderReport)
@@ -862,8 +861,7 @@ func TestClientPublishRTCPReport(t *testing.T) {
 		rr.ProcessFrame(time.Now(), StreamTypeRTCP, f.Payload)
 
 		err = base.InterleavedFrame{
-			TrackID:    0,
+			Channel: 1,
-			StreamType: StreamTypeRTCP,
 			Payload: rr.Report(time.Now()),
 		}.Write(bconn.Writer)
 		require.NoError(t, err)
@@ -871,7 +869,7 @@ func TestClientPublishRTCPReport(t *testing.T) {
 		f.Payload = make([]byte, 2048)
 		err = f.Read(bconn.Reader)
 		require.NoError(t, err)
-		require.Equal(t, StreamTypeRTP, f.StreamType)
+		require.Equal(t, 0, f.Channel)
 
 		req, err = readRequest(bconn.Reader)
 		require.NoError(t, err)

client_read_test.go

@@ -346,8 +346,7 @@ func TestClientRead(t *testing.T) {
 
 				case "tcp", "tls":
 					err = base.InterleavedFrame{
-						TrackID:    0,
+						Channel: 0,
-						StreamType: StreamTypeRTP,
 						Payload: []byte{0x01, 0x02, 0x03, 0x04},
 					}.Write(bconn.Writer)
 					require.NoError(t, err)
@@ -372,8 +371,7 @@ func TestClientRead(t *testing.T) {
 					f.Payload = make([]byte, 2048)
 					err := f.Read(bconn.Reader)
 					require.NoError(t, err)
-					require.Equal(t, 0, f.TrackID)
+					require.Equal(t, 1, f.Channel)
-					require.Equal(t, StreamTypeRTCP, f.StreamType)
 					require.Equal(t, []byte{0x05, 0x06, 0x07, 0x08}, f.Payload)
 					close(frameRecv)
 				}
@@ -520,8 +518,7 @@ func TestClientReadPartial(t *testing.T) {
 		require.NoError(t, err)
 
 		err = base.InterleavedFrame{
-			TrackID:    0,
+			Channel: 0,
-			StreamType: StreamTypeRTP,
 			Payload: []byte{0x01, 0x02, 0x03, 0x04},
 		}.Write(bconn.Writer)
 		require.NoError(t, err)
@@ -907,8 +904,7 @@ func TestClientReadAutomaticProtocol(t *testing.T) {
 			require.NoError(t, err)
 
 			err = base.InterleavedFrame{
-				TrackID:    0,
+				Channel: 0,
-				StreamType: StreamTypeRTP,
 				Payload: []byte("\x00\x00\x00\x00"),
 			}.Write(bconn.Writer)
 			require.NoError(t, err)
@@ -1101,8 +1097,7 @@ func TestClientReadAutomaticProtocol(t *testing.T) {
 			require.NoError(t, err)
 
 			base.InterleavedFrame{
-				TrackID:    0,
+				Channel: 0,
-				StreamType: StreamTypeRTP,
 				Payload: []byte("\x00\x00\x00\x00"),
 			}.Write(bconn.Writer)
 
@@ -1315,8 +1310,7 @@ func TestClientReadPause(t *testing.T) {
 						})
 					} else {
 						base.InterleavedFrame{
-							TrackID:    0,
+							Channel: 0,
-							StreamType: StreamTypeRTP,
 							Payload: []byte("\x00\x00\x00\x00"),
 						}.Write(bconn.Writer)
 					}
@@ -1617,16 +1611,14 @@ func TestClientReadRTCPReport(t *testing.T) {
 			Payload: []byte{0x01, 0x02, 0x03, 0x04},
 		}).Marshal()
 		err = base.InterleavedFrame{
-			TrackID:    0,
+			Channel: 0,
-			StreamType: StreamTypeRTP,
 			Payload: byts,
 		}.Write(bconn.Writer)
 		require.NoError(t, err)
 		rs.ProcessFrame(time.Now(), StreamTypeRTP, byts)
 
