media in java

8/13/2019 Media in Java

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2000 Prentice Hall, Inc. All rights reserved.

Java Multimedia: Images, Animation,

Audio and Video

Outline30.1 Introduction30.2 Loading, Displaying and Scaling Images30.3 Loading and Playing Audio Clips30.4 Animating a Series of Images30.5 Animation Issues30.6 Customizing Applets via the HTMLparamTag30.7 Image Maps30.8 Java Plug-In30.9 Internet and World Wide Web Resources


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30.1 Introduction

Revolution in computer industry

Before, computers used for high-speed calculations

Now, data manipulation important

Multimedia

"sizzle" of Java - images, sound, video CDs, DVDs, video cards

Demands extraordinary computing power

Fast processors making multimedia possible

Java Has built-in multimedia capabilities

Most programming languages do not

Develop powerful multimedia applications


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30.2 Loading, Displaying and Scaling

Images

Java Multimedia

Graphics, images, animations, sounds, and video

Begin with images

Class Image(java.awt)

Abstract class, cannot create an object directly Must request that an Imagebe loaded and returned to you

ClassApplet(superclass of JApplet) has this method

getImage( imageLocation, filename );

imageLocation - getDocumentBase()- URL

(address) of HTML file

filename - Java supports .gifand .jpg(.jpeg)


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Images (II)

Displaying Images with drawImage Many overloaded versions

g.drawImage( myImage, x, y, ImageObserver );

myImage - Imageobject

x,y - coordinates to display image

ImageObserver- object on which image is displayed Use "this"to indicate the applet

Can be any object that implements ImageObserverinterface

g.drawImage( myImage, x, y, width, height,ImageObserver );

widthand height- dimensions of image (automaticallyscaled)

getWidth(), getHeight()- return dimensions of

applet


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Images (III)

Class ImageIcon

Not an abstract class (can create objects)

Example constructor

private ImageIcon myIcon;

myIcon = new ImageIcon( "myIcon.gif" );

Displaying Iconswith methodpaintIconmyIcon.paintIcon( Component, Graphics, x, y )

Component - Componentobject on which to display image

(this)

Graphics- Graphicsobject used to render image (g)

x, y- coordinates of Icon


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Images (IV)

Usage

ImageIcons are simpler than Images

Create objects directly

No need for ImageObserverreference

However, cannot scale ImageIcons

Scaling

Use ImageIconmethod getImage

Returns Imagereference

This can be used with drawImageand be scaled


7/372000 Prentice Hall, Inc. All rights reserved.

Outline

Image Example

1. import

1.1 Declare objects

2. init()

2.1 Initialize objects

3.paint()

3.1 drawImagecalls

1 // Fig. 30.1: LoadImageAndScale.java

2 // Load an image and display it in its original size

3 // and scale it to twice its original width and height.

4 // Load and display the same image as an ImageIcon.

5 importjava.applet.Applet;

6 importjava.awt.*;

7 importjavax.swing.*;

8

9 public classLoadImageAndScale extendsJApplet {

10 privateImage logo1;

11 privateImageIcon logo2;

12

13 // load the image when the applet is loaded

14 public voidinit()

15 {

16 logo1 = getImage( getDocumentBase(), "logo.gif" );

17 logo2 = newImageIcon( "logo.gif" );

18 }

19

20 // display the image

21 public voidpaint( Graphics g )

22 {23 // draw the original image

24 g.drawImage( logo1, 0, 0, this);

25

26 // draw the image scaled to fit the width of the applet

27 // and the height of the applet minus 120 pixels

28 g.drawImage( logo1, 0, 120,

29 getWidth(), getHeight() - 120, this);

30

31 // draw the icon using its paintIcon method



Outline

3.2paintIconcall

Program Output

32 logo2.paintIcon( this, g, 180, 0 );

33 }

34 }



30.3 Loading and Playing Audio Clips

Audio clips

Require speakers and a sound board

Sound engine - plays audio clips

Supports .au, .wav, .aif, .mid

Java Media Framework supports additional formats

Playing audio clips

playmethod inApplet

Plays clip once, marked for garbage collection when finished

play( location, soundFileName );

location - getDocumentBase(URL of HTML file)

play( soundURL );

soundURL- URL that contains location and filename of clip



30.3 Loading and Playing Audio Clips (II)

Playing audio clips MethodplayfromAudioClipinterface

More flexible thanAppletmethodplay

Audio stored in program, can be reused

getAudioClip

Returns reference to anAudioClip

Same format asAppletmethodplay

getAudioClip( location, filename )

getAudioClip( soundURL )

OnceAudioCliploaded, use methodsplay- plays audio once

loop- continuous loops audio in background

stop- terminates clip that is currently playing



Outline

1. import

1.1 Declare objects

2. init

2.1 Set layout

1 // Fig. 30.2: LoadAudioAndPlay.java

2 // Load an audio clip and play it.

