Example of MP3 Play for M5Stack Core2

PlayMP3FromSDToDAC.ino

#pragma mark - Depend ESP8266Audio and ESP8266_Spiram libraries
/* 
cd ~/Arduino/libraries
git clone https://github.com/earlephilhower/ESP8266Audio
git clone https://github.com/Gianbacchio/ESP8266_Spiram
*/


#include <M5Core2.h>
#include <driver/i2s.h>
#include <WiFi.h>
#include "AudioFileSourceSD.h"
#include "AudioFileSourceID3.h"
#include "AudioGeneratorMP3.h"
#include "AudioOutputI2S.h"


AudioGeneratorMP3 *mp3;
AudioFileSourceSD *file;
AudioOutputI2S *out;
AudioFileSourceID3 *id3;

#define OUTPUT_GAIN 10

void setup()
{
  M5.begin();
  M5.Axp.SetSpkEnable(true);

  WiFi.mode(WIFI_OFF); 
  delay(500);
  
  M5.Lcd.setTextFont(2);
  M5.Lcd.printf("Sample MP3 playback begins...\n");
  Serial.printf("Sample MP3 playback begins...\n");

  // pno_cs from https://ccrma.stanford.edu/~jos/pasp/Sound_Examples.html
  file = new AudioFileSourceSD("/mp3/chikichiki.mp3");
  id3 = new AudioFileSourceID3(file);
  out = new AudioOutputI2S(0, 0); // Output to builtInDAC
  out->SetPinout(12, 0, 2);
  out->SetOutputModeMono(true);
  out->SetGain((float)OUTPUT_GAIN/100.0);
  mp3 = new AudioGeneratorMP3();
  mp3->begin(id3, out);
}

void loop()
{
  if (mp3->isRunning()) {
    if (!mp3->loop()) mp3->stop();
  } else {
    Serial.printf("MP3 done\n");
    delay(1000);
  }
}

Sure this works? Cant get any results... File was uploaded correctly to SPIFFS.

This is for SD cards, not SPIFFS.

use AudioFileSourceSPIFFS.

You need to rewrite the SPIFFS part. Please refer to here.

Perhaps you also need to add the following line.

SPIFFS.begin();