JMF issues for video conferencing

Question

I've have been playing with JMF for a few weeks now, trying different things, specifically creating a video conference app, like everybody else here.
I've noticed several weird issues, and was hoping somebody could provide feedback on them;
1) when setting the format for the tracks on a transmitting processor, I get a Class Cast Exception:
TrackControl track[] = processor.getTrackControls();
FormatControl fc = null;
for (int i=0; i < track.length; i++) {
if (!retval && track[i] instanceof FormatControl) {
try {
fc = (FormatControl) track.setFormat(new VideoFormat(VideoFormat.JPEG_RTP));
retval = true;
} catch (Exception e) {
// Always goes here, ClassCastException thrown on Format
System.out.println("Info: exception setting track");
} else {
track[i].setEnabled(false);
2) The image coming from the webcam is flipped, which I transport as so, and just flip the image using drawImage. Is there a better way of doing this, because I assume not all webcams will capture the image flipped, and I have read that encryption works better if the image is not flipped.
3) Client freezes when server stops broadcasting. I'm using a medialocator on the client with the rtp url to the broadcasting datasink. How can I capture the stop broadcasting event on the client and stop the client process cleanly?
4) Server freezes when I stop broadcasting and have a client connected to the rtp locator. I use a processor.close() call on the server which works fine when no clients are connected to the rtp url of the broadcast. When a client is connected the close call hangs indefinately, even when I close the client.
5) Performace is really slow. When the client connects to the media locator rtp url (running on the same machine) it takes upto 2 minutes to initialize, and transfer seems to be sparadic. The transfer often stops and starts again, but I'm not even going through the internet, I'm broadcasting on my local machine, with my client running on the same machine. I use a new laptop with 256MB, performance of the machine is fine.
Any advice would be greatly appreciated.

Answer 1

3) Client freezes when server stops broadcasting. I'm using a medialocator on the client with the rtp url to the broadcasting datasink. How can I capture the stop broadcasting event on the client and stop the client process cleanly?
If your client s/w implements ReceiveStreamListener then you can use
*     ReceiveStream Listener
public void update(ReceiveStreamEvent e)
     RTPManager rtpM = (RTPManager)e.getSource();
     Object obj = e.getReceiveStream();
     if(obj != null)
     ReceiveStream rS = (ReceiveStream)obj;
     DataSource dS = rS.getDataSource();
     if(e instanceof StreamMappedEvent)
          System.out.println("Received an RTP StreamMappedEvent");
     else if(e instanceof NewReceiveStreamEvent)
          System.out.println("Received an RTP NewReceiveStreamEvent");
          try{
          rS = ((NewReceiveStreamEvent)e).getReceiveStream();
          if(participant != null)
               establishPlayer(participant.getCNAME(), dS, rtpM);
          else
               establishPlayer(null, dS, rtpM);
          }catch(Exception eX){
          eX.printStackTrace();
     else if(e instanceof InactiveReceiveStreamEvent)
          System.out.println("Received an RTP InactiveReceiveStreamEvent");
     else if(e instanceof ActiveReceiveStreamEvent)
          System.out.println("Received an RTP ActiveReceiveStreamEvent from '" + participant.getCNAME() + "' with '" + dS + "' DataSource");
     else if(e instanceof RemotePayloadChangeEvent)
          System.out.println("Received an RTP RemotePayloadChangeEvent");
you can do something appropriate in the InactiveReceiveStreamEvent
NOTE there isn't a way to recover the straem after this, so your expectation wo0uld be that the server-side is also shutting the stream down