fix overriding of previously-received RTP packets that leaded to crashes

RTP packets were previously take from a buffer pool. This was messing
up the Client, since that buffer pool was used by multiple routines at
once, and was probably messing up the Server too, since packets can be
pushed to different queues and there's no guarantee that these queues
have an overall size less than ReadBufferCount.

This buffer pool is removed; this decreases performance but avoids bugs.

client.go

@@ -236,7 +236,6 @@ type Client struct {
 	medias             map[*media.Media]*clientMedia
 	tcpMediasByChannel map[int]*clientMedia
 	lastRange          *headers.Range
-	rtpPacketBuffer    *rtpPacketMultiBuffer // play
 	checkStreamTimer   *time.Timer
 	checkStreamInitial bool
 	tcpLastFrameTime   *int64
@@ -630,7 +629,6 @@ func (c *Client) playRecordStart() {
 
 	if c.state == clientStatePlay {
 		c.keepaliveTimer = time.NewTimer(c.keepalivePeriod)
-		c.rtpPacketBuffer = newRTPPacketMultiBuffer(uint64(c.ReadBufferCount))
 
 		switch *c.effectiveTransport {
 		case TransportUDP:

client_play_test.go

@@ -5,6 +5,7 @@ import (
 	"crypto/tls"
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 	"sync/atomic"
 	"testing"
@@ -274,10 +275,16 @@ func TestClientPlay(t *testing.T) {
 				err = forma.Init()
 				require.NoError(t, err)
 
-				medias := media.Medias{&media.Media{
-					Type:    "application",
-					Formats: []format.Format{forma},
-				}}
+				medias := media.Medias{
+					&media.Media{
+						Type:    "application",
+						Formats: []format.Format{forma},
+					},
+					&media.Media{
+						Type:    "application",
+						Formats: []format.Format{forma},
+					},
+				}
 				medias.SetControls()
 
 				err = conn.WriteResponse(&base.Response{
@@ -290,87 +297,92 @@ func TestClientPlay(t *testing.T) {
 				})
 				require.NoError(t, err)
 
-				req, err = conn.ReadRequest()
-				require.NoError(t, err)
-				require.Equal(t, base.Setup, req.Method)
-				require.Equal(t, mustParseURL(scheme+"://"+listenIP+":8554/test/stream?param=value/mediaID=0"), req.URL)
+				var l1s [2]net.PacketConn
+				var l2s [2]net.PacketConn
+				var clientPorts [2]*[2]int
 
-				var inTH headers.Transport
-				err = inTH.Unmarshal(req.Header["Transport"])
-				require.NoError(t, err)
-
-				th := headers.Transport{}
-
-				var l1 net.PacketConn
-				var l2 net.PacketConn
-
-				switch transport {
-				case "udp":
-					v := headers.TransportDeliveryUnicast
-					th.Delivery = &v
-					th.Protocol = headers.TransportProtocolUDP
-					th.ClientPorts = inTH.ClientPorts
-					th.ServerPorts = &[2]int{34556, 34557}
-
-					l1, err = net.ListenPacket("udp", listenIP+":34556")
+				for i := 0; i < 2; i++ {
+					req, err = conn.ReadRequest()
 					require.NoError(t, err)
-					defer l1.Close()
+					require.Equal(t, base.Setup, req.Method)
+					require.Equal(t, mustParseURL(
+						scheme+"://"+listenIP+":8554/test/stream?param=value/mediaID="+strconv.FormatInt(int64(i), 10)), req.URL)
 
-					l2, err = net.ListenPacket("udp", listenIP+":34557")
-					require.NoError(t, err)
-					defer l2.Close()
-
-				case "multicast":
-					v := headers.TransportDeliveryMulticast
-					th.Delivery = &v
-					th.Protocol = headers.TransportProtocolUDP
-					v2 := net.ParseIP("224.1.0.1")
-					th.Destination = &v2
-					th.Ports = &[2]int{25000, 25001}
-
-					l1, err = net.ListenPacket("udp", "224.0.0.0:25000")
-					require.NoError(t, err)
-					defer l1.Close()
-
-					p := ipv4.NewPacketConn(l1)
-
-					intfs, err := net.Interfaces()
+					var inTH headers.Transport
+					err = inTH.Unmarshal(req.Header["Transport"])
 					require.NoError(t, err)
 
