A Q about i-frame and p-frame

Question

http://www.interactivetvweb.org/tutorial/mhp/javamedia.shtml
in this tutorial, at the end, it talks about i-frame and p-frame.
i have an xlet that will need to switch iframe backgrounds very often. this p-frame idea will save the memory.
so anyone has tried it?
can provide at least a pseudocode?

Answer 1

I have known how to display i-frame read from a one-frame-only m2v file, which is the epg.m2v in the code below.
but after this, i can't even switch to other channels, seems like machine is hanging, have to reboot.
i am asking what causes this and how to display a p-frame on top of the iframe.
my code is as below:
////////////////////////start***********************/////////////
scene.setVisible(true);
g = scene.getGraphics();
MediaLocator myLocator;
DripFeedDataSource dripSource=null;
Player player=null;
MediaLocator driplocator = new MediaLocator("dripfeed://");
try
dripSource = (DripFeedDataSource) Manager.createDataSource(driplocator);
player = Manager.createPlayer(dripSource);
catch(Exception e){System.out.println(e.toString());}
if (player != null){
player.realize();
player.prefetch();
player.start();
try {
int size,size1;
InputStream in = new FileInputStream("epg.m2v");
InputStream in1 = new FileInputStream("small.m2v");// trying p-frame
size = in.available();
size1 = in1.available();// size of p-frame
byte[] frame = new byte[size];
byte[] frame1 = new byte[size1];// array of p-frame
in.read(frame);
in1.read(frame1);//read p-frame
in.close();
in1.close();//close reading
if (dripSource != null)
dripSource.feed(frame);
Thread.sleep(3000);//as spec says don't feed again within 500ms
dripSource.feed(frame1);//feeding p-frame?
Thread.sleep(10000);
player.stop();//can this stop it? coz i can't switch channels any more
catch (Exception ex) {
ex.printStackTrace();
////////////******************ends******************/////////
thanks