Supported codecs:

• AAC
• aptX[-LL/-HD]
• LDAC
• Opus 05 (PipeWire)
• LC3plus HR

The original ESP32-WROOM is the only ESP32 chip that supports Bluetooth A2DP.

The AAC codec requires PSRAM. It will only work on ESP32 boards such as WROVER or ESP32-CAM. The decoder requires a lot of memory. The serial flash and PSRAM must be run at 80Mhz in order to decode fast enough. Set the CPU frequency to 240Mhz. See sdkconfig.defaults for the required configurations.

Use v5.1.4-a2dp-codecs branch from https://github.com/cfint/esp-idf

Add additional codecs to to components/bt/host/bluedroid/external/ in esp-idf.

• master branch @ https://github.com/cfint/libfreeaptx-esp
  • Add submodule to components/bt/host/bluedroid/external/libfreeaptx
• idf_component branch @ https://github.com/cfint/arduino-fdk-aac
  • Add submodule to components/bt/host/bluedroid/external/arduino-fdk-aac

Build this project as you would an esp-idf project.

The bluetooth stack on Linux keeps a cache of the bluetooth codec configurations per device. If an A2DP sink changes its list of codecs then the cache needs to be cleared. "Forget" the ESP32 bluetooth device and pair it again to re-enumerate the list of codecs. The cache is located at /var/lib/bluetooth/<FF:FF:FF:FF:FF:FF>/cache/<AA:AA:AA:AA:AA:AA>. Where <FF:FF:FF:FF:FF:FF> is the mac address of the bluetooth device on your computer. <AA:AA:AA:AA:AA:AA> is the mac address of the ESP32 bluetooth device.