Transmit and receive from the same ip address?

Question

Helpers:
We 've been using transmit/Receive for a while, I read all the discussions. No one seem really know does the transmit send to a destination IP address and the destination receive from the same IP or the IP address the sender send from?
like sender send from: java Transmitter 123.4.3.162 5000
receiver receive from: java Receive 123.4.3.162 5000
or sender send from: java Transmitter 123.4.3.162 5000
receiver receive from: java Receive 10.118.5.162 5000
I think the frist one is correct, does anyone has clear idea and experience about it.
Desperate coder!

Answer 1

Receiver code is as follows
import java.io.*;
import java.awt.*;
import java.net.*;
import java.awt.event.*;
import java.util.Vector;
import javax.media.*;
import javax.media.rtp.*;
import javax.media.rtp.event.*;
import javax.media.rtp.rtcp.*;
import javax.media.protocol.*;
import javax.media.protocol.DataSource;
import javax.media.format.AudioFormat;
import javax.media.format.VideoFormat;
import javax.media.Format;
import javax.media.format.FormatChangeEvent;
import javax.media.control.BufferControl;
public class AVReceive2 implements ReceiveStreamListener, SessionListener,ControllerListener
String sessions[] = null;
RTPManager mgrs[] = null;
Vector playerWindows = null;
boolean dataReceived = false;
Object dataSync = new Object();
public AVReceive2(String sessions[])
          this.sessions = sessions;
protected boolean initialize()
try
          InetAddress ipAddr;
     SessionAddress localAddr = new SessionAddress();
          SessionAddress destAddr;
          mgrs = new RTPManager[sessions.length];
          playerWindows = new Vector();
          SessionLabel session;
          for (int i = 0; i < sessions.length; i++)
               try
     session = new SessionLabel(sessions);
          catch (IllegalArgumentException e)
     System.err.println("Failed to parse the session address given: " + sessions[i]);
                    return false;
System.err.println(" - Open RTP session for: addr: " + session.addr + " port: " + session.port + " ttl: " + session.ttl);
     mgrs[i] = (RTPManager) RTPManager.newInstance();
     mgrs[i].addSessionListener(this);
     mgrs[i].addReceiveStreamListener(this);
     ipAddr = InetAddress.getByName(session.addr);
          if( ipAddr.isMulticastAddress())
// local and remote address pairs are identical:
localAddr= new SessionAddress( ipAddr,session.port,session.ttl);
destAddr = new SessionAddress( ipAddr,session.port,session.ttl);
                    else
localAddr= new SessionAddress( InetAddress.getLocalHost(),session.port);
destAddr = new SessionAddress( ipAddr, session.port);
          mgrs[i].initialize( localAddr);
BufferControl bc = (BufferControl)mgrs[i].getControl("javax.media.control.BufferControl");
                    if (bc != null)
          bc.setBufferLength(350);
               mgrs[i].addTarget(destAddr);
          catch (Exception e)
System.err.println("Cannot create the RTP Session: " + e.getMessage());
return false;
     long then = System.currentTimeMillis();
long waitingPeriod = 30000; // wait for a maximum of 30 secs.
          try
          synchronized (dataSync)
while (!dataReceived && System.currentTimeMillis() - then < waitingPeriod)
                    if (!dataReceived)
                              System.err.println(" - Waiting for RTP data to arrive...");
                    dataSync.wait(1000);
          catch (Exception e) {}
          if (!dataReceived)
System.err.println("No RTP data was received.");
          close();
          return false;
return true;
public boolean isDone()
          return playerWindows.size() == 0;
protected void close()
          for (int i = 0; i < playerWindows.size(); i++)
          try
     ((PlayerWindow)playerWindows.elementAt(i)).close();
          catch (Exception e) {}
          playerWindows.removeAllElements();
     // close the RTP session.
          for (int i = 0; i < mgrs.length; i++)
          if (mgrs[i] != null)
mgrs[i].removeTargets( "Closing session from AVReceive2");
mgrs[i].dispose();
                    mgrs[i] = null;
PlayerWindow find(Player p)
          for (int i = 0; i < playerWindows.size(); i++)
          PlayerWindow pw = (PlayerWindow)playerWindows.elementAt(i);
          if (pw.player == p)
                    return pw;
          return null;
PlayerWindow find(ReceiveStream strm)
          for (int i = 0; i < playerWindows.size(); i++)
          PlayerWindow pw = (PlayerWindow)playerWindows.elementAt(i);
          if (pw.stream == strm)
                    return pw;
          return null;
public synchronized void update(SessionEvent evt)
          if (evt instanceof NewParticipantEvent)
     Participant p = ((NewParticipantEvent)evt).getParticipant();
System.err.println(" - A new participant had just joined: " + p.getCNAME());
public synchronized void update( ReceiveStreamEvent evt)
     RTPManager mgr = (RTPManager)evt.getSource();
Participant participant = evt.getParticipant();     // could be null.
ReceiveStream stream = evt.getReceiveStream(); // could be null.
          if (evt instanceof RemotePayloadChangeEvent)
System.err.println(" - Received an RTP PayloadChangeEvent.");
System.err.println("Sorry, cannot handle payload change.");
          System.exit(0);
          else
          if (evt instanceof NewReceiveStreamEvent)
          try {
stream = ((NewReceiveStreamEvent)evt).getReceiveStream();
DataSource ds = stream.getDataSource();
          // Find out the formats.
RTPControl ctl = (RTPControl)ds.getControl("javax.media.rtp.RTPControl");
                    if (ctl != null)
System.err.println(" - Recevied new RTP stream: " + ctl.getFormat());
                    else
System.err.println(" - Recevied new RTP stream");
                    if (participant == null)
System.err.println(" The sender of this stream had yet to be identified.");
                    else