-					for _, intf := range intfs {
-						err := p.JoinGroup(&intf, &net.UDPAddr{IP: net.ParseIP("224.1.0.1")})
+					var th headers.Transport
+
+					switch transport {
+					case "udp":
+						v := headers.TransportDeliveryUnicast
+						th.Delivery = &v
+						th.Protocol = headers.TransportProtocolUDP
+						th.ClientPorts = inTH.ClientPorts
+						clientPorts[i] = inTH.ClientPorts
+						th.ServerPorts = &[2]int{34556 + i*2, 34557 + i*2}
+
+						l1s[i], err = net.ListenPacket("udp", listenIP+":"+strconv.FormatInt(int64(th.ServerPorts[0]), 10))
 						require.NoError(t, err)
+						defer l1s[i].Close()
+
+						l2s[i], err = net.ListenPacket("udp", listenIP+":"+strconv.FormatInt(int64(th.ServerPorts[1]), 10))
+						require.NoError(t, err)
+						defer l2s[i].Close()
+
+					case "multicast":
+						v := headers.TransportDeliveryMulticast
+						th.Delivery = &v
+						th.Protocol = headers.TransportProtocolUDP
+						v2 := net.ParseIP("224.1.0.1")
+						th.Destination = &v2
+						th.Ports = &[2]int{25000 + i*2, 25001 + i*2}
+
+						l1s[i], err = net.ListenPacket("udp", "224.0.0.0:"+strconv.FormatInt(int64(th.Ports[0]), 10))
+						require.NoError(t, err)
+						defer l1s[i].Close()
+
+						p := ipv4.NewPacketConn(l1s[i])
+
+						intfs, err := net.Interfaces()
+						require.NoError(t, err)
+
+						for _, intf := range intfs {
+							err := p.JoinGroup(&intf, &net.UDPAddr{IP: net.ParseIP("224.1.0.1")})
+							require.NoError(t, err)
+						}
+
+						l2s[i], err = net.ListenPacket("udp", "224.0.0.0:25001")
+						require.NoError(t, err)
+						defer l2s[i].Close()
+
+						p = ipv4.NewPacketConn(l2s[i])
+
+						intfs, err = net.Interfaces()
+						require.NoError(t, err)
+
+						for _, intf := range intfs {
+							err := p.JoinGroup(&intf, &net.UDPAddr{IP: net.ParseIP("224.1.0.1")})
+							require.NoError(t, err)
+						}
+
+					case "tcp", "tls":
+						v := headers.TransportDeliveryUnicast
+						th.Delivery = &v
+						th.Protocol = headers.TransportProtocolTCP
+						th.InterleavedIDs = &[2]int{0 + i*2, 1 + i*2}
 					}
 
-					l2, err = net.ListenPacket("udp", "224.0.0.0:25001")
+					err = conn.WriteResponse(&base.Response{
+						StatusCode: base.StatusOK,
+						Header: base.Header{
+							"Transport": th.Marshal(),
+						},
+					})
 					require.NoError(t, err)
-					defer l2.Close()
-
-					p = ipv4.NewPacketConn(l2)
-
-					intfs, err = net.Interfaces()
-					require.NoError(t, err)
-
-					for _, intf := range intfs {
-						err := p.JoinGroup(&intf, &net.UDPAddr{IP: net.ParseIP("224.1.0.1")})
-						require.NoError(t, err)
-					}
-
-				case "tcp", "tls":
-					v := headers.TransportDeliveryUnicast
-					th.Delivery = &v
-					th.Protocol = headers.TransportProtocolTCP
-					th.InterleavedIDs = &[2]int{0, 1}
 				}
 
-				err = conn.WriteResponse(&base.Response{
-					StatusCode: base.StatusOK,
-					Header: base.Header{
-						"Transport": th.Marshal(),
-					},
-				})
-				require.NoError(t, err)
-
 				req, err = conn.ReadRequest()
 				require.NoError(t, err)
 				require.Equal(t, base.Play, req.Method)
@@ -382,56 +394,58 @@ func TestClientPlay(t *testing.T) {
 				})
 				require.NoError(t, err)
 
