QuickTime for Java: A Developer's Notebook

Chapter 7. Audio Media

This is the first of three chapters dealing with specific media types. Video will be covered in Chapter 8, and several other kinds of media—including things you might not have thought of as media, such as text and time codes—will be covered in Chapter 9.

It’s possible that you’ve never thought of QuickTime as being the engine for audio-only applications—the ubiquity of QuickTime’s .mov file format probably makes it more readily recognized as a video standard. But QuickTime’s support for audio has been critical to many applications. For example, the fact that QuickTime was already ported to Windows made bringing iTunes and its music store over to Windows a lot easier.

In fact, iTunes is probably responsible for getting QuickTime onto a lot more Windows machines than it would have reached otherwise. So, I’ll begin with a few labs that are particularly applicable to the MP3s and AACs collected by iTunes users.

Reading Information from MP3 Files

If you’ve ever listened to an MP3 music file—and at this point, who hasn’t—you’ve surely appreciated the fact that useful information like artist, song title, album title, etc., is stored inside the file. Not only does this make it convenient to organize your music, but also, when you move a song from one device to another, this metadata travels with it.

The most widely accepted standard for doing this is the ID3 standard, which puts this metadata into parts of the file that are not interpreted as containing audio data—MP3s ...