libavcodec/mpeg12.c

   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 libavcodec/mpeg12.c
  25  * MPEG-1/2 decoder
  26  */
  27
  28 //#define DEBUG
  29 #include "internal.h"
  30 #include "avcodec.h"
  31 #include "dsputil.h"
  32 #include "mpegvideo.h"
  33
  34 #include "mpeg12.h"
  35 #include "mpeg12data.h"
  36 #include "mpeg12decdata.h"
  37 #include "bytestream.h"
  38 #include "vdpau_internal.h"
  39 #include "xvmc_internal.h"
  40
  41 //#undef NDEBUG
  42 //#include <assert.h>
  43
  44
  45 #define MV_VLC_BITS 9
  46 #define MBINCR_VLC_BITS 9
  47 #define MB_PAT_VLC_BITS 9
  48 #define MB_PTYPE_VLC_BITS 6
  49 #define MB_BTYPE_VLC_BITS 6
  50
  51 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
  52                               DCTELEM *block,
  53                               int n);
  54 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
  55                               DCTELEM *block,
  56                               int n);
  57 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n);
  58 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
  59                                         DCTELEM *block,
  60                                         int n);
  61 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
  62                                     DCTELEM *block,
  63                                     int n);
  64 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n);
  65 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
  66 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
  67 static void exchange_uv(MpegEncContext *s);
  68
  69 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
  70                                            PIX_FMT_XVMC_MPEG2_IDCT,
  71                                            PIX_FMT_XVMC_MPEG2_MC,
  72                                            PIX_FMT_NONE};
  73
  74 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  75
  76
  77 #define INIT_2D_VLC_RL(rl, static_size)\
  78 {\
  79     static RL_VLC_ELEM rl_vlc_table[static_size];\
  80     INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
  81              &rl.table_vlc[0][1], 4, 2,\
  82              &rl.table_vlc[0][0], 4, 2, static_size);\
  83 \
  84     rl.rl_vlc[0]= rl_vlc_table;\
  85     init_2d_vlc_rl(&rl);\
  86 }
  87
  88 static void init_2d_vlc_rl(RLTable *rl)
  89 {
  90     int i;
  91
  92     for(i=0; i<rl->vlc.table_size; i++){
  93         int code= rl->vlc.table[i][0];
  94         int len = rl->vlc.table[i][1];
  95         int level, run;
  96
  97         if(len==0){ // illegal code
  98             run= 65;
  99             level= MAX_LEVEL;
 100         }else if(len<0){ //more bits needed
 101             run= 0;
 102             level= code;
 103         }else{
 104             if(code==rl->n){ //esc
 105                 run= 65;
 106                 level= 0;
 107             }else if(code==rl->n+1){ //eob
 108                 run= 0;
 109                 level= 127;
 110             }else{
 111                 run=   rl->table_run  [code] + 1;
 112                 level= rl->table_level[code];
 113             }
 114         }
 115         rl->rl_vlc[0][i].len= len;
 116         rl->rl_vlc[0][i].level= level;
 117         rl->rl_vlc[0][i].run= run;
 118     }
 119 }
 120
 121 void ff_mpeg12_common_init(MpegEncContext *s)
 122 {
 123
 124     s->y_dc_scale_table=
 125     s->c_dc_scale_table= mpeg2_dc_scale_table[s->intra_dc_precision];
 126
 127 }
 128
 129 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 130     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 131     s->last_dc[1] = s->last_dc[0];
 132     s->last_dc[2] = s->last_dc[0];
 133     memset(s->last_mv, 0, sizeof(s->last_mv));
 134 }
 135
 136
 137 /******************************************/
 138 /* decoding */
 139
 140 static VLC mv_vlc;
 141 static VLC mbincr_vlc;
 142 static VLC mb_ptype_vlc;
 143 static VLC mb_btype_vlc;
 144 static VLC mb_pat_vlc;
 145
 146 av_cold void ff_mpeg12_init_vlcs(void)
 147 {
 148     static int done = 0;
 149
 150     if (!done) {
 151         done = 1;
 152
 153         INIT_VLC_STATIC(&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(&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(&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(&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(&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);
 168
 169         INIT_VLC_STATIC(&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(&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         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
 176         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
 177
 178         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
 179         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
 180     }
 181 }
 182
 183 static inline int get_dmv(MpegEncContext *s)
 184 {
 185     if(get_bits1(&s->gb))
 186         return 1 - (get_bits1(&s->gb) << 1);
 187     else
 188         return 0;
 189 }
 190
 191 static inline int get_qscale(MpegEncContext *s)
 192 {
 193     int qscale = get_bits(&s->gb, 5);
 194     if (s->q_scale_type) {
 195         return non_linear_qscale[qscale];
 196     } else {
 197         return qscale << 1;
 198     }
 199 }
 200
 201 /* motion type (for MPEG-2) */
 202 #define MT_FIELD 1
 203 #define MT_FRAME 2
 204 #define MT_16X8  2
 205 #define MT_DMV   3
 206
 207 static int mpeg_decode_mb(MpegEncContext *s,
 208                           DCTELEM block[12][64])
 209 {
 210     int i, j, k, cbp, val, mb_type, motion_type;
 211     const int mb_block_count = 4 + (1<< s->chroma_format);
 212
 213     dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 214
 215     assert(s->mb_skipped==0);
 216
 217     if (s->mb_skip_run-- != 0) {
 218         if (s->pict_type == FF_P_TYPE) {
 219             s->mb_skipped = 1;
 220             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 221         } else {
 222             int mb_type;
 223
 224             if(s->mb_x)
 225                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
 226             else
 227                 mb_type= s->current_picture.mb_type[ s->mb_width + (s->mb_y-1)*s->mb_stride - 1]; // FIXME not sure if this is allowed in MPEG at all
 228             if(IS_INTRA(mb_type))
 229                 return -1;
 230
 231             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 232                 mb_type | MB_TYPE_SKIP;
 233 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 234
 235             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 236                 s->mb_skipped = 1;
 237         }
 238
 239         return 0;
 240     }
 241
 242     switch(s->pict_type) {
 243     default:
 244     case FF_I_TYPE:
 245         if (get_bits1(&s->gb) == 0) {
 246             if (get_bits1(&s->gb) == 0){
 247                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
 248                 return -1;
 249             }
 250             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 251         } else {
 252             mb_type = MB_TYPE_INTRA;
 253         }
 254         break;
 255     case FF_P_TYPE:
 256         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 257         if (mb_type < 0){
 258             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 259             return -1;
 260         }
 261         mb_type = ptype2mb_type[ mb_type ];
 262         break;
