BOX_C0_SHIFT      670 jquant2.c        maxc0 = minc0 + ((1 << BOX_C0_SHIFT) - (1 << C0_SHIFT));
BOX_C0_SHIFT      881 jquant2.c        minc0 = (c0 << BOX_C0_SHIFT) + ((1 << C0_SHIFT) >> 1);