OS X and iOS Kernel Programming

Summary

In this chapter, we have covered the following areas:

• Digital audio and Pulse Code Modulation (PCM), which is a technique for converting an analog audio signal into a digital representation. We have also looked at how PCM samples are encoded and interleaved channel by channel.
• The Core Audio architecture, which collectively provides sound/audio support to Mac OS X and iOS. The cornerstone of Core Audio is the HAL, which coordinates the use of audio hardware on behalf of clients and allows multiple clients to access audio hardware simultaneously.
• The Core Audio HAL, which always uses 32-bit floating-point format to represent audio samples. A driver is therefore responsible for converting the native format of the hardware to or from this ...