I'm trying to achieve a very simple task in iOS. I would like to get audio from a Bluetooth microphone and play the audio simultaneously using the built-in speaker.
Here is what I have right now. The app allows users to choose a speaker and a microphone source. However, whenever I pick a built-in speaker, the app will switch to a built-in microphone. And whenever I pick a Bluetooth microphone, the app will use the Bluetooth speaker. There is no way I can use the Bluetooth microphone and the built-in speaker separately.
import UIKit
import AVFoundation
import AVKit
class ViewController: UIViewController {
var engine = AVAudioEngine()
let player = AVAudioPlayerNode()
let audioSession = AVAudioSession()
var routePickerView = AVRoutePickerView(frame: CGRect(x: 0, y: 0, width: 0, height: 50))
let bus = 0
var isRunning = false
@IBOutlet weak var viewHolder: UIStackView!
override func viewDidLoad() {
super.viewDidLoad()
setUpAVRoutePicker()
setUpAVSession()
}
func setUpAVRoutePicker() {
viewHolder.addArrangedSubview(routePickerView)
}
func setUpAVSession() {
do {
try audioSession.setCategory(AVAudioSession.Category.playAndRecord, options: [.defaultToSpeaker, .allowBluetooth, .allowBluetoothA2DP, .allowAirPlay])
try audioSession.setMode(AVAudioSession.Mode.default)
try audioSession.overrideOutputAudioPort(AVAudioSession.PortOverride.speaker)
try audioSession.setActive(true)
} catch {
print("Error setting up AV session!")
print(error)
}
}
@IBAction func start(_ sender: AnyObject) {
isRunning = !isRunning
sender.setTitle(isRunning ? "Stop" : "Start", for: .normal)
if isRunning {
engine.attach(player)
let inputFormat = engine.inputNode.inputFormat(forBus: bus)
engine.connect(player, to: engine.mainMixerNode, format: inputFormat)
engine.inputNode.installTap(onBus: bus, bufferSize: 512, format: inputFormat) { (buffer, time) -> Void in
self.player.scheduleBuffer(buffer)
}
do {
try engine.start()
} catch {
print("Engine start error")
print(error)
return
}
player.play()
} else {
engine.inputNode.removeTap(onBus: bus)
engine.stop()
player.stop()
}
}
@IBAction func onInputBtnClicked(_ sender: AnyObject) {
let controller = UIAlertController(title: "Select Input", message: "", preferredStyle: UIAlertController.Style.actionSheet)
for input in audioSession.availableInputs ?? [] {
controller.addAction(UIAlertAction(title: input.portName, style: UIAlertAction.Style.default, handler: { action in
do {
try self.audioSession.setPreferredInput(input)
} catch {
print("Setting preferred input error")
print(error)
}
}))
}
present(controller, animated: true, completion: nil)
}
}
It seems like it's impossible to achieve that (https://stackoverflow.com/a/24519938/6308776), which is kinda crazy. I know that it's possible to achieve such a simple task on Android, but it looks like it's not possible for iOS. Does anyone have any ideas?
p/s: I would like to use a Bluetooth headset, and I don't want to have the transmission via wifi.