 263     case FF_B_TYPE:
 264         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 265         if (mb_type < 0){
 266             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 267             return -1;
 268         }
 269         mb_type = btype2mb_type[ mb_type ];
 270         break;
 271     }
 272     dprintf(s->avctx, "mb_type=%x\n", mb_type);
 273 //    motion_type = 0; /* avoid warning */
 274     if (IS_INTRA(mb_type)) {
 275         s->dsp.clear_blocks(s->block[0]);
 276
 277         if(!s->chroma_y_shift){
 278             s->dsp.clear_blocks(s->block[6]);
 279         }
 280
 281         /* compute DCT type */
 282         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
 283             !s->frame_pred_frame_dct) {
 284             s->interlaced_dct = get_bits1(&s->gb);
 285         }
 286
 287         if (IS_QUANT(mb_type))
 288             s->qscale = get_qscale(s);
 289
 290         if (s->concealment_motion_vectors) {
 291             /* just parse them */
 292             if (s->picture_structure != PICT_FRAME)
 293                 skip_bits1(&s->gb); /* field select */
 294
 295             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 296                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 297             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 298                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 299
 300             skip_bits1(&s->gb); /* marker */
 301         }else
 302             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 303         s->mb_intra = 1;
 304         //if 1, we memcpy blocks in xvmcvideo
 305         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 306             ff_xvmc_pack_pblocks(s,-1);//inter are always full blocks
 307             if(s->swap_uv){
 308                 exchange_uv(s);
 309             }
 310         }
 311
 312         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 313             if(s->flags2 & CODEC_FLAG2_FAST){
 314                 for(i=0;i<6;i++) {
 315                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
 316                 }
 317             }else{
 318                 for(i=0;i<mb_block_count;i++) {
 319                     if (mpeg2_decode_block_intra(s, *s->pblocks[i], i) < 0)
 320                         return -1;
 321                 }
 322             }
 323         } else {
 324             for(i=0;i<6;i++) {
 325                 if (mpeg1_decode_block_intra(s, *s->pblocks[i], i) < 0)
 326                     return -1;
 327             }
 328         }
 329     } else {
 330         if (mb_type & MB_TYPE_ZERO_MV){
 331             assert(mb_type & MB_TYPE_CBP);
 332
 333             s->mv_dir = MV_DIR_FORWARD;
 334             if(s->picture_structure == PICT_FRAME){
 335                 if(!s->frame_pred_frame_dct)
 336                     s->interlaced_dct = get_bits1(&s->gb);
 337                 s->mv_type = MV_TYPE_16X16;
 338             }else{
 339                 s->mv_type = MV_TYPE_FIELD;
 340                 mb_type |= MB_TYPE_INTERLACED;
 341                 s->field_select[0][0]= s->picture_structure - 1;
 342             }
 343
 344             if (IS_QUANT(mb_type))
 345                 s->qscale = get_qscale(s);
 346
 347             s->last_mv[0][0][0] = 0;
 348             s->last_mv[0][0][1] = 0;
 349             s->last_mv[0][1][0] = 0;
 350             s->last_mv[0][1][1] = 0;
 351             s->mv[0][0][0] = 0;
 352             s->mv[0][0][1] = 0;
 353         }else{
 354             assert(mb_type & MB_TYPE_L0L1);
 355 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 356             /* get additional motion vector type */
 357             if (s->frame_pred_frame_dct)
 358                 motion_type = MT_FRAME;
 359             else{
 360                 motion_type = get_bits(&s->gb, 2);
 361                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 362                     s->interlaced_dct = get_bits1(&s->gb);
 363             }
 364
 365             if (IS_QUANT(mb_type))
 366                 s->qscale = get_qscale(s);
 367
 368             /* motion vectors */
 369             s->mv_dir= (mb_type>>13)&3;
 370             dprintf(s->avctx, "motion_type=%d\n", motion_type);
 371             switch(motion_type) {
 372             case MT_FRAME: /* or MT_16X8 */
 373                 if (s->picture_structure == PICT_FRAME) {
 374                     mb_type |= MB_TYPE_16x16;
 375                     s->mv_type = MV_TYPE_16X16;
 376                     for(i=0;i<2;i++) {
 377                         if (USES_LIST(mb_type, i)) {
 378                             /* MT_FRAME */
 379                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
 380                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
 381                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
 382                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
 383                             /* full_pel: only for MPEG-1 */
 384                             if (s->full_pel[i]){
 385                                 s->mv[i][0][0] <<= 1;
 386                                 s->mv[i][0][1] <<= 1;
 387                             }
 388                         }
 389                     }
 390                 } else {
 391                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 392                     s->mv_type = MV_TYPE_16X8;
 393                     for(i=0;i<2;i++) {
 394                         if (USES_LIST(mb_type, i)) {
 395                             /* MT_16X8 */
 396                             for(j=0;j<2;j++) {
 397                                 s->field_select[i][j] = get_bits1(&s->gb);
 398                                 for(k=0;k<2;k++) {
 399                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 400                                                              s->last_mv[i][j][k]);
 401                                     s->last_mv[i][j][k] = val;
 402                                     s->mv[i][j][k] = val;
 403                                 }
 404                             }
 405                         }
 406                     }
 407                 }
 408                 break;
 409             case MT_FIELD:
 410                 s->mv_type = MV_TYPE_FIELD;
 411                 if (s->picture_structure == PICT_FRAME) {
 412                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 413                     for(i=0;i<2;i++) {
 414                         if (USES_LIST(mb_type, i)) {
 415                             for(j=0;j<2;j++) {
 416                                 s->field_select[i][j] = get_bits1(&s->gb);
 417                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 418                                                          s->last_mv[i][j][0]);
 419                                 s->last_mv[i][j][0] = val;
 420                                 s->mv[i][j][0] = val;
 421                                 dprintf(s->avctx, "fmx=%d\n", val);
 422                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 423                                                          s->last_mv[i][j][1] >> 1);
 424                                 s->last_mv[i][j][1] = val << 1;
 425                                 s->mv[i][j][1] = val;
 426                                 dprintf(s->avctx, "fmy=%d\n", val);
 427                             }
