I've been able to play a mp3 over a PCM5102 DAC using the lib at https://github.com/earlephilhower/ESP8266Audio - works well. Should be pretty easy to play any supported format.
However I want to display VU values somewhere (whatever the output is, a LCD screen or LEDs). For this I supposed I need access to N samples and compute an average. The question is, how do I get access to the samples values ?
My code is something very close to https://github.com/earlephilhower/ESP82 ... SPIFFS.ino (I'm using LittleFS instead of SPIFFS).