private static void Ifct8(ArraySlice <float> bloque, ArraySlice <float> res, float[,] tIcos)
{
float dc = bloque[0] * tIcos[0, 0];
float suma02 = 0;
suma02 += bloque[4] * tIcos[4, 0];
float suma01 = 0;
suma01 += bloque[2] * tIcos[2, 0];
suma01 += bloque[6] * tIcos[6, 0];
float suma11 = 0;
suma11 += bloque[2] * tIcos[2, 1];
suma11 += bloque[6] * tIcos[6, 1];
float suma00 = 0;
suma00 += bloque[1] * tIcos[1, 0];
suma00 += bloque[3] * tIcos[3, 0];
suma00 += bloque[5] * tIcos[5, 0];
suma00 += bloque[7] * tIcos[7, 0];
float suma10 = 0;
suma10 += bloque[1] * tIcos[1, 1];
suma10 += bloque[3] * tIcos[3, 1];
suma10 += bloque[5] * tIcos[5, 1];
suma10 += bloque[7] * tIcos[7, 1];
float suma20 = 0;
suma20 += bloque[1] * tIcos[1, 2];
suma20 += bloque[3] * tIcos[3, 2];
suma20 += bloque[5] * tIcos[5, 2];
suma20 += bloque[7] * tIcos[7, 2];
float suma30 = 0;
suma30 += bloque[1] * tIcos[1, 3];
suma30 += bloque[3] * tIcos[3, 3];
suma30 += bloque[5] * tIcos[5, 3];
suma30 += bloque[7] * tIcos[7, 3];
float p00 = dc + suma02;
float p01 = dc - suma02;
float p10 = p00 + suma01;
float p11 = p00 - suma01;
float p12 = p01 + suma11;
float p13 = p01 - suma11;
res[0] = p10 + suma00;
res[7] = p10 - suma00;
res[3] = p11 + suma30;
res[4] = p11 - suma30;
res[1] = p12 + suma10;
res[6] = p12 - suma10;
res[2] = p13 + suma20;
res[5] = p13 - suma20;
}