 		err = base.InterleavedFrame{
-			TrackID:    0,
+			Channel: 1,
-			StreamType: StreamTypeRTCP,
 			Payload: rs.Report(time.Now()),
 		}.Write(bconn.Writer)
 		require.NoError(t, err)
@@ -1635,7 +1627,7 @@ func TestClientReadRTCPReport(t *testing.T) {
 		f.Payload = make([]byte, 2048)
 		err = f.Read(bconn.Reader)
 		require.NoError(t, err)
-		require.Equal(t, StreamTypeRTCP, f.StreamType)
+		require.Equal(t, 1, f.Channel)
 		pkt, err := rtcp.Unmarshal(f.Payload)
 		require.NoError(t, err)
 		rr, ok := pkt[0].(*rtcp.ReceiverReport)
@@ -1654,8 +1646,7 @@ func TestClientReadRTCPReport(t *testing.T) {
 		}, rr)
 
 		err = base.InterleavedFrame{
-			TrackID:    0,
+			Channel: 0,
-			StreamType: StreamTypeRTP,
 			Payload: byts,
 		}.Write(bconn.Writer)
 		require.NoError(t, err)
@@ -1940,15 +1931,13 @@ func TestClientReadIgnoreTCPInvalidTrack(t *testing.T) {
 		require.NoError(t, err)
 
 		err = base.InterleavedFrame{
-			TrackID:    3,
+			Channel: 6,
-			StreamType: StreamTypeRTP,
 			Payload: []byte{0x01, 0x02, 0x03, 0x04},
 		}.Write(bconn.Writer)
 		require.NoError(t, err)
 
 		err = base.InterleavedFrame{
-			TrackID:    0,
+			Channel: 0,
-			StreamType: StreamTypeRTP,
 			Payload: []byte{0x05, 0x06, 0x07, 0x08},
 		}.Write(bconn.Writer)
 		require.NoError(t, err)

clientconn.go

@@ -31,6 +31,20 @@ const (
 	clientConnUDPKeepalivePeriod = 30 * time.Second
 )
 
+func clientChannelToTrackID(channel int) (int, StreamType) {
+	if (channel % 2) == 0 {
+		return channel / 2, StreamTypeRTP
+	}
+	return (channel - 1) / 2, StreamTypeRTCP
+}
+
+func clientTrackIDToChannel(trackID int, streamType StreamType) int {
+	if streamType == StreamTypeRTP {
+		return trackID * 2
+	}
+	return (trackID * 2) + 1
+}
+
 func isErrNOUDPPacketsReceivedRecently(err error) bool {
 	_, ok := err.(liberrors.ErrClientNoUDPPacketsRecently)
 	return ok
@@ -617,15 +631,17 @@ func (cc *ClientConn) runBackgroundPlayTCP() error {
 				return
 			}
 
-			track, ok := cc.tracks[frame.TrackID]
+			trackID, streamType := clientChannelToTrackID(frame.Channel)
+
+			track, ok := cc.tracks[trackID]
 			if !ok {
 				continue
 			}
 
 			now := time.Now()
 			atomic.StoreInt64(&lastFrameTime, now.Unix())
-			track.rtcpReceiver.ProcessFrame(now, frame.StreamType, frame.Payload)
+			track.rtcpReceiver.ProcessFrame(now, streamType, frame.Payload)
-			cc.pullReadCB()(frame.TrackID, frame.StreamType, frame.Payload)
+			cc.pullReadCB()(trackID, streamType, frame.Payload)
 		}
 	}()
 
@@ -736,7 +752,9 @@ func (cc *ClientConn) runBackgroundRecordTCP() error {
 				return
 			}
 
-			cc.pullReadCB()(frame.TrackID, frame.StreamType, frame.Payload)
+			trackID, streamType := clientChannelToTrackID(frame.Channel)
+
+			cc.pullReadCB()(trackID, streamType, frame.Payload)
 		}
 	}()
 
@@ -1347,8 +1365,7 @@ func (cc *ClientConn) doSetup(
 			return nil, liberrors.ErrClientTransportHeaderNoInterleavedIDs{}
 		}
 
