Speech framework crash required condition is false: nullptr == Tap() when the view appears the second time;
as per the internet, audioEngine.inputNode.removeTap(onBus: 0) should resolve the issue but doesn’t . . .
import Speech
class SpeechRecognizer: ObservableObject {
let audioEngine = AVAudioEngine()
let speechRecognizer: SFSpeechRecognizer? = SFSpeechRecognizer()
let request = SFSpeechAudioBufferRecognitionRequest()
var recognitionTask: SFSpeechRecognitionTask?
func instantiateSpeechRecognition() {
SFSpeechRecognizer.requestAuthorization { authStatus in
switch authStatus {
case .authorized:
do {
try self.startRecording()
} catch let error {
print("There was a problem starting recording: \(error.localizedDescription)")
}
case .denied:
print("Speech recognition authorization denied")
case .restricted:
print("Not available on this device")
case .notDetermined:
print("Not determined")
default:
print("xxxx")
}
}
}
func startRecording() throws {
let node = audioEngine.inputNode
let recordingFormat = node.outputFormat(forBus: 0)
node.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { buffer, _ in
self.request.append(buffer)
}
audioEngine.prepare()
try audioEngine.start()
self.recognize()
}
func recognize() {
recognitionTask = speechRecognizer?.recognitionTask(with: request, resultHandler: { result, error in
if let result = result {
let bestString = result.bestTranscription.formattedString
var lastString: String = ""
for segment in result.bestTranscription.segments {
let indexTo = bestString.index(bestString.startIndex, offsetBy: segment.substringRange.location)
lastString = String(bestString[indexTo...].lowercased())
}
self.triggerButton(resultString: lastString)
} else if let error = error {
print(error)
}
})
}
func stopRecording() {
audioEngine.stop()
request.endAudio()
audioEngine.inputNode.removeTap(onBus: 0)
recognitionTask?.cancel()
recognitionTask = nil
}
// TODO in training view
func triggerButton(resultString: String) {
print(resultString)
}
}
struct TrainingView: View {
@State private var recognizeSpeech = true
@EnvironmentObject var speechRecognizer: SpeechRecognizer
var body: some View {
VStack(spacing: 20) {
Toggle(isOn: $recognizeSpeech) {
if recognizeSpeech {
Text("Speech recognition for data collection")
.fixedSize(horizontal: false, vertical: true)
.font(.subheadline)
} else {
Text("XXX")
}
}
.padding()
.onReceive([self.recognizeSpeech].publisher.first()) { value in
if value {
speechRecognizer.instantiateSpeechRecognition()
} else {
speechRecognizer.stopRecording()
}
}
}
}
}