SHIFT_INV_COL      34 libavcodec/ps2/idct_mmi.c #define SHIFT_INV_COL   (1 + BITS_INV_ACC)
SHIFT_INV_COL      51 libavcodec/x86/idct_mmx_xvid.c #define SHIFT_INV_COL   (1 + BITS_INV_ACC) //6