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A Core Audio Recording Studio

Although Core Audio encompasses much more than recording and playing back audio, it can be useful to compare its capabilities to elements in a recording studio. A simple hardware-based recording studio may have a few instruments with some effect units feeding into a mixing deck, along with audio from a MIDI keyboard, as shown in Figure 1-4. The mixer can output the signal to studio monitors as well as a recording device, such as a tape deck (or perhaps a hard drive).

Much of the hardware used in a studio can be replaced by software-based equivalents. Specialized music studio applications can record, synthesize, edit, mix, process, and play back audio. They can also record, edit, process, and play back MIDI data, interfacing with both hardware and software MIDI instruments. In Mac OS X, applications rely on Core Audio services to handle all of these tasks, as shown in Figure 1-5.

As you can see, audio units make up much of the signal chain. Other Core Audio interfaces provide application-level support, allowing applications to obtain audio or MIDI data in various formats and output it to files or output devices. “Core Audio Programming Interfaces” discusses the constituent interfaces of Core Audio in more detail.

However, Core Audio lets you do much more than mimic a recording studio on a computer. You can use Core Audio for everything from playing simple system sounds to creating compressed audio files to providing an immersive sonic experience for game players.

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