 428                         }
 429                     }
 430                 } else {
 431                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 432                     for(i=0;i<2;i++) {
 433                         if (USES_LIST(mb_type, i)) {
 434                             s->field_select[i][0] = get_bits1(&s->gb);
 435                             for(k=0;k<2;k++) {
 436                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 437                                                          s->last_mv[i][0][k]);
 438                                 s->last_mv[i][0][k] = val;
 439                                 s->last_mv[i][1][k] = val;
 440                                 s->mv[i][0][k] = val;
 441                             }
 442                         }
 443                     }
 444                 }
 445                 break;
 446             case MT_DMV:
 447                 s->mv_type = MV_TYPE_DMV;
 448                 for(i=0;i<2;i++) {
 449                     if (USES_LIST(mb_type, i)) {
 450                         int dmx, dmy, mx, my, m;
 451                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 452                                                 s->last_mv[i][0][0]);
 453                         s->last_mv[i][0][0] = mx;
 454                         s->last_mv[i][1][0] = mx;
 455                         dmx = get_dmv(s);
 456                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 457                                                 s->last_mv[i][0][1] >> 1);
 458                         dmy = get_dmv(s);
 459
 460
 461                         s->last_mv[i][0][1] = my<<1;
 462                         s->last_mv[i][1][1] = my<<1;
 463
 464                         s->mv[i][0][0] = mx;
 465                         s->mv[i][0][1] = my;
 466                         s->mv[i][1][0] = mx;//not used
 467                         s->mv[i][1][1] = my;//not used
 468
 469                         if (s->picture_structure == PICT_FRAME) {
 470                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 471
 472                             //m = 1 + 2 * s->top_field_first;
 473                             m = s->top_field_first ? 1 : 3;
 474
 475                             /* top -> top pred */
 476                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 477                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
 478                             m = 4 - m;
 479                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 480                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
 481                         } else {
 482                             mb_type |= MB_TYPE_16x16;
 483
 484                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
 485                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
 486                             if(s->picture_structure == PICT_TOP_FIELD)
 487                                 s->mv[i][2][1]--;
 488                             else
 489                                 s->mv[i][2][1]++;
 490                         }
 491                     }
 492                 }
 493                 break;
 494             default:
 495                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
 496                 return -1;
 497             }
 498         }
 499
 500         s->mb_intra = 0;
 501         if (HAS_CBP(mb_type)) {
 502             s->dsp.clear_blocks(s->block[0]);
 503
 504             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
 505             if(mb_block_count > 6){
 506                  cbp<<= mb_block_count-6;
 507                  cbp |= get_bits(&s->gb, mb_block_count-6);
 508                  s->dsp.clear_blocks(s->block[6]);
 509             }
 510             if (cbp <= 0){
 511                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
 512                 return -1;
 513             }
 514
 515             //if 1, we memcpy blocks in xvmcvideo
 516             if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 517                 ff_xvmc_pack_pblocks(s,cbp);
 518                 if(s->swap_uv){
 519                     exchange_uv(s);
 520                 }
 521             }
 522
 523             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 524                 if(s->flags2 & CODEC_FLAG2_FAST){
 525                     for(i=0;i<6;i++) {
 526                         if(cbp & 32) {
 527                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
 528                         } else {
 529                             s->block_last_index[i] = -1;
 530                         }
 531                         cbp+=cbp;
 532                     }
 533                 }else{
 534                     cbp<<= 12-mb_block_count;
 535
 536                     for(i=0;i<mb_block_count;i++) {
 537                         if ( cbp & (1<<11) ) {
 538                             if (mpeg2_decode_block_non_intra(s, *s->pblocks[i], i) < 0)
 539                                 return -1;
 540                         } else {
 541                             s->block_last_index[i] = -1;
 542                         }
 543                         cbp+=cbp;
 544                     }
 545                 }
 546             } else {
 547                 if(s->flags2 & CODEC_FLAG2_FAST){
 548                     for(i=0;i<6;i++) {
 549                         if (cbp & 32) {
 550                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
 551                         } else {
 552                             s->block_last_index[i] = -1;
 553                         }
 554                         cbp+=cbp;
 555                     }
 556                 }else{
 557                     for(i=0;i<6;i++) {
 558                         if (cbp & 32) {
 559                             if (mpeg1_decode_block_inter(s, *s->pblocks[i], i) < 0)
 560                                 return -1;
 561                         } else {
 562                             s->block_last_index[i] = -1;
 563                         }
 564                         cbp+=cbp;
 565                     }
 566                 }
 567             }
 568         }else{
 569             for(i=0;i<12;i++)
 570                 s->block_last_index[i] = -1;
 571         }
 572     }
 573
 574     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
 575
 576     return 0;
 577 }
 578
 579 /* as H.263, but only 17 codes */
 580 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 581 {
 582     int code, sign, val, l, shift;
 583
 584     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 585     if (code == 0) {
 586         return pred;
 587     }
 588     if (code < 0) {
 589         return 0xffff;
 590     }
 591
 592     sign = get_bits1(&s->gb);
 593     shift = fcode - 1;
 594     val = code;
 595     if (shift) {
 596         val = (val - 1) << shift;
 597         val |= get_bits(&s->gb, shift);
 598         val++;
 599     }
 600     if (sign)
 601         val = -val;
 602     val += pred;
 603
 604     /* modulo decoding */
 605     l= INT_BIT - 5 - shift;
 606     val = (val<<l)>>l;
 607     return val;
 608 }
 609
 610 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 611                                DCTELEM *block,
 612                                int n)
 613 {
 614     int level, dc, diff, i, j, run;
 615     int component;