System.err.println(" The stream comes from: " + participant.getCNAME());
// create a player by passing datasource to the Media Manager
Player p = javax.media.Manager.createPlayer(ds);
                    if (p == null)
                    return;
               p.addControllerListener(this);
                    p.realize();
     PlayerWindow pw = new PlayerWindow(p, stream);
     playerWindows.addElement(pw);
               synchronized (dataSync)
                    dataReceived = true;
                    dataSync.notifyAll();
          catch (Exception e)
     System.err.println("NewReceiveStreamEvent exception " + e.getMessage());
                    return;
          else
          if (evt instanceof StreamMappedEvent)
               if (stream != null && stream.getDataSource() != null)
                    DataSource ds = stream.getDataSource();
          // Find out the formats.
RTPControl ctl = (RTPControl)ds.getControl("javax.media.rtp.RTPControl");
     System.err.println(" - The previously unidentified stream ");
                    if (ctl != null)
     System.err.println(" " + ctl.getFormat());
     System.err.println(" had now been identified as sent by: " + participant.getCNAME());
          else
          if (evt instanceof ByeEvent)
System.err.println(" - Got \"bye\" from: " + participant.getCNAME());
          PlayerWindow pw = find(stream);
          if (pw != null)
                    pw.close();
          playerWindows.removeElement(pw);
public synchronized void controllerUpdate(ControllerEvent ce)
          Player p = (Player)ce.getSourceController();
          if (p == null)
          return;
     // Get this when the internal players are realized.
          if (ce instanceof RealizeCompleteEvent)
          PlayerWindow pw = find(p);
          if (pw == null)
          // Some strange happened.
          System.err.println("Internal error!");
                    System.exit(-1);
          pw.initialize();
          pw.setVisible(true);
          p.start();
          if (ce instanceof ControllerErrorEvent)
          p.removeControllerListener(this);
          PlayerWindow pw = find(p);
          if (pw != null)
                    pw.close();
          playerWindows.removeElement(pw);
     System.err.println("AVReceive2 internal error: " + ce);
class SessionLabel
          public String addr = null;
          public int port;
          public int ttl = 1;
SessionLabel(String session) throws IllegalArgumentException
          int off;
          String portStr = null, ttlStr = null;
          if (session != null && session.length() > 0)
     while (session.length() > 1 && session.charAt(0) == '/')
          session = session.substring(1);
          // Now see if there's a addr specified.
                    off = session.indexOf('/');
                    if (off == -1)
                    if (!session.equals(""))
               addr = session;
                    else
          addr = session.substring(0, off);
          session = session.substring(off + 1);
          // Now see if there's a port specified
          off = session.indexOf('/');
                    if (off == -1)
                    if (!session.equals(""))
                    portStr = session;
                         else
          portStr = session.substring(0, off);
          session = session.substring(off + 1);
          // Now see if there's a ttl specified
                              off = session.indexOf('/');
                              if (off == -1)
                              if (!session.equals(""))
                                        ttlStr = session;
               else
          ttlStr = session.substring(0, off);
          if (addr == null)
     throw new IllegalArgumentException();
          if (portStr != null)
                    try {
          Integer integer = Integer.valueOf(portStr);
                    if (integer != null)
                              port = integer.intValue();
          catch (Throwable t)
          throw new IllegalArgumentException();
          else
          throw new IllegalArgumentException();
          if (ttlStr != null)
                    try {
          Integer integer = Integer.valueOf(ttlStr);
                    if (integer != null)
               ttl = integer.intValue();
                    catch (Throwable t)
          throw new IllegalArgumentException();
class PlayerWindow extends Frame {
     Player player;
     ReceiveStream stream;
     PlayerWindow(Player p, ReceiveStream strm) {
     player = p;
     stream = strm;
     public void initialize() {
     add(new PlayerPanel(player));
     public void close() {
     player.close();
     setVisible(false);
     dispose();
     public void addNotify() {
     super.addNotify();
     pack();
class PlayerPanel extends Panel {
     Component vc, cc;
     PlayerPanel(Player p) {
     setLayout(new BorderLayout());
     if ((vc = p.getVisualComponent()) != null)
          add("Center", vc);
     if ((cc = p.getControlPanelComponent()) != null)
          add("South", cc);
     public Dimension getPreferredSize() {
     int w = 0, h = 0;
     if (vc != null) {
          Dimension size = vc.getPreferredSize();
          w = size.width;
          h = size.height;
     if (cc != null) {
          Dimension size = cc.getPreferredSize();
          if (w == 0)
          w = size.width;
          h += size.height;
     if (w < 160)
          w = 160;
     return new Dimension(w, h);
public static void main(String args[])
          String[] argv = new String[2];
          argv[0] = "100.210.0.220/42050";
          argv[1] = "100.210.0.220/4002";
          AVReceive2 avReceive = new AVReceive2(argv);
          if (!avReceive.initialize())
     System.err.println("Failed to initialize the sessions.");
          System.exit(-1);
          try {
          while (!avReceive.isDone())
                    Thread.sleep(1000);
          } catch (Exception e) {}
          System.err.println("Exiting AVReceive2");