我正在尝试处理一个更大的项目，该项目涉及创建RTSP服务器和客户端对以便流式传输音乐。现在，我只是在研究如何实现RTSP客户端并使用VLC作为服务器，以便我可以检查我是否理解了这部分问题。
（请注意，我没有完全为这个客户编写代码。我是从在线资源中找到它并为了测试目的稍微改了一下。对于我的项目，我打算只使用这个客户作为灵感的基础）< / p>
在VLC上，这是我使用GUI设置流时生成的输出流代码
:sout=#transcode{vcodec=h264,vb=0,scale=0,acodec=mp4a,ab=128,channels=2,samplerate=44100}:rtp{sdp=rtsp://:5544/stream} :no-sout-rtp-sap :no-sout-standard-sap :sout-all :ttl=1 :sout-keep
请注意，我能够在另一个VLC媒体播放器实例上成功接收此流，因此我至少可以确定它是否正确传输流，至少在我运行它的本地计算机上。< / p>
以下是我的java客户端的代码
/*Client.java*/
/* ------------------
Client
usage: java Client [Server hostname] [Server RTSP listening port] [Video file requested]
---------------------- */
import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import javax.swing.Timer;
public class Client{
//GUI
//----
JFrame f = new JFrame("Client");
JButton setupButton = new JButton("Setup");
JButton playButton = new JButton("Play");
JButton pauseButton = new JButton("Pause");
JButton tearButton = new JButton("Teardown");
JPanel mainPanel = new JPanel();
JPanel buttonPanel = new JPanel();
JLabel iconLabel = new JLabel();
ImageIcon icon;
//RTP variables:
//----------------
DatagramPacket rcvdp; //UDP packet received from the server
DatagramSocket RTPsocket; //socket to be used to send and receive UDP packets
static int RTP_RCV_PORT = 5544; //port where the client will receive the RTP packets
Timer timer; //timer used to receive data from the UDP socket
byte[] buf; //buffer used to store data received from the server
//RTSP variables
//----------------
//rtsp states
final static int INIT = 0;
final static int READY = 1;
final static int PLAYING = 2;
static int state; //RTSP state == INIT or READY or PLAYING
Socket RTSPsocket; //socket used to send/receive RTSP messages
//input and output stream filters
static BufferedReader RTSPBufferedReader;
static BufferedWriter RTSPBufferedWriter;
static String VideoFileName; //video file to request to the server
int RTSPSeqNb = 0; //Sequence number of RTSP messages within the session
int RTSPid = 0; //ID of the RTSP session (given by the RTSP Server)
final static String CRLF = "\r\n";
//Video constants:
//------------------
static int MJPEG_TYPE = 26; //RTP payload type for MJPEG video
//--------------------------
//Constructor
//--------------------------
public Client() {
//build GUI
//--------------------------
//Frame
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
//Buttons
buttonPanel.setLayout(new GridLayout(1,0));
buttonPanel.add(setupButton);
buttonPanel.add(playButton);
buttonPanel.add(pauseButton);
buttonPanel.add(tearButton);
setupButton.addActionListener(new setupButtonListener());
playButton.addActionListener(new playButtonListener());
pauseButton.addActionListener(new pauseButtonListener());
tearButton.addActionListener(new tearButtonListener());
//Image display label
iconLabel.setIcon(null);
//frame layout
mainPanel.setLayout(null);
mainPanel.add(iconLabel);
mainPanel.add(buttonPanel);
iconLabel.setBounds(0,0,380,280);
buttonPanel.setBounds(0,280,380,50);
f.getContentPane().add(mainPanel, BorderLayout.CENTER);
f.setSize(new Dimension(390,370));
f.setVisible(true);
//init timer
//--------------------------
timer = new Timer(20, new timerListener());
timer.setInitialDelay(0);
timer.setCoalesce(true);
//allocate enough memory for the buffer used to receive data from the server
buf = new byte[15000];
}
//------------------------------------
//main
//------------------------------------
public static void main(String argv[]) throws Exception
{
//Create a Client object
Client theClient = new Client();
//get server RTSP port and IP address from the command line
//------------------
int RTSP_server_port = 5544;
String ServerHost = "localhost";
InetAddress ServerIPAddr = InetAddress.getByName(ServerHost);
//get video filename to request:
VideoFileName = "M13_Assignment.mp4";
//Establish a TCP connection with the server to exchange RTSP messages
//------------------
theClient.RTSPsocket = new Socket(ServerIPAddr, RTSP_server_port);
//Set input and output stream filters:
RTSPBufferedReader = new BufferedReader(new InputStreamReader(theClient.RTSPsocket.getInputStream()) );
RTSPBufferedWriter = new BufferedWriter(new OutputStreamWriter(theClient.RTSPsocket.getOutputStream()) );
//init RTSP state:
state = INIT;
}
//------------------------------------
//Handler for buttons
//------------------------------------
//.............
