static void deinterlace_line_inplace_c(uint8_t *lum_m4, uint8_t *lum_m3,
                                       uint8_t *lum_m2, uint8_t *lum_m1,
                                       uint8_t *lum, int size)
{
    const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
    int sum;

    for(;size > 0;size--) {
        sum = -lum_m4[0];
        sum += lum_m3[0] << 2;
        sum += lum_m2[0] << 1;
        lum_m4[0]=lum_m2[0];
        sum += lum_m1[0] << 2;
        sum += -lum[0];
        lum_m2[0] = cm[(sum + 4) >> 3];
        lum_m4++;
        lum_m3++;
        lum_m2++;
        lum_m1++;
        lum++;
    }
}