ios - 执行 SFSpeechAudioBufferRecognitionRequest 时出错 Domain=kAFAssistantErrorDomain Code=216

Question

我在使用 objective-c 语言实现 SFSpeechAudioBufferRecognitionRequest 时遇到错误。这是我的代码..它在一天前就开始工作了。错误是 Domain=kAFAssistantErrorDomain Code=216 "(null)"

- (void)startListening {

// Initialize the AVAudioEngine
audioEngine = [[AVAudioEngine alloc] init];

// Make sure there's not a recognition task already running
if (recognitionTask) {
    [recognitionTask cancel];
    recognitionTask = nil;
}

// Starts an AVAudio Session
NSError *error;
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:&error];
[audioSession setActive:YES withOptions:AVAudioSessionSetActiveOptionNotifyOthersOnDeactivation error:&error];

// Starts a recognition process, in the block it logs the input or stops the audio
// process if there's an error.
recognitionRequest = [[SFSpeechAudioBufferRecognitionRequest alloc] init];
 inputNode = audioEngine.inputNode;
recognitionRequest.shouldReportPartialResults = NO;
recognitionRequest.taskHint = SFSpeechRecognitionTaskHintDictation;
[self startWaveAudio];

// Sets the recording format
AVAudioFormat *recordingFormat = [inputNode outputFormatForBus:0];
[inputNode installTapOnBus:0 bufferSize:4096 format:recordingFormat block:^(AVAudioPCMBuffer * _Nonnull buffer, AVAudioTime * _Nonnull when) {
    [recognitionRequest appendAudioPCMBuffer:buffer];
}];

// Starts the audio engine, i.e. it starts listening.
[audioEngine prepare];
[audioEngine startAndReturnError:&error];


__block BOOL isFinal = NO;

recognitionTask = [speechRecognizer recognitionTaskWithRequest:recognitionRequest resultHandler:^(SFSpeechRecognitionResult * _Nullable result, NSError * _Nullable error) {

    [self stopWaveAudio];

    if (result) {
        // Whatever you say in the microphone after pressing the button should be being logged
        // in the console.
        NSLog(@"RESULT:%@",result.bestTranscription.formattedString);

        for (SFTranscription *tra in result.transcriptions) {
            NSLog(@"Multiple Results : %@", tra.formattedString);
        }

        if(isFinal == NO) {
            [self calculateResultOfSpeechWithResultString:result.bestTranscription.formattedString];
        }
        isFinal = !result.isFinal;
    }
    if (error || isFinal) {
        NSLog(@"Error Description : %@", error);
        [self stopRecording];

    }
}];
}

- (IBAction)tap2TlkBtnPrsd:(UIButton *)sender {
  if (audioEngine.isRunning) {
   [self stopRecording];
} else {
    [self startListening];
}

isMicOn = !isMicOn;
micPrompt = NO;

}

-(void)stopRecording {

       // dispatch_async(dispatch_get_main_queue(), ^{

            if(audioEngine.isRunning){
                [inputNode removeTapOnBus:0];
                [inputNode reset];
                [audioEngine stop];
                [recognitionRequest endAudio];
                [recognitionTask cancel];
                recognitionTask = nil;
                recognitionRequest = nil;
            }
       // });


}

并且尝试了不同的方式，比如在请求语音后附加音频缓冲区..

如果可能的话，谁能告诉我我怎样才能实现这样的场景，比如用户会拼出这个词，结果只会是那个词？

Answer 1

我在取消识别任务的时候同样出现Error=216。 SFSpeechRecognitionResult 的 isFinal 属性只有在识别器认为说话者已经结束时才为真。因此，当您第一次尝试执行 isFinal = !result.isFinal; 时，它是 False 并且您的 isFinal 标志调用 block where is stopRecording()，用[recognitionTask cancel];取消它。

因此，如果您只想要第一个转录(单词)，您可以调用 bestTranscription 的第一段的 substring 属性，然后调用 [识别任务完成];.

...
if (result) {
    // First transcription
    NSLog(@"RESULT:%@",[[result.bestTranscription.segments.firstObject] substring]);
    [recognitionTask finish];
    [self stopRecording];
}
if (error) {
    NSLog(@"Error Description : %@", error);
    [recognitionTask cancel];
    [self stopRecording];
}
...
-(void)stopRecording {

        if(audioEngine.isRunning){
            [inputNode removeTapOnBus:0];
            [inputNode reset];
            [audioEngine stop];
            [recognitionRequest endAudio];
            recognitionTask = nil;
            recognitionRequest = nil;
        }

}