KonstaT
commented
1 day ago I can't reproduce such issue. Most likely you have some USB audio device connected in which case you're not even supposed to get audio output from the 3.5mm jack.
Just to be sure, please provide logcat and output of cat /proc/asound/cards and getprop | grep audio.
I've so far had success with audio output from 3.5mm audio jack on Raspberry pi 4 model B while using the android-13 branch. However when I upgraded to using android-14 I'm no longer getting any audio output from the 3.5mm audio jack. I've tested both the car (aosp_rpi4_car) and normal (aosp_rpi4-userdebug) version but neither have any audio on the 3.5mm jack. I am however able to get audio when I plug in a speaker via usb.
With the investigation I've done so far I can see that the audio_hal library for usb is being called (functions like "adev_open_output_stream" and "out_write" in "hardware/libhardware/modules/usbaudio/audio_hal.c") but the same functions in "audio_hw.c" in "device/brcm/rpi4/audio" is not called on android 14 like they are on android 13, which is my guess why the audio is audible in usb device but not 3.5mm jack on android 14.
I've also read in aosp documentation about how Audio HAL is moving from using HIDL to use AIDL instead for Audio HAL in android (https://source.android.com/docs/core/audio/aidl-implement) so I wonder if that could have anything to do with it, but I have no more specific evidence to suggest that.