-				// server -> client (RTP)
-				switch transport {
-				case "udp":
-					l1.WriteTo(testRTPPacketMarshaled, &net.UDPAddr{
-						IP:   net.ParseIP("127.0.0.1"),
-						Port: th.ClientPorts[0],
-					})
+				for i := 0; i < 2; i++ {
+					// server -> client (RTP)
+					switch transport {
+					case "udp":
+						l1s[i].WriteTo(testRTPPacketMarshaled, &net.UDPAddr{
+							IP:   net.ParseIP("127.0.0.1"),
+							Port: clientPorts[i][0],
+						})
 
-				case "multicast":
-					l1.WriteTo(testRTPPacketMarshaled, &net.UDPAddr{
-						IP:   net.ParseIP("224.1.0.1"),
-						Port: 25000,
-					})
+					case "multicast":
+						l1s[i].WriteTo(testRTPPacketMarshaled, &net.UDPAddr{
+							IP:   net.ParseIP("224.1.0.1"),
+							Port: 25000,
+						})
 
-				case "tcp", "tls":
-					err := conn.WriteInterleavedFrame(&base.InterleavedFrame{
-						Channel: 0,
-						Payload: testRTPPacketMarshaled,
-					}, make([]byte, 1024))
-					require.NoError(t, err)
-				}
-
-				// client -> server (RTCP)
-				switch transport {
-				case "udp", "multicast":
-					// skip firewall opening
-					if transport == "udp" {
-						buf := make([]byte, 2048)
-						_, _, err := l2.ReadFrom(buf)
+					case "tcp", "tls":
+						err := conn.WriteInterleavedFrame(&base.InterleavedFrame{
+							Channel: 0 + i*2,
+							Payload: testRTPPacketMarshaled,
+						}, make([]byte, 1024))
 						require.NoError(t, err)
 					}
 
-					buf := make([]byte, 2048)
-					n, _, err := l2.ReadFrom(buf)
-					require.NoError(t, err)
-					packets, err := rtcp.Unmarshal(buf[:n])
-					require.NoError(t, err)
-					require.Equal(t, &testRTCPPacket, packets[0])
-					close(packetRecv)
+					// client -> server (RTCP)
+					switch transport {
+					case "udp", "multicast":
+						// skip firewall opening
+						if transport == "udp" {
+							buf := make([]byte, 2048)
+							_, _, err := l2s[i].ReadFrom(buf)
+							require.NoError(t, err)
+						}
 
-				case "tcp", "tls":
-					f, err := conn.ReadInterleavedFrame()
-					require.NoError(t, err)
-					require.Equal(t, 1, f.Channel)
-					packets, err := rtcp.Unmarshal(f.Payload)
-					require.NoError(t, err)
-					require.Equal(t, &testRTCPPacket, packets[0])
-					close(packetRecv)
+						buf := make([]byte, 2048)
+						n, _, err := l2s[i].ReadFrom(buf)
+						require.NoError(t, err)
+						packets, err := rtcp.Unmarshal(buf[:n])
+						require.NoError(t, err)
+						require.Equal(t, &testRTCPPacket, packets[0])
+
+					case "tcp", "tls":
+						f, err := conn.ReadInterleavedFrame()
+						require.NoError(t, err)
+						require.Equal(t, 1+i*2, f.Channel)
+						packets, err := rtcp.Unmarshal(f.Payload)
+						require.NoError(t, err)
+						require.Equal(t, &testRTCPPacket, packets[0])
+					}
 				}
 
+				close(packetRecv)
+
 				req, err = conn.ReadRequest()
 				require.NoError(t, err)
 				require.Equal(t, base.Teardown, req.Method)
@@ -464,16 +478,28 @@ func TestClientPlay(t *testing.T) {
 				}(),
 			}
 
-			err = readAll(&c,
-				scheme+"://"+listenIP+":8554/test/stream?param=value",
-				func(medi *media.Media, forma format.Format, pkt *rtp.Packet) {
-					require.Equal(t, &testRTPPacket, pkt)
-					err := c.WritePacketRTCP(medi, &testRTCPPacket)
-					require.NoError(t, err)
-				})
+			u, err := url.Parse(scheme + "://" + listenIP + ":8554/test/stream?param=value")
+			require.NoError(t, err)
+
+			err = c.Start(u.Scheme, u.Host)
 			require.NoError(t, err)
 			defer c.Close()
 
