implement automatic protocol switching; fix #13

connclient.go

@@ -228,8 +228,6 @@ func (c *ConnClient) Do(req *base.Request) (*base.Response, error) {
 }
 
 // Options writes an OPTIONS request and reads a response.
-// Since this method is not implemented by every RTSP server, the function
-// does not fail if the returned code is StatusNotFound.
 func (c *ConnClient) Options(u *base.URL) (*base.Response, error) {
 	err := c.checkState(map[connClientState]struct{}{
 		connClientStateInitial:   {},
@@ -248,8 +246,8 @@ func (c *ConnClient) Options(u *base.URL) (*base.Response, error) {
 		return nil, err
 	}
 
-	if res.StatusCode != base.StatusOK && res.StatusCode != base.StatusNotFound {
+	if res.StatusCode != base.StatusOK {
-		return nil, fmt.Errorf("bad status code: %d (%s)", res.StatusCode, res.StatusMessage)
+		return res, fmt.Errorf("bad status code: %d (%s)", res.StatusCode, res.StatusMessage)
 	}
 
 	c.getParameterSupported = func() bool {
@@ -291,8 +289,10 @@ func (c *ConnClient) Describe(u *base.URL) (Tracks, *base.Response, error) {
 		return nil, nil, err
 	}
 
-	switch res.StatusCode {
+	if res.StatusCode != base.StatusOK {
-	case base.StatusOK:
+		return nil, res, fmt.Errorf("bad status code: %d (%s)", res.StatusCode, res.StatusMessage)
+	}
+
 	contentType, ok := res.Header["Content-Type"]
 	if !ok || len(contentType) != 1 {
 		return nil, nil, fmt.Errorf("Content-Type not provided")
@@ -308,19 +308,6 @@ func (c *ConnClient) Describe(u *base.URL) (Tracks, *base.Response, error) {
 	}
 
 	return tracks, res, nil
-
-	case base.StatusMovedPermanently, base.StatusFound,
-		base.StatusSeeOther, base.StatusNotModified, base.StatusUseProxy:
-		location, ok := res.Header["Location"]
-		if !ok || len(location) != 1 {
-			return nil, nil, fmt.Errorf("Location not provided")
-		}
-
-		return nil, res, nil
-
-	default:
-		return nil, nil, fmt.Errorf("bad status code: %d (%s)", res.StatusCode, res.StatusMessage)
-	}
 }
 
 // build an URL by merging baseUrl with the control attribute from track.Media.
@@ -485,7 +472,7 @@ func (c *ConnClient) Setup(u *base.URL, mode headers.TransportMode, proto base.S
 			rtpListener.close()
 			rtcpListener.close()
 		}
-		return nil, fmt.Errorf("bad status code: %d (%s)", res.StatusCode, res.StatusMessage)
+		return res, fmt.Errorf("bad status code: %d (%s)", res.StatusCode, res.StatusMessage)
 	}
 
 	th, err := headers.ReadTransport(res.Header["Transport"])
@@ -575,7 +562,7 @@ func (c *ConnClient) Pause() (*base.Response, error) {
 	}
 
 	if res.StatusCode != base.StatusOK {
-		return nil, fmt.Errorf("bad status code: %d (%s)", res.StatusCode, res.StatusMessage)
+		return res, fmt.Errorf("bad status code: %d (%s)", res.StatusCode, res.StatusMessage)
 	}
 
 	switch c.state {

dialer.go

@@ -33,9 +33,9 @@ func DialPublish(address string, tracks Tracks) (*ConnClient, error) {
 
 // Dialer allows to initialize a ConnClient.
 type Dialer struct {
-	// (optional) the stream protocol.
+	// (optional) the stream protocol (UDP or TCP).
-	// It defaults to StreamProtocolUDP.
+	// If nil, it is chosen automatically (first UDP, then, if it fails, TCP).
-	StreamProtocol StreamProtocol
+	StreamProtocol *StreamProtocol
 
 	// (optional) timeout of read operations.
 	// It defaults to 10 seconds
@@ -113,30 +113,54 @@ func (d Dialer) DialRead(address string) (*ConnClient, error) {
 		return nil, err
 	}
 
