Java media framework

Java Media Framework

1. Java MEDIA FRAMEWORK Ms. Vishwakarma Payal Rambali Shailkumari M.Sc.-II (Computer Science) Roll No: 05

2. Outline What is Java Media Framework? Creating Media Player . Prefetching the Media . Adding the Player to your Application . Registering the Applet as a Listener . Starting the Player . Cleaning up and Stopping the Player . The States of the Player . Adding Controls to the Player . Setting the Media Time and Changing Rate . Features of JMF .

3. What is Java Media Framework ? The java media framework provides the means to present all kinds of interesting media type. The java media framework is an API for integrating advanced media formats into java, such as video and sound. The media framework has several components, including media players, media capture, and conferencing . A key to any of these topics is in providing a timing mechanism, which determines when the next part of the media should be played. It is important to have a mechanism to keep a video stream playing at the same speed as accompanying sound stream.

4. Creating a Media Player By creating an applet that uses a media player. Putting the media into applet involve a few basic steps: Create the URL for media file. Create the player for the media. Tell the player to prefetch . Add the player to the applet. Start the player.

5. Creating a Media Player To create the player you utilize the Manager class. The Manager class is actually the hub for getting both the timebase and the players. The first task is to create an URL for file then to create the player. Example : In the BasicPlayer class, following are happens in the init() method.

6. Creating a Player and it’s associated URL try { mediaURL =new URL( getDocumentBase (), mediafile ); Player= Manager.createPlayer ( mediaURL ); } catch( IOException e) { System.out.println (“URL for “+ mediafile ” is invalid); }

7. Prefetching the Media Prefetching causes two things: 1. The player goes through a process called realization. 2. It then starts to download the media file so that some of it can be cached. This reduces the latency time before the player can start actually playing the media. Example : In the BasicPlayer class, following are happens in the start() method.

8. In the start method ,we prefetch the media we are going to play. Example: public void start() { if(player!=null) { //prefetch starts the player . player.prefetch (); } } Prefetching the Media

9. Adding Player to your Application Adding the player to application is actually kind of tricky . The player itself is not an AWT component. So you don’t add the player it self ,but it’s visual representation. To get the visual component ,player has a method called getVisualComponent (). Player has a method called getState () that returns the state of the current player . ControllerListener has one method- ControllerUpdate ( ControllerEvent ).

10. We can use the ControllerUpdate method to know when the media has been fetched. ControllerUpdate () method is called each time the state of the controller changes. Example: Adding Player to your Application public synchronized void control update( ControllerEvent event) { if(event instanceof RealizeCompleteEvent ) { if(( VisualComponent = player.getVisualCompent ())!=null) add(“ center”,visualComponent ); validate(); } }

11. Registering the Applet as a Listener To have the player call ControllerUpdate () you must first register your application with the player. Just like all java.awt.event listener after a component has been registered as listener ,it’s the method will be call any time an event occurs. For the current purposes you will add the addControllerListener code to the init() method of the applet.

12. Public void init () { String mediaFile =null; URL mediaURL =null; setLayout (new BorderLayout ()); If(( mediaFile = getParameter (“file”))==null) { System.err.print (“Media file not present”); System.err.print (“Required parameter is ‘file’ ”); } else { try { mediaURL = new URL( getDocumentBase (), mediafile ); player= manager.createPlayer ( mediaURL ); } } Registering the Applet as a Listener

13. Starting the Player start() which tells player to start. The more fundamental methods allows to start the player and specify when it will actually display it’s media. The syncstart () method is the method that actually causes the player to start. Example : If(event instanceof PrefetchCompleteEvent ) { player.start (); }

14. Cleaning Up and Stopping the Player stop() method must be used to stop the media player and clean up. The stop() method is called when browser leaves the current web pages. After browser leaves the page, we should stop playing the current media. One addition step we should take-removing the media from memory. The player has deallocate() method. As soon as you know that you no longer need a media ,you should tell the player to deallocate it so that it can be garbage collected.

15. Using both the player’s stop() and deallcoate () methods, you can create the applets stop method. Example: Public void stop() { if(player!=null) { player.deallocate (); } } Cleaning Up and Stopping the Player

16. States of the Players There are different states that player goes through during normal operation. Unrealized realize() Realizing Realized Prefetch () Prefetching Prefetch Start()/deallocate() Start deallocate()

17. Unrealized: At this stage, the player does not know anything about the media except what the URL to the media is. Realizing: In the realizing state, the player acquired all of resources that are non-exclusive. Realized: When the player enters the realized state, the RealizeCompleteEvent is issued. Prefetching: To get the player to move into the prefetching state, you can use the prefetch() method. States of the Players

18. Prefetched : Entering the prefetched state, a player issues the PrefetchCompleteEvent . Started : When player is started, it enters the started state. States of the Players

19. Adding Controls to the Players Example: Public synchronized void controllerUpdate ( ControllerEvent event) { if(event isnstaceofRealizeCompleteEvent ) { if(( visualComponent = player.getVisualComponent ())!=null) if( visualComponent !=null) add(“ South”,controlComponent ); else add ( “ Center”,controlComponent ); }} Each type of the player has the capability to give you a set of controls using the ControlPanelComponent () method. Like the getVisualComponent () method, the getControlPanelComponent () cannot be used until after the player has been realized.

20. Setting the media time and Changing rate The setMediaTime () method takes long parameter and that number represents the time in nanoseconds. The setRate () method returns to you the actual rate that has been applied. Example : if(event isnstaceofPrefetchCompleteEvent ) { System.out.println (“Prefetching : ” + newDate ()); player.setRate ((float)2.0); player.start (); }

21. Features of JMF JMF supports many popular media formats such as JPEG, MPEG-1, MPEG-2, QuickTime, AVI, WAV, MP3, GSM, G723, H263, and MIDI. JMF supports popular media access protocols such as file, HTTP, HTTPS, FTP, RTP, and RTSP. JMF uses a well-defined event reporting mechanism that follows the “Observer” design pattern. JMF uses the “Factory” design pattern that simplifies the creation of JMF objects. The JMF support the reception and transmission of media streams using Real-time Transport Protocol (RTP) and JMF supports management of RTP sessions.

22. References Book: Advanced JAVA Websites: http://www.programming.com/GepBook/Chapter7/M3L1.ppt https://web.cs.dal.ca/~mheywood/CSCI6506/HandOuts/N04-Deception.pdf

23. Thank you . . .!!!!!