User guide

Figures, Tables, and Listings

Defining an Audio Session 10

Figure 1-1 The system manages competing audio demands 13

Listing 1-1 Activating an audio session using the AV Foundation framework 15

Working with Categories 18

Figure 2-1 Sending different files to different audio routes 21

Listing 2-1 Setting the audio session category using the AV Foundation framework 22

Responding to Interruptions 26

Figure 3-1 An audio session gets interrupted 28

Table 3-1 What should happen during an audio session interruption 26

Table 3-2 Audio interruption handling techniques according to audio technology 27

Listing 3-1 An interruption-started delegate method for an audio player 29

Listing 3-2 An interruption-ended delegate method for an audio player 30

Optimizing Your App for Device Hardware 32

Table 4-1 Choosing preferred hardware values 32

Listing 4-1 Setting and querying hardware values 33

Listing 4-2 Specifying preferred I/O buffer duration using the AVAudioSession class 35

Listing 4-3 Obtaining the current audio hardware sample rate using the AVAudioSession class 35

Listing 4-4 Using preprocessor conditional statements 36

Responding to Route Changes 37

Figure 5-1 Handling audio hardware route changes 37

Fine-Tuning an Audio Session for Players 40

Table 6-1 Configuring audio sessions when using a movie player 41

Audio Session Categories and Modes 47

Table B-1 Audio session category behavior 47

Table B-2 Modes and associated categories 48