add working server example

examples/server.go

@@ -4,17 +4,35 @@ package main
 
 import (
 	"fmt"
+	"log"
 	"strings"
+	"sync"
 
 	"github.com/aler9/gortsplib"
 	"github.com/aler9/gortsplib/pkg/base"
+	"github.com/aler9/gortsplib/pkg/headers"
 )
 
+// This example shows how to
+// 1. create a RTSP server
+// 2. allow a single client to publish a stream with TCP
+// 3. allow multiple clients to read that stream with TCP
+
+var mutex sync.Mutex
+var publisher *gortsplib.ServerConn
+var sdp []byte
+var readers = make(map[*gortsplib.ServerConn]struct{})
+
+// this is called for each incoming connection
 func handleConn(conn *gortsplib.ServerConn) {
 	defer conn.Close()
 
+	log.Printf("client connected")
+
+	// this is called when a request arrives
 	onRequest := func(req *base.Request) (*base.Response, error) {
 		switch req.Method {
+		// the Options method must return all available methods
 		case base.Options:
 			return &base.Response{
 				StatusCode: base.StatusOK,
@@ -25,32 +43,178 @@ func handleConn(conn *gortsplib.ServerConn) {
 						string(base.Setup),
 						string(base.Play),
 						string(base.Record),
-						string(base.Pause),
 						string(base.Teardown),
 					}, ", ")},
 				},
 			}, nil
 
+		// the Describe method must return the SDP of the stream
+		case base.Describe:
+			mutex.Lock()
+			defer mutex.Unlock()
+
+			// no one is publishing yet
+			if publisher == nil {
+				return &base.Response{
+					StatusCode: base.StatusNotFound,
+				}, nil
+			}
+
+			return &base.Response{
+				StatusCode: base.StatusOK,
+				Header: base.Header{
+					"Content-Base": base.HeaderValue{req.URL.String() + "/"},
+					"Content-Type": base.HeaderValue{"application/sdp"},
+				},
+				Content: sdp,
+			}, nil
+
+		// the Announce method is called by publishers
+		case base.Announce:
+			ct, ok := req.Header["Content-Type"]
+			if !ok || len(ct) != 1 {
+				return &base.Response{
+					StatusCode: base.StatusBadRequest,
+				}, fmt.Errorf("Content-Type header missing")
+			}
+
+			if ct[0] != "application/sdp" {
+				return &base.Response{
+					StatusCode: base.StatusBadRequest,
+				}, fmt.Errorf("unsupported Content-Type '%s'", ct)
+			}
+
+			tracks, err := gortsplib.ReadTracks(req.Content)
+			if err != nil {
+				return &base.Response{
+					StatusCode: base.StatusBadRequest,
+				}, fmt.Errorf("invalid SDP: %s", err)
+			}
+
+			if len(tracks) == 0 {
+				return &base.Response{
+					StatusCode: base.StatusBadRequest,
+				}, fmt.Errorf("no tracks defined")
+			}
+
+			mutex.Lock()
+			defer mutex.Unlock()
+
+			if publisher != nil {
+				return &base.Response{
+					StatusCode: base.StatusBadRequest,
+				}, fmt.Errorf("someone is already publishing")
+			}
+
+			publisher = conn
+			sdp = tracks.Write()
+
+			return &base.Response{
+				StatusCode: base.StatusOK,
+				Header: base.Header{
+					"Session": base.HeaderValue{"12345678"},
+				},
+			}, nil
+
+		// The Setup method is called
+		// * by publishers, after Announce
+		// * by readers
+		case base.Setup:
+			th, err := headers.ReadTransport(req.Header["Transport"])
+			if err != nil {
+				return &base.Response{
+					StatusCode: base.StatusBadRequest,
+				}, fmt.Errorf("transport header: %s", err)
+			}
+
+			// support TCP only
+			if th.Protocol == gortsplib.StreamProtocolUDP {
+				return &base.Response{
+					StatusCode: base.StatusUnsupportedTransport,
+				}, nil
+			}
+
+			return &base.Response{
+				StatusCode: base.StatusOK,
+				Header: base.Header{
+					"Transport": req.Header["Transport"],
+					"Session":   base.HeaderValue{"12345678"},
+				},
+			}, nil
+
+		// The Play method is called by readers, after Setup
+		case base.Play:
+			mutex.Lock()
+			defer mutex.Unlock()
+
+			readers[conn] = struct{}{}
+
+			conn.EnableReadFrames(true)
+			conn.EnableReadTimeout(false)
+
+			return &base.Response{
+				StatusCode: base.StatusOK,
+				Header: base.Header{
+					"Session": base.HeaderValue{"12345678"},
+				},
+			}, nil
+
+		// The Record method is called by publishers, after Announce and Setup
+		case base.Record:
+			mutex.Lock()
+			defer mutex.Unlock()
+
+			if conn != publisher {
+				return &base.Response{
+					StatusCode: base.StatusBadRequest,
+				}, fmt.Errorf("someone is already publishing")
+			}
+
+			conn.EnableReadFrames(true)
+			conn.EnableReadTimeout(true)
+
+			return &base.Response{
+				StatusCode: base.StatusOK,
+				Header: base.Header{
+					"Session": base.HeaderValue{"12345678"},
+				},
+			}, nil
+
+		// The Teardown method is called to close a session
 		case base.Teardown:
 			return &base.Response{
 				StatusCode: base.StatusOK,
-				Header:     base.Header{},
 			}, fmt.Errorf("terminated")
 		}
 
 		return &base.Response{
 			StatusCode: base.StatusBadRequest,
-			Header:     base.Header{},
 		}, fmt.Errorf("unhandled method: %v", req.Method)
 	}
 
-	onFrame := func(id int, typ gortsplib.StreamType, buf []byte) {
+	// this is called when a frame arrives
+	onFrame := func(trackID int, typ gortsplib.StreamType, buf []byte) {
+		mutex.Lock()
+		defer mutex.Unlock()
+
+		// if we are the publisher, route frames to readers
+		if conn == publisher {
+			for r := range readers {
+				r.WriteFrame(trackID, typ, buf)
+			}
+		}
 	}
 
-	done := conn.Read(onRequest, onFrame)
+	err := <-conn.Read(onRequest, onFrame)
+	log.Printf("client disconnected (%s)", err)
 
-	err := <-done
-	panic(err)
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	if conn == publisher {
+		publisher = nil
+		sdp = nil
+	}
 }
 
 func main() {
@@ -59,6 +223,7 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
+	log.Printf("server is ready")
 
 	// accept connections
 	for {