3 * Copyright (c) 2000, 2001 Fabrice Bellard
4 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
6 * This file is part of FFmpeg.
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.
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.
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
28 #define UNCHECKED_BITSTREAM_READER 1
30 #include "libavutil/attributes.h"
31 #include "libavutil/avassert.h"
32 #include "libavutil/timecode.h"
36 #include "mpegvideo.h"
37 #include "error_resilience.h"
39 #include "mpeg12data.h"
40 #include "bytestream.h"
41 #include "vdpau_internal.h"
44 uint8_t ff_mpeg12_static_rl_table_store
[2][2][2*MAX_RUN
+ MAX_LEVEL
+ 3];
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
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
70 #define INIT_2D_VLC_RL(rl, static_size)\
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);\
77 static av_cold
void init_2d_vlc_rl(RLTable
*rl
, unsigned static_size
)
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
);
85 for (i
= 0; i
< vlc
.table_size
; i
++) {
86 int code
= vlc
.table
[i
][0];
87 int len
= vlc
.table
[i
][1];
90 if (len
== 0) { // illegal code
93 } else if (len
<0) { //more bits needed
97 if (code
== rl
->n
) { //esc
100 } else if (code
== rl
->n
+1) { //eob
104 run
= rl
->table_run
[code
] + 1;
105 level
= rl
->table_level
[code
];
108 rl
->rl_vlc
[0][i
].len
= len
;
109 rl
->rl_vlc
[0][i
].level
= level
;
110 rl
->rl_vlc
[0][i
].run
= run
;
114 av_cold
void ff_mpeg12_common_init(MpegEncContext
*s
)
117 s
->y_dc_scale_table
=
118 s
->c_dc_scale_table
= ff_mpeg2_dc_scale_table
[s
->intra_dc_precision
];
122 void ff_mpeg1_clean_buffers(MpegEncContext
*s
)
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
));
131 /******************************************/
137 VLC ff_dc_chroma_vlc
;
144 av_cold
void ff_mpeg12_init_vlcs(void)
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);
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]);
176 INIT_2D_VLC_RL(ff_rl_mpeg1
, 680);
177 INIT_2D_VLC_RL(ff_rl_mpeg2
, 674);
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
185 int ff_mpeg1_find_frame_end(ParseContext
*pc
, const uint8_t *buf
, int buf_size
, AVCodecParserContext
*s
)
188 uint32_t state
= pc
->state
;
190 /* EOF considered as end of frame */
196 1 first_SEQEXT -> 0/2
197 2 first field start -> 3/0
198 3 second_SEQEXT -> 2/0
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;
211 pc
->frame_start_found
= (pc
->frame_start_found
+ 1) & 3;
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
) {
218 pc
->frame_start_found
= 4;
220 if (state
== SEQ_END_CODE
) {
221 pc
->frame_start_found
= 0;
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;
236 if (pc
->frame_start_found
== 0 && s
&& state
== PICTURE_START_CODE
) {
237 ff_fetch_timestamp(s
, i
- 3, 1);
242 return END_NOT_FOUND
;