+			medias, baseURL, _, err := c.Describe(u)
+			require.NoError(t, err)
+
+			err = c.SetupAll(medias, baseURL)
+			require.NoError(t, err)
+
+			c.OnPacketRTPAny(func(medi *media.Media, forma format.Format, pkt *rtp.Packet) {
+				require.Equal(t, &testRTPPacket, pkt)
+				err := c.WritePacketRTCP(medi, &testRTCPPacket)
+				require.NoError(t, err)
+			})
+
+			_, err = c.Play(nil)
+			require.NoError(t, err)
+
 			<-packetRecv
 		})
 	}

clientmedia.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/pion/rtcp"
+	"github.com/pion/rtp"
 
 	"github.com/aler9/gortsplib/v2/pkg/base"
 	"github.com/aler9/gortsplib/v2/pkg/media"
@@ -187,7 +188,7 @@ func (cm *clientMedia) readRTPTCPPlay(payload []byte) error {
 	now := time.Now()
 	atomic.StoreInt64(cm.c.tcpLastFrameTime, now.Unix())
 
-	pkt := cm.c.rtpPacketBuffer.next()
+	pkt := &rtp.Packet{}
 	err := pkt.Unmarshal(payload)
 	if err != nil {
 		return err
@@ -259,7 +260,7 @@ func (cm *clientMedia) readRTPUDPPlay(payload []byte) error {
 		return nil
 	}
 
-	pkt := cm.c.rtpPacketBuffer.next()
+	pkt := &rtp.Packet{}
 	err := pkt.Unmarshal(payload)
 	if err != nil {
 		cm.c.OnDecodeError(err)

rtppacketmultibuffer.go

@@ -1,24 +0,0 @@
-package gortsplib
-
-import (
-	"github.com/pion/rtp"
-)
-
-type rtpPacketMultiBuffer struct {
-	count   uint64
-	buffers []rtp.Packet
-	cur     uint64
-}
-
-func newRTPPacketMultiBuffer(count uint64) *rtpPacketMultiBuffer {
-	return &rtpPacketMultiBuffer{
-		count:   count,
-		buffers: make([]rtp.Packet, count),
-	}
-}
-
-func (mb *rtpPacketMultiBuffer) next() *rtp.Packet {
-	ret := &mb.buffers[mb.cur%mb.count]
-	mb.cur++
-	return ret
-}

server_record_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"crypto/tls"
 	"net"
+	"strconv"
 	"testing"
 	"time"
 
@@ -499,18 +500,24 @@ func TestServerRecord(t *testing.T) {
 						// send RTCP packets directly to the session.
 						// these are sent after the response, only if onRecord returns StatusOK.
 						ctx.Session.WritePacketRTCP(ctx.Session.AnnouncedMedias()[0], &testRTCPPacket)
+						ctx.Session.WritePacketRTCP(ctx.Session.AnnouncedMedias()[1], &testRTCPPacket)
 
-						ctx.Session.OnPacketRTPAny(func(medi *media.Media, forma format.Format, pkt *rtp.Packet) {
-							require.Equal(t, ctx.Session.AnnouncedMedias()[0], medi)
-							require.Equal(t, ctx.Session.AnnouncedMedias()[0].Formats[0], forma)
-							require.Equal(t, &testRTPPacket, pkt)
-						})
+						for i := 0; i < 2; i++ {
+							ctx.Session.OnPacketRTP(
+								ctx.Session.AnnouncedMedias()[i],
+								ctx.Session.AnnouncedMedias()[i].Formats[0],
+								func(pkt *rtp.Packet) {
+									require.Equal(t, &testRTPPacket, pkt)
+								})
 
-						ctx.Session.OnPacketRTCPAny(func(medi *media.Media, pkt rtcp.Packet) {
-							require.Equal(t, ctx.Session.AnnouncedMedias()[0], medi)
-							require.Equal(t, &testRTCPPacket, pkt)
-							ctx.Session.WritePacketRTCP(ctx.Session.AnnouncedMedias()[0], &testRTCPPacket)
-						})
+							ci := i
+							ctx.Session.OnPacketRTCP(
+								ctx.Session.AnnouncedMedias()[i],
+								func(pkt rtcp.Packet) {
+									require.Equal(t, &testRTCPPacket, pkt)
+									ctx.Session.WritePacketRTCP(ctx.Session.AnnouncedMedias()[ci], &testRTCPPacket)
+								})
+						}
 
 						return &base.Response{
 							StatusCode: base.StatusOK,
@@ -549,7 +556,7 @@ func TestServerRecord(t *testing.T) {
 
