Tau: [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: PlatformException(startRecorder, startRecorder, Failure to start recorder, null)

[AbdallahLabib]

This error happens to me even if I make toFile: 'flutter_example.aac' as in the package example ..
here is my log:

I/flutter (15733): ---> openRecorderCompleted: true
I/flutter (15733): <--- openRecorderCompleted: true
I/flutter (15733): <--- openAudioSession
I/flutter (15733): FS:<--- openAudioSession
I/flutter (15733): ********* record outputpath : /data/user/0/com.q8intouch.hareem/cache/c34s2.aac
I/flutter (15733): FS:---> startRecorder
I/flutter (15733): FS:---> _startRecorder.
I/flutter (15733): Calling instance.startRecorder
E/MediaRecorder(15733): start failed: -38
E/SoundMediaRecorder(15733): Exception:
E/SoundMediaRecorder(15733): java.lang.IllegalStateException
E/SoundMediaRecorder(15733):    at android.media.MediaRecorder.start(Native Method)
E/SoundMediaRecorder(15733):    at com.dooboolab.TauEngine.q.a(:182)
E/SoundMediaRecorder(15733):    at com.dooboolab.TauEngine.m.r(:239)
E/SoundMediaRecorder(15733):    at f.e.b.e.M(:259)
E/SoundMediaRecorder(15733):    at f.e.b.f.onMethodCall(:118)
E/SoundMediaRecorder(15733):    at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(:233)
E/SoundMediaRecorder(15733):    at io.flutter.embedding.engine.dart.DartMessenger.handleMessageFromDart(:85)
E/SoundMediaRecorder(15733):    at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(:818)
E/SoundMediaRecorder(15733):    at android.os.MessageQueue.nativePollOnce(Native Method)
E/SoundMediaRecorder(15733):    at android.os.MessageQueue.next(MessageQueue.java:325)
E/SoundMediaRecorder(15733):    at android.os.Looper.loop(Looper.java:142)
E/SoundMediaRecorder(15733):    at android.app.ActivityThread.main(ActivityThread.java:6494)
E/SoundMediaRecorder(15733):    at java.lang.reflect.Method.invoke(Native Method)
E/SoundMediaRecorder(15733):    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
E/SoundMediaRecorder(15733):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
E/MediaRecorder(15733): resume called in an invalid state: 0
E/MediaRecorder(15733): stop called in an invalid state: 0
D/SoundMediaRecorder(15733): Error Stop Recorder
E/FlautoRecorder(15733): Error starting recordernull
E/flutter (15733): [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: PlatformException(startRecorder, startRecorder, Failure to start recorder, null)
E/flutter (15733): #0      StandardMethodCodec.decodeEnvelope
package:flutter/…/services/message_codecs.dart:597
E/flutter (15733): #1      MethodChannel._invokeMethod
package:flutter/…/services/platform_channel.dart:158
E/flutter (15733): <asynchronous suspension>
E/flutter (15733): #2      FlutterSoundRecorder._startRecorder
package:flutter_sound/public/flutter_sound_recorder.dart:662
E/flutter (15733): <asynchronous suspension>
E/flutter (15733): #3      FlutterSoundRecorder.startRecorder.<anonymous closure>
package:flutter_sound/public/flutter_sound_recorder.dart:584
E/flutter (15733): <asynchronous suspension>
E/flutter (15733): #4      BasicLock.synchronized
package:synchronized/src/basic_lock.dart:33
E/flutter (15733): <asynchronous suspension>
E/flutter (15733): #5      FlutterSoundRecorder.startRecorder
package:flutter_sound/public/flutter_sound_recorder.dart:583
E/flutter (15733): <asynchronous suspension>

[mhstoller]

Can you provide the exact code you're using to open the audio session and start the recorder? Also can you provide the output of flutter pub deps | grep flutter_sound?

[Larpoux]

What are your parameters to openAudioSession() and startRecorder() ?

