public Receiver(SessionAddress local, SessionAddress target) throws IOException {
    mgr = RTPManager.newInstance();
    mgr.addReceiveStreamListener(this);
    try {
      mgr.initialize(local);
      mgr.addTarget(target);
    } catch (InvalidSessionAddressException e) {
      e.printStackTrace();
    }
    BufferControl bc = (BufferControl) mgr.getControl("javax.media.control.BufferControl");
    if (bc != null) bc.setBufferLength(350);
    addWindowListener(
        new WindowAdapter() {

          public void windowClosing(WindowEvent e) {
            disconnect();
          }
        });
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setVisible(false);
  }
  public static void main(String[] args) {
    if (args.length != 2) {
      System.out.println("Usage: rtpaudio <targetIP> <targetPort>");
      System.exit(0);
    }

    try {
      RegistryDefaults.setDefaultFlags(RegistryDefaults.FMJ);

      // create a clean registry
      RegistryDefaults.unRegisterAll(RegistryDefaults.ALL);
      RegistryDefaults.registerAll(RegistryDefaults.FMJ);

      // remove all capture devices
      Vector deviceList = (Vector) CaptureDeviceManager.getDeviceList(null).clone();
      for (int i = 0; i < deviceList.size(); i++) {
        CaptureDeviceInfo cdi = (CaptureDeviceInfo) deviceList.elementAt(i);
        CaptureDeviceManager.removeDevice(cdi);
      }

      // update capture device list
      new net.sf.fmj.media.cdp.javasound.CaptureDevicePlugger().addCaptureDevices();
      PlugInManager.commit();

      deviceList = (Vector) CaptureDeviceManager.getDeviceList(null).clone();
      if ((null == deviceList) || (deviceList.size() == 0)) {
        System.out.println("### ERROR found no audio capture device");
        System.exit(0);
      }

      // enumerate all codec
      Vector codecList = PlugInManager.getPlugInList(null, null, PlugInManager.CODEC);
      System.out.println("found " + codecList.size() + " codec");
      for (int i = 0; i < codecList.size(); i++) {
        String aCodecClass = (String) codecList.elementAt(i);
        System.out.println("# " + (i + 1) + " " + aCodecClass);
      }

      // fetch first available audio capture device
      deviceList = (Vector) CaptureDeviceManager.getDeviceList(null).clone();
      CaptureDeviceInfo captureDeviceInfo = (CaptureDeviceInfo) deviceList.elementAt(0);
      System.out.println("### using " + captureDeviceInfo.getName());
      System.out.println("### locator " + captureDeviceInfo.getLocator());

      javax.media.protocol.DataSource dataSource =
          javax.media.Manager.createDataSource(
              new javax.media.MediaLocator(captureDeviceInfo.getLocator().toString()));
      // javax.media.protocol.DataSource dataSource =
      // javax.media.Manager.createDataSource(new
      // javax.media.MediaLocator("javasound://"));
      System.out.println("### created datasource " + dataSource.getClass().getName());

      javax.media.control.FormatControl[] formatControls =
          ((javax.media.protocol.CaptureDevice) dataSource).getFormatControls();
      System.out.println("got format control " + formatControls[0].getClass().getName());

      System.out.println("current format is " + formatControls[0].getFormat());

      // set audio capture format
      javax.media.Format[] formats = formatControls[0].getSupportedFormats();
      for (int i = 0; i < formats.length; i++) {
        javax.media.format.AudioFormat af = (javax.media.format.AudioFormat) formats[i];
        if ((af.getChannels() == 1) && (af.getSampleSizeInBits() == 16)) {
          if (af.getSampleRate() == Format.NOT_SPECIFIED) {
            javax.media.format.AudioFormat newAudioFormat =
                new javax.media.format.AudioFormat(
                    af.getEncoding(),
                    8000.0f,
                    javax.media.Format.NOT_SPECIFIED,
                    javax.media.Format.NOT_SPECIFIED);
            // javax.media.format.AudioFormat newAudioFormat = new
            // javax.media.format.AudioFormat(af.getEncoding(),
            // 44100.0f, javax.media.Format.NOT_SPECIFIED,
            // javax.media.Format.NOT_SPECIFIED);
            formatControls[0].setFormat(newAudioFormat.intersects(af));
            break;
          }
        }
      }
      System.out.println("current format is now " + formatControls[0].getFormat());

      FrameProcessingControl fpc = null;