-	_, err = conn.Options(u)
+	res, err := conn.Options(u)
 	if err != nil {
+		// since this method is not implemented by every RTSP server,
+		// return only if status code is not 404
+		if res == nil || res.StatusCode != base.StatusNotFound {
 			conn.Close()
 			return nil, err
 		}
+	}
 
 	tracks, res, err := conn.Describe(u)
 	if err != nil {
-		conn.Close()
+		// redirect
-		return nil, err
+		if res != nil && res.StatusCode >= base.StatusMovedPermanently &&
-	}
+			res.StatusCode <= base.StatusUseProxy &&
-
+			len(res.Header["Location"]) == 1 {
-	if res.StatusCode >= base.StatusMovedPermanently &&
-		res.StatusCode <= base.StatusUseProxy {
 			conn.Close()
 			return d.DialRead(res.Header["Location"][0])
 		}
 
-	for _, track := range tracks {
+		conn.Close()
-		_, err := conn.Setup(u, headers.TransportModePlay, d.StreamProtocol, track, 0, 0)
+		return nil, err
+	}
+
+	proto := func() StreamProtocol {
+		if d.StreamProtocol != nil {
+			return *d.StreamProtocol
+		}
+		return StreamProtocolUDP
+	}()
+
+	for i, track := range tracks {
+		res, err := conn.Setup(u, headers.TransportModePlay, proto, track, 0, 0)
+		if err != nil {
+			// switch protocol automatically
+			if i == 0 && d.StreamProtocol == nil && res != nil &&
+				res.StatusCode == base.StatusUnsupportedTransport {
+				proto = StreamProtocolTCP
+				_, err := conn.Setup(u, headers.TransportModePlay, proto, track, 0, 0)
 				if err != nil {
 					conn.Close()
 					return nil, err
 				}
+			} else {
+				conn.Close()
+				return nil, err
+			}
+		}
 	}
 
 	_, err = conn.Play()
@@ -160,11 +184,15 @@ func (d Dialer) DialPublish(address string, tracks Tracks) (*ConnClient, error)
 		return nil, err
 	}
 
-	_, err = conn.Options(u)
+	res, err := conn.Options(u)
 	if err != nil {
+		// since this method is not implemented by every RTSP server,
+		// return only if status code is not 404
+		if res == nil || res.StatusCode != base.StatusNotFound {
 			conn.Close()
 			return nil, err
 		}
+	}
 
 	_, err = conn.Announce(u, tracks)
 	if err != nil {
@@ -172,12 +200,30 @@ func (d Dialer) DialPublish(address string, tracks Tracks) (*ConnClient, error)
 		return nil, err
 	}
 
-	for _, track := range tracks {
+	proto := func() StreamProtocol {
-		_, err = conn.Setup(u, headers.TransportModeRecord, d.StreamProtocol, track, 0, 0)
+		if d.StreamProtocol != nil {
+			return *d.StreamProtocol
+		}
+		return StreamProtocolUDP
+	}()
+
+	for i, track := range tracks {
+		res, err := conn.Setup(u, headers.TransportModeRecord, proto, track, 0, 0)
+		if err != nil {
+			// switch protocol automatically
+			if i == 0 && d.StreamProtocol == nil && res != nil &&
+				res.StatusCode == base.StatusUnsupportedTransport {
+				proto = StreamProtocolTCP
+				_, err := conn.Setup(u, headers.TransportModePlay, proto, track, 0, 0)
 				if err != nil {
 					conn.Close()
 					return nil, err
 				}
+			} else {
+				conn.Close()
+				return nil, err
+			}
+		}
 	}
 
 	_, err = conn.Record()

dialer_test.go

@@ -59,7 +59,7 @@ func (c *container) wait() int {
 	return int(code)
 }
 
-func TestDialReadParallel(t *testing.T) {
+func TestDialRead(t *testing.T) {
 	for _, proto := range []string{
 		"udp",
 		"tcp",
@@ -85,12 +85,16 @@ func TestDialReadParallel(t *testing.T) {
 
 			time.Sleep(1 * time.Second)
 
-			dialer := func() Dialer {
+			dialer := Dialer{
+				StreamProtocol: func() *StreamProtocol {
 					if proto == "udp" {
-					return Dialer{}
+						v := StreamProtocolUDP
+						return &v
+					}
+					v := StreamProtocolTCP
+					return &v
+				}(),
 			}
-				return Dialer{StreamProtocol: StreamProtocolTCP}
-			}()
 
 			conn, err := dialer.DialRead("rtsp://localhost:8554/teststream")
 			require.NoError(t, err)
@@ -115,7 +119,48 @@ func TestDialReadParallel(t *testing.T) {
 	}
 }
 
