Regarding the problem of playing the same song over and over again when playing the playlist of SPRESENSE,

static void update_alias_file(const char*dirname)
{
  char fname [64];
  File file;
  uint32_t size;
  uint32_t*buffer;
  uint32_ti;

  sprintf(fname, "%s/alias_list_alltrack.bin", dirname);

  /* Read alias file into buffer*/
  file=File(fname,FILE_READ);
  size = file.size();
  buffer=(uint32_t*)malloc(size);
  file.read(buffer,size);
  file.close();

  /* Create the correct alias file*/
  if(buffer[1]==0x0){
    unlink(fname);
    file=File(fname,FILE_WRITE);
    for(i=0;i<size/4;i+=2){
      file.write(uint8_t*)&buffer[i], 4);
    }
    file.close();
  }
  free(buffer);
  thePlaylist.select(Playlist::ListTypeAllTrack, "");
}

success=thePlaylist.init(playlist_dirname);
  if(!success){
    printf("ERROR: no exist playlist file%s/TRACK_DB.CSV\n",
           playlist_dirname);
    while(1);
  }

  update_alias_file(playlist_dirname); // ★★★ Add