change OnFrame signature

connclient.go

@@ -79,12 +79,19 @@ type ConnClient struct {
 	udpRtcpListeners      map[int]*connClientUDPListener
 	tcpFrameBuffer        *multibuffer.MultiBuffer
 	getParameterSupported bool
-	backgroundError       error
-	writeFrameMutex       sync.RWMutex
-	writeFrameOpen        bool
-	readCB                func(int, StreamType, []byte, error)
 
+	// read only
+	readCB func(int, StreamType, []byte)
+
+	// publish only
+	publishError error
+	publishMutex sync.RWMutex
+	publishOpen  bool
+
+	// in
 	backgroundTerminate chan struct{}
+
+	// out
 	backgroundDone chan struct{}
 }
 

connclientpublish.go

@@ -61,7 +61,7 @@ func (c *ConnClient) Record() (*base.Response, error) {
 	}
 
 	c.state = connClientStateRecord
-	c.writeFrameOpen = true
+	c.publishOpen = true
 	c.backgroundTerminate = make(chan struct{})
 	c.backgroundDone = make(chan struct{})
 
@@ -78,9 +78,9 @@ func (c *ConnClient) backgroundRecordUDP() {
 	defer close(c.backgroundDone)
 
 	defer func() {
-		c.writeFrameMutex.Lock()
+		c.publishMutex.Lock()
-		defer c.writeFrameMutex.Unlock()
+		defer c.publishMutex.Unlock()
-		c.writeFrameOpen = false
+		c.publishOpen = false
 	}()
 
 	// disable deadline
@@ -102,11 +102,11 @@ func (c *ConnClient) backgroundRecordUDP() {
 	case <-c.backgroundTerminate:
 		c.nconn.SetReadDeadline(time.Now())
 		<-readerDone
-		c.backgroundError = fmt.Errorf("terminated")
+		c.publishError = fmt.Errorf("terminated")
 		return
 
 	case err := <-readerDone:
-		c.backgroundError = err
+		c.publishError = err
 		return
 	}
 }
@@ -115,9 +115,9 @@ func (c *ConnClient) backgroundRecordTCP() {
 	defer close(c.backgroundDone)
 
 	defer func() {
-		c.writeFrameMutex.Lock()
+		c.publishMutex.Lock()
-		defer c.writeFrameMutex.Unlock()
+		defer c.publishMutex.Unlock()
-		c.writeFrameOpen = false
+		c.publishOpen = false
 	}()
 
 	<-c.backgroundTerminate
@@ -126,11 +126,11 @@ func (c *ConnClient) backgroundRecordTCP() {
 // WriteFrame writes a frame.
 // This can be used only after Record().
 func (c *ConnClient) WriteFrame(trackId int, streamType StreamType, content []byte) error {
-	c.writeFrameMutex.RLock()
+	c.publishMutex.RLock()
-	defer c.writeFrameMutex.RUnlock()
+	defer c.publishMutex.RUnlock()
 
-	if !c.writeFrameOpen {
+	if !c.publishOpen {
-		return c.backgroundError
+		return c.publishError
 	}
 
 	if *c.streamProtocol == StreamProtocolUDP {

connclientread.go

@@ -33,16 +33,18 @@ func (c *ConnClient) Play() (*base.Response, error) {
 	return res, nil
 }
 
-func (c *ConnClient) backgroundPlayUDP() {
+func (c *ConnClient) backgroundPlayUDP(onFrameDone chan error) {
 	defer close(c.backgroundDone)
 
+	var returnError error
+
 	defer func() {
 		for trackId := range c.udpRtpListeners {
 			c.udpRtpListeners[trackId].stop()
 			c.udpRtcpListeners[trackId].stop()
 		}
 
-		c.readCB(0, 0, nil, c.backgroundError)
+		onFrameDone <- returnError
 	}()
 
 	for trackId := range c.udpRtpListeners {
@@ -79,7 +81,7 @@ func (c *ConnClient) backgroundPlayUDP() {
 		case <-c.backgroundTerminate:
 			c.nconn.SetReadDeadline(time.Now())
 			<-readerDone
-			c.backgroundError = fmt.Errorf("terminated")
+			returnError = fmt.Errorf("terminated")
 			return
 
 		case <-reportTicker.C:
@@ -104,7 +106,7 @@ func (c *ConnClient) backgroundPlayUDP() {
 			if err != nil {
 				c.nconn.SetReadDeadline(time.Now())
 				<-readerDone
-				c.backgroundError = err
+				returnError = err
 				return
 			}
 
@@ -117,22 +119,26 @@ func (c *ConnClient) backgroundPlayUDP() {
 				if now.Sub(last) >= c.d.ReadTimeout {
 					c.nconn.SetReadDeadline(time.Now())
 					<-readerDone
-					c.backgroundError = fmt.Errorf("no packets received recently (maybe there's a firewall/NAT in between)")
+					returnError = fmt.Errorf("no packets received recently (maybe there's a firewall/NAT in between)")
 					return
 				}
 			}
 
 		case err := <-readerDone:
-			c.backgroundError = err
+			returnError = err
 			return
 		}
 	}
 }
 