 			<-nconnOpened
 
-			medias := media.Medias{testH264Media.Clone()}
+			medias := media.Medias{testH264Media.Clone(), testH264Media.Clone()}
 			medias.SetControls()
 
 			res, err := writeReqReadRes(conn, base.Request{
@@ -566,54 +573,61 @@ func TestServerRecord(t *testing.T) {
 
 			<-sessionOpened
 
-			inTH := &headers.Transport{
-				Delivery: func() *headers.TransportDelivery {
-					v := headers.TransportDeliveryUnicast
-					return &v
-				}(),
-				Mode: func() *headers.TransportMode {
-					v := headers.TransportModeRecord
-					return &v
-				}(),
-			}
-
-			var l1 net.PacketConn
-			var l2 net.PacketConn
-
-			if transport == "udp" {
-				inTH.Protocol = headers.TransportProtocolUDP
-				inTH.ClientPorts = &[2]int{35466, 35467}
-
-				l1, err = net.ListenPacket("udp", "localhost:35466")
-				require.NoError(t, err)
-				defer l1.Close()
-
-				l2, err = net.ListenPacket("udp", "localhost:35467")
-				require.NoError(t, err)
-				defer l2.Close()
-			} else {
-				inTH.Protocol = headers.TransportProtocolTCP
-				inTH.InterleavedIDs = &[2]int{0, 1}
-			}
-
-			res, err = writeReqReadRes(conn, base.Request{
-				Method: base.Setup,
-				URL:    mustParseURL("rtsp://localhost:8554/teststream/mediaID=0"),
-				Header: base.Header{
-					"CSeq":      base.HeaderValue{"2"},
-					"Transport": inTH.Marshal(),
-				},
-			})
-			require.NoError(t, err)
-			require.Equal(t, base.StatusOK, res.StatusCode)
-
+			var l1s [2]net.PacketConn
+			var l2s [2]net.PacketConn
 			var sx headers.Session
-			err = sx.Unmarshal(res.Header["Session"])
-			require.NoError(t, err)
+			var serverPorts [2]*[2]int
 
-			var th headers.Transport
-			err = th.Unmarshal(res.Header["Transport"])
-			require.NoError(t, err)
+			for i := 0; i < 2; i++ {
+				inTH := &headers.Transport{
+					Delivery: func() *headers.TransportDelivery {
+						v := headers.TransportDeliveryUnicast
+						return &v
+					}(),
+					Mode: func() *headers.TransportMode {
+						v := headers.TransportModeRecord
+						return &v
+					}(),
+				}
+
+				if transport == "udp" {
+					inTH.Protocol = headers.TransportProtocolUDP
+					inTH.ClientPorts = &[2]int{35466 + i*2, 35467 + i*2}
+
+					l1s[i], err = net.ListenPacket("udp", "localhost:"+strconv.FormatInt(int64(inTH.ClientPorts[0]), 10))
+					require.NoError(t, err)
+					defer l1s[i].Close()
+
+					l2s[i], err = net.ListenPacket("udp", "localhost:"+strconv.FormatInt(int64(inTH.ClientPorts[1]), 10))
+					require.NoError(t, err)
+					defer l2s[i].Close()
+				} else {
+					inTH.Protocol = headers.TransportProtocolTCP
+					inTH.InterleavedIDs = &[2]int{2 + i*2, 3 + i*2}
+				}
+
+				res, err = writeReqReadRes(conn, base.Request{
+					Method: base.Setup,
+					URL:    mustParseURL("rtsp://localhost:8554/teststream/mediaID=" + strconv.FormatInt(int64(i), 10)),
+					Header: base.Header{
+						"CSeq":      base.HeaderValue{"2"},
+						"Transport": inTH.Marshal(),
+					},
+				})
+				require.NoError(t, err)
+				require.Equal(t, base.StatusOK, res.StatusCode)
+
+				err = sx.Unmarshal(res.Header["Session"])
+				require.NoError(t, err)
+
+				var th headers.Transport
+				err = th.Unmarshal(res.Header["Transport"])
+				require.NoError(t, err)
+
+				if transport == "udp" {
+					serverPorts[i] = th.ServerPorts
+				}
+			}
 
 			res, err = writeReqReadRes(conn, base.Request{
 				Method: base.Record,
@@ -626,62 +640,66 @@ func TestServerRecord(t *testing.T) {
 			require.NoError(t, err)
 			require.Equal(t, base.StatusOK, res.StatusCode)
 
