Merge pull request #272 from ZSC714725/rtsp-transport

[opt] rtsp: client端使用UDP收到461则切换成TCP（反之也然）

pkg/rtsp/client_command_session.go

@@ -39,6 +39,10 @@ const (
 	CcstPushSession
 )
 
+var (
+	ErrUnsupportedTransport = fmt.Errorf("Unsupported Transport")
+)
+
 type ClientCommandSessionOption struct {
 	DoTimeoutMs int
 	OverTcp     bool
@@ -389,29 +393,49 @@ func (session *ClientCommandSession) writeAnnounce() error {
 }
 
 func (session *ClientCommandSession) writeSetup() error {
-	if session.sdpCtx.HasVideoAControl() {
-		uri := session.sdpCtx.MakeVideoSetupUri(session.urlCtx.RawUrlWithoutUserInfo)
+	setup := func(setupUri string) error {
 		if session.option.OverTcp {
-			if err := session.writeOneSetupTcp(uri); err != nil {
-				return err
+			if err := session.writeOneSetupTcp(setupUri); err != nil {
+				// 461情况下尝试切换UDP重试
+				if err == ErrUnsupportedTransport {
+					if err := session.writeOneSetup(setupUri); err != nil {
+						return err
+					}
+
+					session.option.OverTcp = false
+				} else {
+					return err
+				}
 			}
 		} else {
-			if err := session.writeOneSetup(uri); err != nil {
-				return err
+			if err := session.writeOneSetup(setupUri); err != nil {
+				// 461情况尝试切换TCP重试
+				if err == ErrUnsupportedTransport {
+					if err = session.writeOneSetupTcp(setupUri); err != nil {
+						return err
+					}
+
+					session.option.OverTcp = true
+				} else {
+					return err
+				}
 			}
 		}
+
+		return nil
+	}
+
+	if session.sdpCtx.HasVideoAControl() {
+		uri := session.sdpCtx.MakeVideoSetupUri(session.urlCtx.RawUrlWithoutUserInfo)
+		if err := setup(uri); err != nil {
+			return err
+		}
 	}
 	// can't else if
 	if session.sdpCtx.HasAudioAControl() {
 		uri := session.sdpCtx.MakeAudioSetupUri(session.urlCtx.RawUrlWithoutUserInfo)
-		if session.option.OverTcp {
-			if err := session.writeOneSetupTcp(uri); err != nil {
-				return err
-			}
-		} else {
-			if err := session.writeOneSetup(uri); err != nil {
-				return err
-			}
+		if err := setup(uri); err != nil {
+			return err
 		}
 	}
 	return nil
@@ -438,6 +462,12 @@ func (session *ClientCommandSession) writeOneSetup(setupUri string) error {
 		return err
 	}
 
+	if ctx.StatusCode == "461" {
+		// 切换transport尝试继续
+		err = ErrUnsupportedTransport
+		return err
+	}
+
 	session.sessionId = strings.Split(ctx.Headers.Get(HeaderSession), ";")[0]
 
 	rRtpPort, rRtcpPort, err := parseServerPort(ctx.Headers.Get(HeaderTransport))
@@ -508,6 +538,11 @@ func (session *ClientCommandSession) writeOneSetupTcp(setupUri string) error {
 		return err
 	}
 
+	if ctx.StatusCode == "461" {
+		err = ErrUnsupportedTransport
+		return err
+	}
+
 	session.sessionId = strings.Split(ctx.Headers.Get(HeaderSession), ";")[0]
 
 	// TODO chef: 这里没有解析回传的channel id了，因为我假定了它和request中的是一致的