      // adujst recording buffer ( to adjust latency )
      dataSource.stop();
      Object[] controls = dataSource.getControls();
      for (int i = 0; i < controls.length; i++) {
        String className = controls[i].getClass().getName();
        if (-1 != className.indexOf("JavaSoundBufferControl")) {
          javax.media.control.BufferControl bc = (javax.media.control.BufferControl) controls[i];
          System.out.println(
              "### current javasound buffer length is " + bc.getBufferLength() + " ms");
          bc.setBufferLength(40);
          System.out.println(
              "### current javasound buffer length is " + bc.getBufferLength() + " ms");
        } else if (-1 != className.indexOf("JitterBufferControl")) {
          javax.media.control.BufferControl bc = (javax.media.control.BufferControl) controls[i];
          System.out.println("### current jitter buffer length is " + bc.getBufferLength() + " ms");
          bc.setBufferLength(80);
          System.out.println("### current jitter buffer length is " + bc.getBufferLength() + " ms");
        } else if (-1 != className.indexOf("FPC")) {
          fpc = (FrameProcessingControl) controls[i];
          System.out.println("### found bitrate control " + fpc.getClass());
        }
      }
      dataSource.start();

      // create processor
      javax.media.Processor processor = javax.media.Manager.createProcessor(dataSource);
      System.out.println("### created processor " + processor.getClass().getName());

      processor.configure();
      for (int idx = 0; idx < 100; idx++) {
        if (processor.getState() == Processor.Configured) {
          break;
        }
        Thread.sleep(100);
      }
      System.out.println("### processor state " + processor.getState());

      processor.setContentDescriptor(
          new javax.media.protocol.ContentDescriptor(ContentDescriptor.RAW_RTP));

      javax.media.control.TrackControl[] tracks = processor.getTrackControls();
      // /tracks[0].setFormat(new
      // javax.media.format.AudioFormat(javax.media.format.AudioFormat.ULAW_RTP,
      // 8000, 8, 1));
      tracks[0].setFormat(
          new javax.media.format.AudioFormat(javax.media.format.AudioFormat.GSM_RTP, 8000, 8, 1));

      processor.realize();
      for (int idx = 0; idx < 100; idx++) {
        if (processor.getState() == Controller.Realized) {
          break;
        }
        Thread.sleep(100);
      }
      System.out.println("### processor state " + processor.getState());

      javax.media.protocol.DataSource dataOutput = processor.getDataOutput();
      System.out.println("### processor data output " + dataOutput.getClass().getName());

      // BitRateControl
      BitRateControl bitrateControl = null;

      Object[] controls2 = dataOutput.getControls();
      for (int i = 0; i < controls2.length; i++) {
        if (controls2[i] instanceof BitRateControl) {
          bitrateControl = (BitRateControl) controls2[i];
          System.out.println("### found bitrate control " + bitrateControl.getClass());
          break;
        }
      }

      // PacketSizeControl
      Object[] controls3 = processor.getControls();
      for (int i = 0; i < controls3.length; i++) {
        if (controls3[i] instanceof PacketSizeControl) {
          PacketSizeControl psc = (PacketSizeControl) controls3[i];
          System.out.println("### current packetsize is " + psc.getPacketSize() + " bytes");
          psc.setPacketSize(66);
          System.out.println("### current packetsize is " + psc.getPacketSize() + " bytes");
          break;
        }
      }

      // enumerate all controls of the processor
      Object[] pcontrols = processor.getControls();
      for (int i = 0; i < pcontrols.length; i++) {
        System.out.println("processor control " + i + " " + pcontrols[i]);
      }

      javax.media.rtp.RTPManager rtpManager = javax.media.rtp.RTPManager.newInstance();

      javax.media.rtp.SessionAddress local =
          new javax.media.rtp.SessionAddress(
              InetAddress.getLocalHost(), Integer.valueOf(args[1]).intValue());
      javax.media.rtp.SessionAddress target =
          new javax.media.rtp.SessionAddress(
              InetAddress.getByName(args[0]), Integer.valueOf(args[1]).intValue());

      rtpManager.initialize(local);
      rtpManager.addTarget(target);

      javax.media.rtp.SendStream sendStream = rtpManager.createSendStream(dataOutput, 0);
      sendStream.start();

      processor.start();
      Thread.sleep(1000);

      System.out.println("\n>>>>>>  TRANSMITTING ULAW/RTP AUDIO NOW");
      while (2 > 1) {
        Thread.sleep(1000);

        if (null != bitrateControl) {
          TransmissionStats stats = sendStream.getSourceTransmissionStats();
          System.out.println(
              "rtp audio send: bitrate="
                  + bitrateControl.getBitRate()
                  + " (pdu="
                  + stats.getPDUTransmitted()
                  + " bytes="
                  + stats.getBytesTransmitted()
                  + " overrun="
                  + fpc.getFramesDropped()
                  + ")");
        }
      }
    } catch (Exception ex) {
      ex.printStackTrace();
    }

    System.exit(0);
  }