flutter_voice_processor 1.0.10

A Flutter plugin that delivers audio buffers for real-time processing.

example/lib/main.dart

//
// Copyright 2020-2021 Picovoice Inc.
//
// You may not use this file except in compliance with the license. A copy of the license is located in the "LICENSE"
// file accompanying this source.
//
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
// an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
//

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

void main() {
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  bool _isButtonDisabled = false;
  bool _isProcessing = false;
  VoiceProcessor? _voiceProcessor;
  Function? _removeListener;
  Function? _removeListener2;
  Function? _errorListener;

  @override
  void initState() {
    super.initState();
    _initVoiceProcessor();
  }

  void _initVoiceProcessor() async {
    _voiceProcessor = VoiceProcessor.getVoiceProcessor(512, 16000);
  }

  Future<void> _startProcessing() async {
    this.setState(() {
      _isButtonDisabled = true;
    });

    _removeListener = _voiceProcessor?.addListener(_onBufferReceived);
    _removeListener2 = _voiceProcessor?.addListener(_onBufferReceived2);
    _errorListener = _voiceProcessor?.addErrorListener(_onErrorReceived);
    try {
      if (await _voiceProcessor?.hasRecordAudioPermission() ?? false) {
        await _voiceProcessor?.start();
        this.setState(() {
          _isProcessing = true;
        });
      } else {
        print("Recording permission not granted");
      }
    } on PlatformException catch (ex) {
      print("Failed to start recorder: " + ex.toString());
    } finally {
      this.setState(() {
        _isButtonDisabled = false;
      });
    }
  }

  void _onBufferReceived(dynamic eventData) {
    print("Listener 1 received buffer of size ${eventData.length}!");
  }

  void _onBufferReceived2(dynamic eventData) {
    print("Listener 2 received buffer of size ${eventData.length}!");
  }

  void _onErrorReceived(dynamic eventData) {
    String errorMsg = eventData as String;
    print(errorMsg);
  }

  Future<void> _stopProcessing() async {
    this.setState(() {
      _isButtonDisabled = true;
    });

    await _voiceProcessor?.stop();
    _removeListener?.call();
    _removeListener2?.call();
    _errorListener?.call();

    this.setState(() {
      _isButtonDisabled = false;
      _isProcessing = false;
    });
  }

  void _toggleProcessing() async {
    if (_isProcessing) {
      await _stopProcessing();
    } else {
      await _startProcessing();
    }
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Voice Processor'),
        ),
        body: Center(
          child: _buildToggleProcessingButton(),
        ),
      ),
    );
  }

  Widget _buildToggleProcessingButton() {
    return new ElevatedButton(
      onPressed: _isButtonDisabled ? null : _toggleProcessing,
      child: Text(_isProcessing ? "Stop" : "Start",
          style: TextStyle(fontSize: 20)),
    );
  }
}