Print the default sound output device name on macOS 12.0.

README.md

Usage

$ swift main.swift
Default output device: MacBook Pro Speakers

main.swift

import AudioToolbox

func main() {
  var address = AudioObjectPropertyAddress(
    mSelector: AudioObjectPropertySelector(kAudioHardwarePropertyDefaultOutputDevice),
    mScope: AudioObjectPropertyScope(kAudioObjectPropertyScopeGlobal),
    mElement: AudioObjectPropertyElement(kAudioObjectPropertyElementMain)
  )

  var size = UInt32(MemoryLayout<AudioDeviceID>.size)
  var deviceID = AudioDeviceID()

  // Get device ID.
  AudioObjectGetPropertyData(
    AudioObjectID(kAudioObjectSystemObject), &address, 0, nil, &size, &deviceID)

  // Get output device name.
  var deviceNameRef: CFString? = nil

  address.mSelector = kAudioObjectPropertyName
  size = UInt32(MemoryLayout<CFString?>.size)

  AudioObjectGetPropertyData(deviceID, &address, 0, nil, &size, &deviceNameRef)

  guard let deviceName = deviceNameRef else {
    return
  }

  print("Default output device: \(deviceName)")
}

main()