I am attempting to use Apple's SFSpeechRecognition (xcode 9, ios11, swift 4). The following code uses a timer to start a new request for speech recognition. I have background capability on, microphone usage granted and speech recognition granted. If the phone is unlocked, everything works as expected. But when the phone is locked, I receive the following error:
2018-02-20 22:24:47.522562-0500 Speech-Recognition-Demo[3505:1234188] [Utility] +[AFAggregator logDictationFailedWithError:] Error Domain=kAFAssistantErrorDomain Code=1700 "(null)"
According to this link, speech recognition doesn't seem to work when app is in background mode but this information is old. I'm hoping someone has solved this or found a workaround.
Has anyone solved this problem or can anyone suggest something to try? My alternative is to require the Apple Watch for my app and I'd REALLY like to avoid that...
import UIKit
import Speech
class SpeechDetectionViewController: UIViewController,
SFSpeechRecognizerDelegate {
@IBOutlet weak var detectedTextLabel: UILabel!
@IBOutlet weak var colorView: UIView!
@IBOutlet weak var startButton: UIButton!
let audioEngine = AVAudioEngine()
let speechRecognizer: SFSpeechRecognizer? = SFSpeechRecognizer()
var request: SFSpeechAudioBufferRecognitionRequest?
var recognitionTask: SFSpeechRecognitionTask?
var isRecording = false
// timers
var timer = Timer()
let timerInterval = 5.0
var secondsElapsed = 0
// toggle for taking commands
var takeCommands = true
override func viewDidLoad() {
super.viewDidLoad()
self.requestSpeechAuthorization()
timer = Timer.scheduledTimer(timeInterval: timerInterval,target: self,selector: #selector(timerAction(timer:)) ,userInfo: nil,repeats: true)
}
@objc func timerAction(timer:Timer){
/* if takeCommands {
startRecording()
} else {
stopRecording()
}
takeCommands = !takeCommands
print("takeCommands: \(takeCommands)")
*/
startRecording()
}
//MARK: IBActions and Cancel
@IBAction func startButtonTapped(_ sender: UIButton) {
startRecording()
}
func startRecording(){
if isRecording {
print("STOP talking.")
request?.endAudio() // Added line to mark end of recording
request = nil
//audioEngine.stop()
if let node = audioEngine.inputNode {
node.removeTap(onBus: 0)
}
recognitionTask?.cancel()
isRecording = false
startButton.backgroundColor = UIColor.gray
} else {
print("START talking.")
self.recordAndRecognizeSpeech()
isRecording = true
startButton.backgroundColor = UIColor.red
}
}
func stopRecording() {
//audioEngine.stop()
if let node = audioEngine.inputNode {
node.removeTap(onBus: 0)
}
recognitionTask?.cancel()
isRecording = false
startButton.backgroundColor = UIColor.gray
}
//MARK: - Recognize Speech
func recordAndRecognizeSpeech() {
request = SFSpeechAudioBufferRecognitionRequest()
guard let node = audioEngine.inputNode else { return }
let recordingFormat = node.outputFormat(forBus: 0)
node.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { buffer, _ in
self.request?.append(buffer)
}
if !audioEngine.isRunning {
audioEngine.prepare()
do {
try audioEngine.start()
} catch {
self.sendAlert(message: "There has been an audio engine error.")
return print(error)
}
}
guard let myRecognizer = SFSpeechRecognizer() else {
self.sendAlert(message: "Speech recognition is not supported for your current locale.")
return
}
if !myRecognizer.isAvailable {
self.sendAlert(message: "Speech recognition is not currently available. Check back at a later time.")
// Recognizer is not available right now
return
}
recognitionTask = speechRecognizer?.recognitionTask(with: request!, resultHandler: { result, error in
if result != nil { // check to see if result is empty (i.e. no speech found)
if let result = result {
let bestString = result.bestTranscription.formattedString
self.detectedTextLabel.text = bestString
var lastString: String = ""
for segment in result.bestTranscription.segments {
let indexTo = bestString.index(bestString.startIndex, offsetBy: segment.substringRange.location)
lastString = bestString.substring(from: indexTo)
}
self.checkForColorsSaid(resultString: lastString)
} else if let error = error {
self.sendAlert(message: "There has been a speech recognition error")
print(error)
}
}
})
}
//MARK: - Check Authorization Status
func requestSpeechAuthorization() {
SFSpeechRecognizer.requestAuthorization { authStatus in
OperationQueue.main.addOperation {
switch authStatus {
case .authorized:
self.startButton.isEnabled = true
case .denied:
self.startButton.isEnabled = false
self.detectedTextLabel.text = "User denied access to speech recognition"
case .restricted:
self.startButton.isEnabled = false
self.detectedTextLabel.text = "Speech recognition restricted on this device"
case .notDetermined:
self.startButton.isEnabled = false
self.detectedTextLabel.text = "Speech recognition not yet authorized"
}
}
}
}
//MARK: - UI / Set view color.
func checkForColorsSaid(resultString: String) {
switch resultString {
case "red":
colorView.backgroundColor = UIColor.red
case "orange":
colorView.backgroundColor = UIColor.orange
case "yellow":
colorView.backgroundColor = UIColor.yellow
case "green":
colorView.backgroundColor = UIColor.green
case "blue":
colorView.backgroundColor = UIColor.blue
case "purple":
colorView.backgroundColor = UIColor.purple
case "black":
colorView.backgroundColor = UIColor.black
case "white":
colorView.backgroundColor = UIColor.white
case "gray":
colorView.backgroundColor = UIColor.gray
default: break
}
}
//MARK: - Alert
func sendAlert(message: String) {
let alert = UIAlertController(title: "Speech Recognizer Error", message: message, preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
}