 616     RLTable *rl = &ff_rl_mpeg1;
 617     uint8_t * const scantable= s->intra_scantable.permutated;
 618     const uint16_t *quant_matrix= s->intra_matrix;
 619     const int qscale= s->qscale;
 620
 621     /* DC coefficient */
 622     component = (n <= 3 ? 0 : n - 4 + 1);
 623     diff = decode_dc(&s->gb, component);
 624     if (diff >= 0xffff)
 625         return -1;
 626     dc = s->last_dc[component];
 627     dc += diff;
 628     s->last_dc[component] = dc;
 629     block[0] = dc*quant_matrix[0];
 630     dprintf(s->avctx, "dc=%d diff=%d\n", dc, diff);
 631     i = 0;
 632     {
 633         OPEN_READER(re, &s->gb);
 634         /* now quantify & encode AC coefficients */
 635         for(;;) {
 636             UPDATE_CACHE(re, &s->gb);
 637             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 638
 639             if(level == 127){
 640                 break;
 641             } else if(level != 0) {
 642                 i += run;
 643                 j = scantable[i];
 644                 level= (level*qscale*quant_matrix[j])>>4;
 645                 level= (level-1)|1;
 646                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 647                 LAST_SKIP_BITS(re, &s->gb, 1);
 648             } else {
 649                 /* escape */
 650                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 651                 UPDATE_CACHE(re, &s->gb);
 652                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 653                 if (level == -128) {
 654                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
 655                 } else if (level == 0) {
 656                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
 657                 }
 658                 i += run;
 659                 j = scantable[i];
 660                 if(level<0){
 661                     level= -level;
 662                     level= (level*qscale*quant_matrix[j])>>4;
 663                     level= (level-1)|1;
 664                     level= -level;
 665                 }else{
 666                     level= (level*qscale*quant_matrix[j])>>4;
 667                     level= (level-1)|1;
 668                 }
 669             }
 670             if (i > 63){
 671                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 672                 return -1;
 673             }
 674
 675             block[j] = level;
 676         }
 677         CLOSE_READER(re, &s->gb);
 678     }
 679     s->block_last_index[n] = i;
 680    return 0;
 681 }
 682
 683 int ff_mpeg1_decode_block_intra(MpegEncContext *s,
 684                                 DCTELEM *block,
 685                                 int n)
 686 {
 687     return mpeg1_decode_block_intra(s, block, n);
 688 }
 689
 690 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 691                                DCTELEM *block,
 692                                int n)
 693 {
 694     int level, i, j, run;
 695     RLTable *rl = &ff_rl_mpeg1;
 696     uint8_t * const scantable= s->intra_scantable.permutated;
 697     const uint16_t *quant_matrix= s->inter_matrix;
 698     const int qscale= s->qscale;
 699
 700     {
 701         OPEN_READER(re, &s->gb);
 702         i = -1;
 703         // special case for first coefficient, no need to add second VLC table
 704         UPDATE_CACHE(re, &s->gb);
 705         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 706             level= (3*qscale*quant_matrix[0])>>5;
 707             level= (level-1)|1;
 708             if(GET_CACHE(re, &s->gb)&0x40000000)
 709                 level= -level;
 710             block[0] = level;
 711             i++;
 712             SKIP_BITS(re, &s->gb, 2);
 713             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 714                 goto end;
 715         }
 716 #if MIN_CACHE_BITS < 19
 717         UPDATE_CACHE(re, &s->gb);
 718 #endif
 719         /* now quantify & encode AC coefficients */
 720         for(;;) {
 721             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 722
 723             if(level != 0) {
 724                 i += run;
 725                 j = scantable[i];
 726                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 727                 level= (level-1)|1;
 728                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 729                 SKIP_BITS(re, &s->gb, 1);
 730             } else {
 731                 /* escape */
 732                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 733                 UPDATE_CACHE(re, &s->gb);
 734                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 735                 if (level == -128) {
 736                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 737                 } else if (level == 0) {
 738                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 739                 }
 740                 i += run;
 741                 j = scantable[i];
 742                 if(level<0){
 743                     level= -level;
 744                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 745                     level= (level-1)|1;
 746                     level= -level;
 747                 }else{
 748                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 749                     level= (level-1)|1;
 750                 }
 751             }
 752             if (i > 63){
 753                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 754                 return -1;
 755             }
 756
 757             block[j] = level;
 758 #if MIN_CACHE_BITS < 19
 759             UPDATE_CACHE(re, &s->gb);
 760 #endif
 761             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 762                 break;
 763 #if MIN_CACHE_BITS >= 19
 764             UPDATE_CACHE(re, &s->gb);
 765 #endif
 766         }
 767 end:
 768         LAST_SKIP_BITS(re, &s->gb, 2);
 769         CLOSE_READER(re, &s->gb);
 770     }
 771     s->block_last_index[n] = i;
 772     return 0;
 773 }
 774
 775 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
 776 {
 777     int level, i, j, run;
 778     RLTable *rl = &ff_rl_mpeg1;
 779     uint8_t * const scantable= s->intra_scantable.permutated;
 780     const int qscale= s->qscale;
 781
 782     {
 783         OPEN_READER(re, &s->gb);
 784         i = -1;
 785         // special case for first coefficient, no need to add second VLC table
 786         UPDATE_CACHE(re, &s->gb);
 787         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 788             level= (3*qscale)>>1;
 789             level= (level-1)|1;
 790             if(GET_CACHE(re, &s->gb)&0x40000000)
 791                 level= -level;
 792             block[0] = level;
 793             i++;
 794             SKIP_BITS(re, &s->gb, 2);
 795             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 796                 goto end;
 797         }
 798 #if MIN_CACHE_BITS < 19
 799         UPDATE_CACHE(re, &s->gb);
 800 #endif
 801
 802         /* now quantify & encode AC coefficients */
 803         for(;;) {
 804             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 805
 806             if(level != 0) {
 807                 i += run;
 808                 j = scantable[i];
 809                 level= ((level*2+1)*qscale)>>1;
 810                 level= (level-1)|1;
 811                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 812                 SKIP_BITS(re, &s->gb, 1);
