STEP_C1           822 third_party/libjpeg/jquant2.c     inc1 = inc1 * (2 * STEP_C1) + STEP_C1 * STEP_C1;
STEP_C1           845 third_party/libjpeg/jquant2.c 	xx1 += 2 * STEP_C1 * STEP_C1;