avfoundation-ref

AVAudioSession categories define audio behavior: use .playback for output-only, .record for input-only, and .playAndRecord for both. Set the category, mode, and options via AVAudioSession.sharedInstance().setCategory(_:mode:options:) to handle interruptions and route changes automatically.

AVAudioSession manages system-level audio routing, interruptions, and categories. AVAudioEngine provides a node-based pipeline for mixing, processing, and scheduling audio files with lower latency, suited for real-time synthesis and complex mixing workflows.

Create an AVAudioEngine instance, attach an AVAudioPlayerNode to the engine, connect it to the output node, load an audio file into AVAudioFile, schedule it on the player node, start the engine, and call play() on the node to begin playback.

Yes. Set AVAudioSession category to .record or .playAndRecord, configure appropriate options, and use input selection to route from AirPods. AVAudioEngine taps and file scheduling enable bit-perfect capture and storage for post-processing.

Register for AVAudioSession.interruptionNotification and AVAudioSession.routeChangeNotification. Check notification userInfo to determine interruption type and route change reason, then pause/resume playback or reconfigure the audio pipeline accordingly.

Use AVAudioSession's preferredInput and setPreferredInput() to select microphone sources. For UI-driven selection, present a route picker view or custom interface to let users choose between built-in mic, AirPods, external interfaces, and Bluetooth devices.