Flutter Isolate

[germes96]

The offline transcriber works very well when run on the ui Thread, but it blocks the interface.

When run in isolation or compute mode the result is always empty.

  SendPort sendPort = data[0];
  final String filePath = data[1]; //0 is for FileName
  logger.i('THE REVEIVE AUDIO PATH ${filePath}');
  final sherpa_onnx.OfflineRecognizer? _recognizer = data[2]; //0 is for FileName

  final waveData = sherpa_onnx.readWave(filePath);
  final stream = _recognizer?.createStream();
  stream?.acceptWaveform(samples: waveData.samples, sampleRate: waveData.sampleRate);

  final startTime = DateTime.now();
  _recognizer?.decode(stream!);
  var result = _recognizer?.getResult(stream!);

  final endTime = DateTime.now();
  final duration = endTime.difference(startTime).inMilliseconds;
  logger.i('Task duration: $duration milliseconds, data: ${result?.text}');
  stream?.free();
  sendPort.send(result?.text ?? 'BAD ASR');
}

```Future<String> transcribeInCompute(List<dynamic> data) async {
  final String filePath = data[0]; //0 is for FileName
  logger.i('THE REVEIVE AUDIO PATH ${filePath}');
  final sherpa_onnx.OfflineRecognizer? _recognizer = data[1]; //0 is for FileName

  final waveData = sherpa_onnx.readWave(filePath);
  final stream = _recognizer?.createStream();
  stream?.acceptWaveform(samples: waveData.samples, sampleRate: waveData.sampleRate);

  final startTime = DateTime.now();
  _recognizer?.decode(stream!);
  var result = _recognizer?.getResult(stream!);

  final endTime = DateTime.now();
  final duration = endTime.difference(startTime).inMilliseconds;
  logger.i('Task duration: $duration milliseconds, data: ${result?.text}');
  stream?.free();
  return result?.text ?? 'BAD ASR';
}

[csukuangfj]

could you check that _recognizer.ptr is not 0?

Also, make sure you have called init sherpa onnx binding in the isolate.

[germes96]

Thanks. The solution was to init sherpa_onnx binding in the isolate. Now the ptr is good.