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Imported Debian version 2.4.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / mpeg12.c
CommitLineData
2ba45a60
DM		 1/*
2 * MPEG-1/2 decoder
3 * Copyright (c) 2000, 2001 Fabrice Bellard
4 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23/**
24 * @file
25 * MPEG-1/2 decoder
26 */
27
28#define UNCHECKED_BITSTREAM_READER 1
29
30#include "libavutil/attributes.h"
31#include "libavutil/avassert.h"
32#include "libavutil/timecode.h"
33
34#include "internal.h"
35#include "avcodec.h"
36#include "mpegvideo.h"
37#include "error_resilience.h"
38#include "mpeg12.h"
39#include "mpeg12data.h"
40#include "bytestream.h"
41#include "vdpau_internal.h"
42#include "thread.h"
43
44uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
45
46static const uint8_t table_mb_ptype[7][2] = {
47 { 3, 5 }, // 0x01 MB_INTRA
48 { 1, 2 }, // 0x02 MB_PAT
49 { 1, 3 }, // 0x08 MB_FOR
50 { 1, 1 }, // 0x0A MB_FOR|MB_PAT
51 { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
52 { 1, 5 }, // 0x12 MB_QUANT|MB_PAT
53 { 2, 5 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
54};
55
56static const uint8_t table_mb_btype[11][2] = {
57 { 3, 5 }, // 0x01 MB_INTRA
58 { 2, 3 }, // 0x04 MB_BACK
59 { 3, 3 }, // 0x06 MB_BACK|MB_PAT
60 { 2, 4 }, // 0x08 MB_FOR
61 { 3, 4 }, // 0x0A MB_FOR|MB_PAT
62 { 2, 2 }, // 0x0C MB_FOR|MB_BACK
63 { 3, 2 }, // 0x0E MB_FOR|MB_BACK|MB_PAT
64 { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
65 { 2, 6 }, // 0x16 MB_QUANT|MB_BACK|MB_PAT
66 { 3, 6 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
67 { 2, 5 }, // 0x1E MB_QUANT|MB_FOR|MB_BACK|MB_PAT
68};
69
70#define INIT_2D_VLC_RL(rl, static_size)\
71{\
72 static RL_VLC_ELEM rl_vlc_table[static_size];\
73 rl.rl_vlc[0] = rl_vlc_table;\
74 init_2d_vlc_rl(&rl, static_size);\
75}
76
77static av_cold void init_2d_vlc_rl(RLTable *rl, unsigned static_size)
78{
79 int i;
80 VLC_TYPE table[680][2] = {{0}};
81 VLC vlc = { .table = table, .table_allocated = static_size };
82 av_assert0(static_size <= FF_ARRAY_ELEMS(table));
83 init_vlc(&vlc, TEX_VLC_BITS, rl->n + 2, &rl->table_vlc[0][1], 4, 2, &rl->table_vlc[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
84
85 for (i = 0; i < vlc.table_size; i++) {
86 int code = vlc.table[i][0];
87 int len = vlc.table[i][1];
88 int level, run;
89
90 if (len == 0) { // illegal code
91 run = 65;
92 level = MAX_LEVEL;
93 } else if (len<0) { //more bits needed
94 run = 0;
95 level = code;
96 } else {
97 if (code == rl->n) { //esc
98 run = 65;
99 level = 0;
100 } else if (code == rl->n+1) { //eob
101 run = 0;
102 level = 127;
103 } else {
104 run = rl->table_run [code] + 1;
105 level = rl->table_level[code];
106 }
107 }
108 rl->rl_vlc[0][i].len = len;
109 rl->rl_vlc[0][i].level = level;
110 rl->rl_vlc[0][i].run = run;
111 }
112}
113
114av_cold void ff_mpeg12_common_init(MpegEncContext *s)
115{
116
117 s->y_dc_scale_table =
118 s->c_dc_scale_table = ff_mpeg2_dc_scale_table[s->intra_dc_precision];
119
120}
121
122void ff_mpeg1_clean_buffers(MpegEncContext *s)
123{
124 s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
125 s->last_dc[1] = s->last_dc[0];
126 s->last_dc[2] = s->last_dc[0];
127 memset(s->last_mv, 0, sizeof(s->last_mv));
128}
129
130
131/******************************************/
132/* decoding */
133
134VLC ff_mv_vlc;
135
136VLC ff_dc_lum_vlc;
137VLC ff_dc_chroma_vlc;
138
139VLC ff_mbincr_vlc;
