连续语音识别。使用 SFSpeechRecognizer (ios10-beta)

Question

我正在尝试继续。在 iOS 10 测试版上使用 AVCapture 进行语音识别。我已设置captureOutput(...) 以不断获取CMSampleBuffers。我将这些缓冲区直接放入我之前设置的SFSpeechAudioBufferRecognitionRequest 中：

... do some setup
  SFSpeechRecognizer.requestAuthorization { authStatus in
    if authStatus == SFSpeechRecognizerAuthorizationStatus.authorized {
      self.m_recognizer = SFSpeechRecognizer()
      self.m_recognRequest = SFSpeechAudioBufferRecognitionRequest()
      self.m_recognRequest?.shouldReportPartialResults = false
      self.m_isRecording = true
    } else {
      print("not authorized")
    }
  }
.... do further setup


func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {

if(!m_AV_initialized) {
  print("captureOutput(...): not initialized !")
  return
}
if(!m_isRecording) {
  return
}

let formatDesc = CMSampleBufferGetFormatDescription(sampleBuffer)
let mediaType = CMFormatDescriptionGetMediaType(formatDesc!)
if (mediaType == kCMMediaType_Audio) {
  // process audio here
  m_recognRequest?.appendAudioSampleBuffer(sampleBuffer)
}
return
}

整个过程只持续了几秒钟。然后不再调用 captureOutput 。如果我注释掉 appendAudioSampleBuffer(sampleBuffer) 行，那么只要应用程序运行（如预期的那样），就会调用 captureOutput。显然，将样本缓冲区放入语音识别引擎会以某种方式阻止进一步的执行。我猜想可用的缓冲区会在一段时间后被消耗掉，并且进程会以某种方式停止，因为它无法再获得缓冲区？？？

我应该提到，在前 2 秒内记录的所有内容都会导致正确识别。我只是不知道 SFSpeech API 是如何工作的，因为 Apple 没有在 beta 文档中添加任何文本。顺便说一句：如何使用 SFSpeechAudioBufferRecognitionRequest.endAudio() ？

这里有人知道吗？

谢谢 克里斯

Answer 1

我将语音识别 WWDC 开发人员谈话中的 SpeakToMe 示例 Swift 代码转换为 Objective-C，它对我有用。对于 Swift，请参见 https://developer.apple.com/videos/play/wwdc2016/509/，对于 Objective-C，请参见下文。

- (void) viewDidAppear:(BOOL)animated {

_recognizer = [[SFSpeechRecognizer alloc] initWithLocale:[NSLocale localeWithLocaleIdentifier:@"en-US"]];
[_recognizer setDelegate:self];
[SFSpeechRecognizer requestAuthorization:^(SFSpeechRecognizerAuthorizationStatus authStatus) {
    switch (authStatus) {
        case SFSpeechRecognizerAuthorizationStatusAuthorized:
            //User gave access to speech recognition
            NSLog(@"Authorized");
            break;

        case SFSpeechRecognizerAuthorizationStatusDenied:
            //User denied access to speech recognition
            NSLog(@"SFSpeechRecognizerAuthorizationStatusDenied");
            break;

        case SFSpeechRecognizerAuthorizationStatusRestricted:
            //Speech recognition restricted on this device
            NSLog(@"SFSpeechRecognizerAuthorizationStatusRestricted");
            break;

        case SFSpeechRecognizerAuthorizationStatusNotDetermined:
            //Speech recognition not yet authorized

            break;

        default:
            NSLog(@"Default");
            break;
    }
}];

audioEngine = [[AVAudioEngine alloc] init];
_speechSynthesizer  = [[AVSpeechSynthesizer alloc] init];         
[_speechSynthesizer setDelegate:self];
}


-(void)startRecording
{
[self clearLogs:nil];

NSError * outError;

AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryRecord error:&outError];
[audioSession setMode:AVAudioSessionModeMeasurement error:&outError];
[audioSession setActive:true withOptions:AVAudioSessionSetActiveOptionNotifyOthersOnDeactivation  error:&outError];

request2 = [[SFSpeechAudioBufferRecognitionRequest alloc] init];

inputNode = [audioEngine inputNode];

if (request2 == nil) {
    NSLog(@"Unable to created a SFSpeechAudioBufferRecognitionRequest object");
}

if (inputNode == nil) {

    NSLog(@"Unable to created a inputNode object");
}

request2.shouldReportPartialResults = true;

_currentTask = [_recognizer recognitionTaskWithRequest:request2
                delegate:self];

[inputNode installTapOnBus:0 bufferSize:4096 format:[inputNode outputFormatForBus:0] block:^(AVAudioPCMBuffer *buffer, AVAudioTime *when){
    NSLog(@"Block tap!");

    [request2 appendAudioPCMBuffer:buffer];

}];

    [audioEngine prepare];
    [audioEngine startAndReturnError:&outError];
    NSLog(@"Error %@", outError);
}

- (void)speechRecognitionTask:(SFSpeechRecognitionTask *)task didFinishRecognition:(SFSpeechRecognitionResult *)result {

NSLog(@"speechRecognitionTask:(SFSpeechRecognitionTask *)task didFinishRecognition");
NSString * translatedString = [[[result bestTranscription] formattedString] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

[self log:translatedString];

if ([result isFinal]) {
    [audioEngine stop];
    [inputNode removeTapOnBus:0];
    _currentTask = nil;
    request2 = nil;
}
}

Answer 2

我已成功连续使用 SFSpeechRecognizer。 重点是使用AVCaptureSession来捕捉音频并传输到SpeechRecognizer。 对不起，我的 Swift 很差，所以只有 ObjC 版本。

这是我的示例代码（省略了一些 UI 代码，一些重要的已标记）：

@interface ViewController ()<AVCaptureAudioDataOutputSampleBufferDelegate,SFSpeechRecognitionTaskDelegate>
@property (nonatomic, strong) AVCaptureSession *capture;
@property (nonatomic, strong) SFSpeechAudioBufferRecognitionRequest *speechRequest;
@end

@implementation ViewController
- (void)startRecognizer
{
    [SFSpeechRecognizer requestAuthorization:^(SFSpeechRecognizerAuthorizationStatus status) {
        if (status == SFSpeechRecognizerAuthorizationStatusAuthorized){
            NSLocale *local =[[NSLocale alloc] initWithLocaleIdentifier:@"fr_FR"];
            SFSpeechRecognizer *sf =[[SFSpeechRecognizer alloc] initWithLocale:local];
            self.speechRequest = [[SFSpeechAudioBufferRecognitionRequest alloc] init];
            [sf recognitionTaskWithRequest:self.speechRequest delegate:self];
            // should call startCapture method in main queue or it may crash
            dispatch_async(dispatch_get_main_queue(), ^{
                [self startCapture];
            });
        }
    }];
}

- (void)endRecognizer
{
    // END capture and END voice Reco
    // or Apple will terminate this task after 30000ms.
    [self endCapture];
    [self.speechRequest endAudio];
}

- (void)startCapture
{
    NSError *error;
    self.capture = [[AVCaptureSession alloc] init];
    AVCaptureDevice *audioDev = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
    if (audioDev == nil){
        NSLog(@"Couldn't create audio capture device");
        return ;
    }

    // create mic device
    AVCaptureDeviceInput *audioIn = [AVCaptureDeviceInput deviceInputWithDevice:audioDev error:&error];
    if (error != nil){
        NSLog(@"Couldn't create audio input");
        return ;
    }

