Added RTSP Server functionality

rtsp/RTSPServer.go

@@ -0,0 +1,159 @@
+package rtsp
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"net"
+	"strconv"
+	"strings"
+
+	"github.com/jonas-koeritz/actioncam/libipcamera"
+)
+
+// Server implements the RTSP protocol to serve a H.264 stream
+type Server struct {
+	localIP       string
+	localPort     int
+	listener      net.Listener
+	remoteRTPPort int
+	remoteIP      string
+	rtpRelay      *libipcamera.RTPRelay
+	camera        *libipcamera.Camera
+	sdp           string
+}
+
+// CreateServer creates a new Server instance
+func CreateServer(localIP string, port int, camera *libipcamera.Camera) *Server {
+	server := &Server{
+		localIP:       localIP,
+		localPort:     port,
+		camera:        camera,
+		remoteRTPPort: 0,
+		remoteIP:      "",
+		sdp:           "v=0\r\ns=ActionCamera\r\nm=video 0 RTP/AVP 99\r\na=rtpmap:99 H264/90000",
+	}
+	return server
+}
+
+// ListenAndServe starts listening for connections and handles them
+func (s *Server) ListenAndServe() error {
+	log.Printf("%+v\n", *s)
+	listener, err := net.Listen("tcp4", fmt.Sprintf("%s:%d", s.localIP, s.localPort))
+	if err != nil {
+		return err
+	}
+	s.listener = listener
+
+	log.Printf("RTSP Server waiting for connections on %s:%d\n", s.localIP, s.localPort)
+
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			log.Printf("ERROR accepting connection: %s\n", err)
+		}
+
+		log.Printf("Accepted new RTSP Client %s\n", conn.RemoteAddr().String())
+
+		go s.handleClient(conn)
+	}
+}
+
+func (s *Server) handleClient(conn net.Conn) error {
+	packet := make([]string, 0)
+	scanner := bufio.NewScanner(conn)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if len(line) > 0 {
+			packet = append(packet, line)
+		} else {
+			s.handleRequest(packet, conn)
+			packet = make([]string, 0)
+		}
+	}
+	return nil
+}
+
+func (s *Server) handleRequest(packet []string, conn net.Conn) {
+	fmt.Printf("C->S:\n%s\n", packet)
+
+	request := strings.Split(packet[0], " ")
+	if len(request) != 3 {
+		log.Printf("Received invalid request")
+		return
+	}
+
+	method := request[0]
+	headers := make(map[string]string, 0)
+	for _, header := range packet[1:] {
+		parts := strings.Split(header, ":")
+		if len(parts) >= 2 {
+			headers[parts[0]] = strings.Join(parts[1:], ":")
+		}
+	}
+
+	switch method {
+	case "OPTIONS":
+		writeStatus(conn, 200, "OK")
+		replyCSeq(conn, headers)
+		conn.Write([]byte("Public: DESCRIBE, SETUP, PLAY, PAUSE, RECORD\r\n\r\n"))
+	case "DESCRIBE":
+		writeStatus(conn, 200, "OK")
+		replyCSeq(conn, headers)
+		writeHeader(conn, "Content-Type", "application/sdp")
+		writeHeader(conn, "Content-Length", fmt.Sprintf("%d", len(s.sdp)))
+		conn.Write([]byte(fmt.Sprintf("\r\n%s\r\n", s.sdp)))
+	case "SETUP":
+		transportDescription := strings.Split(headers["Transport"], ";")
+		rtpDescription := transportDescription[len(transportDescription)-1]
+		remoteRTPPort, err := strconv.ParseInt(strings.Split(strings.Split(rtpDescription, "=")[1], "-")[0], 10, 32)
+		if err != nil {
+			log.Printf("ERROR Parsing RTP description: %s\n", err)
+			return
+		}
+		s.remoteRTPPort = int(remoteRTPPort)
+		s.remoteIP = (conn.RemoteAddr().(*net.TCPAddr)).IP.String()
+
+		log.Printf("Preparing to Stream to %s:%d\n", s.remoteIP, s.remoteRTPPort)
+
+		writeStatus(conn, 200, "OK")
+		replyCSeq(conn, headers)
+		writeHeader(conn, "Transport", headers["Transport"]+";ssrc=0")
+		writeHeader(conn, "Session", "1")
+		conn.Write([]byte("\r\n"))
+
+	case "PLAY":
+		s.rtpRelay = libipcamera.CreateRTPRelay(net.ParseIP(s.remoteIP), s.remoteRTPPort)
+		s.camera.StartPreviewStream()
+
+		writeStatus(conn, 200, "OK")
+		replyCSeq(conn, headers)
+		writeHeader(conn, "Session", "1")
+		writeHeader(conn, "RTP-Info", "url="+request[1]+";seq=0;rtptime=0")
+		conn.Write([]byte("\r\n"))
+	case "TEARDOWN":
+		s.rtpRelay.Stop()
+		writeStatus(conn, 200, "OK")
+		replyCSeq(conn, headers)
+		conn.Write([]byte("\r\n"))
+	default:
+		return
+	}
+}
+
+func writeStatus(conn net.Conn, status int, statusWord string) {
+	conn.Write([]byte(fmt.Sprintf("RTSP/1.0 %d %s\r\n", status, statusWord)))
+}
+
+func replyCSeq(conn net.Conn, headers map[string]string) {
+	writeHeader(conn, "CSeq", headers["CSeq"])
+}
+
+func writeHeader(conn net.Conn, key, value string) {
+	conn.Write([]byte(fmt.Sprintf("%s: %s\r\n", key, value)))
+}
+
+// Stop stops listening for connections
+func (s *Server) Stop() {
+	s.listener.Close()
+}