Vosk Flutter Plugin

Flutter plugin for Vosk speech recognition.

Platform Support

Android	iOS	MacOS	Web	Linux	Windows
✔	➖	➖	➖	✔	✔

Usage

Configurations

Follow the instruction at the Installing page of the package.

Android

Add this pro guard rules in android/app/proguard-rules.pro(if the file does not exist - create it):

-keep class com.sun.jna.* { *; }
-keepclassmembers class * extends com.sun.jna.* { public *; }

If you want to use a microphone input, add the microphone permission to your AndroidManifest.xml:

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

Load model

flutter:
  assets:
    - assets/models/

final vosk = VoskFlutterPlugin.instance();
final enSmallModelPath = await ModelLoader()
    .loadFromAssets('assets/models/vosk-model-small-en-us-0.15.zip');

Create recognizer

final recognizer = await vosk.createRecognizer(
    model: model,
    sampleRate: sampleRate,
);
final recognizerWithGrammar = await vosk.createRecognizer(
    model: model,
    sampleRate: sampleRate,
    grammar: ['one', 'two', 'three'],
);

Recognize audio data

Uint8List audioBytes = ...; // audio data in PCM 16-bit mono format
List<String> results = [];
int chunkSize = 8192;
int pos = 0;

while (pos + chunkSize < audioBytes.length) {
    final resultReady = await recognizer.acceptWaveformBytes(
      Uint8List.fromList(audioBytes.getRange(pos, pos + chunkSize).toList()));
    pos += chunkSize;
    
    if (resultReady) {
      print(await recognizer.getResult());
    } else {
      print(await recognizer.getPartialResult());
    }
}
await recognizer.acceptWaveformBytes(
  Uint8List.fromList(audioBytes.getRange(pos, audioBytes.length).toList()));
print(await recognizer.getFinalResult());

Recognize microphone data

Android

final speechService = await vosk.initSpeechService(recognizer);
speechService.onPartial().forEach((partial) => print(partial));
speechService.onResult().forEach((result) => print(result));
await speechService.start();

Linux & Windows

Use any suitable plugin to get the microphone input and pass it to a recognizer