    // add mic device in capture object
    if ([self.capture canAddInput:audioIn] == NO){
        NSLog(@"Couldn't add audio input");
        return ;
    }
    [self.capture addInput:audioIn];
    // export audio data
    AVCaptureAudioDataOutput *audioOutput = [[AVCaptureAudioDataOutput alloc] init];
    [audioOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];
    if ([self.capture canAddOutput:audioOutput] == NO){
        NSLog(@"Couldn't add audio output");
        return ;
    }
    [self.capture addOutput:audioOutput];
    [audioOutput connectionWithMediaType:AVMediaTypeAudio];
    [self.capture startRunning];
}

-(void)endCapture
{
    if (self.capture != nil && [self.capture isRunning]){
        [self.capture stopRunning];
    }
}

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{
    [self.speechRequest appendAudioSampleBuffer:sampleBuffer];
}
// some Recognition Delegate
@end

Answer 3

这是@cube 答案的 Swift (3.0) 实现：

import UIKit
import Speech
import AVFoundation


class ViewController: UIViewController  {
  @IBOutlet weak var console: UITextView!

  var capture: AVCaptureSession?
  var speechRequest: SFSpeechAudioBufferRecognitionRequest?
  override func viewDidLoad() {
    super.viewDidLoad()
  }
  override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    startRecognizer()
  }

  func startRecognizer() {
    SFSpeechRecognizer.requestAuthorization { (status) in
      switch status {
      case .authorized:
        let locale = NSLocale(localeIdentifier: "fr_FR")
        let sf = SFSpeechRecognizer(locale: locale as Locale)
        self.speechRequest = SFSpeechAudioBufferRecognitionRequest()
        sf?.recognitionTask(with: self.speechRequest!, delegate: self)
        DispatchQueue.main.async {

        }
      case .denied:
        fallthrough
      case .notDetermined:
        fallthrough
      case.restricted:
        print("User Autorization Issue.")
      }
    }

  }

  func endRecognizer() {
    endCapture()
    speechRequest?.endAudio()
  }

  func startCapture() {

    capture = AVCaptureSession()

    guard let audioDev = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeAudio) else {
      print("Could not get capture device.")
      return
    }

    guard let audioIn = try? AVCaptureDeviceInput(device: audioDev) else {
      print("Could not create input device.")
      return
    }

    guard true == capture?.canAddInput(audioIn) else {
      print("Couls not add input device")
      return
    }

    capture?.addInput(audioIn)

    let audioOut = AVCaptureAudioDataOutput()
    audioOut.setSampleBufferDelegate(self, queue: DispatchQueue.main)

    guard true == capture?.canAddOutput(audioOut) else {
      print("Could not add audio output")
      return
    }

    capture?.addOutput(audioOut)
    audioOut.connection(withMediaType: AVMediaTypeAudio)
    capture?.startRunning()


  }

  func endCapture() {

    if true == capture?.isRunning {
      capture?.stopRunning()
    }
  }
}

extension ViewController: AVCaptureAudioDataOutputSampleBufferDelegate {
  func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {
    speechRequest?.appendAudioSampleBuffer(sampleBuffer)
  }

}

extension ViewController: SFSpeechRecognitionTaskDelegate {

  func speechRecognitionTask(_ task: SFSpeechRecognitionTask, didFinishRecognition recognitionResult: SFSpeechRecognitionResult) {
    console.text = console.text + "\n" + recognitionResult.bestTranscription.formattedString
  }
}

不要忘记在info.plist文件中为NSSpeechRecognitionUsageDescription添加一个值，否则它会崩溃。

Answer 4

事实证明，Apple 的新本机语音识别不会自动检测语音静音结束（错误？），这对您的情况很有用，因为语音识别激活了近一分钟（最长期限，允许苹果的服务）。 因此，基本上，如果您需要连续 ASR，则必须在您的委托触发时重新启动语音识别：

func speechRecognitionTask(task: SFSpeechRecognitionTask, didFinishSuccessfully successfully: Bool) //wether succesfully= true or not

