diff --git a/format/rtspv2/client.go b/format/rtspv2/client.go
index e244a39..9ca70ab 100644
--- a/format/rtspv2/client.go
+++ b/format/rtspv2/client.go
@@ -106,6 +106,21 @@ type RTSPClientOptions struct {
 }
 
 func Dial(options RTSPClientOptions) (*RTSPClient, error) {
+	u, err := url.Parse(options.URL)
+	if err != nil {
+		return nil, err
+	}
+	if u.Port() == "" {
+		u.Host = fmt.Sprintf("%s:%s", u.Host, "554")
+	}
+	conn, err := net.DialTimeout("tcp", u.Host, options.DialTimeout)
+	if err != nil {
+		return nil, err
+	}
+	return DialWithConn(options, conn)
+}
+
+func DialWithConn(options RTSPClientOptions, conn net.Conn) (*RTSPClient, error) {
 	client := &RTSPClient{
 		headers:             make(map[string]string),
 		Signals:             make(chan int, 100),
@@ -124,10 +139,6 @@ func Dial(options RTSPClientOptions) (*RTSPClient, error) {
 	if err != nil {
 		return nil, err
 	}
-	conn, err := net.DialTimeout("tcp", client.pURL.Host, client.options.DialTimeout)
-	if err != nil {
-		return nil, err
-	}
 	err = conn.SetDeadline(time.Now().Add(client.options.ReadWriteTimeout))
 	if err != nil {
 		return nil, err