Flutter实时语音转文字插件livespeechtotext的使用

Live Speech-To-Text

轻松为您的Flutter应用程序添加语音识别功能，实现语音控制特性。通过这个插件可以更方便地将说出的话语转换成文本。

SDK

• Android

  • MinSDK 21 /CompileSDK 31
  • 在android/local.properties中设置：

    def flutterMinSdkVersion = localProperties.getProperty('flutter.minSdkVersion')
    if (flutterMinSdkVersion == null) {
        flutterMinSdkVersion = '21'
    }
    
    def flutterCompileSdkVersion = localProperties.getProperty('flutter.compileSdkVersion')
    if (flutterCompileSdkVersion == null) {
        flutterCompileSdkVersion = '31'
    }
    

  • 在android/app/build.gradle中设置：

    android {
        ...
        compileSdkVersion flutterCompileSdkVersion.toInteger()
        ...
    
        defaultConfig {
          ...
          minSdkVersion flutterMinSdkVersion.toInteger()
          ...
        }
    }
    

• iOS

  • 此包在目标iOS 13上进行了测试。

Permissions

强烈建议使用permission_handler:^9.2.0包来确保用户已授予所需的权限。

• Android

  • 在android/app/src/{debug,main,profile}/AndroidManifest.xml中添加：

    <uses-permission android:name="android.permission.RECORD_AUDIO" />
    <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
    

• iOS

  • 在ios/Runner/Info.plist中添加：

    <key>NSMicrophoneUsageDescription</key>
    <string>您的语音输入对于语音转文本功能是必需的</string>
    <key>NSSpeechRecognitionUsageDescription</key>
    <string>允许应用从您的语音获取文本输入</string>
    

  • 在ios/Podfile中：
    • 首先参考指南
    • 取消注释以下行：

      ## dart: PermissionGroup.microphone
      'PERMISSION_MICROPHONE=1',
      
      ## dart: PermissionGroup.speech
      'PERMISSION_SPEECH_RECOGNIZER=1',
      

Troubleshoots

• Android Emulator（无Android Studio）在MacOS 13上无法接收麦克风输入
  • 打开“活动监视器”找到类似’qemu’的进程名，获取完整进程名。
  • 运行命令：

    sudo defaults write com.apple.security.device.microphone qemu-system-aarch64 -bool true
    

  • 重启模拟器。

示例代码

下面是一个完整的示例demo，展示了如何使用livespeechtotext插件：

import 'dart:developer';
import 'dart:io';

import 'package:flutter/material.dart';
import 'dart:async';

import 'package:flutter/services.dart';
import 'package:livespeechtotext/livespeechtotext.dart';
import 'package:permission_handler/permission_handler.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();

  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  late Livespeechtotext _livespeechtotextPlugin;
  late String _recognisedText;
  String? _localeDisplayName = '';
  StreamSubscription<dynamic>? onSuccessEvent;

  bool microphoneGranted = false;

  @override
  void initState() {
    super.initState();
    _livespeechtotextPlugin = Livespeechtotext();

    _livespeechtotextPlugin.getLocaleDisplayName().then((value) => setState(
          () => _localeDisplayName = value,
        ));

    _recognisedText = '';
  }

  @override
  void dispose() {
    onSuccessEvent?.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Live Speech To Text'),
        ),
        body: Center(
          child: Column(
            children: [
              Text(_recognisedText),
              if (!microphoneGranted)
                ElevatedButton(
                  onPressed: () {
                    binding();
                  },
                  child: const Text("Check Permissions"),
                ),
              ElevatedButton(
                  onPressed: microphoneGranted
                      ? () {
                          print("start button pressed");
                          try {
                            _livespeechtotextPlugin.start();
                          } on PlatformException {
                            print('error');
                          }
                        }
                      : null,
                  child: const Text('Start')),
              ElevatedButton(
                  onPressed: microphoneGranted
                      ? () {
                          print("stop button pressed");
                          try {
                            _livespeechtotextPlugin.stop();
                          } on PlatformException {
                            print('error');
                          }
                        }
                      : null,
                  child: const Text('Stop')),
              Text("Locale: $_localeDisplayName"),
            ],
          ),
        ),
      ),
    );
  }

  Future<dynamic> binding() async {
    onSuccessEvent?.cancel();

    return Future.wait([]).then((_) async {
      // Check if the user has already granted microphone permission.
      var permissionStatus = await Permission.microphone.status;

      // If the user has not granted permission, prompt them for it.
      if (!microphoneGranted) {
        await Permission.microphone.request();

        // Check if the user has already granted the permission.
        permissionStatus = await Permission.microphone.status;

        if (!permissionStatus.isGranted) {
          return Future.error('Microphone access denied');
        }
      }

      // Check if the user has already granted speech permission.
      if (Platform.isIOS) {
        var speechStatus = await Permission.speech.status;

        // If the user has not granted permission, prompt them for it.
        if (!microphoneGranted) {
          await Permission.speech.request();

          // Check if the user has already granted the permission.
          speechStatus = await Permission.speech.status;

          if (!speechStatus.isGranted) {
            return Future.error('Speech access denied');
          }
        }
      }

      return Future.value(true);
    }).then((value) {
      microphoneGranted = true;

      // listen to event "success"
      onSuccessEvent =
          _livespeechtotextPlugin.addEventListener("success", (value) {
        if (value.runtimeType != String) return;
        if ((value as String).isEmpty) return;

        setState(() {
          _recognisedText = value;
        });
      });

      setState(() {});
    }).onError((error, stackTrace) {
      // toast
      log(error.toString());
      // open app setting
    });
  }
}

此示例展示了如何初始化插件、请求必要的权限、开始和停止语音识别，并显示识别到的文本。希望这能帮助您更好地理解和使用livespeechtotext插件。