STEP_C2           823 third_party/libjpeg/jquant2.c     inc2 = inc2 * (2 * STEP_C2) + STEP_C2 * STEP_C2;
STEP_C2           840 third_party/libjpeg/jquant2.c 	  xx2 += 2 * STEP_C2 * STEP_C2;