STA013 MP3 Decoder

ST has a chip able to process MP3 data and output the processed data in many formats (including I2S and also direct DAC output)

An interesting documentation about it:

https://www.compuphase.com/mp3/sta013.htm

How to install NuttX on Teensy 4.0/4.1 board

./teensy_loader_cli -w -v --mcu=TEENSY40 ~/nuttx/incubator-nuttx/nuttx.hex 
Teensy Loader, Command Line, Version 2.2
Read "/home/bashton/nuttx/incubator-nuttx/nuttx.hex": 73803 bytes, 3.6% usage
Found HalfKay Bootloader
Programming...................................................................
Booting