The ESP32 Microcontroller from Espressif provides a Bluetooth A2DP functionality that can receive sound data e.g. from your Mobile Phone or send it e.g. to Bluetooth Speakers. I am providing a simple API for this in my ESP-A2DP project.
Most users are using this as library in the Arduino IDE or sometimes in PlatformIO.
Quite some time ago I made the project independent of the Arduino API, and now I took up the task to test it using the Espressif IDF.
A detailed description how to use the project as IDF Component can be found here.