Learning Core Audio: A Hands-On Guide to Audio Programming for Mac and iOS

3. Audio Processing with Core Audio

The last chapter introduced some essential concepts of digital audio. So how does Core Audio handle them? Chapter 1, “Overview of Core Audio,” gave you an overview of the major areas of interest in Core Audio. This chapter digs down to a more detailed level to see how Core Audio models and processes digital audio data.

We’ll start with the issue of representing sample data and formats in Core Audio’s various data structures, and then turn our attention to the APIs that can do interesting stuff with those structures.

Audio Data Formats

Core Audio views audio data as streams of packets. The contents of a stream’s packets are described by its AudioStreamBasicDescription, which we introduced briefly in the last ...