`startRecorder` doesn't seem to access Android native code

Version of flutter_sound

1.4.2 up to 2.0.0. Haven’t tested in previous versions.

flutter doctor

[v] Flutter (Channel stable, v1.12.13+hotfix.5, on Microsoft Windows [Version 10.0.16299.15], locale en-US) [v] Android toolchain - develop for Android devices (Android SDK version 29.0.0) [v] Android Studio (version 3.4) [v] VS Code, 64-bit edition (version 1.35.0) [v] Connected device (1 available)

Platforms you faced the error (IOS or Android or both?)

Android. Haven’t thoroughly tested in iOS, however it doesn’t record as well.

Expected behavior

Upon call of FlutterSound#startRecorder, future should resolve and FlutterSound.onRecorderStateChanged stream should be active.

Actual behavior

FlutterSound#startRecorder future doesnt resolve and will await forever because it gets stuck at _channel.invokeMethod('startRecorder'...); https://github.com/dooboolab/flutter_sound/blob/f0054692f83e5d3ab520ebe07ab4924b2bcaa1e5/lib/flutter_sound.dart#L170

Tested environment (Emulator? Real Device?)

• Emulators with Android SDK 28 and 29
• Samsung Galaxy S6 Edge (Android version 7.0)

Steps to reproduce the behavior

1. Create a new flutter project
2. Add flutter_sound: 2.0.0 in pubspec.yaml
3. Add code in main.dart such that it calls startRecorder (see code below)
4. Press button that calls startRecorder to start recording

main.dart:

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_sound/android_encoder.dart';
import 'package:flutter_sound/flutter_sound.dart';
import 'package:intl/intl.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  bool _isRecording = false;
  List<String> _path = [null, null, null, null, null, null, null];
  StreamSubscription _recorderSubscription;
  StreamSubscription _dbPeakSubscription;
  StreamSubscription _playerSubscription;
  FlutterSound flutterSound;

  String _recorderTxt = '00:00:00';
  double _dbLevel;

  @override
  void initState() {
    super.initState();
    flutterSound = FlutterSound();
    flutterSound.setSubscriptionDuration(0.01);
    flutterSound.setDbPeakLevelUpdate(0.8);
    flutterSound.setDbLevelEnabled(true);
  }

  static const List<String> paths = [
    'sound.aac', // DEFAULT
    'sound.aac', // CODEC_AAC
    'sound.opus', // CODEC_OPUS
    'sound.caf', // CODEC_CAF_OPUS
    'sound.mp3', // CODEC_MP3
    'sound.ogg', // CODEC_VORBIS
    'sound.wav', // CODEC_PCM
  ];
  t_CODEC _codec = t_CODEC.CODEC_AAC;

  void startRecorder() async {
    print('start recorder');
    try {
      String path = await flutterSound.startRecorder(
        paths[_codec.index],
        codec: _codec,
        sampleRate: 16000,
        bitRate: 16000,
        numChannels: 1,
        androidAudioSource: AndroidAudioSource.MIC,
      );
      print('startRecorder: $path');

      _recorderSubscription = flutterSound.onRecorderStateChanged.listen((e) {
        DateTime date = new DateTime.fromMillisecondsSinceEpoch(
            e.currentPosition.toInt(),
            isUtc: true);
        String txt = DateFormat('mm:ss:SS', 'en_GB').format(date);

        this.setState(() {
          this._recorderTxt = txt.substring(0, 8);
        });
      });
      _dbPeakSubscription =
          flutterSound.onRecorderDbPeakChanged.listen((value) {
        print("got update -> $value");
        setState(() {
          this._dbLevel = value;
        });
      });

      this.setState(() {
        this._isRecording = true;
        this._path[_codec.index] = path;
      });
    } catch (err) {
      print('startRecorder error: $err');
      setState(() {
        this._isRecording = false;
      });
    }
  }

  void stopRecorder() async {
    print('stop recorder');
    try {
      String result = await flutterSound.stopRecorder();
      print('stopRecorder: $result');

      if (_recorderSubscription != null) {
        _recorderSubscription.cancel();
        _recorderSubscription = null;
      }
      if (_dbPeakSubscription != null) {
        _dbPeakSubscription.cancel();
        _dbPeakSubscription = null;
      }
    } catch (err) {
      print('stopRecorder error: $err');
    }
    this.setState(() {
      this._isRecording = false;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Column(
          children: <Widget>[
            FlatButton(
              child: Text(_isRecording.toString()),
              onPressed: _isRecording ? stopRecorder : startRecorder,
            ),
            Text(_recorderTxt)
          ],
        ),
      ),
    );
  }
}

Thank you!

[Boehrsi]

Just checked the example project and it works. But as soon as I replace

String path = await flutterSound.startRecorder
      (
        paths[_codec.index],
        codec: _codec,
        sampleRate: 16000,
        bitRate: 16000,
        numChannels: 1,
        androidAudioSource: AndroidAudioSource.MIC,
      );

with

String path = await flutterSound.startRecorder(null);

nothing happens when pressing the recording button.It looks like some of the assumed default values aren’t valid on my device (Samsung S7 on Android 8.0.0).

[hyochan]

Just checked the example project and it works. But as soon as I replace

String path = await flutterSound.startRecorder
      (
        paths[_codec.index],
        codec: _codec,
        sampleRate: 16000,
        bitRate: 16000,
        numChannels: 1,
        androidAudioSource: AndroidAudioSource.MIC,
      );

with

String path = await flutterSound.startRecorder(null);

nothing happens when pressing the recording button.It looks like some of the assumed default values aren’t valid on my device (Samsung S7 on Android 8.0.0).

Thanks for trying out~! We’ve narrowed down the problem so I’ll look up at the weekend.