Text To Speech

A flutter text to speech plugin (Swift,Kotlin)

Features

• Android, iOS, Web, Windows & macOS
  • speak
  • stop
  • get languages
  • set language
  • set speech rate
  • set speech volume
  • set speech pitch
• Android, iOS, Web & macOS
  • is language available
• Android, iOS, macOS, Web, & Windows
  • get voices
  • set voice
• Android, iOS
  • speech marks (requires iOS 7+ and Android 26+)
  • synthesize to file (requires iOS 13+)
• Android, iOS, Web, & Windows
  • pause
• Android
  • set silence
  • is language installed
  • are languages installed
  • get engines
  • set engine
  • get default engine
  • get default voice
  • set queue mode
  • get max speech input length
• iOS
  • set shared instance
  • set audio session category

Usage

macOS

OSX version: 10.15

Example App from the macOS_app branch

Web

Website from the example directory.

Android

Change the minimum Android sdk version to 21 (or higher) in your android/app/build.gradle file.

minSdkVersion 21

Update the Kotlin Gradle Plugin Version

Change the verision of the Kotlin Gradle plugin to 1.9.10.
If your project was created with a version of Flutter before 3.19, go to the android/build.gradle file and update the ext.kotlin_version:

ext.kotlin_version = '1.9.10'

Otherwise go to android/settings.gradle and update the verion of the plugin org.jetbrains.kotlin.android:

id "org.jetbrains.kotlin.android" version "1.9.10" apply false

Apps targeting Android 11 that use text-to-speech should declare TextToSpeech.Engine.INTENT_ACTION_TTS_SERVICE in the queries elements of their manifest.

<queries>
  <intent>
    <action android:name="android.intent.action.TTS_SERVICE" />
  </intent>
</queries>

Pausing on Android

Android TTS does not support the pause function natively, so we have implemented a work around. We utilize the native onRangeStart() method to determine the index of start when pause is invoked. We use that index to create a new text the next time speak is invoked. Due to using onRangeStart(), pause works on SDK versions >= 26. Also, if using start and end offsets inside of setProgressHandler(), you'll need to keep a track of them if using pause since they will update once the new text is created when speak is called after being paused.

await flutterTts.pause()

iOS

There's a known issue with integrating plugins that use Swift into a Flutter project created with the Objective-C template. Flutter#16049

Example

To use this plugin :

• add the dependency to your pubspec.yaml file.

  dependencies:
    flutter:
      sdk: flutter
    flutter_tts:

• instantiate FlutterTts

FlutterTts flutterTts = FlutterTts();

To set shared audio instance (iOS only):

await flutterTts.setSharedInstance(true);

To set audio category and options with optional mode (iOS only). The following setup allows background music and in-app audio session to continue simultaneously:

await flutterTts.setIosAudioCategory(IosTextToSpeechAudioCategory.ambient,
     [
          IosTextToSpeechAudioCategoryOptions.allowBluetooth,
          IosTextToSpeechAudioCategoryOptions.allowBluetoothA2DP,
          IosTextToSpeechAudioCategoryOptions.mixWithOthers
     ],
     IosTextToSpeechAudioMode.voicePrompt
);

To await speak completion.

await flutterTts.awaitSpeakCompletion(true);

To await synthesize to file completion.

await flutterTts.awaitSynthCompletion(true);

speak, stop, getLanguages, setLanguage, setSpeechRate, getVoices, setVoice, setVolume, setPitch, isLanguageAvailable, setSharedInstance

Future _speak() async{
    var result = await flutterTts.speak("Hello World");
    if (result == 1) setState(() => ttsState = TtsState.playing);
}

Future _stop() async{
    var result = await flutterTts.stop();
    if (result == 1) setState(() => ttsState = TtsState.stopped);
}

List<dynamic> languages = await flutterTts.getLanguages;

await flutterTts.setLanguage("en-US");

await flutterTts.setSpeechRate(1.0);

await flutterTts.setVolume(1.0);

await flutterTts.setPitch(1.0);

await flutterTts.isLanguageAvailable("en-US");

// iOS, Android and Web only
//see the "Pausing on Android" section for more info
await flutterTts.pause();

// iOS, macOS, and Android only
// The last parameter is an optional boolean value for isFullPath (defaults to false)
await flutterTts.synthesizeToFile("Hello World", Platform.isAndroid ? "tts.wav" : "tts.caf", false);

// Each voice is a Map containing at least these keys: name, locale
// - iOS, macOS only: quality, gender, identifier
// - Android only: quality, latency, network_required, features 
List<Map> voices = await flutterTts.getVoices;

await flutterTts.setVoice({"name": "Karen", "locale": "en-AU"});
// iOS, macOS only
await flutterTts.setVoice({"identifier": "com.apple.voice.compact.en-AU.Karen"});

// iOS only
await flutterTts.setSharedInstance(true);

// Android only
await flutterTts.speak("Hello World", focus: true);

await flutterTts.setSilence(2);

await flutterTts.getEngines;

await flutterTts.getDefaultVoice;

await flutterTts.isLanguageInstalled("en-AU");

await flutterTts.areLanguagesInstalled(["en-AU", "en-US"]);

await flutterTts.setQueueMode(1);

await flutterTts.getMaxSpeechInputLength;

await flutterTts.setAudioAttributesForNavigation();

Listening for platform calls

flutterTts.setStartHandler(() {
  setState(() {
    ttsState = TtsState.playing;
  });
});

flutterTts.setCompletionHandler(() {
  setState(() {
    ttsState = TtsState.stopped;
  });
});

flutterTts.setProgressHandler((String text, int startOffset, int endOffset, String word) {
  setState(() {
    _currentWord = word;
  });
});

flutterTts.setErrorHandler((msg) {
  setState(() {
    ttsState = TtsState.stopped;
  });
});

flutterTts.setCancelHandler((msg) {
  setState(() {
    ttsState = TtsState.stopped;
  });
});

// Android, iOS and Web
flutterTts.setPauseHandler((msg) {
  setState(() {
    ttsState = TtsState.paused;
  });
});

flutterTts.setContinueHandler((msg) {
  setState(() {
    ttsState = TtsState.continued;
  });
});

Getting Started

For help getting started with Flutter, view our online documentation.

For help on editing plugin code, view the documentation.