REALBasic: TDG, 2nd Edition

Chapter 27. Movies

This chapter describes REALbasic’s support for movies. The first order of business is to consider what a movie is, since the term has an unexpectedly wide meaning. Figure 27-1 shows a REALbasic window displaying what one normally thinks of as a movie; but the notion, and the technology, can go well beyond this.

Figure 27-1. A movie that looks like a movie

A movie, in the most intuitive and fundamental sense, is time-based sight andsound—an animated succession of images, possibly accompanied by a sound track. Now, this concept masks a number of complex issues: Animated how? How does the timing work? Where is the data stored, and in what format? The user is shielded from these and many other questions thanks to a powerful and self-contained technology, QuickTime. Movies are full of redundant data, because successive images are typically similar to one another; QuickTime sees to it that the data is stored in compressed format, and expands it when the movie needs to be shown. Movies may involve images of varying duration shown at varying rates, and they may call for coordination of multiple tracks, such as sound and video, or several video components; QuickTime handles these relationships. When a movie is actually shown, an area of a window needs successive images drawn into it, with minimal flicker, and sound must emerge from the speaker; QuickTime takes care ...