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|a Introduction, "Entropy isn't what it used to be." The hard part about designing computers-or about designing computer softwareis in figuring out how the whole works will deal with the people who ultimately pay for it. Far more processor time is typically required to maintain a "user interface" than is tied up doing the sort of work a computer would consider to be respectable employment. The days when a computer the size of Nebraska could think for a week and a half and print out a single number to the cheers and adoration of a room full of people in lab coats ended several eons ago. Even given mice and reasonably decent monitors, personal computers haven't really been able to communicate with people in something approaching human terms. Windows is arguably easier to work with than typing commands at a DOS prompt-if you have enough memory to run it-but it still insists on expressing itself using phenomena that are unique to computers. Multimedia offers to let software authors achieve something a bit closer to a really human user interface for Windows applications. It will let you create singing software-a truly disturbing thought-or, in more useful terms, software that can speak, display graphics, and play music that doesn't sound like a backyard full of cats getting together to make more cats. While this is the sort of thing that happens all the time in science fiction movies, it hasn't been practical for most computers until recently. A side from simply providing hooks to perform these sorts of functions, the Windows multimedia extensions offer a standardized set of drivers and data formats to handle most of the things you'd probably want to do with multimedia. This means that pretty well anyone running Windows with a minimal level of multimedia hardware will be able to hear your software sing. As with most of the device-independent aspects of Windows, you'll be able to write applications that will support a wide selection of devices without ever seeing most of them. When an aspect of multimedia turns up in a magazine article or as the filler at the end of "CNN Headline News," it often seems more like someone desperately searching for a new reason to sell you another card for your sys tem than a genuinely useful extension of what a personal computer can do. It's really something you have to work with for a while to properly appreciate. The first time you watch a movie play in a window or listen to your system playing truly orchestral music through your stereo, you'll probably begin to get a feel for how bad computer user interfaces have been until now. A pound of multimedia to go, please. The really exemplary aspect of multimedia under Windows is that it's about the most fun thing you can do with a computer that doesn't involve killing aliens. More to the point, it's very productive and leadig edge. You can play with it for days and not have to feel even a bit guilty about doing so. It might involve just listening to sound bites from Monty Python movies and looking at pictures, but no one is likely to point out his or her own lack of sophistication by saying so. Perhaps better still, when you finally do complete and ship your own multimedia applications, all sorts of other people will be able to have just as much fun and waste just as much time playing with them as you did creating them. In its most extreme sense, multimedia has the capability to bring joy to the entire western world even to its lawyers-and to utterly cease all productive work for the foreseeable future. While you've probably bought this book for a specific function-to learn how to play wave files or unpack Phot0-CDs, for example-it's worth mentioning that multimedia is exceedingly open ended. It's probably best defined as that which could conceivably be contained in a box with the word multimedia printed on the outside. It's a blank canvas, upon which your imagination can splash whatever colors you like. Think of this book as a stack of paint cans. It will provide you with the elemental functions to handle some of the most useful parts of multimedia under Windows. Because of the modular nature of these functions, you'll be able to assemble them into any application you can imagine. Multimedia is like that-there are all sorts of places to go where no human foobt has thus far trodden. Or no mouse, if you prefer. A choice of media In writing this book, I've tried to select those aspects of multimedia for Windows that seem reasonably mainstream and useful. I've also tried to keep the depth of explanation commensurate with what most software authors are likely to want to do with them. This book won't tell you absolutely everything about any of the subjects it deals with, and if you' re like most people, you won't want to know absolutely everything. Everything is a fairly large number. As a final note, all books have a substantial lead time between when they're written and when they're read. As of this writing, much of the documentation for the development packages discussed in this book was a bit flaky, and contained a few errors. Microsoft's manuals for the Multimedia Development Kit, a central element of the applications in this book, contained several prize turkeys, each one guaranteed to frustrate you for hours if you happen to believe it. All the code in this book works-you can find the compiled applications it generates in the \APPS directory of the companion CD-ROM, ready to run. In situations where this book seems to contradict the documentation from Microsoft and Kodak and such, you'll probably find that it's safer to trust the book. The lead time inherent in this book might well mean that some of these problems will have been addressed by their respective owners by the time you read this. However, in most larger companies bugs have to become pretty hoary and carnivorous before they're dealt with.
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