QuickTime for Java: A Developer's Notebook

Chapter 4. Working with Components

When QuickTime came out in 1990, it could play movies the size of a postage stamp—barely—on $7,000 hardware. It used audio and video codecs that, although still supported today, have long since been abandoned by users. Yet it’s been a smooth transition from Apple Video to Cinepak to MPEG-4. This is thanks to an extraordinarily modular design—most of the heavy lifting in QuickTime is performed by components , or shared code fragments that can be discovered and used dynamically. Components provide support for importing and exporting image and movie formats, performing image and sound compression and decompression, accessing system resources, and much more. The QuickTime installer provides components for many features, and components added later by the end user, from either Apple or third parties, can provide more functionality, like support for more media formats.

Components aren’t always front-and-center in the API—after all, the first few chapters have managed to avoid mentioning them entirely. QuickTime has been assumed to just “do the right thing” when it comes to opening files and turning them into movies, decompressing and rendering the data, saving it to disk, etc. When needed, QuickTime looks through its catalog of components for required functionality and gets what it needs.

But sometimes it’s desirable or necessary for the developer to work with components more directly, to figure out what’s available or to specify behavior. Figuring out ...