转载https://blog.csdn.net/king20168/article/details/52759843
// 函数功能是计算8×8块的哈达玛变换,并计算其SAD值,m2[8][8]存放最终的变换结果
Int xCalcHADs8x8_ISlice(Pel *piOrg, Int iStrideOrg) { Int k, i, j, jj; Int diff[64], m1[8][8], m2[8][8], m3[8][8], iSumHad = 0; //把8×8块像素存放在一维数组中 for( k = 0; k < 64; k += 8 ) { diff[k+0] = piOrg[0] ; diff[k+1] = piOrg[1] ; diff[k+2] = piOrg[2] ; diff[k+3] = piOrg[3] ; diff[k+4] = piOrg[4] ; diff[k+5] = piOrg[5] ; diff[k+6] = piOrg[6] ; diff[k+7] = piOrg[7] ; piOrg += iStrideOrg; //指针指向下一行 } //horizontal 水平变换,计算V=X×H, for (j=0; j < 8; j++) { jj = j << 3; //一次算8个,乘8换行 m2[j][0] = diff[jj ] + diff[jj+4]; m2[j][1] = diff[jj+1] + diff[jj+5]; m2[j][2] = diff[jj+2] + diff[jj+6]; m2[j][3] = diff[jj+3] + diff[jj+7]; m2[j][4] = diff[jj ] - diff[jj+4]; m2[j][5] = diff[jj+1] - diff[jj+5]; m2[j][6] = diff[jj+2] - diff[jj+6]; m2[j][7] = diff[jj+3] - diff[jj+7]; m1[j][0] = m2[j][0] + m2[j][2]; m1[j][1] = m2[j][1] + m2[j][3]; m1[j][2] = m2[j][0] - m2[j][2]; m1[j][3] = m2[j][1] - m2[j][3]; m1[j][4] = m2[j][4] + m2[j][6]; m1[j][5] = m2[j][5] + m2[j][7]; m1[j][6] = m2[j][4] - m2[j][6]; m1[j][7] = m2[j][5] - m2[j][7]; m2[j][0] = m1[j][0] + m1[j][1]; m2[j][1] = m1[j][0] - m1[j][1]; m2[j][2] = m1[j][2] + m1[j][3]; m2[j][3] = m1[j][2] - m1[j][3]; m2[j][4] = m1[j][4] + m1[j][5]; m2[j][5] = m1[j][4] - m1[j][5]; m2[j][6] = m1[j][6] + m1[j][7]; m2[j][7] = m1[j][6] - m1[j][7]; } //vertical 垂直变换,计算H×V for (i=0; i < 8; i++) { m3[0][i] = m2[0][i] + m2[4][i]; m3[1][i] = m2[1][i] + m2[5][i]; m3[2][i] = m2[2][i] + m2[6][i]; m3[3][i] = m2[3][i] + m2[7][i]; m3[4][i] = m2[0][i] - m2[4][i]; m3[5][i] = m2[1][i] - m2[5][i]; m3[6][i] = m2[2][i] - m2[6][i]; m3[7][i] = m2[3][i] - m2[7][i]; m1[0][i] = m3[0][i] + m3[2][i]; m1[1][i] = m3[1][i] + m3[3][i]; m1[2][i] = m3[0][i] - m3[2][i]; m1[3][i] = m3[1][i] - m3[3][i]; m1[4][i] = m3[4][i] + m3[6][i]; m1[5][i] = m3[5][i] + m3[7][i]; m1[6][i] = m3[4][i] - m3[6][i]; m1[7][i] = m3[5][i] - m3[7][i]; m2[0][i] = m1[0][i] + m1[1][i]; m2[1][i] = m1[0][i] - m1[1][i]; m2[2][i] = m1[2][i] + m1[3][i]; m2[3][i] = m1[2][i] - m1[3][i]; m2[4][i] = m1[4][i] + m1[5][i]; m2[5][i] = m1[4][i] - m1[5][i]; m2[6][i] = m1[6][i] + m1[7][i]; m2[7][i] = m1[6][i] - m1[7][i]; } for (i = 0; i < 8; i++) { for (j = 0; j < 8; j++) { iSumHad += abs(m2[i][j]); } } iSumHad -= abs(m2[0][0]); iSumHad =(iSumHad+2)>>2; //除以系数4,并向上取整 return(iSumHad); }