-			// server -> client (direct)
-			if transport == "udp" {
-				buf := make([]byte, 2048)
-				n, _, err := l2.ReadFrom(buf)
-				require.NoError(t, err)
-				require.Equal(t, testRTCPPacketMarshaled, buf[:n])
-			} else {
-				f, err := conn.ReadInterleavedFrame()
-				require.NoError(t, err)
-				require.Equal(t, 1, f.Channel)
-				require.Equal(t, testRTCPPacketMarshaled, f.Payload)
+			for i := 0; i < 2; i++ {
+				// server -> client (direct)
+				if transport == "udp" {
+					buf := make([]byte, 2048)
+					n, _, err := l2s[i].ReadFrom(buf)
+					require.NoError(t, err)
+					require.Equal(t, testRTCPPacketMarshaled, buf[:n])
+				} else {
+					f, err := conn.ReadInterleavedFrame()
+					require.NoError(t, err)
+					require.Equal(t, 3+i*2, f.Channel)
+					require.Equal(t, testRTCPPacketMarshaled, f.Payload)
+				}
+
+				// skip firewall opening
+				if transport == "udp" {
+					buf := make([]byte, 2048)
+					_, _, err := l2s[i].ReadFrom(buf)
+					require.NoError(t, err)
+				}
+
+				// client -> server
+				if transport == "udp" {
+					l1s[i].WriteTo(testRTPPacketMarshaled, &net.UDPAddr{
+						IP:   net.ParseIP("127.0.0.1"),
+						Port: serverPorts[i][0],
+					})
+
+					l2s[i].WriteTo(testRTCPPacketMarshaled, &net.UDPAddr{
+						IP:   net.ParseIP("127.0.0.1"),
+						Port: serverPorts[i][1],
+					})
+				} else {
+					err := conn.WriteInterleavedFrame(&base.InterleavedFrame{
+						Channel: 2 + i*2,
+						Payload: testRTPPacketMarshaled,
+					}, make([]byte, 1024))
+					require.NoError(t, err)
+
+					err = conn.WriteInterleavedFrame(&base.InterleavedFrame{
+						Channel: 3 + i*2,
+						Payload: testRTCPPacketMarshaled,
+					}, make([]byte, 1024))
+					require.NoError(t, err)
+				}
 			}
 
-			// skip firewall opening
-			if transport == "udp" {
-				buf := make([]byte, 2048)
-				_, _, err := l2.ReadFrom(buf)
-				require.NoError(t, err)
-			}
-
-			// client -> server
-			if transport == "udp" {
-				l1.WriteTo(testRTPPacketMarshaled, &net.UDPAddr{
-					IP:   net.ParseIP("127.0.0.1"),
-					Port: th.ServerPorts[0],
-				})
-
-				l2.WriteTo(testRTCPPacketMarshaled, &net.UDPAddr{
-					IP:   net.ParseIP("127.0.0.1"),
-					Port: th.ServerPorts[1],
-				})
-			} else {
-				err := conn.WriteInterleavedFrame(&base.InterleavedFrame{
-					Channel: 0,
-					Payload: testRTPPacketMarshaled,
-				}, make([]byte, 1024))
-				require.NoError(t, err)
-
-				err = conn.WriteInterleavedFrame(&base.InterleavedFrame{
-					Channel: 1,
-					Payload: testRTCPPacketMarshaled,
-				}, make([]byte, 1024))
-				require.NoError(t, err)
-			}
-
-			// server -> client (RTCP)
-			if transport == "udp" {
-				buf := make([]byte, 2048)
-				n, _, err := l2.ReadFrom(buf)
-				require.NoError(t, err)
-				require.Equal(t, testRTCPPacketMarshaled, buf[:n])
-			} else {
-				f, err := conn.ReadInterleavedFrame()
-				require.NoError(t, err)
-				require.Equal(t, 1, f.Channel)
-				require.Equal(t, testRTCPPacketMarshaled, f.Payload)
+			for i := 0; i < 2; i++ {
+				// server -> client (RTCP)
+				if transport == "udp" {
+					buf := make([]byte, 2048)
+					n, _, err := l2s[i].ReadFrom(buf)
+					require.NoError(t, err)
+					require.Equal(t, testRTCPPacketMarshaled, buf[:n])
+				} else {
+					f, err := conn.ReadInterleavedFrame()
+					require.NoError(t, err)
+					require.Equal(t, 3+i*2, f.Channel)
+					require.Equal(t, testRTCPPacketMarshaled, f.Payload)
+				}
 			}
 
