setVolume values / question

[h1aji]

I was comparing setVolume

ESP_VS1053_Library/src/VS1053.cpp

Lines 189 to 218 in f501eb7

	void VS1053::setVolume(uint8_t vol) {
	// Set volume. Both left and right.
	// Input value is 0..100. 100 is the loudest.
	uint8_t valueL, valueR; // Values to send to SCI_VOL
	curvol = vol; // Save for later use
	valueL = vol;
	valueR = vol;
	if (curbalance < 0) {
	valueR = max(0, vol + curbalance);
	} else if (curbalance > 0) {
	valueL = max(0, vol - curbalance);
	}
	valueL = map(valueL, 0, 100, 0xFE, 0x00); // 0..100% to left channel
	valueR = map(valueR, 0, 100, 0xFE, 0x00); // 0..100% to right channel
	writeRegister(SCI_VOL, (valueL << 8) | valueR); // Volume left and right
	}
	void VS1053::setBalance(int8_t balance) {
	if (balance > 100) {
	curbalance = 100;
	} else if (balance < -100) {
	curbalance = -100;
	} else {
	curbalance = balance;
	}
	}

with the code from Adafruit

void Adafruit_VS1053::setVolume(uint8_t left, uint8_t right) {
  // accepts values between 0 and 255 for left and right.
  uint16_t v;
  v = left;
  v <<= 8;
  v |= right;

  noInterrupts(); // cli();
  sciWrite(VS1053_REG_VOLUME, v);
  interrupts(); // sei();
}

And found that maximum value for setVolume is 254. So, which value would be correct in this case?

[Dr-Dawg]

The map function maps the values from 0-100 to 0-254 (= 0xFE ), see
https://www.arduino.cc/reference/de/language/functions/math/map/
So basically both funtions do the same. Using a range from 0-100 is of course coarser, but imho is more intuitive and does not really make a difference.