JMF : Audio can not be played from the remote machine

Question

Hi,
I am developing voice chat application.
As the moment this writing I can capture from mic and play it from the same machine.
But when I capture and transmit audio from one machine and try to play from remote machine in LAN it does not work.
Could anybody tell me please What would be the possible causes for this ? I have given the code below.
//Transmitter
package lsf.telphony.test;
import java.io.IOException;
import java.util.Vector;
import javax.media.CannotRealizeException;
import javax.media.CaptureDeviceInfo;
import javax.media.CaptureDeviceManager;
import javax.media.DataSink;
import javax.media.Format;
import javax.media.Manager;
import javax.media.MediaLocator;
import javax.media.NoDataSinkException;
import javax.media.NoDataSourceException;
import javax.media.NoProcessorException;
import javax.media.NotRealizedError;
import javax.media.Processor;
import javax.media.ProcessorModel;
import javax.media.format.AudioFormat;
import javax.media.protocol.ContentDescriptor;
import javax.media.protocol.DataSource;
public class MediaTransmetter implements Runnable
     private MediaLocator mediaLocator = null;
     private DataSink dataSink = null;
     private Processor mediaProcessor = null;
     public static String errorString;
     private CaptureDeviceInfo captureDeviceInfo = null;
     public MediaTransmetter(String rtpURL)
          DataSource dataSource = null;
          ProcessorModel model = null;
          Format formats[] = null;
          ContentDescriptor contentDescriptor = null;
          try
               captureDeviceInfo = getCaptureDevice();
               mediaLocator = captureDeviceInfo.getLocator();
               dataSource = javax.media.Manager.createDataSource(mediaLocator);
               contentDescriptor = new ContentDescriptor(ContentDescriptor.RAW_RTP);
               formats = new Format[] { new AudioFormat (AudioFormat.LINEAR) };
               model = new ProcessorModel(dataSource, formats, contentDescriptor);
               mediaProcessor = Manager.createRealizedProcessor(model);               
               MediaLocator outputLocator = new MediaLocator(rtpURL);
               dataSink = Manager.createDataSink(mediaProcessor.getDataOutput(), outputLocator);               
          } catch (Exception e)
               e.printStackTrace();
     @SuppressWarnings("unchecked") //check for this statement
     private CaptureDeviceInfo getCaptureDevice()
          CaptureDeviceInfo captureDeviceInfo;
          Vector<CaptureDeviceInfo> deviceListVector = CaptureDeviceManager.getDeviceList(new AudioFormat(AudioFormat.LINEAR));
          for (int i = 0; i < deviceListVector.size(); i++)
               captureDeviceInfo = (CaptureDeviceInfo)deviceListVector.elementAt(i);
               System.out.println("captureDeviceInfo = " + captureDeviceInfo);
               return captureDeviceInfo; // here the firt element is return. Add to login to get the specific CaptureDeviceInfo object.
          return null;
     @Override
     public void run()
          try
               dataSink.open();
               dataSink.start();
          } catch (SecurityException e)
               e.printStackTrace();
          } catch (IOException e)
               e.printStackTrace();
          mediaProcessor.start();
          System.out.println("Transmitting started successfully.");
     public static  void main(String[] args) { // Loads pastry settings
          MediaTransmetter mediaTransmetter = new MediaTransmetter("rtp://192.168.2.2/audio");
          Thread mediaTransmetterThread = new Thread(mediaTransmetter);
          mediaTransmetterThread.start();
}//AudioReceiver
package lsf.telphony.test;
import javax.media.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
public class MediaReceiver extends JFrame implements Runnable
     private static final long serialVersionUID = 1L;
     private static final String FRAME_TITLE = "Telphony Media Player";
     private static final String CONTROL_PANEL_TITLE = "Control Panel";
     private static final int LOC_X = 100;
     private static final int LOC_Y = 100;
     private static final int HEIGHT = 500;
     private static final int WIDTH = 500;
     private Player player = null;
     private JTabbedPane tabPane = null;
     public MediaReceiver()
          super(FRAME_TITLE);
          setLocation(LOC_X, LOC_Y);
          setSize(WIDTH, HEIGHT);
          tabPane = new JTabbedPane();
          getContentPane().add(tabPane);
          addWindowListener(new WindowAdapter()
               public void windowClosing(WindowEvent e)
                    closeCurrentPlayer();
                    System.exit(0);
     private JPanel createMainPanel()
          JPanel mainPanel = new JPanel();
          GridBagLayout gbl = new GridBagLayout();
          GridBagConstraints gbc = new GridBagConstraints();
          mainPanel.setLayout(gbl);
          boolean visualComponentExists = false;
          if (player.getVisualComponent() != null)
               visualComponentExists = true;
               gbc.gridx = 0;
               gbc.gridy = 0;
               gbc.weightx = 1;
               gbc.weighty = 1;
               gbc.fill = GridBagConstraints.BOTH;
               mainPanel.add(player.getVisualComponent(), gbc);
          if ((player.getGainControl() != null) && (player.getGainControl().getControlComponent() != null))
               gbc.gridx = 1;
               gbc.gridy = 0;
               gbc.weightx = 0;
               gbc.weighty = 1;
               gbc.gridheight = 2;
               gbc.fill = GridBagConstraints.VERTICAL;
               mainPanel.add(player.getGainControl().getControlComponent(), gbc);
          if (player.getControlPanelComponent() != null)
               gbc.gridx = 0;
               gbc.gridy = 1;
               gbc.weightx = 1;
               gbc.gridheight = 1;
               if (visualComponentExists)
                    gbc.fill = GridBagConstraints.HORIZONTAL;
                    gbc.weighty = 0;
               } else
                    gbc.fill = GridBagConstraints.BOTH;
                    gbc.weighty = 1;
               mainPanel.add(player.getControlPanelComponent(), gbc);
          return mainPanel;
     public void setMediaLocator(MediaLocator locator) throws Exception, IOException, NoPlayerException,
               CannotRealizeException
          setPlayer(Manager.createRealizedPlayer(locator));
     public void setPlayer(Player newPlayer)
          closeCurrentPlayer();
          player = newPlayer;
          tabPane.removeAll();
          if (player == null)
               return;
          tabPane.add(CONTROL_PANEL_TITLE, createMainPanel());
          Control[] controls = player.getControls();
          for (int i = 0; i < controls.length; i++)
               if (controls.getControlComponent() != null)
                    tabPane.add(controls[i].getControlComponent());
     private void closeCurrentPlayer()
          if (player != null)
               player.stop();
               player.close();
     public static void printUsage()
          System.out.println("Usage: java MediaPlayerFrame mediaLocator");
     public void run()
          try
               MediaReceiver mpf = new MediaReceiver();
               mpf.setMediaLocator(new MediaLocator("rtp://192.168.2.2:10000/audio"));
               mpf.show();
          } catch (Exception t)
               t.printStackTrace();
     public static void main(String[] args) { // Loads pastry settings
          MediaReceiver mediaReceiver = new MediaReceiver();
          Thread mediaReceiverThread = new Thread(mediaReceiver);
          mediaReceiverThread.start();

