void RGB2YCrCb(signed char pixelmatrix[MACRO_BLOCK_SIZE][MACRO_BLOCK_SIZE*3],signed char YMatrix[MATRIX_SIZE][MATRIX_SIZE],signed char CrMatrix[MATRIX_SIZE][MATRIX_SIZE],signed char CbMatrix[MATRIX_SIZE][MATRIX_SIZE], unsigned int sample)
{
unsigned int row, col, rowoffset, coloffset, xoffset, yoffset;
for(row = 0;row < MATRIX_SIZE; row++) {
for(col = 0; col < MATRIX_SIZE; col++) {
coloffset = (sample&0x01)*8;
rowoffset = (sample&0x02)*4;
YMatrix[row][col] = RGB2Y(pixelmatrix[row+rowoffset][(col+coloffset)*3+2],pixelmatrix[row+rowoffset][(col+coloffset)*3+1],pixelmatrix[row+rowoffset][(col+coloffset)*3]) - 128;
if (col%2==0) {
yoffset = (sample&0x01)*4;
xoffset = (sample&0x02)*2;
if (row%2==0) {
CrMatrix[xoffset+(row>>1)][yoffset+(col>>1)] = RGB2Cr(pixelmatrix[row+rowoffset][(col+coloffset)*3+2],pixelmatrix[row+rowoffset][(col+coloffset)*3+1],pixelmatrix[row+rowoffset][(col+coloffset)*3]) - 128;
} else {
CbMatrix[xoffset+((row)>>2)][yoffset+(col>>2)] = RGB2Cb(pixelmatrix[row+rowoffset][(col+coloffset)*3+2],pixelmatrix[row+rowoffset][(col+coloffset)*3+1],pixelmatrix[row+rowoffset][(col+coloffset)*3]) - 128;
}
}
void subsample(const BGR rgb[16][16], short cb[8][8], short cr[8][8])
{
for (unsigned r = 0; r < 8; r++)
for (unsigned c = 0; c < 8; c++)
{
unsigned rr = (r << 1);
unsigned cc = (c << 1);
// calculating average values
color R = (rgb[rr][cc].Red + rgb[rr][cc + 1].Red + rgb[rr + 1][cc].Red + rgb[rr + 1][cc + 1].Red) >> 2;
color G = (rgb[rr][cc].Green + rgb[rr][cc + 1].Green + rgb[rr + 1][cc].Green + rgb[rr + 1][cc + 1].Green) >> 2;
color B = (rgb[rr][cc].Blue + rgb[rr][cc + 1].Blue + rgb[rr + 1][cc].Blue + rgb[rr + 1][cc + 1].Blue) >> 2;
cb[r][c] = (short) RGB2Cb(R, G, B) - 128;
cr[r][c] = (short) RGB2Cr(R, G, B) - 128;
}
}
void subsample2(const BGR rgb[16][16], conv Y[2][2][8][8], conv cb[8][8], conv cr[8][8])
{
unsigned r, c;
for (r = 0; r < 16; r += 2)
for (c = 0; c < 16; c += 2)
{
//unsigned rr, cc;
unsigned i, j, k, l;
unsigned sR, sG, sB;
unsigned R, G, B;
i = r >> 3, j = c >> 3,
k = r & 7, l = c & 7;
sR = R = rgb[r][c].Red,
sG = G = rgb[r][c].Green,
sB = B = rgb[r][c].Blue;
Y[i][j][k][l] = RGB2Y(R, G, B)-128;
sR += R = rgb[r][c+1].Red,
sG += G = rgb[r][c+1].Green,
sB += B = rgb[r][c+1].Blue;
Y[i][j][k][l+1] = RGB2Y(R, G, B)-128;
sR += R = rgb[r+1][c].Red,
sG += G = rgb[r+1][c].Green,
sB += B = rgb[r+1][c].Blue;
Y[i][j][k+1][l] = RGB2Y(R, G, B)-128;
sR += R = rgb[r+1][c+1].Red,
sG += G = rgb[r+1][c+1].Green,
sB += B = rgb[r+1][c+1].Blue;
Y[i][j][k+1][l+1] = RGB2Y(R, G, B)-128;
// calculating an average values
R = sR >> 2,
G = sG >> 2,
B = sB >> 2;
//rr = r >> 1, cc = c >> 1;
cb[r>>1][c>>1] = (conv)RGB2Cb(R, G, B)-128;
cr[r>>1][c>>1] = (conv)RGB2Cr(R, G, B)-128;
}
}