3 importjava.applet.*;

4 importjava.awt.*;

5 importjava.awt.event.*;


7

8 public classLoadAudioAndPlay extendsJApplet {9 privateAudioClip sound1, sound2, currentSound;

10 privateJButton playSound, loopSound, stopSound;

11 privateJComboBox chooseSound;

12

13 // load the image when the applet begins executing


15 {

16 Container c = getContentPane();

17 c.setLayout( newFlowLayout() );

18

19 String choices[] = { "Welcome", "Hi" };

20 chooseSound = newJComboBox( choices );

21 chooseSound.addItemListener(

22 newItemListener() {

23 public voiditemStateChanged( ItemEvent e )24 {

25 currentSound.stop();

26

27 currentSound =

28 chooseSound.getSelectedIndex() == 0 ?

29 sound1 : sound2;

30 }

31 }

32 );



Outline

2.2 Add buttons

2.3 Initialize audio

clips

3. stop

4. ClassButtonHandler

33 c.add( chooseSound );

34

35 ButtonHandler handler = newButtonHandler();

36 playSound = newJButton( "Play" );

37 playSound.addActionListener( handler );

38 c.add( playSound );

39 loopSound = newJButton( "Loop" );

40 loopSound.addActionListener( handler );41 c.add( loopSound );

42 stopSound = newJButton( "Stop" );

43 stopSound.addActionListener( handler );

44 c.add( stopSound );

45

46 sound1 = getAudioClip(

47 getDocumentBase(), "welcome.wav" );

48 sound2 = getAudioClip(

49 getDocumentBase(), "hi.au" );

50 currentSound = sound1;

51 }

52

53 // stop the sound when the user switches Web pages

54 // (i.e., be polite to the user)

55 public voidstop()56 {


58 }

59

60 private classButtonHandler implementsActionListener {

61 public voidactionPerformed( ActionEvent e )

62 {

63 if( e.getSource() == playSound )

64 currentSound.play();

65 l if ( tS () l S d )



Outline

Program Output

65 else if( e.getSource() == loopSound )

66 currentSound.loop();

67 else if( e.getSource() == stopSound )


69 }

70 }

71 }


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30.4 Animating a Series of Images (II)

Method repaint Calls update, which callspaintComponent

Subclasses of JComponentshould draw in method

paintComponent

Call superclass'spaintComponentto make sure Swingcomponents displayed properly

View area

Width and height specify entire window, not client area

Dimensionobjects Containwidthand heightvalues

myDimObject = new Dimension( 100, 200 );

myDimObject.width



30.4 Animating a Series of Images (III)

getImageLoadStatus

ImageIconmethod Determines if image is completely loaded into memory

Only complete images should be displayed (smooth animation)

If loaded, returnsMediaTracker.COMPLETE

MediaTracker

Can determine when images are loaded, or force program to

wait if not

ImageIconcreates ourMediaTrackerfor us

1 // Fig 30 3: LogoAnimator java



Outline

1. import

1.1 implements

ActionListener

1.2 Declare objects

1.3 Constructor

1.4 InitializeImageIconarray

2.paintComponent

2.1 Call to superclasspaintComponent

1 // Fig. 30.3: LogoAnimator.java

2 // Animation a series of images

3 importjava.awt.*;



6

7 public classLogoAnimator extendsJPanel

8 implementsActionListener {9 protectedImageIcon images[];

10 protected inttotalImages = 30,

11 currentImage = 0,

12 animationDelay = 50; // 50 millisecond delay

13 protectedTimer animationTimer;

14

15 publicLogoAnimator()

16 {

17 setSize( getPreferredSize() );

18

19 images = newImageIcon[ totalImages ];

20

21 for( inti = 0; i < images.length; ++i )

22 images[ i ] =

23 newImageIcon( "images/deitel" + i + ".gif" );24

25 startAnimation();

26 }

27

28 public voidpaintComponent( Graphics g )

29 {

30 super.paintComponent( g );

31

32 if ( images[ currentImage ] getImageLoadStatus() ==



Outline

2.2 If image loaded,display it (paintIcon)

2.3 IncrementcurrentImage

3.actionPerformed

3.1startAnimation

3.2 stopAnimation

3.3getMinimumSize

32 if( images[ currentImage ].getImageLoadStatus() ==

33 MediaTracker.COMPLETE ) {

34 images[ currentImage ].paintIcon( this, g, 0, 0 );

35 currentImage = ( currentImage + 1 ) % totalImages;

36 }

37 }

38

39 publicvoidactionPerformed( ActionEvent e )40 {

41 repaint();

42 }

43

44 public voidstartAnimation()

45 {

46 if( animationTimer == null) {

47 currentImage = 0;48 animationTimer = newTimer( animationDelay, this);

49 animationTimer.start();

