1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#ifndef AVCODEC_AVDCT_H
20#define AVCODEC_AVDCT_H
21
22#include "libavutil/opt.h"
23
24/**
25 * AVDCT context.
26 * @note function pointers can be NULL if the specific features have been
27 *       disabled at build time.
28 */
29typedef struct AVDCT {
30    const AVClass *av_class;
31
32    void (*idct)(int16_t *block /* align 16 */);
33
34    /**
35     * IDCT input permutation.
36     * Several optimized IDCTs need a permutated input (relative to the
37     * normal order of the reference IDCT).
38     * This permutation must be performed before the idct_put/add.
39     * Note, normally this can be merged with the zigzag/alternate scan<br>
40     * An example to avoid confusion:
41     * - (->decode coeffs -> zigzag reorder -> dequant -> reference IDCT -> ...)
42     * - (x -> reference DCT -> reference IDCT -> x)
43     * - (x -> reference DCT -> simple_mmx_perm = idct_permutation
44     *    -> simple_idct_mmx -> x)
45     * - (-> decode coeffs -> zigzag reorder -> simple_mmx_perm -> dequant
46     *    -> simple_idct_mmx -> ...)
47     */
48    uint8_t idct_permutation[64];
49
50    void (*fdct)(int16_t *block /* align 16 */);
51
52
53    /**
54     * DCT algorithm.
55     * must use AVOptions to set this field.
56     */
57    int dct_algo;
58
59    /**
60     * IDCT algorithm.
61     * must use AVOptions to set this field.
62     */
63    int idct_algo;
64} AVDCT;
65
66/**
67 * Allocates a AVDCT context.
68 * This needs to be initialized with avcodec_dct_init() after optionally
69 * configuring it with AVOptions.
70 *
71 * To free it use av_free()
72 */
73AVDCT *avcodec_dct_alloc(void);
74int avcodec_dct_init(AVDCT *);
75
76const AVClass *avcodec_dct_get_class(void);
77
78#endif /* AVCODEC_AVDCT_H */
79