-func TestDialReadRedirectParallel(t *testing.T) {
+func TestDialReadAutomaticProtocol(t *testing.T) {
+	cnt1, err := newContainer("rtsp-simple-server", "server", []string{
+		"protocols: [tcp]\n",
+	})
+	require.NoError(t, err)
+	defer cnt1.close()
+
+	time.Sleep(1 * time.Second)
+
+	cnt2, err := newContainer("ffmpeg", "publish", []string{
+		"-re",
+		"-stream_loop", "-1",
+		"-i", "/emptyvideo.ts",
+		"-c", "copy",
+		"-f", "rtsp",
+		"-rtsp_transport", "tcp",
+		"rtsp://localhost:8554/teststream",
+	})
+	require.NoError(t, err)
+	defer cnt2.close()
+
+	time.Sleep(1 * time.Second)
+
+	dialer := Dialer{StreamProtocol: nil}
+
+	conn, err := dialer.DialRead("rtsp://localhost:8554/teststream")
+	require.NoError(t, err)
+
+	var firstFrame int32
+	frameRecv := make(chan struct{})
+	done := conn.OnFrame(func(id int, typ StreamType, content []byte) {
+		if atomic.SwapInt32(&firstFrame, 1) == 0 {
+			close(frameRecv)
+		}
+	})
+
+	<-frameRecv
+	conn.Close()
+	<-done
+}
+
+func TestDialReadRedirect(t *testing.T) {
 	cnt1, err := newContainer("rtsp-simple-server", "server", []string{
 		"paths:\n" +
 			"  path1:\n" +
@@ -158,7 +203,7 @@ func TestDialReadRedirectParallel(t *testing.T) {
 	<-done
 }
 
-func TestDialReadPauseParallel(t *testing.T) {
+func TestDialReadPause(t *testing.T) {
 	for _, proto := range []string{
 		"udp",
 		"tcp",
@@ -184,12 +229,16 @@ func TestDialReadPauseParallel(t *testing.T) {
 
 			time.Sleep(1 * time.Second)
 
-			dialer := func() Dialer {
+			dialer := Dialer{
+				StreamProtocol: func() *StreamProtocol {
 					if proto == "udp" {
-					return Dialer{}
+						v := StreamProtocolUDP
+						return &v
+					}
+					v := StreamProtocolTCP
+					return &v
+				}(),
 			}
-				return Dialer{StreamProtocol: StreamProtocolTCP}
-			}()
 
 			conn, err := dialer.DialRead("rtsp://localhost:8554/teststream")
 			require.NoError(t, err)
@@ -255,12 +304,16 @@ func TestDialPublishSerial(t *testing.T) {
 			track, err := NewTrackH264(0, sps, pps)
 			require.NoError(t, err)
 
-			dialer := func() Dialer {
+			dialer := Dialer{
+				StreamProtocol: func() *StreamProtocol {
 					if proto == "udp" {
-					return Dialer{}
+						v := StreamProtocolUDP
+						return &v
+					}
+					v := StreamProtocolTCP
+					return &v
+				}(),
 			}
-				return Dialer{StreamProtocol: StreamProtocolTCP}
-			}()
 
 			conn, err := dialer.DialPublish("rtsp://localhost:8554/teststream",
 				Tracks{track})
@@ -337,12 +390,16 @@ func TestDialPublishParallel(t *testing.T) {
 			var conn *ConnClient
 			defer func() { conn.Close() }()
 
-			dialer := func() Dialer {
+			dialer := Dialer{
+				StreamProtocol: func() *StreamProtocol {
 					if ca.proto == "udp" {
-					return Dialer{}
+						v := StreamProtocolUDP
+						return &v
+					}
+					v := StreamProtocolTCP
+					return &v
+				}(),
 			}
-				return Dialer{StreamProtocol: StreamProtocolTCP}
-			}()
 
 			go func() {
 				defer close(writerDone)
@@ -421,12 +478,16 @@ func TestDialPublishPauseSerial(t *testing.T) {
 			track, err := NewTrackH264(0, sps, pps)
 			require.NoError(t, err)
 