这是我使用的录音/语音识别 SWIFT 代码，它运行良好。如果您不需要，请忽略我计算麦克风音量平均功率的部分。我用它来动画波形。不要忘记设置 SFSpeechRecognitionTaskDelegate，是委托方法，如果需要额外代码，请告诉我。

func startNativeRecording() throws {
        LEVEL_LOWPASS_TRIG=0.01
        //Setup Audio Session
        node = audioEngine.inputNode!
        let recordingFormat = node!.outputFormatForBus(0)
        node!.installTapOnBus(0, bufferSize: 1024, format: recordingFormat){(buffer, _) in
            self.nativeASRRequest.appendAudioPCMBuffer(buffer)

 //Code to animate a waveform with the microphone volume, ignore if you don't need it:
            var inNumberFrames:UInt32 = buffer.frameLength;
            var samples:Float32 = buffer.floatChannelData[0][0]; //https://github.com/apple/swift-evolution/blob/master/proposals/0107-unsaferawpointer.md
            var avgValue:Float32 = 0;
            vDSP_maxmgv(buffer.floatChannelData[0], 1, &avgValue, vDSP_Length(inNumberFrames)); //Accelerate Framework
            //vDSP_maxmgv returns peak values
            //vDSP_meamgv returns mean magnitude of a vector

            let avg3:Float32=((avgValue == 0) ? (0-100) : 20.0)
            var averagePower=(self.LEVEL_LOWPASS_TRIG*avg3*log10f(avgValue)) + ((1-self.LEVEL_LOWPASS_TRIG)*self.averagePowerForChannel0) ;
            print("AVG. POWER: "+averagePower.description)
            dispatch_async(dispatch_get_main_queue(), { () -> Void in
                //print("VU: "+vu.description)
                var fAvgPwr=CGFloat(averagePower)
                print("AvgPwr: "+fAvgPwr.description)

                var waveformFriendlyValue=0.5+fAvgPwr //-0.5 is AvgPwrValue when user is silent
                if(waveformFriendlyValue<0){waveformFriendlyValue=0} //round values <0 to 0
                self.waveview.hidden=false
                self.waveview.updateWithLevel(waveformFriendlyValue)
            })
        }
        audioEngine.prepare()
        try audioEngine.start()
        isNativeASRBusy=true
        nativeASRTask = nativeSpeechRecognizer?.recognitionTaskWithRequest(nativeASRRequest, delegate: self)
        nativeSpeechRecognizer?.delegate=self
  //I use this timer to track no speech timeouts, ignore if not neeeded:
        self.endOfSpeechTimeoutTimer = NSTimer.scheduledTimerWithTimeInterval(utteranceTimeoutSeconds, target: self, selector:  #selector(ViewController.stopNativeRecording), userInfo: nil, repeats: false)
    }

Answer 5

如果您启用仅在设备上识别，它不会在 1 分钟后自动停止语音识别。

.requiresOnDeviceRecognition = true

更多关于 requiresOnDeviceRecognition ;

https://developer.apple.com/documentation/speech/sfspeechrecognitionrequest/3152603-requiresondevicerecognition

Answer 6

这在我的应用程序中完美运行。 您可以通过 saifurrahman3126@gmail.com 进行查询 苹果不允许用户连续翻译超过一分钟。 https://developer.apple.com/documentation/speech/sfspeechrecognizercheck here

“计划将音频持续时间限制为一分钟。语音识别对电池寿命和网络使用造成了相对较高的负担。为了尽量减少这种负担，框架会停止持续时间超过一分钟的语音识别任务。这个限制是类似于键盘相关的听写。” 这是 Apple 在其文档中所说的。

