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

Question

我正在尝试执行续。在 iOS 10 测试版上使用 AVCapture 进行语音识别。我设置了 captureOutput(...) 以持续获取 CMSampleBuffers。我将这些缓冲区直接放入我之前设置的 SFSpeechAudioBufferRecognitionRequest 中，如下所示:

... 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
}

整个过程只用了几秒钟。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)，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？？？

我应该提一下，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 究竟是如何工作的，因为 Apple 没有将任何文本放入 beta 文档中。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，请参阅 https://developer.apple.com/videos/play/wwdc2016/509/ ，或者对于 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;
}
}