Answer 1

By the way the program does not terminate immediately after starting it. According to your advice I tried removing running it inside in a thread and making it sleep at several points appropriate. No luck.
I wonder why packets are not sending even the program is running until the end of the line with no exception.
Have you tried to capture RTP packet traffic with Wireshark or similar kind of network analyzing software with this kind of program?
I am doubt whether my program is actually transmitting packets but unable to capture those due to the error with transmitter.
Even with the Wireshark It does not capture outgoing packets.
And another thing I noticed with netstat is it shows two pots get opened when running the application but those ports are not the one I note in the program.
For example I run the program with port number as 10000 (sink: setOutputLocator rtp://192.168.2.104:10000/audio). But when I check it with netstat some other ports are open.
i.e
nuwan@nuwan-laptop:~/eclipse$ netstat -anup
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
udp 0 0 0.0.0.0:68 0.0.0.0:* -
udp 0 0 0.0.0.0:40526 0.0.0.0:* -
udp 0 0 0.0.0.0:5353 0.0.0.0:* -
udp6       0      0 127.0.1.1:28864         ::: 10772/java*
udp6       0      0 127.0.1.1:28865         ::: 10772/java*
nuwan@nuwan-laptop:~/eclipse$
And each time when I start the program these two ports are changed also.
And foreign address is not shown ? Any comment for that??
Is there anything that can be drawn from above information which caused for not working my program.
This is killing me. And also making me sharper. And I cant leave this behind also. So highly appreciate you time and help.
Thanks.