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/*
* This file is part of AtracDEnc.
*
* AtracDEnc is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* AtracDEnc is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with AtracDEnc; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "mdct.h"
#include <iostream>
namespace NMDCT {
static std::vector<TFloat> CalcSinCos(size_t n, TFloat scale)
{
std::vector<TFloat> tmp(n >> 1);
const TFloat alpha = 2.0 * M_PI / (8.0 * n);
const TFloat omiga = 2.0 * M_PI / n;
scale = sqrt(scale/n);
for (size_t i = 0; i < (n >> 2); ++i) {
tmp[2 * i + 0] = scale * cos(omiga * i + alpha);
tmp[2 * i + 1] = scale * sin(omiga * i + alpha);
}
return tmp;
}
TMDCTBase::TMDCTBase(size_t n, TFloat scale)
: N(n)
, SinCos(CalcSinCos(n, scale))
{
FFTIn = (kiss_fft_cpx*) malloc(sizeof(kiss_fft_cpx) * N >> 2);
FFTOut = (kiss_fft_cpx*) malloc(sizeof(kiss_fft_cpx) * N >> 2);
FFTPlan = kiss_fft_alloc(N >> 2, false, nullptr, nullptr);
}
TMDCTBase::~TMDCTBase()
{
kiss_fft_free(FFTPlan);
free(FFTOut);
free(FFTIn);
}
} // namespace NMDCT
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