scummvm/math/mdct.h

66 lines
1.7 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
// Based on xoreos' (I)RDFT code which is in turn
// Based upon the (I)MDCT code in FFmpeg
// Copyright (c) 2002 Fabrice Bellard
#ifndef MATH_MDCT_H
#define MATH_MDCT_H
#include "common/scummsys.h"
namespace Math {
class FFT;
/** (Inverse) Modified Discrete Cosine Transforms. */
class MDCT {
public:
MDCT(int bits, bool inverse, double scale);
~MDCT();
/** Compute MDCT of size N = 2^nbits. */
void calcMDCT(float *output, const float *input);
/** Compute inverse MDCT of size N = 2^nbits. */
void calcIMDCT(float *output, const float *input);
private:
int _bits;
int _size;
float *_tCos;
float *_tSin;
FFT *_fft;
/** Compute the middle half of the inverse MDCT of size N = 2^nbits,
* thus excluding the parts that can be derived by symmetry.
*/
void calcHalfIMDCT(float *output, const float *input);
};
} // End of namespace Math
#endif // MATH_MDCT_H