Flutter/Dart：任何语言的语音转文本（离线和连续）

Question

是否有任何软件包可用于创建可将语音处理为文本的应用程序？

它应该包括以下功能：

离线语音转文本
连续收听（10-30分钟）
识别器适用于Android/IOS支持的所有语言

到目前为止我找到了这个 https://pub.dev/packages/speech_recognition 但它说：

the iOS API sends intermediate results, On my Android device, only the final transcription is received

Other limitations: On iOS, by default the plugin is configured for French, English, Russian, Spanish, Italian. On Android, without additional installations, it will probably works only with the default device locale.

有人测试过这个包并且有好的结果？或者您还有其他建议吗？

Answer 1

https://pub.dev/packages/speech_recognition是最好的选择。它基于 SpeechRecognizer 并提供离线语音到文本。

无法连续收听。即使付费的在线 Cloud Speech-to-Text API 也不允许这样做，因为它很危险（滥用等）。

在 iOS 上，插件默认配置为法语、英语、俄语、西班牙语、意大利语，但您可以将缺少的语言添加到 swift 源文件中。

所以你最终不会找到更好的语音识别插件，即使它并不完美。

Answer 2

我现在正在使用 https://pub.dev/packages/speech_to_text。它得到积极维护并且工作得很好。我觉得可以写一些自定义代码让它连续监听。

编辑：

应要求，请看下面的持续收听逻辑。我只是将它用作概念证明，因此我不会推荐将它用于生产应用程序。据我所知 Android API 不支持开箱即用的连续收听。

SpeechRecognitionBloc

import 'package:bloc/bloc.dart';
import 'package:meta/meta.dart';
import 'package:template_mobile/core/sevices/speech_recognition_service.dart';
import 'package:template_mobile/core/state/event/speech_recognition_event.dart';
import 'package:template_mobile/core/state/state/speech_recognition_state.dart';

class SpeechRecognitionBloc
    extends Bloc<SpeechRecognitionEvent, SpeechRecognitionState> {
  final SpeechRecognitionService speechRecognitionService;

  SpeechRecognitionBloc({
    @required this.speechRecognitionService,
  }) : assert(speechRecognitionService != null) {
    speechRecognitionService.errors.stream.listen((errorResult) {
      add(SpeechRecognitionErrorEvent(
        error: "${errorResult.errorMsg} - ${errorResult.permanent}",
      ));
    });

    speechRecognitionService.statuses.stream.listen((status) {
      if (state is SpeechRecognitionRecognizedState) {
        var currentState = state as SpeechRecognitionRecognizedState;
        if (currentState.finalResult) {
          add(SpeechRecognitionStatusChangedEvent());
        }
      }
    });

    speechRecognitionService.words.stream.listen((speechResult) {
      add(SpeechRecognitionRecognizedEvent(
        words: speechResult.recognizedWords,
        finalResult: speechResult.finalResult,
      ));
    });
  }

  @override
  SpeechRecognitionState get initialState =>
      SpeechRecognitionUninitializedState();

  @override
  Stream<SpeechRecognitionState> mapEventToState(
      SpeechRecognitionEvent event) async* {
    if (event is SpeechRecognitionInitEvent) {
      var hasSpeech = await speechRecognitionService.initSpeech();
      if (hasSpeech) {
        yield SpeechRecognitionAvailableState();
      } else {
        yield SpeechRecognitionUnavailableState();
      }
    }

    if (event is SpeechRecognitionStartPressEvent) {
      yield SpeechRecognitionStartPressedState();
      add(SpeechRecognitionStartEvent());
    }

    if (event is SpeechRecognitionStartEvent) {
      speechRecognitionService.startListening();
      yield SpeechRecognitionStartedState();
    }

    if (event is SpeechRecognitionStopPressEvent) {
      yield SpeechRecognitionStopPressedState();
      add(SpeechRecognitionStopEvent());
    }

    if (event is SpeechRecognitionStopEvent) {
      speechRecognitionService.stopListening();
      yield SpeechRecognitionStopedState();
    }

    if (event is SpeechRecognitionCancelEvent) {
      speechRecognitionService.cancelListening();
      yield SpeechRecognitionCanceledState();
    }

    if (event is SpeechRecognitionRecognizedEvent) {
      yield SpeechRecognitionRecognizedState(
          words: event.words, finalResult: event.finalResult);
      if (event.finalResult == true &&
          speechRecognitionService.statuses.value == 'notListening') {
        await Future.delayed(Duration(milliseconds: 50));
        add(SpeechRecognitionStatusChangedEvent());
      }
    }

    if (event is SpeechRecognitionErrorEvent) {
      yield SpeechRecognitionErrorState(error: event.error);
      // Just for UI updates for the state to propagates
      await Future.delayed(Duration(milliseconds: 50));
      add(SpeechRecognitionInitEvent());
      await Future.delayed(Duration(milliseconds: 50));
      add(SpeechRecognitionStartPressEvent());
    }

    if (event is SpeechRecognitionStatusChangedEvent) {
      yield SpeechRecognitionStatusState();
      add(SpeechRecognitionStartPressEvent());
    }
  }
}

语音识别服务

import 'dart:async';

import 'package:rxdart/rxdart.dart';
import 'package:speech_to_text/speech_recognition_error.dart';
import 'package:speech_to_text/speech_recognition_result.dart';
import 'package:speech_to_text/speech_to_text.dart';

class SpeechRecognitionService {
  final SpeechToText speech = SpeechToText();

  var errors = StreamController<SpeechRecognitionError>();
  var statuses = BehaviorSubject<String>();
  var words = StreamController<SpeechRecognitionResult>();

  var _localeId = '';

  Future<bool> initSpeech() async {
    bool hasSpeech = await speech.initialize(
      onError: errorListener,
      onStatus: statusListener,
    );

    if (hasSpeech) {
      var systemLocale = await speech.systemLocale();
      _localeId = systemLocale.localeId;
    }

    return hasSpeech;
  }

  void startListening() {
    speech.stop();
    speech.listen(
        onResult: resultListener,
        listenFor: Duration(minutes: 1),
        localeId: _localeId,
        onSoundLevelChange: null,
        cancelOnError: true,
        partialResults: true);
  }

  void errorListener(SpeechRecognitionError error) {
    errors.add(error);
  }

  void statusListener(String status) {
    statuses.add(status);
  }

  void resultListener(SpeechRecognitionResult result) {
    words.add(result);
  }

  void stopListening() {
    speech.stop();
  }

  void cancelListening() {
    speech.cancel();
  }
}

Answer 3

如果您愿意编写自定义平台特定代码https://flutter.dev/docs/development/platform-integration/platform-channels, for Android you can use https://github.com/alphacep/vosk-android-demo来获得您想要的。

另一种方法是构建您自己的键盘 IME 以使用 How Can I Implement Google Voice Typing In My Application? 中建议的语音输入。

Flutter/Dart：任何语言的语音转文本（离线和连续）

Flutter/Dart: speech to text (offline and continuous) for any language

flutter

dart

speech-recognition

speech-to-text