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"
37 #include "mpegvideo.h"
38 #include "error_resilience.h"
40 #include "mpeg12data.h"
41 #include "bytestream.h"
42 #include "vdpau_internal.h"
43 #include "xvmc_internal.h"
46 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
48 static const uint8_t table_mb_ptype[7][2] = {
49 { 3, 5 }, // 0x01 MB_INTRA
50 { 1, 2 }, // 0x02 MB_PAT
51 { 1, 3 }, // 0x08 MB_FOR
52 { 1, 1 }, // 0x0A MB_FOR|MB_PAT
53 { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
54 { 1, 5 }, // 0x12 MB_QUANT|MB_PAT
55 { 2, 5 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
58 static const uint8_t table_mb_btype[11][2] = {
59 { 3, 5 }, // 0x01 MB_INTRA
60 { 2, 3 }, // 0x04 MB_BACK
61 { 3, 3 }, // 0x06 MB_BACK|MB_PAT
62 { 2, 4 }, // 0x08 MB_FOR
63 { 3, 4 }, // 0x0A MB_FOR|MB_PAT
64 { 2, 2 }, // 0x0C MB_FOR|MB_BACK
65 { 3, 2 }, // 0x0E MB_FOR|MB_BACK|MB_PAT
66 { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
67 { 2, 6 }, // 0x16 MB_QUANT|MB_BACK|MB_PAT
68 { 3, 6 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
69 { 2, 5 }, // 0x1E MB_QUANT|MB_FOR|MB_BACK|MB_PAT
72 #define INIT_2D_VLC_RL(rl, static_size)\
74 static RL_VLC_ELEM rl_vlc_table[static_size];\
75 INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
76 &rl.table_vlc[0][1], 4, 2,\
77 &rl.table_vlc[0][0], 4, 2, static_size);\
79 rl.rl_vlc[0] = rl_vlc_table;\
83 static av_cold void init_2d_vlc_rl(RLTable *rl)
87 for (i = 0; i < rl->vlc.table_size; i++) {
88 int code = rl->vlc.table[i][0];
89 int len = rl->vlc.table[i][1];
92 if (len == 0) { // illegal code
95 } else if (len<0) { //more bits needed
99 if (code == rl->n) { //esc
102 } else if (code == rl->n+1) { //eob
106 run = rl->table_run [code] + 1;
107 level = rl->table_level[code];
110 rl->rl_vlc[0][i].len = len;
111 rl->rl_vlc[0][i].level = level;
112 rl->rl_vlc[0][i].run = run;
116 av_cold void ff_mpeg12_common_init(MpegEncContext *s)
119 s->y_dc_scale_table =
120 s->c_dc_scale_table = ff_mpeg2_dc_scale_table[s->intra_dc_precision];
124 void ff_mpeg1_clean_buffers(MpegEncContext *s)
126 s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
127 s->last_dc[1] = s->last_dc[0];
128 s->last_dc[2] = s->last_dc[0];
129 memset(s->last_mv, 0, sizeof(s->last_mv));
133 /******************************************/
139 VLC ff_dc_chroma_vlc;
146 av_cold void ff_mpeg12_init_vlcs(void)
153 INIT_VLC_STATIC(&ff_dc_lum_vlc, DC_VLC_BITS, 12,
154 ff_mpeg12_vlc_dc_lum_bits, 1, 1,
155 ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
156 INIT_VLC_STATIC(&ff_dc_chroma_vlc, DC_VLC_BITS, 12,
157 ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
158 ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
159 INIT_VLC_STATIC(&ff_mv_vlc, MV_VLC_BITS, 17,
160 &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
161 &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
162 INIT_VLC_STATIC(&ff_mbincr_vlc, MBINCR_VLC_BITS, 36,
163 &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
164 &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
165 INIT_VLC_STATIC(&ff_mb_pat_vlc, MB_PAT_VLC_BITS, 64,
166 &ff_mpeg12_mbPatTable[0][1], 2, 1,
167 &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
169 INIT_VLC_STATIC(&ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
170 &table_mb_ptype[0][1], 2, 1,
171 &table_mb_ptype[0][0], 2, 1, 64);
172 INIT_VLC_STATIC(&ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
173 &table_mb_btype[0][1], 2, 1,
174 &table_mb_btype[0][0], 2, 1, 64);
175 ff_init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
176 ff_init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
178 INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
179 INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
184 * Find the end of the current frame in the bitstream.
185 * @return the position of the first byte of the next frame, or -1
187 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
190 uint32_t state = pc->state;
192 /* EOF considered as end of frame */
198 1 first_SEQEXT -> 0/2
199 2 first field start -> 3/0
200 3 second_SEQEXT -> 2/0
204 for (i = 0; i < buf_size; i++) {
205 av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4);
206 if (pc->frame_start_found & 1) {
207 if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80)
208 pc->frame_start_found--;
209 else if (state == EXT_START_CODE + 2) {
210 if ((buf[i] & 3) == 3)
211 pc->frame_start_found = 0;
213 pc->frame_start_found = (pc->frame_start_found + 1) & 3;
217 i = avpriv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1;
218 if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) {
220 pc->frame_start_found = 4;
222 if (state == SEQ_END_CODE) {
223 pc->frame_start_found = 0;
227 if (pc->frame_start_found == 2 && state == SEQ_START_CODE)
228 pc->frame_start_found = 0;
229 if (pc->frame_start_found < 4 && state == EXT_START_CODE)
230 pc->frame_start_found++;
231 if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) {
232 if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) {
233 pc->frame_start_found = 0;
238 if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) {
239 ff_fetch_timestamp(s, i - 3, 1);
244 return END_NOT_FOUND;