-		if thRes.InterleavedIDs[0] != th.InterleavedIDs[0] ||
+		if *thRes.InterleavedIDs != *th.InterleavedIDs {
-			thRes.InterleavedIDs[1] != th.InterleavedIDs[1] {
 			return nil, liberrors.ErrClientTransportHeaderInvalidInterleavedIDs{
 				Expected: *th.InterleavedIDs, Value: *thRes.InterleavedIDs,
 			}
@@ -1665,10 +1682,11 @@ func (cc *ClientConn) WriteFrame(trackID int, streamType StreamType, payload []b
 		cc.tcpWriteMutex.Lock()
 		defer cc.tcpWriteMutex.Unlock()
 
+		channel := clientTrackIDToChannel(trackID, streamType)
+
 		cc.nconn.SetWriteDeadline(now.Add(cc.c.WriteTimeout))
 		return base.InterleavedFrame{
-			TrackID:    trackID,
+			Channel: channel,
-			StreamType: streamType,
 			Payload: payload,
 		}.Write(cc.bw)
 	}

pkg/base/interleavedframe.go

@@ -60,11 +60,8 @@ func ReadInterleavedFrameOrResponse(frame *InterleavedFrame, res *Response, br *
 // InterleavedFrame is an interleaved frame, and allows to transfer binary data
 // within RTSP/TCP connections. It is used to send and receive RTP and RTCP packets with TCP.
 type InterleavedFrame struct {
-	// track id
+	// channel id
-	TrackID int
+	Channel int
-
-	// stream type
-	StreamType StreamType
 
 	// frame payload
 	Payload []byte
@@ -88,15 +85,7 @@ func (f *InterleavedFrame) Read(br *bufio.Reader) error {
 			framelen, len(f.Payload))
 	}
 
-	// convert channel into TrackID and StreamType
+	f.Channel = int(header[1])
-	channel := header[1]
-	f.TrackID, f.StreamType = func() (int, StreamType) {
-		if (channel % 2) == 0 {
-			return int(channel / 2), StreamTypeRTP
-		}
-		return int((channel - 1) / 2), StreamTypeRTCP
-	}()
-
 	f.Payload = f.Payload[:framelen]
 
 	_, err = io.ReadFull(br, f.Payload)
@@ -108,15 +97,7 @@ func (f *InterleavedFrame) Read(br *bufio.Reader) error {
 
 // Write writes an InterleavedFrame into a buffered writer.
 func (f InterleavedFrame) Write(bw *bufio.Writer) error {
-	// convert TrackID and StreamType into channel
+	buf := []byte{0x24, byte(f.Channel), 0x00, 0x00}
-	channel := func() uint8 {
-		if f.StreamType == StreamTypeRTP {
-			return uint8(f.TrackID * 2)
-		}
-		return uint8((f.TrackID * 2) + 1)
-	}()
-
-	buf := []byte{0x24, channel, 0x00, 0x00}
 	binary.BigEndian.PutUint16(buf[2:], uint16(len(f.Payload)))
 
 	_, err := bw.Write(buf)

pkg/base/interleavedframe_test.go

@@ -17,8 +17,7 @@ var casesInterleavedFrame = []struct {
 		name: "rtp",
 		enc:  []byte{0x24, 0x6, 0x0, 0x4, 0x1, 0x2, 0x3, 0x4},
 		dec: InterleavedFrame{
-			TrackID:    3,
+			Channel: 6,
-			StreamType: StreamTypeRTP,
 			Payload: []byte{0x01, 0x02, 0x03, 0x04},
 		},
 	},
@@ -26,8 +25,7 @@ var casesInterleavedFrame = []struct {
 		name: "rtcp",
 		enc:  []byte{0x24, 0xd, 0x0, 0x4, 0x5, 0x6, 0x7, 0x8},
 		dec: InterleavedFrame{
-			TrackID:    6,
+			Channel: 13,
-			StreamType: StreamTypeRTCP,
 			Payload: []byte{0x05, 0x06, 0x07, 0x08},
 		},
 	},
@@ -113,8 +111,7 @@ func TestInterleavedFrameWriteErrors(t *testing.T) {
 		t.Run(ca.name, func(t *testing.T) {
 			bw := bufio.NewWriterSize(&limitedBuffer{cap: ca.cap}, 1)
 			err := InterleavedFrame{
-				TrackID:    3,
+				Channel: 3,
-				StreamType: StreamTypeRTP,
 				Payload: []byte{0x01, 0x02, 0x03, 0x04},
 			}.Write(bw)
 			require.Equal(t, "capacity reached", err.Error())

