al_get_pixel_size - Man Page

#include <allegro5/allegro.h>

int al_get_pixel_size(int format)

Return the number of bytes that a pixel of the given format occupies. For blocked pixel formats (e.g. compressed formats), this returns 0.

ALLEGRO_PIXEL_FORMAT(3), al_get_pixel_format_bits(3)

al_get_pixel_format_bits(3).