 813             } else {
 814                 /* escape */
 815                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 816                 UPDATE_CACHE(re, &s->gb);
 817                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 818                 if (level == -128) {
 819                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 820                 } else if (level == 0) {
 821                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 822                 }
 823                 i += run;
 824                 j = scantable[i];
 825                 if(level<0){
 826                     level= -level;
 827                     level= ((level*2+1)*qscale)>>1;
 828                     level= (level-1)|1;
 829                     level= -level;
 830                 }else{
 831                     level= ((level*2+1)*qscale)>>1;
 832                     level= (level-1)|1;
 833                 }
 834             }
 835
 836             block[j] = level;
 837 #if MIN_CACHE_BITS < 19
 838             UPDATE_CACHE(re, &s->gb);
 839 #endif
 840             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 841                 break;
 842 #if MIN_CACHE_BITS >= 19
 843             UPDATE_CACHE(re, &s->gb);
 844 #endif
 845         }
 846 end:
 847         LAST_SKIP_BITS(re, &s->gb, 2);
 848         CLOSE_READER(re, &s->gb);
 849     }
 850     s->block_last_index[n] = i;
 851     return 0;
 852 }
 853
 854
 855 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 856                                DCTELEM *block,
 857                                int n)
 858 {
 859     int level, i, j, run;
 860     RLTable *rl = &ff_rl_mpeg1;
 861     uint8_t * const scantable= s->intra_scantable.permutated;
 862     const uint16_t *quant_matrix;
 863     const int qscale= s->qscale;
 864     int mismatch;
 865
 866     mismatch = 1;
 867
 868     {
 869         OPEN_READER(re, &s->gb);
 870         i = -1;
 871         if (n < 4)
 872             quant_matrix = s->inter_matrix;
 873         else
 874             quant_matrix = s->chroma_inter_matrix;
 875
 876         // special case for first coefficient, no need to add second VLC table
 877         UPDATE_CACHE(re, &s->gb);
 878         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 879             level= (3*qscale*quant_matrix[0])>>5;
 880             if(GET_CACHE(re, &s->gb)&0x40000000)
 881                 level= -level;
 882             block[0] = level;
 883             mismatch ^= level;
 884             i++;
 885             SKIP_BITS(re, &s->gb, 2);
 886             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 887                 goto end;
 888         }
 889 #if MIN_CACHE_BITS < 19
 890         UPDATE_CACHE(re, &s->gb);
 891 #endif
 892
 893         /* now quantify & encode AC coefficients */
 894         for(;;) {
 895             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 896
 897             if(level != 0) {
 898                 i += run;
 899                 j = scantable[i];
 900                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 901                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 902                 SKIP_BITS(re, &s->gb, 1);
 903             } else {
 904                 /* escape */
 905                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 906                 UPDATE_CACHE(re, &s->gb);
 907                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 908
 909                 i += run;
 910                 j = scantable[i];
 911                 if(level<0){
 912                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
 913                     level= -level;
 914                 }else{
 915                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 916                 }
 917             }
 918             if (i > 63){
 919                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 920                 return -1;
 921             }
 922
 923             mismatch ^= level;
 924             block[j] = level;
 925 #if MIN_CACHE_BITS < 19
 926             UPDATE_CACHE(re, &s->gb);
 927 #endif
 928             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 929                 break;
 930 #if MIN_CACHE_BITS >= 19
 931             UPDATE_CACHE(re, &s->gb);
 932 #endif
 933         }
 934 end:
 935         LAST_SKIP_BITS(re, &s->gb, 2);
 936         CLOSE_READER(re, &s->gb);
 937     }
 938     block[63] ^= (mismatch & 1);
 939
 940     s->block_last_index[n] = i;
 941     return 0;
 942 }
 943
 944 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 945                                DCTELEM *block,
 946                                int n)
 947 {
 948     int level, i, j, run;
 949     RLTable *rl = &ff_rl_mpeg1;
 950     uint8_t * const scantable= s->intra_scantable.permutated;
 951     const int qscale= s->qscale;
 952     OPEN_READER(re, &s->gb);
 953     i = -1;
 954
 955     // special case for first coefficient, no need to add second VLC table
 956     UPDATE_CACHE(re, &s->gb);
 957     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 958         level= (3*qscale)>>1;
 959         if(GET_CACHE(re, &s->gb)&0x40000000)
 960             level= -level;
 961         block[0] = level;
 962         i++;
 963         SKIP_BITS(re, &s->gb, 2);
 964         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 965             goto end;
 966     }
 967 #if MIN_CACHE_BITS < 19
 968     UPDATE_CACHE(re, &s->gb);
 969 #endif
 970
 971     /* now quantify & encode AC coefficients */
 972     for(;;) {
 973         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 974
 975         if(level != 0) {
 976             i += run;
 977             j = scantable[i];
 978             level= ((level*2+1)*qscale)>>1;
 979             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 980             SKIP_BITS(re, &s->gb, 1);
 981         } else {
 982             /* escape */
 983             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 984             UPDATE_CACHE(re, &s->gb);
 985             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 986
 987             i += run;
 988             j = scantable[i];
 989             if(level<0){
 990                 level= ((-level*2+1)*qscale)>>1;
 991                 level= -level;
 992             }else{
 993                 level= ((level*2+1)*qscale)>>1;
 994             }
 995         }
 996
 997         block[j] = level;
 998 #if MIN_CACHE_BITS < 19
 999         UPDATE_CACHE(re, &s->gb);
1000 #endif
1001         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
1002             break;
1003 #if MIN_CACHE_BITS >=19
1004         UPDATE_CACHE(re, &s->gb);
1005 #endif
1006     }
1007 end:
1008     LAST_SKIP_BITS(re, &s->gb, 2);
1009     CLOSE_READER(re, &s->gb);
1010     s->block_last_index[n] = i;
1011     return 0;
1012 }
1013
1014
1015 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1016                                DCTELEM *block,
1017                                int n)
1018 {
1019     int level, dc, diff, i, j, run;
1020     int component;
1021     RLTable *rl;
1022     uint8_t * const scantable= s->intra_scantable.permutated;
1023     const uint16_t *quant_matrix;
1024     const int qscale= s->qscale;
1025     int mismatch;
1026
1027     /* DC coefficient */
1028     if (n < 4){
1029         quant_matrix = s->intra_matrix;
1030         component = 0;
1031     }else{