pkg/liberrors/server.go

@@ -168,14 +168,11 @@ func (e ErrServerTransportHeaderNoInterleavedIDs) Error() string {
 }
 
 // ErrServerTransportHeaderInvalidInterleavedIDs is an error that can be returned by a server.
-type ErrServerTransportHeaderInvalidInterleavedIDs struct {
+type ErrServerTransportHeaderInvalidInterleavedIDs struct{}
-	Expected [2]int
-	Value    [2]int
-}
 
 // Error implements the error interface.
 func (e ErrServerTransportHeaderInvalidInterleavedIDs) Error() string {
-	return fmt.Sprintf("invalid interleaved IDs, expected %v, got %v", e.Expected, e.Value)
+	return "invalid interleaved IDs"
 }
 
 // ErrServerTracksDifferentProtocols is an error that can be returned by a server.

server_publish_test.go

@@ -850,15 +850,13 @@ func TestServerPublish(t *testing.T) {
 
 			} else {
 				err = base.InterleavedFrame{
-					TrackID:    0,
+					Channel: 0,
-					StreamType: StreamTypeRTP,
 					Payload: []byte{0x01, 0x02, 0x03, 0x04},
 				}.Write(bconn.Writer)
 				require.NoError(t, err)
 
 				err = base.InterleavedFrame{
-					TrackID:    0,
+					Channel: 1,
-					StreamType: StreamTypeRTCP,
 					Payload: []byte{0x05, 0x06, 0x07, 0x08},
 				}.Write(bconn.Writer)
 				require.NoError(t, err)
@@ -881,7 +879,7 @@ func TestServerPublish(t *testing.T) {
 				f.Payload = make([]byte, 2048)
 				err := f.Read(bconn.Reader)
 				require.NoError(t, err)
-				require.Equal(t, StreamTypeRTCP, f.StreamType)
+				require.Equal(t, 1, f.Channel)
 				require.Equal(t, []byte{0x09, 0x0A, 0x0B, 0x0C}, f.Payload)
 			}
 
@@ -1003,8 +1001,7 @@ func TestServerPublishErrorInvalidProtocol(t *testing.T) {
 	require.Equal(t, base.StatusOK, res.StatusCode)
 
 	err = base.InterleavedFrame{
-		TrackID:    0,
+		Channel: 0,
-		StreamType: StreamTypeRTP,
 		Payload: []byte{0x01, 0x02, 0x03, 0x04},
 	}.Write(bconn.Writer)
 	require.NoError(t, err)
@@ -1116,8 +1113,7 @@ func TestServerPublishRTCPReport(t *testing.T) {
 		Payload: []byte{0x01, 0x02, 0x03, 0x04},
 	}).Marshal()
 	err = base.InterleavedFrame{
-		TrackID:    0,
+		Channel: 0,
-		StreamType: StreamTypeRTP,
 		Payload: byts,
 	}.Write(bconn.Writer)
 	require.NoError(t, err)
@@ -1126,7 +1122,7 @@ func TestServerPublishRTCPReport(t *testing.T) {
 	f.Payload = make([]byte, 2048)
 	f.Read(bconn.Reader)
 	require.NoError(t, err)
-	require.Equal(t, StreamTypeRTCP, f.StreamType)
+	require.Equal(t, 1, f.Channel)
 	pkt, err := rtcp.Unmarshal(f.Payload)
 	require.NoError(t, err)
 	rr, ok := pkt[0].(*rtcp.ReceiverReport)
@@ -1145,8 +1141,7 @@ func TestServerPublishRTCPReport(t *testing.T) {
 	}, rr)
 
