From dab15e898dc073afd3a96653189e5db008e44ca4 Mon Sep 17 00:00:00 2001
From: aler9 <46489434+aler9@users.noreply.github.com>
Date: Sun, 29 Dec 2019 12:32:54 +0100
Subject: [PATCH] support RTCP streaming via TCP

---
 main.go        |  2 +-
 rtsp/conn.go   | 14 +++++++-------
 rtsp_client.go | 16 +++++++++++++---
 3 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/main.go b/main.go
index 465d661a..9607e149 100644
--- a/main.go
+++ b/main.go
@@ -117,7 +117,7 @@ func main() {
 
 	p, err := newProgram(*rtspPort, *rtpPort, *rtcpPort)
 	if err != nil {
-		log.Fatal("ERR:", err)
+		log.Fatal("ERR: ", err)
 	}
 
 	p.run()
diff --git a/rtsp/conn.go b/rtsp/conn.go
index a268cfa1..375ea0e0 100644
--- a/rtsp/conn.go
+++ b/rtsp/conn.go
@@ -43,33 +43,33 @@ func (c *Conn) WriteResponse(res *Response) error {
 	return responseEncode(c.c, res)
 }
 
-func (c *Conn) ReadInterleavedFrame(frame []byte) (int, error) {
+func (c *Conn) ReadInterleavedFrame(frame []byte) (int, int, error) {
 	var header [4]byte
 	_, err := io.ReadFull(c.c, header[:])
 	if err != nil {
-		return 0, err
+		return 0, 0, err
 	}
 
 	// connection terminated
 	if header[0] == 0x54 {
-		return 0, io.EOF
+		return 0, 0, io.EOF
 	}
 
 	if header[0] != 0x24 {
-		return 0, fmt.Errorf("wrong magic byte (0x%.2x)", header[0])
+		return 0, 0, fmt.Errorf("wrong magic byte (0x%.2x)", header[0])
 	}
 
 	framelen := binary.BigEndian.Uint16(header[2:])
 	if framelen > 2048 {
-		return 0, fmt.Errorf("frame length greater than 2048")
+		return 0, 0, fmt.Errorf("frame length greater than 2048")
 	}
 
 	_, err = io.ReadFull(c.c, frame[:framelen])
 	if err != nil {
-		return 0, err
+		return 0, 0, err
 	}
 
-	return int(framelen), nil
+	return int(header[1]), int(framelen), nil
 }
 
 func (c *Conn) WriteInterleavedFrame(frame []byte) error {
diff --git a/rtsp_client.go b/rtsp_client.go
index 3b54c32d..0730a214 100644
--- a/rtsp_client.go
+++ b/rtsp_client.go
@@ -132,7 +132,7 @@ func (c *rtspClient) run() {
 			if c.rtpProto == "tcp" {
 				buf := make([]byte, 2048)
 				for {
-					_, err := c.rconn.ReadInterleavedFrame(buf)
+					_, _, err := c.rconn.ReadInterleavedFrame(buf)
 					if err != nil {
 						if err != io.EOF {
 							c.log("ERR: %s", err)
@@ -161,7 +161,7 @@ func (c *rtspClient) run() {
 			if c.rtpProto == "tcp" {
 				buf := make([]byte, 2048)
 				for {
-					n, err := c.rconn.ReadInterleavedFrame(buf)
+					channel, n, err := c.rconn.ReadInterleavedFrame(buf)
 					if err != nil {
 						if err != io.EOF {
 							c.log("ERR: %s", err)
@@ -169,7 +169,17 @@ func (c *rtspClient) run() {
 						return
 					}
 
-					c.p.handleRtp(buf[:n])
+					switch channel {
+					case 0:
+						c.p.handleRtp(buf[:n])
+
+					case 1:
+						c.p.handleRtcp(buf[:n])
+
+					default:
+						c.log("ERR: unsupported channel '%d'", channel)
+						return
+					}
 				}
 			}