AudioRecorder produces empty or corrupted .opus / .mp4 files with duration 0s (possible premature stop or flush issue) after updating from 5.2.0 to 6.1.2

[MazenxELGayar]

🐛 AudioRecorder Produces 0-Second (Corrupted) Recordings after updating from 5.2.0 to 6.1.2

When using the AudioRecorder from the record package inside a Flutter app, the resulting recorded file occasionally has a 0-second duration and appears to be corrupted.

The encoder initializes successfully (AAC LC, Opus, and WAV all tested), but the output file contains only headers and no valid audio data.

---

🧩 Steps to Reproduce

1. Create and start the recorder:

   final filePath =
       '${tempDir.path}/temp.${DateTime.now().millisecondsSinceEpoch}.wav';
   final recorder = AudioRecorder();
   await recorder.start(
     RecordConfig(encoder: AudioEncoder.opus),
     path: filePath,
   );

2. Wait a few seconds.

3. Stop the recording:

   await recorder.stop();

4. Attempt to play or inspect the recorded file — it’s very small (~6–8 KB) and reports 0s duration.

---

✅ Expected Behavior

The file should contain valid audio data of the correct (non-zero) duration.

---

❌ Actual Behavior

• Encoder logs indicate successful initialization:

  D/CCodec (17780): allocate(c2.android.opus.encoder)
  I/CCodecConfig(17780): query failed after returning 9 values (BAD_INDEX)
  D/CCodecBufferChannel: [c2.android.opus.encoder#56] start: updating output delay 0
  

• File path is correctly created:

  /data/user/0/com.doctor.voice.patientDev/cache/temp.1760713610632.opus
  

• But playback duration logs show:

  ! Audio duration is too small 0s — possibly corrupted
  

---

🧠 Environment

Key	Value
Flutter SDK	3.35.4
Android	12
Device	Poco X3 NFC
Permissions	Microphone (granted)
Encoders Tested	Opus, AAC LC, WAV

Dependencies:

record: ^6.1.2
record_android: ^1.4.3
just_audio: ^0.10.5
audio_session: ^0.2.2
audioplayers: ^6.5.1
voice_message_package: ^2.2.1

Old Dependencies:

record: ^5.2.0
record_android: ^1.3.0
audioplayers: ^6.1.0
just_audio: ^0.10.3
audio_session: ^0.2.2
voice_message_package: ^2.2.1

---

🧱 Relevant Code (Simplified)

abstract class BaseRecordingCubit extends Cubit<BaseRecordingState> {
  final AudioRecorder recorder = AudioRecorder();
  String? filePath;

  Future<void> startRecording() async {
    if (await recorder.hasPermission()) {
      filePath =
          '${(await getTemporaryDirectory()).path}/temp.${DateTime.now().millisecondsSinceEpoch}.opus';
      await recorder.start(
        RecordConfig(encoder: AudioEncoder.opus),
        path: filePath!,
      );
    }
  }

  Future<void> stopRecording() async {
    if (await recorder.isRecording()) {
      await recorder.stop();
    }
  }
}

---

📋 Logs

V/MediaPlayer(21075): resetDrmState:  mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
V/MediaPlayer(21075): cleanDrmObj: mDrmObj=null mDrmSessionId=null
D/AudioRecord(21075): set(): inputSource 0, sampleRate 44100, format 0x1, channelMask 0xc, frameCount 3552, notificationFrames 0, sessionId 0, transferType 0, flags 0, attributionSource AttributionSourceState{pid: -1, uid: 11052, packageName: com.doctor.voice.patientDev, attributionTag: (null), token: , renouncedPermissions: [], next: []}uid -1, pid -1,isIsolated:0
D/AudioManager(21075): dispatching onAudioFocusChange(-1) to android.media.AudioManager@9ec5224com.llfbandit.record.record.recorder.AudioRecorder$$ExternalSyntheticLambda0@4eb93a1
V/MediaPlayer(21075): resetDrmState:  mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
V/MediaPlayer(21075): cleanDrmObj: mDrmObj=null mDrmSessionId=null
V/MediaPlayer(21075): resetDrmState:  mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
V/MediaPlayer(21075): cleanDrmObj: mDrmObj=null mDrmSessionId=null
V/MediaPlayer(21075): resetDrmState:  mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
V/MediaPlayer(21075): cleanDrmObj: mDrmObj=null mDrmSessionId=null
V/MediaPlayer(21075): resetDrmState:  mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
V/MediaPlayer(21075): cleanDrmObj: mDrmObj=null mDrmSessionId=null
V/MediaPlayer(21075): resetDrmState:  mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
V/MediaPlayer(21075): cleanDrmObj: mDrmObj=null mDrmSessionId=null
V/MediaPlayer(21075): resetDrmState:  mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
V/MediaPlayer(21075): cleanDrmObj: mDrmObj=null mDrmSessionId=null

[MazenxELGayar]

Fixed by switching back to version 5.2.1

[llfbandit]

Please no ai shit and respect the bug report template.