 			res, err = writeReqReadRes(conn, base.Request{

serversession.go

@@ -173,7 +173,6 @@ type ServerSession struct {
 	udpLastPacketTime     *int64       // publish
 	udpCheckStreamTimer   *time.Timer
 	writer                writer
-	rtpPacketBuffer       *rtpPacketMultiBuffer
 
 	// in
 	request     chan sessionRequestReq
@@ -948,8 +947,6 @@ func (ss *ServerSession) handleRequest(sc *ServerConn, req *base.Request) (*base
 
 		ss.state = ServerSessionStateRecord
 
-		ss.rtpPacketBuffer = newRTPPacketMultiBuffer(uint64(ss.s.ReadBufferCount))
-
 		for _, sm := range ss.setuppedMedias {
 			sm.start()
 		}

serversessionmedia.go

@@ -185,7 +185,7 @@ func (sm *serverSessionMedia) readRTPUDPRecord(payload []byte) error {
 		return nil
 	}
 
-	pkt := sm.ss.rtpPacketBuffer.next()
+	pkt := &rtp.Packet{}
 	err := pkt.Unmarshal(payload)
 	if err != nil {
 		onDecodeError(sm.ss, err)
@@ -265,7 +265,7 @@ func (sm *serverSessionMedia) readRTCPTCPPlay(payload []byte) error {
 }
 
 func (sm *serverSessionMedia) readRTPTCPRecord(payload []byte) error {
-	pkt := sm.ss.rtpPacketBuffer.next()
+	pkt := &rtp.Packet{}
 	err := pkt.Unmarshal(payload)
 	if err != nil {
 		return err

serverstream.go

@@ -292,11 +292,6 @@ func (st *ServerStream) WritePacketRTPWithNTP(medi *media.Media, pkt *rtp.Packet
 
 // WritePacketRTCP writes a RTCP packet to all the readers of the stream.
 func (st *ServerStream) WritePacketRTCP(medi *media.Media, pkt rtcp.Packet) {
-	byts, err := pkt.Marshal()
-	if err != nil {
-		return
-	}
-
 	st.mutex.RLock()
 	defer st.mutex.RUnlock()
 
@@ -305,17 +300,5 @@ func (st *ServerStream) WritePacketRTCP(medi *media.Media, pkt rtcp.Packet) {
 	}
 
 	sm := st.streamMedias[medi]
-
-	// send unicast
-	for r := range st.activeUnicastReaders {
-		sm, ok := r.setuppedMedias[medi]
-		if ok {
-			sm.writePacketRTCP(byts)
-		}
-	}
-
-	// send multicast
-	if sm.multicastHandler != nil {
-		sm.multicastHandler.writePacketRTCP(byts)
-	}
+	sm.writePacketRTCP(st, pkt)
 }

serverstreammedia.go

@@ -3,6 +3,7 @@ package gortsplib
 import (
 	"time"
 
+	"github.com/pion/rtcp"
 	"github.com/pion/rtp"
 
 	"github.com/aler9/gortsplib/v2/pkg/media"
@@ -69,3 +70,23 @@ func (sm *serverStreamMedia) WritePacketRTPWithNTP(ss *ServerStream, pkt *rtp.Pa
 		sm.multicastHandler.writePacketRTP(byts)
 	}
 }
+
+func (sm *serverStreamMedia) writePacketRTCP(ss *ServerStream, pkt rtcp.Packet) {
+	byts, err := pkt.Marshal()
+	if err != nil {
+		return
+	}
+
+	// send unicast
+	for r := range ss.activeUnicastReaders {
+		sm, ok := r.setuppedMedias[sm.media]
+		if ok {
+			sm.writePacketRTCP(byts)
+		}
+	}
+
+	// send multicast
+	if sm.multicastHandler != nil {
+		sm.multicastHandler.writePacketRTCP(byts)
+	}
+}