FFmpeg/libavcodec/dct.h

/*
 * (I)DCT Transforms
 * Copyright (c) 2009 Peter Ross <pross@xvid.org>
 * Copyright (c) 2010 Alex Converse <alex.converse@gmail.com>
 * Copyright (c) 2010 Vitor Sessak
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef AVCODEC_DCT_H
#define AVCODEC_DCT_H

#include "rdft.h"

struct DCTContext {
    int nbits;
    int inverse;
    RDFTContext rdft;
    const float *costab;
    FFTSample *csc2;
    void (*dct_calc)(struct DCTContext *s, FFTSample *data);
    void (*dct32)(FFTSample *out, const FFTSample *in);
};

/**
 * Set up DCT.
 * @param nbits           size of the input array:
 *                        (1 << nbits)     for DCT-II, DCT-III and DST-I
 *                        (1 << nbits) + 1 for DCT-I
 *
 * @note the first element of the input of DST-I is ignored
 */
int  ff_dct_init(DCTContext *s, int nbits, enum DCTTransformType type);
void ff_dct_end (DCTContext *s);

void ff_dct_init_mmx(DCTContext *s);

#endif