void run_dct(int width, int height, float *quant, float *input, int32_t *output)

{

#pragma acc parallel pcopyin(quant[:64]) pcopyin(input[:width*height]) copyout(output[:width*height])

{

#pragma acc for collapse(4)

for (int brow = 0; brow < height / 8; brow++)

{

for (int bcol = 0; bcol < width / 8; bcol++)

{

for (int u = 0; u < 8; u++)

{

for (int v = 0; v < 8; v++)

{

float temp = 0;

#pragma acc for reduction(+:temp) collapse(2)

for (int x = 0; x < 8; x++)

{

for (int y = 0; y < 8; y++)

{

int input_pointer = bcol * 8 + brow * 8 * width + x + (y * width);

float input_value = input[input_pointer];

float cosux = cos((2.0 * x + 1.0) * u * PI / 16.0);

float cosvy = cos((2.0 * y + 1.0) * v * PI / 16.0);

temp += (input_value - 128.0) * cosux * cosvy;

}

}

float quant_val = quant[u + v * 8];

int output_pointer = (bcol + brow * (width / 8)) * 64 + u + v * 8;

float au = (u == 0 ? sqrt(1.0 / 2.0) : 1);

float av = (v == 0 ? sqrt(1.0 / 2.0) : 1);

output[output_pointer] = round((0.25 * au * av * temp) / quant_val);

}

}

}

}

}

}