Internal audio becomes silent when mixing microphone + game audio

[noho501]

Hi @pedroSG94 ,

I'm facing a strange issue and would like to ask if you've ever seen something similar.

Environment

• RootEncoder: latest version
• Android 16
• Device: Infinix Note 60 Pro
• Game: Call of Duty®: Mobile (CODM)

Problem

There are two scenarios:

1. Internal (in-game) audio only → ✅ Works correctly.
2. Microphone + Internal audio (Mix mode) → ❌ Internal game audio disappears, only the microphone is captured.

Interestingly, this issue only happens with COD Mobile on this specific device.

• Other games work correctly.
• I tested the same device with the Glip app, and it can capture both microphone and game audio without any problem.

I modified RootEncoder to add extensive debug logging.

The logs show that:

• MediaProjection is available.
• AudioPlaybackCapture is enabled.
• Both AudioRecord instances are successfully created.
• AudioRecord.startRecording() succeeds.
• AudioRecord.read() for internal audio always returns a valid size (8192).
• No ERROR_BAD_VALUE or ERROR_DEAD_OBJECT is returned.
• Recording state remains RECORDSTATE_RECORDING.

However, the internal audio buffer is always silent:

• internalRms = 0
• internalSilent = true

while the microphone has valid audio data.

I also tried:

• Reversing the startRecording() order (Internal → Microphone).
• Adding a 300 ms delay before starting the microphone.

Unfortunately, the behavior is exactly the same.

Have you ever encountered a similar issue?

Do you know of any device-specific compatibility issues with AudioPlaybackCapture or AudioRecord that could explain why another app (Glip) can capture both microphone and game audio, while RootEncoder always receives silent PCM for the internal audio?

I've attached the debug log for reference.

Any suggestions or ideas would be greatly appreciated.

Thank you!

Infinix-X6878.log

[pedroSG94]

Hello,

No, I never see that. My only suspicious are the flags here:

RootEncoder/encoder/src/main/java/com/pedro/encoder/input/sources/audio/InternalAudioSource.kt

Line 69 in 6e41ffc

.addMatchingUsage(AudioAttributes.USAGE_MEDIA)

[pedroSG94]

One thing that you can try. Go here:

RootEncoder/encoder/src/main/java/com/pedro/encoder/input/audio/MicrophoneManager.java

Line 178 in 6e41ffc

boolean micResult = createMicrophone(audioSource, sampleRate, isStereo, echoCanceler, noiseSuppressor);

Try init first internal audio and then microphone and check if the result is the same.

[noho501]

Thank you! I'll give it a try and share the results with you.

[pedroSG94]

Also try with this branch:
#2132

Using the microphone source MIC, VOICE_COMMUNICATION and VOICE_RECOGNITION.
Also, disable echoCanceler and noiseSuppresor

[noho501]

Okay, Thank you. I will try

[noho501]

@pedroSG94
Unfortunately, it’s still not working. We’ve tried all of the suggested solutions, including your PR, as well as testing each audio source individually, but we’re still seeing the same issue.

debug.log

[pedroSG94]

Hello,

Are you using AccessibilityService?
https://github.com/pedroSG94/RootEncoder/wiki/Recording-audio-while-other-app-use-the-microphone

[noho501]

We tested both scenarios—with and without AccessibilityService—and the issue occurs in both cases.

These are some of the devices that our users have reported as being affected. On other devices, everything works correctly.

• Infinix Note 60 Pro — Android 16
• Vivo iQOO Neo7 Pro (Vivo I2217) — Android 16
• Vivo iQOO 13 (Vivo I2401) — Android 16
• Vivo iQOO Z10 Turbo Pro (Vivo V2453A) — Android 16

[pedroSG94]

Hello,

Ok, this feels like a problem with the audio policy in certains OEMs.
This will be a pain but we need logs to know the way Glip is working and try emulate it. I need this:

1 - Connect your device that produce the problem to your PC
2 - Clear logcat -> adb logcat -c
2 - Start to get full device logs -> adb logcat -b all -v threadtime > rootencoder_audio.txt
3 - Open your app stream based on rootencoder and start record audio to reproduce your problem.
4 - Open other terminal WHILE the problem is happening (the first terminal running adb logcat -b ... must be still getting logs)
5 - Execute this commands:
adb shell dumpsys audio > dumpsys_audio.txt
adb shell dumpsys media.audio_policy > dumpsys_policy.txt
adb shell dumpsys media.audio_flinger > dumpsys_flinger.txt
6 - Stop terminal of the step 2

Repeat using Glip app to compare with your app.
After that, share me all files.

[noho501]

I don't have access to a similar device because this model isn't available in my region, so I can't reproduce the issue myself.

I asked the user to livestream two games on the same device and save the debug logs:

• Blood Strike (works)
• Call of Duty: Mobile (doesn't work)

Could you take a look at the attached logs and see if you notice anything unusual?
Bloodstrike.txt
CODM.txt

[pedroSG94]

Hello,

That logs don't provide a way to know how glip works to avoid audio policy problems.
Are you able to share to the user an app with custom logs to provide more info?

Try add this to your logs:

  fun getAudioInfo(context: Context): String {
    val audioManager = context.applicationContext.getSystemService(Context.AUDIO_SERVICE) as AudioManager
    var info = ""
    audioManager.activeRecordingConfigurations.forEachIndexed { i, c ->
      val kind = if (c.clientAudioSource == MediaRecorder.AudioSource.REMOTE_SUBMIX) "INTERNAL" else "MIC"
      info += "#$i kind=$kind source=${sourceName(c.clientAudioSource)} " +
          "silenced=${c.isClientSilenced} " +
          "sampleRate=${c.format.sampleRate} channels=${c.format.channelCount} " +
          "device=${c.audioDevice?.type ?: "none"}\n"
    }
    return info
  }

If possible, indicate the user stream using the app.
Also, try get this logs in background while Glip is recording to get info about it.

This way we can confirm that the OEM block internal recording and if Glip is able to skip this block or is using a trick. Also, we will know the Glip audio config used and try to emulate it