50 }

51 else // continue from last image displayed

52 if( ! animationTimer.isRunning() )

53 animationTimer.restart();

54 }

55

56 public voidstopAnimation()

57 {

58 animationTimer.stop();

59 }

60

61 publicDimension getMinimumSize()

62 {

63 returngetPreferredSize();

64 }

65



Outline

3.4.getPreferredSize

4. main

65

66 publicDimension getPreferredSize()

67 {

68 return newDimension( 160, 80 );

69 }

70

71 public static voidmain( String args[] )

72 {

73 LogoAnimator anim = newLogoAnimator();

74

75 JFrame app = newJFrame( "Animator test" );

76 app.getContentPane().add( anim, fBorderLayout.CENTER );

77

78 app.addWindowListener(

79 newWindowAdapter() {

80 public voidwindowClosing( WindowEvent e )

81 {

82 System.exit( 0 );

83 }

84 }

85 );

86

87 // The constants 10 and 30 are used below to size the

88 // window 10 pixels wider than the animation and

89 // 30 pixels taller than the animation.

90 app.setSize( anim.getPreferredSize().width + 10,

91 anim.getPreferredSize().height + 30 );

92 app.show();

93 }

94 }


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30.5 Animation Issues

Storing images Interlaced/non-interlaced formats

Specifies order in which pixels are stored

Non-interlaced - pixels stored in order they appear on screen

Image appears in chunks from top to bottom as it is loaded

Interlaced - pixels stored in rows, but out of order

Image appears to fade in and become more clear

Animation flickers Due to updatebeing called in response to repaint

In AWT GUI components

Draws filled rectangle in background color where image was

Draw image, sleep, clear background (flicker), draw nextimage...

Swing's JPaneloverrides updateto avoid this


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30.5 Animation Issues (II)

Double buffering

Used to smooth animations

Program renders one image on screen

Builds next image in off-screen buffer

When time to display next image, done smoothly

Partial images user would have seen (while image loads) are

hidden

All pixels for next image displayed at once

Space/Time tradeoff

Reduces flicker, but can slow animation speed and uses morememory

Used by Swing GUI components by default


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30.6 Customizing Applets via the HTMLparamTag

Applets

Customize through parameters in HTML file that invokesit

Invokes applet LogoApplet

paramtags Each has a nameand a value

Use Applet method getParameter(returns a String)

parameter = getParameter( "animationdelay" );


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30.6 Customizing Applets via the HTMLparamTag (II)

Following example Use the LogoAnimatorclass as before, but modified

slightly

Create Applet LogoApplet

Takes parameters

Creates LogoAnimatorobject using the parameters Plays animation

1 // Fig. 30.4: LogoAnimator.java


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Outline

1. import

1.1 LogoAnimator

class as before

1.2 Constructor to

allow customization

// g g j

2 // Animating a series of images

3 importjava.awt.*;



6

7 public classLogoAnimator extendsJPanel

8 implementsActionListener {9 protectedImageIcon images[];

10 protected inttotalImages = 30,

11 currentImage = 0,

12 animationDelay = 50; // 50 millisecond delay

13 protectedString imageName = "deitel";

14 protectedTimer animationTimer;

15

16 publicLogoAnimator()

17 {

18 initializeAnim();

19 }

20

21 // new constructor to support customization

22 publicLogoAnimator( intnum, intdelay, String name )

23 {24 totalImages = num;

25 animationDelay = delay;

26 imageName = name;

27

28 initializeAnim();

29 }

30

31 private voidinitializeAnim()

32 {

33 images = newImageIcon[ totalImages ];


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Outline

2. Methods as before

g g [ g ]

34

35 for( inti = 0; i < images.length; ++i )

36 images[ i ] = newImageIcon( "images/" +

37 imageName + i + ".gif" );

38

39 // moved here so getPreferredSize can check the size of

40 // the first loaded image.41 setSize( getPreferredSize() );

42

43 startAnimation();

44 }

45

46 public voidpaintComponent( Graphics g )

47 {

48 super.paintComponent( g );

49

50 if( images[ currentImage ].getImageLoadStatus() ==

51 MediaTracker.COMPLETE ) {

52 images[ currentImage ].paintIcon( this, g, 0, 0 );

53 currentImage = ( currentImage + 1 ) % totalImages;

54 }

55 }56

57 public voidactionPerformed( ActionEvent e )

58 {

59 repaint();

60 }

61

62 public voidstartAnimation()

63 {

64 if( animationTimer == null) {

65 currentImage = 0;


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Outline

2. Methods as before

g

66 animationTimer = newTimer( animationDelay, this);

67 animationTimer.start();

68 }

69 else // continue from last image displayed

70 if( ! animationTimer.isRunning() )

71 animationTimer.restart();

72 }73

74 public voidstopAnimation()

75 {

76 animationTimer.stop();

