/* 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 eos' (I)RDFT code which is in turn

// Based upon the (I)DCT code in FFmpeg

// Copyright (c) 2009 Peter Ross <[email protected]>

// Copyright (c) 2010 Alex Converse <[email protected]>

// Copyright (c) 2010 Vitor Sessak

#ifndef MATH_DCT_H

#define MATH_DCT_H

#include "math/cosinetables.h"

namespace Math {

class RDFT;

/**

* @defgroup math_dct Discrete Cosine Transforms

* @ingroup math

*

* @brief Discrete Cosine Transforms.

*

* @{

*/

/**

* (Inverse) Discrete Cosine Transforms.

*

* Used in engines:

* - Scumm

*/

class DCT {

public:

enum TransformType {

DCT_II,

DCT_III,

DCT_I,

DST_I

};

DCT(int bits, TransformType trans);

~DCT();

void calc(float *data) const;

private:

int _bits;

TransformType _trans;

CosineTable _cos;

const float *_tCos;

float *_csc2;

RDFT *_rdft;

void calcDCTI(float *data) const;

void calcDCTII(float *data) const;

void calcDCTIII(float *data) const;

void calcDSTI(float *data) const;

};

/** @} */

} // End of namespace Math

#endif // MATH_DCT_H