1032         quant_matrix = s->chroma_intra_matrix;
1033         component = (n&1) + 1;
1034     }
1035     diff = decode_dc(&s->gb, component);
1036     if (diff >= 0xffff)
1037         return -1;
1038     dc = s->last_dc[component];
1039     dc += diff;
1040     s->last_dc[component] = dc;
1041     block[0] = dc << (3 - s->intra_dc_precision);
1042     dprintf(s->avctx, "dc=%d\n", block[0]);
1043     mismatch = block[0] ^ 1;
1044     i = 0;
1045     if (s->intra_vlc_format)
1046         rl = &ff_rl_mpeg2;
1047     else
1048         rl = &ff_rl_mpeg1;
1049
1050     {
1051         OPEN_READER(re, &s->gb);
1052         /* now quantify & encode AC coefficients */
1053         for(;;) {
1054             UPDATE_CACHE(re, &s->gb);
1055             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1056
1057             if(level == 127){
1058                 break;
1059             } else if(level != 0) {
1060                 i += run;
1061                 j = scantable[i];
1062                 level= (level*qscale*quant_matrix[j])>>4;
1063                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1064                 LAST_SKIP_BITS(re, &s->gb, 1);
1065             } else {
1066                 /* escape */
1067                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1068                 UPDATE_CACHE(re, &s->gb);
1069                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1070                 i += run;
1071                 j = scantable[i];
1072                 if(level<0){
1073                     level= (-level*qscale*quant_matrix[j])>>4;
1074                     level= -level;
1075                 }else{
1076                     level= (level*qscale*quant_matrix[j])>>4;
1077                 }
1078             }
1079             if (i > 63){
1080                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1081                 return -1;
1082             }
1083
1084             mismatch^= level;
1085             block[j] = level;
1086         }
1087         CLOSE_READER(re, &s->gb);
1088     }
1089     block[63]^= mismatch&1;
1090
1091     s->block_last_index[n] = i;
1092     return 0;
1093 }
1094
1095 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1096                                DCTELEM *block,
1097                                int n)
1098 {
1099     int level, dc, diff, j, run;
1100     int component;
1101     RLTable *rl;
1102     uint8_t * scantable= s->intra_scantable.permutated;
1103     const uint16_t *quant_matrix;
1104     const int qscale= s->qscale;
1105
1106     /* DC coefficient */
1107     if (n < 4){
1108         quant_matrix = s->intra_matrix;
1109         component = 0;
1110     }else{
1111         quant_matrix = s->chroma_intra_matrix;
1112         component = (n&1) + 1;
1113     }
1114     diff = decode_dc(&s->gb, component);
1115     if (diff >= 0xffff)
1116         return -1;
1117     dc = s->last_dc[component];
1118     dc += diff;
1119     s->last_dc[component] = dc;
1120     block[0] = dc << (3 - s->intra_dc_precision);
1121     if (s->intra_vlc_format)
1122         rl = &ff_rl_mpeg2;
1123     else
1124         rl = &ff_rl_mpeg1;
1125
1126     {
1127         OPEN_READER(re, &s->gb);
1128         /* now quantify & encode AC coefficients */
1129         for(;;) {
1130             UPDATE_CACHE(re, &s->gb);
1131             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1132
1133             if(level == 127){
1134                 break;
1135             } else if(level != 0) {
1136                 scantable += run;
1137                 j = *scantable;
1138                 level= (level*qscale*quant_matrix[j])>>4;
1139                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1140                 LAST_SKIP_BITS(re, &s->gb, 1);
1141             } else {
1142                 /* escape */
1143                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1144                 UPDATE_CACHE(re, &s->gb);
1145                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1146                 scantable += run;
1147                 j = *scantable;
1148                 if(level<0){
1149                     level= (-level*qscale*quant_matrix[j])>>4;
1150                     level= -level;
1151                 }else{
1152                     level= (level*qscale*quant_matrix[j])>>4;
1153                 }
1154             }
1155
1156             block[j] = level;
1157         }
1158         CLOSE_READER(re, &s->gb);
1159     }
1160
1161     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1162     return 0;
1163 }
1164
1165 typedef struct Mpeg1Context {
1166     MpegEncContext mpeg_enc_ctx;
1167     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1168     int repeat_field; /* true if we must repeat the field */
1169     AVPanScan pan_scan; /** some temporary storage for the panscan */
1170     int slice_count;
1171     int swap_uv;//indicate VCR2
1172     int save_aspect_info;
1173     int save_width, save_height, save_progressive_seq;
1174     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1175
1176 } Mpeg1Context;
1177
1178 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1179 {
1180     Mpeg1Context *s = avctx->priv_data;
1181     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1182     int i;
1183
1184     /* we need some permutation to store matrices,
1185      * until MPV_common_init() sets the real permutation. */
1186     for(i=0;i<64;i++)
1187        s2->dsp.idct_permutation[i]=i;
1188
1189     MPV_decode_defaults(s2);
1190
1191     s->mpeg_enc_ctx.avctx= avctx;
1192     s->mpeg_enc_ctx.flags= avctx->flags;
1193     s->mpeg_enc_ctx.flags2= avctx->flags2;
1194     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1195     ff_mpeg12_init_vlcs();
1196
1197     s->mpeg_enc_ctx_allocated = 0;
1198     s->mpeg_enc_ctx.picture_number = 0;
1199     s->repeat_field = 0;
1200     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1201     avctx->color_range= AVCOL_RANGE_MPEG;
1202     if (avctx->codec->id == CODEC_ID_MPEG1VIDEO)
1203         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1204     else
1205         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
1206     return 0;
1207 }
1208
1209 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1210                                      const uint8_t *new_perm){
1211     uint16_t temp_matrix[64];
1212     int i;
1213
1214     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1215
1216     for(i=0;i<64;i++){
1217         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1218     }
1219 }
1220
1221 static enum PixelFormat mpeg_get_pixelformat(AVCodecContext *avctx){
1222     Mpeg1Context *s1 = avctx->priv_data;
1223     MpegEncContext *s = &s1->mpeg_enc_ctx;
1224
1225     if(avctx->xvmc_acceleration)
1226         return avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1227     else if(avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU){
1228         if(avctx->codec_id == CODEC_ID_MPEG1VIDEO)
1229             return PIX_FMT_VDPAU_MPEG1;
1230         else
1231             return PIX_FMT_VDPAU_MPEG2;
1232     }else{
1233         if(s->chroma_format <  2)
1234             return avctx->get_format(avctx,ff_hwaccel_pixfmt_list_420);
1235         else if(s->chroma_format == 2)
1236             return PIX_FMT_YUV422P;
1237         else
1238             return PIX_FMT_YUV444P;
1239     }
1240 }
1241
1242 /* Call this function when we know all parameters.
