mpeg12: do not decode extradata more than once.
[libav.git] / libavcodec / mpeg12.h
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1/*
2 * MPEG1/2 common code
3 * Copyright (c) 2007 Aurelien Jacobs <aurel@gnuage.org>
4 *
2912e87a 5 * This file is part of Libav.
b66af278 6 *
2912e87a 7 * Libav is free software; you can redistribute it and/or
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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 *
2912e87a 12 * Libav is distributed in the hope that it will be useful,
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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
2912e87a 18 * License along with Libav; if not, write to the Free Software
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19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
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22#ifndef AVCODEC_MPEG12_H
23#define AVCODEC_MPEG12_H
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24
25#include "mpegvideo.h"
26
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27#define DC_VLC_BITS 9
28#define TEX_VLC_BITS 9
29
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30extern VLC ff_dc_lum_vlc;
31extern VLC ff_dc_chroma_vlc;
0da49fca 32
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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?
3fc08304 44 int closed_gop; ///< GOP is closed
58236862 45 int extradata_decoded;
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46} Mpeg1Context;
47
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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);
071083b4 51void ff_mpeg12_init_vlcs(void);
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52
53static inline int decode_dc(GetBitContext *gb, int component)
54{
55 int code, diff;
56
57 if (component == 0) {
6e16398a 58 code = get_vlc2(gb, ff_dc_lum_vlc.table, DC_VLC_BITS, 2);
0da49fca 59 } else {
6e16398a 60 code = get_vlc2(gb, ff_dc_chroma_vlc.table, DC_VLC_BITS, 2);
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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}
b66af278 73
db2f2093 74extern int ff_mpeg1_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
50240e56 75
98790382 76#endif /* AVCODEC_MPEG12_H */