//TO COMPLETE
//.............
//Handler for Setup button
//-----------------------
class setupButtonListener implements ActionListener{
public void actionPerformed(ActionEvent e){
//System.out.println("Setup Button pressed !");
if (state == INIT)
{
try{
//Init non-blocking RTPsocket that will be used to receive data
try{
//construct a new DatagramSocket to receive RTP packets from the server, on port RTP_RCV_PORT
RTPsocket = new DatagramSocket(RTP_RCV_PORT);
//set TimeOut value of the socket to 5msec.
RTPsocket.setSoTimeout(5);
}
catch (SocketException se)
{
System.out.println("Socket exception: "+se);
System.exit(0);
}
//init RTSP sequence number
RTSPSeqNb = 1;
//Send SETUP message to the server
send_RTSP_request("SETUP");
//Wait for the response
if (parse_server_response() != 200)
System.out.println("Invalid Server Response");
else
{
//change RTSP state and print new state
state = READY;
//System.out.println("New RTSP state: ....");
}
}//else if state != INIT then do nothing
catch (Exception ex)
{
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
}
//Handler for Play button
//-----------------------
class playButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e){
//System.out.println("Play Button pressed !");
if (state == READY)
{
try {
//increase RTSP sequence number
RTSPSeqNb = RTSPSeqNb++;
//Send PLAY message to the server
send_RTSP_request("PLAY");
//Wait for the response
if (parse_server_response() != 200)
System.out.println("Invalid Server Response");
else
{
//change RTSP state and print out new state
state=PLAYING;
// System.out.println("New RTSP state: ...")
//start the timer
timer.start();
}
} //else if state != READY then do nothing
catch (Exception ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
}
//Handler for Pause button
//-----------------------
class pauseButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e){
//System.out.println("Pause Button pressed !");
if (state == PLAYING)
{
try {
//increase RTSP sequence number
RTSPSeqNb = RTSPSeqNb++;
//Send PAUSE message to the server
send_RTSP_request("PAUSE");
//Wait for the response
if (parse_server_response() != 200)
System.out.println("Invalid Server Response");
else
{
//change RTSP state and print out new state
state= READY;
//System.out.println("New RTSP state: ...");
//stop the timer
timer.stop();
}
}
//else if state != PLAYING then do nothing
catch (Exception ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
}
//Handler for Teardown button
//-----------------------
class tearButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e){
//System.out.println("Teardown Button pressed !");
//increase RTSP sequence number
RTSPSeqNb = RTSPSeqNb++;
//Send TEARDOWN message to the server
send_RTSP_request("TEARDOWN");
try {
//Wait for the response
if (parse_server_response() != 200)
System.out.println("Invalid Server Response");
else
{
//change RTSP state and print out new state
state=INIT;
//System.out.println("New RTSP state: ...");
//stop the timer
timer.stop();
//exit
System.exit(0);
}
} catch (Exception ex) {
Logger.getLogger(Client.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
//------------------------------------
//Handler for timer
//------------------------------------
class timerListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
//Construct a DatagramPacket to receive data from the UDP socket
rcvdp = new DatagramPacket(buf, buf.length);
try{
//receive the DP from the socket:
RTPsocket.receive(rcvdp);
//create an RTPpacket object from the DP