-			dialer := func() Dialer {
+			dialer := Dialer{
+				StreamProtocol: func() *StreamProtocol {
 					if proto == "udp" {
-					return Dialer{}
+						v := StreamProtocolUDP
+						return &v
+					}
+					v := StreamProtocolTCP
+					return &v
+				}(),
 			}
-				return Dialer{StreamProtocol: StreamProtocolTCP}
-			}()
 
 			conn, err := dialer.DialPublish("rtsp://localhost:8554/teststream",
 				Tracks{track})
@@ -489,12 +550,16 @@ func TestDialPublishPauseParallel(t *testing.T) {
 			track, err := NewTrackH264(0, sps, pps)
 			require.NoError(t, err)
 
-			dialer := func() Dialer {
+			dialer := Dialer{
+				StreamProtocol: func() *StreamProtocol {
 					if proto == "udp" {
-					return Dialer{}
+						v := StreamProtocolUDP
+						return &v
+					}
+					v := StreamProtocolTCP
+					return &v
+				}(),
 			}
-				return Dialer{StreamProtocol: StreamProtocolTCP}
-			}()
 
 			conn, err := dialer.DialPublish("rtsp://localhost:8554/teststream",
 				Tracks{track})

examples/client-publish-options.go

@@ -12,6 +12,7 @@ import (
 )
 
 // This example shows how to
+// * set additional client options
 // * generate RTP/H264 frames from a file with Gstreamer
 // * connect to a RTSP server, announce a H264 track
 // * write the frames of the track
@@ -42,10 +43,10 @@ func main() {
 		panic(err)
 	}
 
-	// Dialer allows to set additional options
+	// Dialer allows to set additional client options
 	dialer := gortsplib.Dialer{
-		// the stream protocol
+		// the stream protocol (UDP or TCP). If nil, it is chosen automatically
-		StreamProtocol: gortsplib.StreamProtocolUDP,
+		StreamProtocol: nil,
 		// timeout of read operations
 		ReadTimeout: 10 * time.Second,
 		// timeout of write operations
@@ -72,7 +73,7 @@ func main() {
 			break
 		}
 
-		// write frames to the server
+		// write track frames
 		err = conn.WriteFrame(track.Id, gortsplib.StreamTypeRtp, buf[:n])
 		if err != nil {
 			fmt.Printf("connection is closed (%s)\n", err)

examples/client-publish-pause.go

@@ -65,7 +65,7 @@ func main() {
 					break
 				}
 
-				// write frames to the server
+				// write track frames
 				err = conn.WriteFrame(track.Id, gortsplib.StreamTypeRtp, buf[:n])
 				if err != nil {
 					break

examples/client-publish.go

@@ -57,7 +57,7 @@ func main() {
 			break
 		}
 
-		// write frames to the server
+		// write track frames
 		err = conn.WriteFrame(track.Id, gortsplib.StreamTypeRtp, buf[:n])
 		if err != nil {
 			fmt.Printf("connection is closed (%s)\n", err)

examples/client-read-options.go

@@ -10,14 +10,15 @@ import (
 )
 
 // This example shows how to
+// * set additional client options
 // * connect to a RTSP server
 // * read all tracks on a path
 
 func main() {
-	// Dialer allows to set additional options
+	// Dialer allows to set additional client options
 	dialer := gortsplib.Dialer{
-		// the stream protocol
+		// the stream protocol (UDP or TCP). If nil, it is chosen automatically
-		StreamProtocol: gortsplib.StreamProtocolUDP,
+		StreamProtocol: nil,
 		// timeout of read operations
 		ReadTimeout: 10 * time.Second,
 		// timeout of write operations
@@ -35,7 +36,7 @@ func main() {
 	}
 	defer conn.Close()
 
-	// read frames from the server
+	// read track frames
 	readerDone := conn.OnFrame(func(id int, typ gortsplib.StreamType, buf []byte) {
 		fmt.Printf("frame from track %d, type %v: %v\n", id, typ, buf)
 	})

examples/client-read-pause.go

@@ -24,7 +24,7 @@ func main() {
 	defer conn.Close()
 
 	for {
-		// read frames from the server
+		// read track frames
 		readerDone := conn.OnFrame(func(id int, typ gortsplib.StreamType, buf []byte) {
 			fmt.Printf("frame from track %d, type %v: %v\n", id, typ, buf)
 		})

examples/client-read.go

@@ -20,7 +20,7 @@ func main() {
 	}
 	defer conn.Close()
 
-	// read frames from the server
+	// read track frames
 	readerDone := conn.OnFrame(func(id int, typ gortsplib.StreamType, buf []byte) {
 		fmt.Printf("frame from track %d, type %v: %v\n", id, typ, buf)
 	})