Introduction

Welcome to what may be the largest revolution in the history of the computer industry. Those who entered the field decades ago were interested in using computers primarily to perform arithmetic calculations at high speed. As the computer field evolved, we began to realize that the data-manipulation capabilities of computers are equally important. The "sizzle" of Java is multimediathe use of sound, images, graphics and video to make applications "come alive." Although most multimedia in Java applications is two-dimensional, Java programmers already can use the Java 3D API to create substantial 3D graphics applications (Sun provides an online tutorial for the Java 3D API at java.sun.com/developer/onlineTraining/java3d).

Multimedia programming offers many new challenges. The field is already enormous and is growing rapidly. People are rushing to equip their computers for multimedia. Most new computers sold today are "multimedia ready," with CD-RW and DVD drives, audio boards and special video capabilities. Economical desktop and laptop computers are so powerful that they can store and play DVD-quality sound and video, and we expect to see further advances in the kinds of programmable multimedia capabilities available through programming languages. One thing that we have learned is to plan for the "impossible"in the computer and communications fields, the "impossible" has repeatedly become reality.

Among users who want graphics, many now want three-dimensional, high-resolution, color graphics. True three-dimensional imaging may become available within the next decade. Imagine having high-resolution, "theater-in-the-round," three-dimensional television. Sporting and entertainment events will seem to take place on your living room floor! Medical students worldwide will see operations being performed thousands of miles away, as if they were occurring in the same room. People will be able to learn how to drive with extremely realistic driving simulators in their homes before they get behind the wheel. The possibilities are exciting and endless.

Multimedia demands extraordinary computing power. Until recently, affordable computers with that kind of power were not available. Today's ultrapowerful processors, like the SPARC Ultra 5 from Sun Microsystems, the Pentium and Itanium 2 from Intel, the PowerPC G5 from IBM and Apple, and the processors from MIPS/Silicon Graphics (among others) make effective multimedia possible. The computer and communications industries will be primary beneficiaries of the multimedia revolution. Users will be willing to pay for the faster processors, larger memories and wider communications bandwidths that support demanding multimedia applications. Ironically, users may not have to pay more, because the fierce competition in these industries has historically driven prices down.

We need programming languages that make creating multimedia applications easy. Most programming languages do not incorporate such capabilities. However, Java, through its class libraries, provides extensive multimedia facilities that enable you to start developing powerful multimedia applications immediately.

This chapter presents several examples of interesting multimedia features that you will need to build useful applications, including:

1. the basics of manipulating images.
2. creating smooth animations.
3. playing audio files with the AudioClip interface.
4. creating image maps that can sense when the cursor is over them, even without a mouse click.
5. playing video files using the Player interface.

The exercises for this chapter suggest dozens of challenging and interesting projects. When we were creating these exercises, the ideas just kept flowing. Multimedia leverages creativity in ways that we did not experience with "conventional" computer capabilities. [Note: Java's multimedia capabilities go far beyond those presented in this chapter. They include the Java Media Framework (JMF) API (for adding audio and video media to an application), Java Sound API (for playing, recording and modifying audio), Java 3D API (for creating and modifying 3D graphics), Java Advanced Imaging API (for image-processing capabilities, such as cropping and scaling), Java Speech API (for inputting voice commands from the user or outputting voice commands to the user), Java 2D API (for creating and modifying 2D graphics, covered in Chapter 12) and Java Image I/O API (for reading from and outputting images to files). Section 21.8 provides Web links for each of these APIs.]