目前，我已经发出了 40 秒的请求，如果你在 40 秒之前说话然后暂停，我会重新连接它，录音会重新开始。

@objc  func startRecording() {
    
    self.fullsTring = ""
    audioEngine.reset()
    
    if recognitionTask != nil {
        recognitionTask?.cancel()
        recognitionTask = nil
    }
    
    let audioSession = AVAudioSession.sharedInstance()
    do {
        try audioSession.setCategory(.record)
        try audioSession.setMode(.measurement)
        try audioSession.setActive(true, options: .notifyOthersOnDeactivation)
        try audioSession.setPreferredSampleRate(44100.0)
        
        if audioSession.isInputGainSettable {
            let error : NSErrorPointer = nil
            
            let success = try? audioSession.setInputGain(1.0)
            
            guard success != nil else {
                print ("audio error")
                return
            }
            if (success != nil) {
                print("\(String(describing: error))")
            }
        }
        else {
            print("Cannot set input gain")
        }
    } catch {
        print("audioSession properties weren't set because of an error.")
    }
    recognitionRequest = SFSpeechAudioBufferRecognitionRequest()
    
    let inputNode = audioEngine.inputNode
    guard let recognitionRequest = recognitionRequest else {
        fatalError("Unable to create an SFSpeechAudioBufferRecognitionRequest object")
    }
    
    recognitionRequest.shouldReportPartialResults = true
    self.timer4 = Timer.scheduledTimer(timeInterval: TimeInterval(40), target: self, selector: #selector(againStartRec), userInfo: nil, repeats: false)
    
    recognitionTask = speechRecognizer.recognitionTask(with: recognitionRequest, resultHandler: { (result, error ) in
        
        var isFinal = false  //8
        
        if result != nil {
            self.timer.invalidate()
            self.timer = Timer.scheduledTimer(timeInterval: TimeInterval(2.0), target: self, selector: #selector(self.didFinishTalk), userInfo: nil, repeats: false)
            
            let bestString = result?.bestTranscription.formattedString
            self.fullsTring = bestString!
            
            self.inputContainerView.inputTextField.text = result?.bestTranscription.formattedString
            
            isFinal = result!.isFinal
            
        }
        if error == nil{
            
        }
        if  isFinal {
            
            self.audioEngine.stop()
            inputNode.removeTap(onBus: 0)
            
            self.recognitionRequest = nil
            self.recognitionTask = nil
            isFinal = false
            
        }
        if error != nil{
            URLCache.shared.removeAllCachedResponses()
            
            self.audioEngine.stop()
            inputNode.removeTap(onBus: 0)
            
            guard let task = self.recognitionTask else {
                return
            }
            task.cancel()
            task.finish()
        }
    })
    audioEngine.reset()
    inputNode.removeTap(onBus: 0)
    
    let recordingFormat = AVAudioFormat(standardFormatWithSampleRate: 44100, channels: 1)
    inputNode.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { (buffer, when) in
        self.recognitionRequest?.append(buffer)
    }
    
    audioEngine.prepare()
    
    do {
        try audioEngine.start()
    } catch {
        print("audioEngine couldn't start because of an error.")
    }
    
    self.hasrecorded = true
}

@objc func againStartRec(){
    
    self.inputContainerView.uploadImageView.setBackgroundImage( #imageLiteral(resourceName: "microphone") , for: .normal)
    self.inputContainerView.uploadImageView.alpha = 1.0
    self.timer4.invalidate()
    timer.invalidate()
    self.timer.invalidate()
    
    if ((self.audioEngine.isRunning)){
        
        self.audioEngine.stop()
        self.recognitionRequest?.endAudio()
        self.recognitionTask?.finish()
    }
    self.timer2 = Timer.scheduledTimer(timeInterval: 2, target: self, selector: #selector(startRecording), userInfo: nil, repeats: false)
}

@objc func didFinishTalk(){
    
    if self.fullsTring != ""{
        
        self.timer4.invalidate()
        self.timer.invalidate()
        self.timer2.invalidate()
        
        if ((self.audioEngine.isRunning)){
            self.audioEngine.stop()
            guard let task = self.recognitionTask else {
                return
            }
            task.cancel()
            task.finish()
        }
    }
}