RBITS
r = i & ((1 << RBITS) - 1);
g = (i >> (RBITS - 4)) & ((1 << GBITS) - 1);
b = (i >> (RBITS + GBITS - 8)) & ((1 << BBITS) - 1);
VIDC_COL(r << (8 - RBITS) | r >> (2 * RBITS - 8),