dct.h

/* 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 <pross@xvid.org>
// Copyright (c) 2010 Alex Converse <alex.converse@gmail.com>
// Copyright (c) 2010 Vitor Sessak

#ifndef COMMON_DCT_H
#define COMMON_DCT_H

#include "common/scummsys.h"
#include "common/math.h"
#include "common/rdft.h"

#include "common/cosinetables.h"

namespace Common {

class DCT {
public:
    enum TransformType {
        DCT_II,
        DCT_III,
        DCT_I,
        DST_I
    };

    DCT(int bits, TransformType trans);
    ~DCT();

    void calc(float *data);

private:
    int _bits;
    TransformType _trans;

    CosineTable _cos;
    const float *_tCos;

    float *_csc2;

    RDFT *_rdft;

    void calcDCTI  (float *data);
    void calcDCTII (float *data);
    void calcDCTIII(float *data);
    void calcDSTI  (float *data);
};

} // End of namespace Common

#endif // COMMON_DCT_H