static inline void idct_col(int16_t *blk, const uint8_t *quant)
{
    int t0, t1, t2, t3, t4, t5, t6, t7, t8, t9, tA, tB, tC, tD, tE, tF;
    int t10, t11, t12, t13;
    int s0, s1, s2, s3, s4, s5, s6, s7;

    s0 = (int) blk[0 * 8] * quant[0 * 8];
    s1 = (int) blk[1 * 8] * quant[1 * 8];
    s2 = (int) blk[2 * 8] * quant[2 * 8];
    s3 = (int) blk[3 * 8] * quant[3 * 8];
    s4 = (int) blk[4 * 8] * quant[4 * 8];
    s5 = (int) blk[5 * 8] * quant[5 * 8];
    s6 = (int) blk[6 * 8] * quant[6 * 8];
    s7 = (int) blk[7 * 8] * quant[7 * 8];

    t0  =  (int)(s3 * 19266U + s5 * 12873U) >> 15;
    t1  =  (int)(s5 * 19266U - s3 * 12873U) >> 15;
    t2  = ((int)(s7 * 4520U  + s1 * 22725U) >> 15) - t0;
    t3  = ((int)(s1 * 4520U  - s7 * 22725U) >> 15) - t1;
    t4  = t0 * 2 + t2;
    t5  = t1 * 2 + t3;
    t6  = t2 - t3;
    t7  = t3 * 2 + t6;
    t8  = (t6 * 11585) >> 14;
    t9  = (t7 * 11585) >> 14;
    tA  = (int)(s2 * 8867U - s6 * 21407U) >> 14;
    tB  = (int)(s6 * 8867U + s2 * 21407U) >> 14;
    tC  = (s0 >> 1) - (s4 >> 1);
    tD  = (s4 >> 1) * 2 + tC;
    tE  = tC - (tA >> 1);
    tF  = tD - (tB >> 1);
    t10 = tF - t5;
    t11 = tE - t8;
    t12 = tE + (tA >> 1) * 2 - t9;
    t13 = tF + (tB >> 1) * 2 - t4;

    blk[0 * 8] = t13 + t4 * 2;
    blk[1 * 8] = t12 + t9 * 2;
    blk[2 * 8] = t11 + t8 * 2;
    blk[3 * 8] = t10 + t5 * 2;
    blk[4 * 8] = t10;
    blk[5 * 8] = t11;
    blk[6 * 8] = t12;
    blk[7 * 8] = t13;
}