Bluetooth Call Audio not audible in RPI4 with Android Automotive OS

[vijay anand]

Hello,

Trying to perform a BT call using RPI4 with "Android Automotive OS version:11", but facing a issue in call audio stream.

Procedure
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1.Followed Pontus Hanssen Github for cloning AOSP 11(Automotive OS)code and flashed to RPi4,
Reference link: https://github.com/PontusHanssen/device_arpi_rpi4/

2.In RPI4, Connect phone via BT  is successful and able to place/ make /receive a call.
3. Able to play  audio files stored internally and A2DP audio also  heard properly in Wired Headset, but on-going call audio is not heard.

Issue
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1. Call audio of On-going call is not heard/syncing with devices(headphones/wired_headset) connected with RPI4.

Support
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Need support on the below queries.
1.Does call_scenarios handling code implemented in Hardware level(Audio_HAL of RPi4)?
2.Does RPi4 board support on-going call audio streaming?
If yes, please suggest the procedure and reference to proceed.
3.Will RPi4 board support only voice_Playback,
or will support both Voice_Playback and Voice_Capture(parameters to enable ALSA pcm_open(), pcm_read(), pcm_write()).