1/*
2 * MPEG1/2 common code
3 * Copyright (c) 2007 Aurelien Jacobs <aurel@gnuage.org>
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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_MPEG12_H
23#define AVCODEC_MPEG12_H
24
25#include "mpegvideo.h"
26
27#define DC_VLC_BITS 9
28#define TEX_VLC_BITS 9
29
30extern VLC ff_dc_lum_vlc;
31extern VLC ff_dc_chroma_vlc;
32
33typedef struct Mpeg1Context {
34    MpegEncContext mpeg_enc_ctx;
35    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
36    int repeat_field; /* true if we must repeat the field */
37    AVPanScan pan_scan;              /**< some temporary storage for the panscan */
38    int slice_count;
39    int swap_uv;//indicate VCR2
40    int save_aspect_info;
41    int save_width, save_height, save_progressive_seq;
42    AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
43    int sync;                        ///< Did we reach a sync point like a GOP/SEQ/KEYFrame?
44    int closed_gop;                  ///< GOP is closed
45    int extradata_decoded;
46} Mpeg1Context;
47
48extern uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
49
50void ff_mpeg12_common_init(MpegEncContext *s);
51void ff_mpeg12_init_vlcs(void);
52
53static inline int decode_dc(GetBitContext *gb, int component)
54{
55    int code, diff;
56
57    if (component == 0) {
58        code = get_vlc2(gb, ff_dc_lum_vlc.table, DC_VLC_BITS, 2);
59    } else {
60        code = get_vlc2(gb, ff_dc_chroma_vlc.table, DC_VLC_BITS, 2);
61    }
62    if (code < 0){
63        av_log(NULL, AV_LOG_ERROR, "invalid dc code at\n");
64        return 0xffff;
65    }
66    if (code == 0) {
67        diff = 0;
68    } else {
69        diff = get_xbits(gb, code);
70    }
71    return diff;
72}
73
74extern int ff_mpeg1_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
75
76#endif /* AVCODEC_MPEG12_H */
77