Terminating app due to uncaught App crashes while using Speech kit ios - ios

Question

I got this error while implementing speech to text:
Terminating app due to uncaught exception
'com.apple.coreaudio.avfaudio', reason: 'required condition is false:
_recordingTap == nil'
and:
ERROR: [0x1b2df5c40] >avae> AVAudioNode.mm:565: CreateRecordingTap:
required condition is false: _recordingTap == nil
Here is the code of my viewController:
public class ViewController: UIViewController, SFSpeechRecognizerDelegate {
// MARK: Properties
private let speechRecognizer = SFSpeechRecognizer(locale: Locale(identifier: "en-US"))!
private var recognitionRequest: SFSpeechAudioBufferRecognitionRequest?
private var recognitionTask: SFSpeechRecognitionTask?
private let audioEngine = AVAudioEngine()
#IBOutlet var textView : UITextView!
#IBOutlet var recordButton : UIButton!
// MARK: UIViewController
public override func viewDidLoad() {
super.viewDidLoad()
// Disable the record buttons until authorization has been granted.
recordButton.isEnabled = false
}
override public func viewDidAppear(_ animated: Bool) {
speechRecognizer.delegate = self
SFSpeechRecognizer.requestAuthorization { authStatus in
/*
The callback may not be called on the main thread. Add an
operation to the main queue to update the record button's state.
*/
OperationQueue.main.addOperation {
switch authStatus {
case .authorized:
self.recordButton.isEnabled = true
case .denied:
self.recordButton.isEnabled = false
self.recordButton.setTitle("User denied access to speech recognition", for: .disabled)
case .restricted:
self.recordButton.isEnabled = false
self.recordButton.setTitle("Speech recognition restricted on this device", for: .disabled)
case .notDetermined:
self.recordButton.isEnabled = false
self.recordButton.setTitle("Speech recognition not yet authorized", for: .disabled)
}
}
}
}
private func startRecording() throws {
// Cancel the previous task if it's running.
if let recognitionTask = recognitionTask {
recognitionTask.cancel()
self.recognitionTask = nil
}
let audioSession = AVAudioSession.sharedInstance()
try audioSession.setCategory(AVAudioSessionCategoryRecord)
try audioSession.setMode(AVAudioSessionModeMeasurement)
try audioSession.setActive(true, with: .notifyOthersOnDeactivation)
recognitionRequest = SFSpeechAudioBufferRecognitionRequest()
guard let inputNode = audioEngine.inputNode else { fatalError("Audio engine has no input node") }
guard let recognitionRequest = recognitionRequest else { fatalError("Unable to created a SFSpeechAudioBufferRecognitionRequest object") }
// Configure request so that results are returned before audio recording is finished
recognitionRequest.shouldReportPartialResults = true
// A recognition task represents a speech recognition session.
// We keep a reference to the task so that it can be cancelled.
recognitionTask = speechRecognizer.recognitionTask(with: recognitionRequest) { result, error in
var isFinal = false
if let result = result {
self.textView.text = result.bestTranscription.formattedString
isFinal = result.isFinal
}
if error != nil || isFinal {
self.audioEngine.stop()
inputNode.removeTap(onBus: 0)
self.recognitionRequest = nil
self.recognitionTask = nil
self.recordButton.isEnabled = true
self.recordButton.setTitle("Start Recording", for: [])
}
}
let recordingFormat = inputNode.outputFormat(forBus: 0)
inputNode.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { (buffer: AVAudioPCMBuffer, when: AVAudioTime) in
self.recognitionRequest?.append(buffer)
}
audioEngine.prepare()
try audioEngine.start()
textView.text = "(Go ahead, I'm listening)"
}
// MARK: SFSpeechRecognizerDelegate
public func speechRecognizer(_ speechRecognizer: SFSpeechRecognizer, availabilityDidChange available: Bool) {
if available {
recordButton.isEnabled = true
recordButton.setTitle("Start Recording", for: [])
} else {
recordButton.isEnabled = false
recordButton.setTitle("Recognition not available", for: .disabled)
}
}
// MARK: Interface Builder actions
#IBAction func recordButtonTapped() {
if audioEngine.isRunning {
audioEngine.stop()
recognitionRequest?.endAudio()
recordButton.isEnabled = false
recordButton.setTitle("Stopping", for: .disabled)
} else {
try! startRecording()
recordButton.setTitle("Stop recording", for: [])
}
}
}

Answer 1

You can try to use it on stop recording
Swift 3:
audioEngine.inputNode?.removeTap(onBus: 0)
It's helped me and should help you too.

Answer 2

You probably already have a tap on the bus and you can't have another one on that same bus. You should removeTapOnBus when you stop your engine.
audioEngine.inputNode?.removeTap(onBus: 0)

Answer 3

The error is telling you that you already have a tap installed on that bus and that you can't have another one.
First you have to remove the tap for that bus. Then again you can install tap on the bus.
let inputNode = audioEngine.inputNode
inputNode.removeTap(onBus: 0)
It will help.