 	err = base.InterleavedFrame{
-		TrackID:    0,
+		Channel: 0,
-		StreamType: StreamTypeRTP,
 		Payload: byts,
 	}.Write(bconn.Writer)
 	require.NoError(t, err)

server_read_test.go

@@ -413,7 +413,7 @@ func TestServerRead(t *testing.T) {
 				v := base.StreamDeliveryUnicast
 				inTH.Delivery = &v
 				inTH.Protocol = base.StreamProtocolTCP
-				inTH.InterleavedIDs = &[2]int{0, 1}
+				inTH.InterleavedIDs = &[2]int{4, 5}
 			}
 
 			res, err := writeReqReadRes(bconn, base.Request{
@@ -509,15 +509,13 @@ func TestServerRead(t *testing.T) {
 				f.Payload = make([]byte, 2048)
 				err := f.Read(bconn.Reader)
 				require.NoError(t, err)
-				require.Equal(t, 0, f.TrackID)
+				require.Equal(t, 4, f.Channel)
-				require.Equal(t, StreamTypeRTP, f.StreamType)
 				require.Equal(t, []byte{0x01, 0x02, 0x03, 0x04}, f.Payload)
 
 				f.Payload = make([]byte, 2048)
 				err = f.Read(bconn.Reader)
 				require.NoError(t, err)
-				require.Equal(t, 0, f.TrackID)
+				require.Equal(t, 5, f.Channel)
-				require.Equal(t, StreamTypeRTCP, f.StreamType)
 				require.Equal(t, []byte{0x05, 0x06, 0x07, 0x08}, f.Payload)
 			}
 
@@ -539,8 +537,7 @@ func TestServerRead(t *testing.T) {
 
 			default:
 				err = base.InterleavedFrame{
-					TrackID:    0,
+					Channel: 5,
-					StreamType: StreamTypeRTCP,
 					Payload: []byte{0x01, 0x02, 0x03, 0x04},
 				}.Write(bconn.Writer)
 				require.NoError(t, err)
@@ -1372,8 +1369,7 @@ func TestServerReadNonSetuppedPath(t *testing.T) {
 	f.Payload = make([]byte, 2048)
 	err = f.Read(bconn.Reader)
 	require.NoError(t, err)
-	require.Equal(t, 0, f.TrackID)
+	require.Equal(t, 0, f.Channel)
-	require.Equal(t, StreamTypeRTP, f.StreamType)
 	require.Equal(t, []byte{0x05, 0x06, 0x07, 0x08}, f.Payload)
 }
 

serverconn.go

@@ -152,18 +152,25 @@ func (sc *ServerConn) run() {
 
 					switch what.(type) {
 					case *base.InterleavedFrame:
+						channel := frame.Channel
+						streamType := base.StreamTypeRTP
+						if (channel % 2) != 0 {
+							channel--
+							streamType = base.StreamTypeRTCP
+						}
+
 						// forward frame only if it has been set up
-						if _, ok := sc.tcpSession.setuppedTracks[frame.TrackID]; ok {
+						if trackID, ok := sc.tcpSession.setuppedTracksByChannel[channel]; ok {
 							if sc.tcpFrameIsRecording {
-								sc.tcpSession.announcedTracks[frame.TrackID].rtcpReceiver.ProcessFrame(time.Now(),
+								sc.tcpSession.announcedTracks[trackID].rtcpReceiver.ProcessFrame(
-									frame.StreamType, frame.Payload)
+									time.Now(), streamType, frame.Payload)
 							}
 
 							if h, ok := sc.s.Handler.(ServerHandlerOnFrame); ok {
 								h.OnFrame(&ServerHandlerOnFrameCtx{
 									Session:    sc.tcpSession,
-									TrackID:    frame.TrackID,
+									TrackID:    trackID,
-									StreamType: frame.StreamType,
+									StreamType: streamType,
 									Payload:    frame.Payload,
 								})
 							}