1243  * It may be called in different places for MPEG-1 and MPEG-2. */
1244 static int mpeg_decode_postinit(AVCodecContext *avctx){
1245     Mpeg1Context *s1 = avctx->priv_data;
1246     MpegEncContext *s = &s1->mpeg_enc_ctx;
1247     uint8_t old_permutation[64];
1248
1249     if (
1250         (s1->mpeg_enc_ctx_allocated == 0)||
1251         avctx->coded_width  != s->width ||
1252         avctx->coded_height != s->height||
1253         s1->save_width != s->width ||
1254         s1->save_height != s->height ||
1255         s1->save_aspect_info != s->aspect_ratio_info||
1256         s1->save_progressive_seq != s->progressive_sequence ||
1257         0)
1258     {
1259
1260         if (s1->mpeg_enc_ctx_allocated) {
1261             ParseContext pc= s->parse_context;
1262             s->parse_context.buffer=0;
1263             MPV_common_end(s);
1264             s->parse_context= pc;
1265         }
1266
1267         if( (s->width == 0 )||(s->height == 0))
1268             return -2;
1269
1270         avcodec_set_dimensions(avctx, s->width, s->height);
1271         avctx->bit_rate = s->bit_rate;
1272         s1->save_aspect_info = s->aspect_ratio_info;
1273         s1->save_width = s->width;
1274         s1->save_height = s->height;
1275         s1->save_progressive_seq = s->progressive_sequence;
1276
1277         /* low_delay may be forced, in this case we will have B-frames
1278          * that behave like P-frames. */
1279         avctx->has_b_frames = !(s->low_delay);
1280
1281         assert((avctx->sub_id==1) == (avctx->codec_id==CODEC_ID_MPEG1VIDEO));
1282         if(avctx->codec_id==CODEC_ID_MPEG1VIDEO){
1283             //MPEG-1 fps
1284             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1285             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1286             //MPEG-1 aspect
1287             avctx->sample_aspect_ratio= av_d2q(
1288                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1289             avctx->ticks_per_frame=1;
1290         }else{//MPEG-2
1291         //MPEG-2 fps
1292             av_reduce(
1293                 &s->avctx->time_base.den,
1294                 &s->avctx->time_base.num,
1295                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num*2,
1296                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1297                 1<<30);
1298             avctx->ticks_per_frame=2;
1299         //MPEG-2 aspect
1300             if(s->aspect_ratio_info > 1){
1301                 //we ignore the spec here as reality does not match the spec, see for example
1302                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1303                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) || 1){
1304                     s->avctx->sample_aspect_ratio=
1305                         av_div_q(
1306                          ff_mpeg2_aspect[s->aspect_ratio_info],
1307                          (AVRational){s->width, s->height}
1308                          );
1309                 }else{
1310                     s->avctx->sample_aspect_ratio=
1311                         av_div_q(
1312                          ff_mpeg2_aspect[s->aspect_ratio_info],
1313                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1314                         );
1315                 }
1316             }else{
1317                 s->avctx->sample_aspect_ratio=
1318                     ff_mpeg2_aspect[s->aspect_ratio_info];
1319             }
1320         }//MPEG-2
1321
1322         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1323         avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
1324         //until then pix_fmt may be changed right after codec init
1325         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
1326             avctx->hwaccel ||
1327             s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
1328             if( avctx->idct_algo == FF_IDCT_AUTO )
1329                 avctx->idct_algo = FF_IDCT_SIMPLE;
1330
1331         /* Quantization matrices may need reordering
1332          * if DCT permutation is changed. */
1333         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1334
1335         if (MPV_common_init(s) < 0)
1336             return -2;
1337
1338         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1339         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1340         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1341         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1342
1343         s1->mpeg_enc_ctx_allocated = 1;
1344     }
1345     return 0;
1346 }
1347
1348 static int mpeg1_decode_picture(AVCodecContext *avctx,
1349                                 const uint8_t *buf, int buf_size)
1350 {
1351     Mpeg1Context *s1 = avctx->priv_data;
1352     MpegEncContext *s = &s1->mpeg_enc_ctx;
1353     int ref, f_code, vbv_delay;
1354
1355     if(mpeg_decode_postinit(s->avctx) < 0)
1356        return -2;
1357
1358     init_get_bits(&s->gb, buf, buf_size*8);
1359
1360     ref = get_bits(&s->gb, 10); /* temporal ref */
1361     s->pict_type = get_bits(&s->gb, 3);
1362     if(s->pict_type == 0 || s->pict_type > 3)
1363         return -1;
1364
1365     vbv_delay= get_bits(&s->gb, 16);
1366     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1367         s->full_pel[0] = get_bits1(&s->gb);
1368         f_code = get_bits(&s->gb, 3);
1369         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1370             return -1;
1371         s->mpeg_f_code[0][0] = f_code;
1372         s->mpeg_f_code[0][1] = f_code;
1373     }
1374     if (s->pict_type == FF_B_TYPE) {
1375         s->full_pel[1] = get_bits1(&s->gb);
1376         f_code = get_bits(&s->gb, 3);
1377         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1378             return -1;
1379         s->mpeg_f_code[1][0] = f_code;
1380         s->mpeg_f_code[1][1] = f_code;
1381     }
1382     s->current_picture.pict_type= s->pict_type;
1383     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1384
1385     if(avctx->debug & FF_DEBUG_PICT_INFO)
1386         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1387
1388     s->y_dc_scale = 8;
1389     s->c_dc_scale = 8;
1390     s->first_slice = 1;
1391     return 0;
1392 }
1393
1394 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1395 {
1396     MpegEncContext *s= &s1->mpeg_enc_ctx;
1397     int horiz_size_ext, vert_size_ext;
1398     int bit_rate_ext;
1399
1400     skip_bits(&s->gb, 1); /* profile and level esc*/
1401     s->avctx->profile= get_bits(&s->gb, 3);
1402     s->avctx->level= get_bits(&s->gb, 4);
1403     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1404     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1405     horiz_size_ext = get_bits(&s->gb, 2);
1406     vert_size_ext = get_bits(&s->gb, 2);
1407     s->width |= (horiz_size_ext << 12);
1408     s->height |= (vert_size_ext << 12);
1409     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1410     s->bit_rate += (bit_rate_ext << 18) * 400;
1411     skip_bits1(&s->gb); /* marker */
1412     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1413
1414     s->low_delay = get_bits1(&s->gb);
1415     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1416
1417     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1418     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1419
1420     dprintf(s->avctx, "sequence extension\n");
1421     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1422     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1423
1424     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1425         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1426                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1427
1428 }
1429
1430 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1431 {
1432     MpegEncContext *s= &s1->mpeg_enc_ctx;
1433     int color_description, w, h;
1434
1435     skip_bits(&s->gb, 3); /* video format */
1436     color_description= get_bits1(&s->gb);
1437     if(color_description){
1438         s->avctx->color_primaries= get_bits(&s->gb, 8);
1439         s->avctx->color_trc      = get_bits(&s->gb, 8);
1440         s->avctx->colorspace     = get_bits(&s->gb, 8);
1441     }
1442     w= get_bits(&s->gb, 14);
1443     skip_bits(&s->gb, 1); //marker
1444     h= get_bits(&s->gb, 14);
1445     skip_bits(&s->gb, 1); //marker
1446
1447     s1->pan_scan.width= 16*w;
1448     s1->pan_scan.height=16*h;
1449
1450     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1451         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1452 }
1453
1454 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1455 {
