xref: /third_party/ffmpeg/libavcodec/mpeg12dec.h (revision cabdff1a)
1/*
2 * MPEG-1/2 decoder header
3 * Copyright (c) 2007 Aurelien Jacobs <aurel@gnuage.org>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#ifndef AVCODEC_MPEG12DEC_H
23#define AVCODEC_MPEG12DEC_H
24
25#include "get_bits.h"
26#include "mpeg12vlc.h"
27#include "rl.h"
28
29#define INIT_2D_VLC_RL(rl, static_size, flags)\
30{\
31    static RL_VLC_ELEM rl_vlc_table[static_size];\
32    rl.rl_vlc[0] = rl_vlc_table;\
33    ff_init_2d_vlc_rl(&rl, static_size, flags);\
34}
35
36void ff_init_2d_vlc_rl(RLTable *rl, unsigned static_size, int flags);
37
38static inline int decode_dc(GetBitContext *gb, int component)
39{
40    int code, diff;
41
42    if (component == 0) {
43        code = get_vlc2(gb, ff_dc_lum_vlc.table, DC_VLC_BITS, 2);
44    } else {
45        code = get_vlc2(gb, ff_dc_chroma_vlc.table, DC_VLC_BITS, 2);
46    }
47    if (code == 0) {
48        diff = 0;
49    } else {
50        diff = get_xbits(gb, code);
51    }
52    return diff;
53}
54
55int ff_mpeg1_decode_block_intra(GetBitContext *gb,
56                                const uint16_t *quant_matrix,
57                                const uint8_t *scantable, int last_dc[3],
58                                int16_t *block, int index, int qscale);
59
60#endif /* AVCODEC_MPEG12DEC_H */
61