DCT::DCT(int bits, TransformType trans) : _bits(bits), _trans(trans), _rdft(0) {
int n = 1 << _bits;
_tCos = getCosineTable(_bits + 2);
_csc2 = new float[n / 2];
_rdft = new RDFT(_bits, (_trans == DCT_III) ? RDFT::IDFT_C2R : RDFT::DFT_R2C);
for (int i = 0; i < (n / 2); i++)
_csc2[i] = 0.5 / sin((M_PI / (2 * n) * (2 * i + 1)));
}
static void fft16(Complex *z) {
float t1, t2, t3, t4, t5, t6;
fft8(z);
fft4(z + 8);
fft4(z + 12);
const float * const cosTable = getCosineTable(4);
TRANSFORM_ZERO(z[0], z[4], z[8], z[12]);
TRANSFORM(z[2], z[6], z[10], z[14], sqrthalf, sqrthalf);
TRANSFORM(z[1], z[5], z[9], z[13], cosTable[1],cosTable[3]);
TRANSFORM(z[3], z[7], z[11], z[15], cosTable[3], cosTable[1]);
}