140VLC ff_mb_ptype_vlc;
141VLC ff_mb_btype_vlc;
142VLC ff_mb_pat_vlc;
143
144av_cold void ff_mpeg12_init_vlcs(void)
145{
146 static int done = 0;
147
148 if (!done) {
149 done = 1;
150
151 INIT_VLC_STATIC(&ff_dc_lum_vlc, DC_VLC_BITS, 12,
152 ff_mpeg12_vlc_dc_lum_bits, 1, 1,
153 ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
154 INIT_VLC_STATIC(&ff_dc_chroma_vlc, DC_VLC_BITS, 12,
155 ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
156 ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
157 INIT_VLC_STATIC(&ff_mv_vlc, MV_VLC_BITS, 17,
158 &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
159 &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
160 INIT_VLC_STATIC(&ff_mbincr_vlc, MBINCR_VLC_BITS, 36,
161 &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
162 &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
163 INIT_VLC_STATIC(&ff_mb_pat_vlc, MB_PAT_VLC_BITS, 64,
164 &ff_mpeg12_mbPatTable[0][1], 2, 1,
165 &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
166
167 INIT_VLC_STATIC(&ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
168 &table_mb_ptype[0][1], 2, 1,
169 &table_mb_ptype[0][0], 2, 1, 64);
170 INIT_VLC_STATIC(&ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
171 &table_mb_btype[0][1], 2, 1,
172 &table_mb_btype[0][0], 2, 1, 64);
173 ff_init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
174 ff_init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
175
176 INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
177 INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
178 }
179}
180
181/**
182 * Find the end of the current frame in the bitstream.
183 * @return the position of the first byte of the next frame, or -1
184 */
185int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
186{
187 int i;
188 uint32_t state = pc->state;
189
190 /* EOF considered as end of frame */
191 if (buf_size == 0)
192 return 0;
193
194/*
195 0 frame start -> 1/4
196 1 first_SEQEXT -> 0/2
197 2 first field start -> 3/0
198 3 second_SEQEXT -> 2/0
199 4 searching end
200*/
201
202 for (i = 0; i < buf_size; i++) {
203 av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4);
204 if (pc->frame_start_found & 1) {
205 if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80)
206 pc->frame_start_found--;
207 else if (state == EXT_START_CODE + 2) {
208 if ((buf[i] & 3) == 3)
209 pc->frame_start_found = 0;
210 else
211 pc->frame_start_found = (pc->frame_start_found + 1) & 3;
212 }
213 state++;
214 } else {
215 i = avpriv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1;
216 if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) {
217 i++;
218 pc->frame_start_found = 4;
219 }
220 if (state == SEQ_END_CODE) {
221 pc->frame_start_found = 0;
222 pc->state=-1;
223 return i+1;
224 }
225 if (pc->frame_start_found == 2 && state == SEQ_START_CODE)
226 pc->frame_start_found = 0;
227 if (pc->frame_start_found < 4 && state == EXT_START_CODE)
228 pc->frame_start_found++;
229 if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) {
230 if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) {
231 pc->frame_start_found = 0;
232 pc->state = -1;
233 return i - 3;
234 }
235 }
236 if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) {
237 ff_fetch_timestamp(s, i - 3, 1);
238 }
239 }
240 }
241 pc->state = state;
242 return END_NOT_FOUND;
243}
244
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