Commit | Line | Data |
---|---|---|
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 | ||
44 | uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3]; | |
45 | ||
46 | static 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 | ||
56 | static 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 | ||
77 | static 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 | ||
114 | av_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 | ||
122 | void 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 | ||
134 | VLC ff_mv_vlc; | |
135 | ||
136 | VLC ff_dc_lum_vlc; | |
137 | VLC ff_dc_chroma_vlc; | |
138 | ||
139 | VLC ff_mbincr_vlc; | |
140 | VLC ff_mb_ptype_vlc; | |
141 | VLC ff_mb_btype_vlc; | |
142 | VLC ff_mb_pat_vlc; | |
143 | ||
144 | av_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 | */ | |
185 | int 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 |