77 }

78

79 publicDimension getMinimumSize()

80 {

81 returngetPreferredSize();

82 }

83

84 publicDimension getPreferredSize()

85 {

86 return newDimension( images[ 0 ].getIconWidth(),

87 images[ 0 ].getIconHeight() );88 }

89

90 public static voidmain( String args[] )

91 {

92 LogoAnimator anim = newLogoAnimator();

93

94 JFrame app = newJFrame( "Animator test" );

95 app.getContentPane().add( anim, BorderLayout.CENTER );

96

97 app.addWindowListener(


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Outline98 newWindowAdapter() {99 public voidwindowClosing( WindowEvent e )

100 {

101 System.exit( 0 );

102 }

103 }

104 );

105

106 app.setSize( anim.getPreferredSize().width + 10,

107 anim.getPreferredSize().height + 30 );

108 app.show();

109 }

110}

111// Fig. 30.4: LogoApplet.java

112// Customizing an applet via HTML parameters

113//

114// HTML parameter "animationdelay" is an int indicating

115// milliseconds to sleep between images (default 50).

116//

117// HTML parameter "imagename" is the base name of the images

118// that will be displayed (i.e., "deitel" is the base name

119// for images "deitel0.gif," "deitel1.gif," etc.). The applet

120// assumes that images are in an "images" subdirectory of

121// the directory in which the applet resides.

122//

123// HTML parameter "totalimages" is an integer representing the

124// total number of images in the animation. The applet assumes

125// images are numbered from 0 to totalimages - 1 (default 30).

126

127importjava.awt.*;


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Outline

Applet

1. init

1.1 Initialize objects

from parameters

1.2 Supply variables toconstructor

2. Set layout

128importjavax.swing.*;

129

130public classLogoApplet extendsJApplet{


132 {

133 String parameter;

134

135 parameter = getParameter( "animationdelay" );

136 intanimationDelay = ( parameter == null? 50 :

137 Integer.parseInt( parameter ) );

138

139 String imageName = getParameter( "imagename" );

140

141 parameter = getParameter( "totalimages" );

142 inttotalImages = ( parameter == null? 0 :

143 Integer.parseInt( parameter ) );

144

145 // Create an instance of LogoAnimator

146 LogoAnimator animator;

147

148 if( imageName == null|| totalImages == 0 )

149 animator = newLogoAnimator();

150 else

151 animator = newLogoAnimator( totalImages,

152 animationDelay, imageName );

153

154 setSize( animator.getPreferredSize().width,

155 animator.getPreferredSize().height );

156 getContentPane().add( animator, BorderLayout.CENTER );

157


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Outline

3. startAnimation

158 animator.startAnimation();

159 }

160}


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30.7 Image Maps Image map

Image that has hot areas

User can click to accomplish a task

Bubble help

When mouse over particular point in screen, small message

displayed in status bar

In the following example

Load several images

Use event handlermouseMovedto find x-coordinate

Based on the x-coordinate, display a message

1 // Fig. 30.5: ImageMap.java


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Outline

1. import

1.1 Declare objects

2. init

2.1

addMouseListener

2.2 Initialize

ImageIcon

2 // Demonstrating an image map.

3 importjava.awt.*;



6

7 public classImageMap extendsJApplet {

8 privateImageIcon mapImage;9 privateintwidth, height;

10


12 {

13 addMouseListener(

14 newMouseAdapter() {

15 public voidmouseExited( MouseEvent e )

16 {

17 showStatus( "Pointer outside applet" );

18 }

19 }

20 );

21

22 addMouseMotionListener(

23 newMouseMotionAdapter() {24 public voidmouseMoved( MouseEvent e )

25 {

26 showStatus( translateLocation( e.getX() ) );

27 }

28 }

29 );

30

31 mapImage = newImageIcon( "icons2.gif" );

32 width = mapImage.getIconWidth();

O

33 height = mapImage.getIconHeight();


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Outline

3.paint

4.translateLocation

4.1 Display messagedepending on x

34 setSize( width, height );

35 }

36

37 public voidpaint( Graphics g )

38 {

39 mapImage.paintIcon( this, g, 0, 0 );

40 }

41

42 publicString translateLocation( intx )

43 {

44 // determine width of each icon (there are 6)

45 inticonWidth = width / 6;

46

47 if( x >= 0 && x iconWidth && x iconWidth * 2 && x iconWidth * 3 && x iconWidth * 4 && x iconWidth * 5 && x


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Outline

Program Output


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30.8 Java Plug-In (II)

Using the Plug in with applets The,andtags must be

converted

Must indicate that Plug-in should be used to execute applet

Java Plug-in 1.2 HTML Converter

Performs conversion for us http://java.sun.com/products/plugin/

Execution

In install directory type java HTMLConverter

Select file to convert and type of conversion


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media in java

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