RTPpacket rtp_packet = new RTPpacket(rcvdp.getData(), rcvdp.getLength());
//print important header fields of the RTP packet received:
System.out.println("Got RTP packet with SeqNum # "+rtp_packet.getsequencenumber()+" TimeStamp "+rtp_packet.gettimestamp()+" ms, of type "+rtp_packet.getpayloadtype());
//print header bitstream:
rtp_packet.printheader();
//get the payload bitstream from the RTPpacket object
int payload_length = rtp_packet.getpayload_length();
byte [] payload = new byte[payload_length];
rtp_packet.getpayload(payload);
//get an Image object from the payload bitstream
Toolkit toolkit = Toolkit.getDefaultToolkit();
Image image = toolkit.createImage(payload, 0, payload_length);
//display the image as an ImageIcon object
icon = new ImageIcon(image);
iconLabel.setIcon(icon);
}
catch (InterruptedIOException iioe){
//System.out.println("Nothing to read");
}
catch (IOException ioe) {
System.out.println("Exception caught: "+ioe);
}
}
}
//------------------------------------
//Parse Server Response
//------------------------------------
private int parse_server_response() throws Exception
{
int reply_code = 0;
try{
//parse status line and extract the reply_code:
String StatusLine = RTSPBufferedReader.readLine();
//System.out.println("RTSP Client - Received from Server:");
System.out.println(StatusLine);
StringTokenizer tokens = new StringTokenizer(StatusLine);
tokens.nextToken(); //skip over the RTSP version
reply_code = Integer.parseInt(tokens.nextToken());
//if reply code is OK get and print the 2 other lines
if (reply_code == 200)
{
String SeqNumLine = RTSPBufferedReader.readLine();
System.out.println(SeqNumLine);
String SessionLine = RTSPBufferedReader.readLine();
System.out.println(SessionLine);
//if state == INIT gets the Session Id from the SessionLine
tokens = new StringTokenizer(SessionLine);
tokens.nextToken(); //skip over the Session:
RTSPid = Integer.parseInt(tokens.nextToken());
}
}
catch(Exception ex)
{
System.out.println("Exception caught c: "+ex);
System.exit(0);
}
return(reply_code);
}
//------------------------------------
//Send RTSP Request
//------------------------------------
//.............
//TO COMPLETE
//.............
private void send_RTSP_request(String request_type)
{
try{
//Use the RTSPBufferedWriter to write to the RTSP socket
//write the request line:
RTSPBufferedWriter.write(request_type+" "+VideoFileName+" RTSP/1.0"+CRLF);
System.out.print(request_type+" "+VideoFileName+" RTSP/1.0"+CRLF);
//write the CSeq line:
RTSPBufferedWriter.write("CSeq "+ RTSPSeqNb +CRLF);
System.out.print("CSeq "+ RTSPSeqNb +CRLF);
//check if request_type is equal to "SETUP" and in this case write the Transport: line advertising to the server the port used to receive the RTP packets RTP_RCV_PORT
if(request_type.equals("SETUP"))
{
RTSPBufferedWriter.write("Transport: RTP/UDP; client_port= "+ RTP_RCV_PORT + CRLF);
System.out.print("Transport: RTP/UDP; client_port= "+ RTP_RCV_PORT + CRLF);
}
//otherwise, write the Session line from the RTSPid field
else
{
RTSPBufferedWriter.write("Session: "+ RTSPid + CRLF);
System.out.print("Session: "+ RTSPid + CRLF);
}
try
{
RTSPBufferedWriter.flush();
}
catch(IOException e)
{
System.out.println("Exception caught a: "+e.toString());
}
}
catch(Exception ex)
{
System.out.println("Exception caught b: "+ex);
System.exit(0);
}
}
}//end of Class Client
客户端将连接到VLC输出流。但是，一旦我尝试按下“设置”按钮，它就会冻结。我用netbeans调试/跟踪了java程序，我发现一旦程序进入parseserverresponse（）方法，它就会挂断。这是由VLC造成的，还是我犯了一个更根本的错误？