[AbdallahLabib]

functions:

import 'dart:io';
import 'dart:math';

import 'package:flutter_sound/public/flutter_sound_recorder.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:path_provider/path_provider.dart' as pathProvider;

class SoundRecorder {
  FlutterSoundRecorder _audioRecorder;
  bool _isRecorderInitialized = false;

  bool get isRecording => _audioRecorder.isRecording;

  String _chars =
      'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz1234567890';
  Random _rnd = Random();
  String getRandomString(int length) => String.fromCharCodes(Iterable.generate(
      length, (_) => _chars.codeUnitAt(_rnd.nextInt(_chars.length))));

  Future init() async {
    _audioRecorder = FlutterSoundRecorder();
    final status = await Permission.microphone.request();
    if (status != PermissionStatus.granted) {
      throw RecordingPermissionException(
          'Microphone permission is not granted');
    }
    await _audioRecorder.openAudioSession();
    _isRecorderInitialized = true;
  }

  Future dispose() async {
    _audioRecorder = FlutterSoundRecorder();
    await _audioRecorder.closeAudioSession();
    _isRecorderInitialized = false;
  }

  Future _record() async {
    if (!_isRecorderInitialized) return;
    Directory tempDir = await pathProvider.getTemporaryDirectory();
    String outputPath = '${tempDir.path}/${getRandomString(5)}.aac';
    print('********* record outputpath : $outputPath');
    await _audioRecorder.startRecorder(toFile: outputPath);
  }

  Future _stop() async {
    if (!_isRecorderInitialized) return;
    await _audioRecorder.stopRecorder();
    _audioRecorder = null;
  }

  Future toggleRecorder() async {
    if (_audioRecorder.isStopped) {
      await _record();
    } else {
      await _stop();
    }
  }
}

widget:

class _VoiceoverPageState extends State<VoiceoverPage> {
  final recorder = SoundRecorder();

  @override
  void initState() {
    super.initState();
    recorder.init();
  }

  @override
  void dispose() {
    recorder.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final width = MediaQuery.of(context).size.width;
    final height = MediaQuery.of(context).size.height;

    return Scaffold(
 body: Column(children: [buildRecordingButton()]),);
}

Widget buildRecordingButton() {
    final isRecording = recorder.isRecording;
    return GestureDetector(
      onTap: () async {
        await recorder.toggleRecorder();
        setState(() {});
      },
      child: Container(
        width: 75,
        height: 75,
        decoration: BoxDecoration(
          shape: BoxShape.circle,
          color: Colors.white,
        ),
        child: Center(
            child: Container(
          margin: EdgeInsets.all(25),
          decoration: BoxDecoration(
            shape: isRecording ? BoxShape.rectangle : BoxShape.circle,
            color: Colors.red,
          ),
        )),
      ),
    );
  }}

[AbdallahLabib]

this is flutter pub deps | grep flutter_sound

flutter_sound 8.1.9
|   |-- flutter...
|   |-- flutter_sound_platform_interface 8.1.9
|   |   |-- flutter...
|   |   |-- meta...
|   |   '-- plugin_platform_interface...
|   |-- flutter_sound_web 8.1.9
|   |   |-- flutter...
|   |   |-- flutter_sound_platform_interface...
|   |   |-- flutter_web_plugins...
|   |   |-- js...
|   |   '-- meta...
|   |-- flutter_spinkit...
|   |-- logger 1.0.0
|   |-- path...
|   |-- path_provider...
|   |-- provider...
|   |-- recase 4.0.0
|   |-- synchronized 3.0.0
|   '-- uuid...

[Larpoux]

I do not see any problem in your code.
Maybe you can try to specify the Codec AAC in start recorder : the recorder do not use the file extension (xxx.aac).

But I would be surprised if this solve your problem : AAC is the default codec, I think.

@mhstoller : do you see any problem in Abdallah's code ?

[mhstoller]

No, actually I've run it on my device and it gets past the startRecorder portion on my phone.

What device and android version are you using for development @AbdallahLabib ?

I/flutter ( 5167): ********* record outputpath : /data/user/0/com.example.recorder_problem/cache/aIy3i.aac
I/flutter ( 5167): FS:---> startRecorder
I/flutter ( 5167): FS:---> _startRecorder.
I/flutter ( 5167): Calling instance.startRecorder
I/flutter ( 5167): ---> startRecorderCompleted: true
I/flutter ( 5167): <--- startRecorderCompleted: true
I/flutter ( 5167): FS:<--- _startRecorder.
I/flutter ( 5167): FS:<--- startRecorder
2
I/flutter ( 5167): FS:---> stopRecorder
I/flutter ( 5167): FS:---> stop
I/flutter ( 5167): ---> stopRecorderCompleted: true
I/flutter ( 5167): <---- stopRecorderCompleted: true
I/flutter ( 5167): FS:<--- stop
I/flutter ( 5167): FS:<--- stopRecorder : /data/user/0/com.example.recorder_problem/cache/aIy3i.aac

[AbdallahLabib]

Thanks guys, the problem was from the emulator .. I can't record from it .. when I tried it from phone it worked very well .. Thanks for your fast reply

[Larpoux]

Good to hear that you solved your problems.
Thanks to @mhstoller who spent time on this 💯