android 12 AudioManager.setCommunicationDevice not working - webview

Question

I'm building a voice call app for android using WebView. Everything works fine except in android 12, I can not use the earpiece (or even wired headphones in some phones) for audio out. The audio is always playing through loudspeaker. And some of the users reported that they can hear the internal ring(Which is a MediaPlayer object) in earpiece, but once the call answered it switches to loudspeaker. And the worst part is, I'm not able to reproduce this issue as this works perfectly on all my test phones (android 12).
My code,
private fun setAudioOutDevice(target: AudioDeviceInfo?) {
//need some delay for bluetooth sco
var audioChangeDelay: Long = 15
if (System.currentTimeMillis() - lastAudioChangeTime <= 300) audioChangeDelay = 300
Handler(Looper.getMainLooper()).postDelayed({
var targetDevice = target
//no device selected. scan all output devices and select one automatically
if (targetDevice == null) {
var wiredHeadsetDevice: AudioDeviceInfo? =
getAudioDevice(AudioDeviceInfo.TYPE_WIRED_HEADSET)
if (wiredHeadsetDevice == null) wiredHeadsetDevice =
getAudioDevice(AudioDeviceInfo.TYPE_WIRED_HEADPHONES)
val bluetoothDevice: AudioDeviceInfo? =
getAudioDevice(AudioDeviceInfo.TYPE_BLUETOOTH_SCO)
val speakerDevice: AudioDeviceInfo? =
getAudioDevice(AudioDeviceInfo.TYPE_BUILTIN_SPEAKER)
val earpieceDevice: AudioDeviceInfo? =
getAudioDevice(AudioDeviceInfo.TYPE_BUILTIN_EARPIECE)
//update global variables
isBluetoothAvailable = bluetoothDevice != null
//disable BT if wired headset connected
if (wiredHeadsetDevice != null) isBluetoothAvailable = false
//choose an output device
targetDevice =
if (callType == videoCall && bluetoothDevice == null && wiredHeadsetDevice == null) speakerDevice
else if (callType == videoCall && wiredHeadsetDevice == null && !isBluetoothAudioEnabled) speakerDevice
else wiredHeadsetDevice
?: if (isBluetoothAvailable && isBluetoothAudioEnabled && bluetoothDevice != null) bluetoothDevice
else earpieceDevice ?: speakerDevice
//no earpiece
if (earpieceDevice == null) {
setBigStatus("Unable to access Earpiece", 0)
}
}
//set output device
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
var success = false
try {
// am.clearCommunicationDevice()
if (targetDevice != null) success = am.setCommunicationDevice(targetDevice)
} catch (e: Exception) {
debugMsg(e.message.toString())
}
if (!success) setBigStatus(getString(R.string.unable_to_set_audio), 0)
}
//older devices, android 11 or lower
else {
am.mode = AudioManager.MODE_IN_COMMUNICATION
if (targetDevice?.type == AudioDeviceInfo.TYPE_BUILTIN_SPEAKER) {
changeSco(false)
am.isSpeakerphoneOn = true
} else {
if (targetDevice?.type == AudioDeviceInfo.TYPE_BLUETOOTH_SCO) changeSco(true)
else changeSco(false)
am.isSpeakerphoneOn = false
}
}
}, audioChangeDelay)
}
private fun changeSco(enable: Boolean) {
if (enable) {
am.startBluetoothSco()
am.isBluetoothScoOn = true
} else {
am.stopBluetoothSco()
am.isBluetoothScoOn = false
}
}
private fun getAudioDevice(type: Int): AudioDeviceInfo? {
val audioDevices = am.getDevices(AudioManager.GET_DEVICES_OUTPUTS)
for (deviceInfo in audioDevices) {
if (type == deviceInfo.type) return deviceInfo
}
return null
}
The above code is working fine on android 11 and lower and even on some android 12 phones. How can I make this work on all devices?
There is an issue tracker here. But it seems that nobody is working on it.
UPDATE Today I tried it on a pixel 3a and it gives mixed behaviors. Sometimes it plays on the earpiece or wired headset but for most of the calls, it plays on the loudspeaker only. And even if I don't set any mode, it automatically switches to MODE_IN_COMMUNICATION right after the stream starts. I think, android is trying to figure out the proper mode by itself and that messing with my app logic.