JAVA MEDIA FRAMEWORK

Ms. Vishwakarma Payal Rambali Shailkumari

M.Sc.-II (Computer Science)

Roll No: 05

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 .

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.

Creating a Media Player

By creating an applet that uses a media player. Putting the

media into applet involve a few basic steps:

1. Create the URL for media file.

2. Create the player for the media.

3. Tell the player to prefetch .

4. Add the player to the applet.

5. Start the player.

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.

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);

}

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.

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

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).

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();

}

}

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.

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

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();

}

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.

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

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()

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

Prefetched :Entering the prefetched state, a player issues the

PrefetchCompleteEvent.

Started : When player is started, it enters the started state.

States of the Players

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.

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();

}

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 followsthe “Observer” design pattern. JMF uses the “Factory” designpattern that simplifies the creation of JMF objects.

The JMF support the reception and transmission of mediastreams using Real-time Transport Protocol (RTP) and JMFsupports management of RTP sessions.

References

Book:

Advanced JAVA

Websites:

http://www.programming.com/GepBook/Chapter7/M3L1.p

pt

https://web.cs.dal.ca/~mheywood/CSCI6506/HandOuts/N

04-Deception.pdf

Thank you . . .!!!!!