Turn your Android phone into a Bluetooth headset

Question

Suppose we have an Android root OS on a device that supports Bluetooth. Can we create an application that advertises itself as a Bluetooth speaker via Bluetooth A2DP?

If possible, any other device could connect to our Bluetooth server application and transmit any music / sound. This server application can then take the music stream and play it locally or even send it to other devices via Wi-Fi. This would theoretically provide a solution for several Bluetooth rooms.

Any idea how to achieve this? What should I start with?

Answer 1

It turns out that there is a very good and detailed answer to the question related to it.

Short answer: it is possible, but it requires a change in the configuration of the Android OS and some fairly low-level NDK development in order to uncover the role of A2DP Sink as the API to be used.

Thanks @BartPlatak for the pointer!