 enum {
   SD_CHIP_SELECT = 4,
   APA106_DATA = 6,
+  SHIFT_REGISTER_CLOCK = 8,
+  SHIFT_REGISTER_LATCH = 9,
+  SHIFT_REGISTER_DATA = 10,
   SD_MISO = 11,
   SD_MOSI = 12,
   SD_CLK = 13,


      if (infile->isOpen()) {
        if (!infile->isDir() && !infile->isHidden() && !infile->isSystem()) {
#ifdef DEBUG
          char buf[13];
          infile->getName(buf, sizeof(buf));
          cout << F("\nOpened prev file: ") << buf;
#endif
          return;
        }

  }
}

void updateVideoIndexDisplay()
{
  static uint8_t last_index;
  if (curr_index == last_index) {
    return;
  }

  last_index = curr_index;
  digitalWrite(SHIFT_REGISTER_LATCH, LOW);
  shiftOut(SHIFT_REGISTER_DATA, SHIFT_REGISTER_CLOCK, LSBFIRST, last_index - 1);
  digitalWrite(SHIFT_REGISTER_LATCH, HIGH);

  cout << F("\nUpdated video index display to video number ") << (int16_t)last_index;
}

void nextFile()
{
  if (infile->isOpen()) {