-func (c *ConnClient) backgroundPlayTCP() {
+func (c *ConnClient) backgroundPlayTCP(onFrameDone chan error) {
 	defer close(c.backgroundDone)
 
-	defer c.readCB(0, 0, nil, c.backgroundError)
+	var returnError error
+
+	defer func() {
+		onFrameDone <- returnError
+	}()
 
 	readerDone := make(chan error)
 	go func() {
@@ -148,7 +154,7 @@ func (c *ConnClient) backgroundPlayTCP() {
 
 			c.rtcpReceivers[frame.TrackId].OnFrame(frame.StreamType, frame.Content)
 
-			c.readCB(frame.TrackId, frame.StreamType, frame.Content, nil)
+			c.readCB(frame.TrackId, frame.StreamType, frame.Content)
 		}
 	}()
 
@@ -169,7 +175,7 @@ func (c *ConnClient) backgroundPlayTCP() {
 		case <-c.backgroundTerminate:
 			c.nconn.SetReadDeadline(time.Now())
 			<-readerDone
-			c.backgroundError = fmt.Errorf("terminated")
+			returnError = fmt.Errorf("terminated")
 			return
 
 		case <-reportTicker.C:
@@ -185,14 +191,27 @@ func (c *ConnClient) backgroundPlayTCP() {
 			}
 
 		case err := <-readerDone:
-			c.backgroundError = err
+			returnError = err
 			return
 		}
 	}
 }
 
 // OnFrame sets a callback that is called when a frame is received.
-func (c *ConnClient) OnFrame(cb func(int, StreamType, []byte, error)) {
+// it returns a channel that is called when the reading stops.
+// routines.
+func (c *ConnClient) OnFrame(cb func(int, StreamType, []byte)) chan error {
+	// channel is buffered, since listening to it is not mandatory
+	onFrameDone := make(chan error, 1)
+
+	err := c.checkState(map[connClientState]struct{}{
+		connClientStatePrePlay: {},
+	})
+	if err != nil {
+		onFrameDone <- err
+		return onFrameDone
+	}
+
 	c.state = connClientStatePlay
 	c.readCB = cb
 	c.backgroundTerminate = make(chan struct{})
@@ -208,8 +227,10 @@ func (c *ConnClient) OnFrame(cb func(int, StreamType, []byte, error)) {
 				[]byte{0x80, 0xc9, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00})
 		}
 
-		go c.backgroundPlayUDP()
+		go c.backgroundPlayUDP(onFrameDone)
 	} else {
-		go c.backgroundPlayTCP()
+		go c.backgroundPlayTCP(onFrameDone)
 	}
+
+	return onFrameDone
 }

connclientudpl.go

@@ -75,7 +75,7 @@ func (l *connClientUDPListener) run() {
 
 		l.c.rtcpReceivers[l.trackId].OnFrame(l.streamType, buf[:n])
 
-		l.c.readCB(l.trackId, l.streamType, buf[:n], nil)
+		l.c.readCB(l.trackId, l.streamType, buf[:n])
 	}
 }
 

dialer.go

@@ -97,7 +97,7 @@ func (d Dialer) Dial(host string) (*ConnClient, error) {
 		udpRtpListeners:   make(map[int]*connClientUDPListener),
 		udpRtcpListeners:  make(map[int]*connClientUDPListener),
 		tcpFrameBuffer:    multibuffer.New(d.ReadBufferCount, clientTCPFrameReadBufferSize),
-		backgroundError:   fmt.Errorf("not running"),
+		publishError:      fmt.Errorf("not running"),
 	}, nil
 }
 

dialer_test.go

@@ -97,13 +97,7 @@ func TestDialReadParallel(t *testing.T) {
 
 			var firstFrame int32
 			frameRecv := make(chan struct{})
-			readerDone := make(chan struct{})
+			done := conn.OnFrame(func(id int, typ StreamType, content []byte) {
-			conn.OnFrame(func(id int, typ StreamType, content []byte, err error) {
-				if err != nil {
-					close(readerDone)
-					return
-				}
-
 				if atomic.SwapInt32(&firstFrame, 1) == 0 {
 					close(frameRecv)
 				}
@@ -111,14 +105,12 @@ func TestDialReadParallel(t *testing.T) {
 
