Comment on How to use phone microphone with Bluetooth FM transmitter?
ruffsl@programming.dev 10 months agoA while back, I tried looking into what it would take to modify Android to disable Bluetooth microphones for wireless headsets, allowing for call audio to be streamed via regular AAC or aptX, and for the call microphone to be captured from the phones internal mic. This would prevent the bit rate for call audio in microphone being effectively halved when using the ancient HFP/HSP Bluetooth codecs, instead allowing for the same call quality as when using a wired headset. This would help when multitasking with different audio sources, such as listening to music while hanging out on discord, without the music being distorted from the lower bit rate of HFP/HSP. This would also benefit regular VoLTE, as the regular call audio quality already exceeds that of legacy Bluetooth headset profiles.
Although, I didn’t manage to tease apart the mechanics of the audio policy configuration files used by the source Android project, given the sparse documentation and vague commit history.
I’d certainly be fine with the awkwardness of holding up and speaking to my phone as if it was in speaker mode, but listening to the call over wireless headphones, in order to improve or double the audio quality. Always wondered what these audio policies fall back to when a Bluetooth device doesn’t have a headset profile, but it’s almost impossible to find high quality consumer grade Bluetooth headphones without a microphone nowadays.