These are some related code segments. enableMic
programmatically is the issue.
private var audioEngine: AVAudioEngine?
private var inputNode: AVAudioNode!
private func setupAudioSession() {
do {
let session = AVAudioSession.sharedInstance()
try session.setCategory(.playAndRecord, options: [.defaultToSpeaker, .allowBluetooth])
try session.setActive(true)
} catch {
print(error)
}
}
func setupAudioEngine() {
audioEngine?.stop()
audioEngine?.reset()
setupAudioSession()
audioEngine = AVAudioEngine()
inputNode = audioEngine?.inputNode
guard let hardwareSampleRate = audioEngine?.inputNode.inputFormat(forBus: 0).sampleRate else { return }
let format = AVAudioFormat(standardFormatWithSampleRate: hardwareSampleRate, channels: 1)
let requiredBufferSize: AVAudioFrameCount = 4800
inputNode.installTap(onBus: 0,
bufferSize: requiredBufferSize,
format: format
) { [self] (buffer: AVAudioPCMBuffer, _: AVAudioTime) in
/* process the buffer */
}
audioEngine?.prepare()
}
func startRecording() {
do {
try audioEngine?.start()
} catch {
print("Could not start audioEngine: \(error)")
}
}
private func observeRouteChanges() {
NotificationCenter.default.addObserver(self,
selector: #selector(handleRouteChange),
name: AVAudioSession.routeChangeNotification,
object: nil)
}
@objc func handleRouteChange(notification: Notification) {
guard let userInfo = notification.userInfo,
let reasonValue = userInfo[AVAudioSessionRouteChangeReasonKey] as? UInt,
let reason = AVAudioSession.RouteChangeReason(rawValue: reasonValue) else {
return
}
switch reason {
case .newDeviceAvailable, .oldDeviceUnavailable:
/* enableMic with current route AVAudioSession.sharedInstance().currentRoute.inputs.first */
default: ()
}
}
private func enableMic(mic: AVAudioSessionPortDescription?) {
let session = AVAudioSession.sharedInstance()
do {
try session.setPreferredInput(mic)
/* re-setup the audio engine and start */
} catch {
print(error)
}
}