Clear input of SFSpeechAudioBufferRecognitionRequest after every result (Swift3)

Question

I have integrated speech to text through this appcoda tutorial. The problem I am facing is I want that user can write/edit something himself, but SFSpeechAudioBufferRecognitionRequest doesn't take into consideration the thing user has typed.

What's the way to send user typed input in SFSpeechAudioBufferRecognitionRequest or any way to clear SFSpeechAudioBufferRecognitionRequest input params before sending new request.

Thanks in advance.

Answer 1

Here is what I use to create my recognition request:

func recordSpeech() throws {
    // Cancel the previous task if it's running.
    if let recognitionTask = recognitionTask {
        recognitionTask.cancel()
        self.recognitionTask = nil
    }

    isRecognizing = true
    self.delegate?.recognitionStarted(sender: self)

    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 {
        print("there was an error in audioEngine.inputNode")
        fatalError("Audio engine has no input node")
    }

    guard let recognitionRequest = recognitionRequest else {
        fatalError("Unable to create 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 = recognizer.recognitionTask(with: recognitionRequest) { result, error in

        func finalizeResult() {
            self.audioEngine.stop()
            inputNode.removeTap(onBus: 0)
            self.recognitionRequest = nil
            self.recognitionTask = nil
        }

        guard error == nil else {
            finalizeResult()
            return
        }

        if !(result?.isFinal)! {

            guard self.isRecognizing else {
                return
            }

                // process partial result
                self.processRecognition(result: result)

            } else {
            finalizeResult()
        }          
    }

    let recordingFormat = inputNode.outputFormat(forBus: 0)
    inputNode.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { (buffer, when) in
        self.recognitionRequest?.append(buffer)
    }

    audioEngine.prepare()

    do {
        try audioEngine.start()
    } catch let error as NSError {
        print("audio engine start error=\(error)")
    }
}

To cancel or stop this at any point I use these methods:

@objc func stopRecording() {
    isRecognizing = false
    audioEngine.stop()
    recognitionRequest?.endAudio()
    self.delegate?.recognitionFinished()
}

func cancelRecording() {
    isRecognizing = false
    audioEngine.stop()
    recognitionTask?.cancel()
    self.delegate?.recognitionFinished()
}

I would setup a button to trigger speech recognition and tie it to recordSpeech(). Then setup a button and tie it to stopRecording(). When the user stops the request, result?.isfinal will be true and you know that is the final text from the first input. The user could then use speech input again for the second set of speech.

Most of my code came from the 2016 WWDC session on Speech Recognition which you can find here:

Transcript

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