serversession.go

@@ -106,6 +106,7 @@ func (s ServerSessionState) String() string {
 
 // ServerSessionSetuppedTrack is a setupped track of a ServerSession.
 type ServerSessionSetuppedTrack struct {
+	tcpChannel  int
 	udpRTPPort  int
 	udpRTCPPort int
 }
@@ -127,6 +128,7 @@ type ServerSession struct {
 	conns                   map[*ServerConn]struct{}
 	state                   ServerSessionState
 	setuppedTracks          map[int]ServerSessionSetuppedTrack
+	setuppedTracksByChannel map[int]int // tcp
 	setuppedProtocol        *base.StreamProtocol
 	setuppedDelivery        *base.StreamDelivery
 	setuppedBaseURL         *base.URL     // publish
@@ -608,13 +610,17 @@ func (ss *ServerSession) handleRequest(sc *ServerConn, req *base.Request) (*base
 				}, liberrors.ErrServerTransportHeaderNoInterleavedIDs{}
 			}
 
-			if inTH.InterleavedIDs[0] != (trackID*2) ||
+			if (inTH.InterleavedIDs[0]+1) != inTH.InterleavedIDs[1] ||
-				inTH.InterleavedIDs[1] != (1+trackID*2) {
+				(inTH.InterleavedIDs[0]%2) != 0 {
 				return &base.Response{
 					StatusCode: base.StatusBadRequest,
-					}, liberrors.ErrServerTransportHeaderInvalidInterleavedIDs{
+				}, liberrors.ErrServerTransportHeaderInvalidInterleavedIDs{}
-						Expected: [2]int{(trackID * 2), (1 + trackID*2)}, Value: *inTH.InterleavedIDs,
 			}
+
+			if _, ok := ss.setuppedTracksByChannel[inTH.InterleavedIDs[0]]; ok {
+				return &base.Response{
+					StatusCode: base.StatusBadRequest,
+				}, liberrors.ErrServerTransportHeaderInvalidInterleavedIDs{}
 			}
 		}
 
@@ -700,7 +706,15 @@ func (ss *ServerSession) handleRequest(sc *ServerConn, req *base.Request) (*base
 				th.ServerPorts = &[2]int{sc.s.udpRTPListener.port(), sc.s.udpRTCPListener.port()}
 
 			default: // TCP
-				ss.setuppedTracks[trackID] = ServerSessionSetuppedTrack{}
+				ss.setuppedTracks[trackID] = ServerSessionSetuppedTrack{
+					tcpChannel: inTH.InterleavedIDs[0],
+				}
+
+				if ss.setuppedTracksByChannel == nil {
+					ss.setuppedTracksByChannel = make(map[int]int)
+				}
+
+				ss.setuppedTracksByChannel[inTH.InterleavedIDs[0]] = trackID
 
 				th.Protocol = base.StreamProtocolTCP
 				de := base.StreamDeliveryUnicast
@@ -1013,7 +1027,7 @@ func (ss *ServerSession) handleRequest(sc *ServerConn, req *base.Request) (*base
 
 // WriteFrame writes a frame to the session.
 func (ss *ServerSession) WriteFrame(trackID int, streamType StreamType, payload []byte) {
-	if _, ok := ss.SetuppedTracks()[trackID]; !ok {
+	if _, ok := ss.setuppedTracks[trackID]; !ok {
 		return
 	}
 
@@ -1036,9 +1050,13 @@ func (ss *ServerSession) WriteFrame(trackID int, streamType StreamType, payload
 			}
 		}
 	} else {
+		channel := ss.setuppedTracks[trackID].tcpChannel
+		if streamType == base.StreamTypeRTCP {
+			channel++
+		}
+
 		ss.tcpConn.tcpFrameWriteBuffer.Push(&base.InterleavedFrame{
-			TrackID:    trackID,
+			Channel: channel,
-			StreamType: streamType,
 			Payload: payload,
 		})
 	}