 			<-frameRecv
 			conn.Close()
-			<-readerDone
+			<-done
 
-			readerDone = make(chan struct{})
+			done = conn.OnFrame(func(id int, typ StreamType, content []byte) {
-			conn.OnFrame(func(id int, typ StreamType, content []byte, err error) {
+				t.Error("should not happen")
-				require.Error(t, err)
-				close(readerDone)
 			})
-			<-readerDone
+			<-done
 		})
 	}
 }
@@ -155,13 +147,7 @@ func TestDialReadRedirectParallel(t *testing.T) {
 
 	var firstFrame int32
 	frameRecv := make(chan struct{})
-	readerDone := make(chan struct{})
+	done := conn.OnFrame(func(id int, typ StreamType, content []byte) {
-	conn.OnFrame(func(id int, typ StreamType, content []byte, err error) {
-		if err != nil {
-			close(readerDone)
-			return
-		}
-
 		if atomic.SwapInt32(&firstFrame, 1) == 0 {
 			close(frameRecv)
 		}
@@ -169,7 +155,7 @@ func TestDialReadRedirectParallel(t *testing.T) {
 
 	<-frameRecv
 	conn.Close()
-	<-readerDone
+	<-done
 }
 
 func TestDialReadPauseParallel(t *testing.T) {
@@ -210,13 +196,7 @@ func TestDialReadPauseParallel(t *testing.T) {
 
 			firstFrame := int32(0)
 			frameRecv := make(chan struct{})
-			readerDone := make(chan struct{})
+			done := conn.OnFrame(func(id int, typ StreamType, content []byte) {
-			conn.OnFrame(func(id int, typ StreamType, content []byte, err error) {
-				if err != nil {
-					close(readerDone)
-					return
-				}
-
 				if atomic.SwapInt32(&firstFrame, 1) == 0 {
 					close(frameRecv)
 				}
@@ -225,20 +205,14 @@ func TestDialReadPauseParallel(t *testing.T) {
 			<-frameRecv
 			_, err = conn.Pause()
 			require.NoError(t, err)
-			<-readerDone
+			<-done
 
 			_, err = conn.Play()
 			require.NoError(t, err)
 
 			firstFrame = int32(0)
 			frameRecv = make(chan struct{})
-			readerDone = make(chan struct{})
+			done = conn.OnFrame(func(id int, typ StreamType, content []byte) {
-			conn.OnFrame(func(id int, typ StreamType, content []byte, err error) {
-				if err != nil {
-					close(readerDone)
-					return
-				}
-
 				if atomic.SwapInt32(&firstFrame, 1) == 0 {
 					close(frameRecv)
 				}
@@ -246,7 +220,7 @@ func TestDialReadPauseParallel(t *testing.T) {
 
 			<-frameRecv
 			conn.Close()
-			<-readerDone
+			<-done
 		})
 	}
 }

examples/client-read-pause.go

@@ -4,6 +4,7 @@ package main
 
 import (
 	"fmt"
+	"time"
 
 	"github.com/aler9/gortsplib"
 )
@@ -24,13 +25,7 @@ func main() {
 
 	for {
 		// read frames from the server
-		readerDone := make(chan struct{})
+		done := conn.OnFrame(func(id int, typ gortsplib.StreamType, buf []byte) {
-		conn.OnFrame(func(id int, typ gortsplib.StreamType, buf []byte, err error) {
-			if err != nil {
-				close(readerDone)
-				return
-			}
-
 			fmt.Printf("frame from track %d, type %v: %v\n", id, typ, buf)
 		})
 
@@ -44,13 +39,13 @@ func main() {
 		}
 
 		// join reader
-		<-readerDone
+		<-done
 
 		// wait
 		time.Sleep(5 * time.Second)
 
 		// play again
-		_, err := conn.Play()
+		_, err = conn.Play()
 		if err != nil {
 			panic(err)
 		}

examples/client-read-tcp.go

@@ -23,18 +23,10 @@ func main() {
 	}
 	defer conn.Close()
 
-	readerDone := make(chan struct{})
-
 	// read frames from the server
-	conn.OnFrame(func(id int, typ gortsplib.StreamType, buf []byte, err error) {
+	done := conn.OnFrame(func(id int, typ gortsplib.StreamType, buf []byte) {
-		if err != nil {
-			fmt.Printf("ERR: %v\n", err)
-			close(readerDone)
-			return
-		}
-
 		fmt.Printf("frame from track %d, type %v: %v\n", id, typ, buf)
 	})
 
-	<-readerDone
+	<-done
 }

examples/client-read-udp.go

@@ -20,18 +20,10 @@ func main() {
 	}
 	defer conn.Close()
 
-	readerDone := make(chan struct{})
-
 	// read frames from the server
-	conn.OnFrame(func(id int, typ gortsplib.StreamType, buf []byte, err error) {
+	done := conn.OnFrame(func(id int, typ gortsplib.StreamType, buf []byte) {
-		if err != nil {
-			fmt.Printf("ERR: %v\n", err)
-			close(readerDone)
-			return
-		}
-
 		fmt.Printf("frame from track %d, type %v: %v\n", id, typ, buf)
 	})
 
-	<-readerDone
+	<-done
 }