1456     MpegEncContext *s= &s1->mpeg_enc_ctx;
1457     int i,nofco;
1458
1459     nofco = 1;
1460     if(s->progressive_sequence){
1461         if(s->repeat_first_field){
1462             nofco++;
1463             if(s->top_field_first)
1464                 nofco++;
1465         }
1466     }else{
1467         if(s->picture_structure == PICT_FRAME){
1468             nofco++;
1469             if(s->repeat_first_field)
1470                 nofco++;
1471         }
1472     }
1473     for(i=0; i<nofco; i++){
1474         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1475         skip_bits(&s->gb, 1); //marker
1476         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1477         skip_bits(&s->gb, 1); //marker
1478     }
1479
1480     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1481         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1482             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1483             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1484             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1485         );
1486 }
1487
1488 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64], uint16_t matrix1[64], int intra){
1489     int i;
1490
1491     for(i=0; i<64; i++) {
1492         int j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1493         int v = get_bits(&s->gb, 8);
1494         if(v==0){
1495             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1496             return -1;
1497         }
1498         if(intra && i==0 && v!=8){
1499             av_log(s->avctx, AV_LOG_ERROR, "intra matrix invalid, ignoring\n");
1500             v= 8; // needed by pink.mpg / issue1046
1501         }
1502         matrix0[j] = v;
1503         if(matrix1)
1504             matrix1[j] = v;
1505     }
1506     return 0;
1507 }
1508
1509 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1510 {
1511     dprintf(s->avctx, "matrix extension\n");
1512
1513     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1514     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1515     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, NULL           , 1);
1516     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, NULL           , 0);
1517 }
1518
1519 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1520 {
1521     MpegEncContext *s= &s1->mpeg_enc_ctx;
1522
1523     s->full_pel[0] = s->full_pel[1] = 0;
1524     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1525     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1526     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1527     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1528     if(!s->pict_type && s1->mpeg_enc_ctx_allocated){
1529         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1530         if(s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1]==15){
1531             if(s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1532                 s->pict_type= FF_I_TYPE;
1533             else
1534                 s->pict_type= FF_P_TYPE;
1535         }else
1536             s->pict_type= FF_B_TYPE;
1537         s->current_picture.pict_type= s->pict_type;
1538         s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1539         s->first_slice= 1;
1540     }
1541     s->intra_dc_precision = get_bits(&s->gb, 2);
1542     s->picture_structure = get_bits(&s->gb, 2);
1543     s->top_field_first = get_bits1(&s->gb);
1544     s->frame_pred_frame_dct = get_bits1(&s->gb);
1545     s->concealment_motion_vectors = get_bits1(&s->gb);
1546     s->q_scale_type = get_bits1(&s->gb);
1547     s->intra_vlc_format = get_bits1(&s->gb);
1548     s->alternate_scan = get_bits1(&s->gb);
1549     s->repeat_first_field = get_bits1(&s->gb);
1550     s->chroma_420_type = get_bits1(&s->gb);
1551     s->progressive_frame = get_bits1(&s->gb);
1552
1553     if(s->picture_structure == PICT_FRAME){
1554         s->first_field=0;
1555         s->v_edge_pos= 16*s->mb_height;
1556     }else{
1557         s->first_field ^= 1;
1558         s->v_edge_pos=  8*s->mb_height;
1559         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1560     }
1561
1562     if(s->alternate_scan){
1563         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1564         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1565     }else{
1566         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1567         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1568     }
1569
1570     /* composite display not parsed */
1571     dprintf(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1572     dprintf(s->avctx, "picture_structure=%d\n", s->picture_structure);
1573     dprintf(s->avctx, "top field first=%d\n", s->top_field_first);
1574     dprintf(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1575     dprintf(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1576     dprintf(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1577     dprintf(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1578     dprintf(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1579     dprintf(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1580 }
1581
1582 static void mpeg_decode_extension(AVCodecContext *avctx,
1583                                   const uint8_t *buf, int buf_size)
1584 {
1585     Mpeg1Context *s1 = avctx->priv_data;
1586     MpegEncContext *s = &s1->mpeg_enc_ctx;
1587     int ext_type;
1588
1589     init_get_bits(&s->gb, buf, buf_size*8);
1590
1591     ext_type = get_bits(&s->gb, 4);
1592     switch(ext_type) {
1593     case 0x1:
1594         mpeg_decode_sequence_extension(s1);
1595         break;
1596     case 0x2:
1597         mpeg_decode_sequence_display_extension(s1);
1598         break;
1599     case 0x3:
1600         mpeg_decode_quant_matrix_extension(s);
1601         break;
1602     case 0x7:
1603         mpeg_decode_picture_display_extension(s1);
1604         break;
1605     case 0x8:
1606         mpeg_decode_picture_coding_extension(s1);
1607         break;
1608     }
1609 }
1610
1611 static void exchange_uv(MpegEncContext *s){
1612     DCTELEM (*tmp)[64];
1613
1614     tmp           = s->pblocks[4];
1615     s->pblocks[4] = s->pblocks[5];
1616     s->pblocks[5] = tmp;
1617 }
1618
1619 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size){
1620     AVCodecContext *avctx= s->avctx;
1621     Mpeg1Context *s1 = (Mpeg1Context*)s;
1622
1623     /* start frame decoding */
1624     if(s->first_field || s->picture_structure==PICT_FRAME){
1625         if(MPV_frame_start(s, avctx) < 0)
1626             return -1;
1627
1628         ff_er_frame_start(s);
1629
1630         /* first check if we must repeat the frame */
1631         s->current_picture_ptr->repeat_pict = 0;
1632         if (s->repeat_first_field) {
1633             if (s->progressive_sequence) {
1634                 if (s->top_field_first)
1635                     s->current_picture_ptr->repeat_pict = 4;
1636                 else
1637                     s->current_picture_ptr->repeat_pict = 2;
1638             } else if (s->progressive_frame) {
1639                 s->current_picture_ptr->repeat_pict = 1;
1640             }
1641         }
1642
1643         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1644     }else{ //second field
1645             int i;
1646
1647             if(!s->current_picture_ptr){
1648                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1649                 return -1;
1650             }
1651
1652             for(i=0; i<4; i++){
1653                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1654                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1655                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1656                 }
1657             }
1658     }
1659
1660     if (avctx->hwaccel) {
1661         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
1662             return -1;
1663     }
1664
1665 // MPV_frame_start will call this function too,
1666 // but we need to call it on every field
1667     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1668         if(ff_xvmc_field_start(s,avctx) < 0)
1669             return -1;
1670
1671     return 0;
1672 }
1673
1674 #define DECODE_SLICE_ERROR -1
1675 #define DECODE_SLICE_OK 0
1676
1677 /**
1678  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1679  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1680  *         DECODE_SLICE_OK if this slice is ok<br>
1681  */
1682 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1683                              const uint8_t **buf, int buf_size)
1684 {
1685     MpegEncContext *s = &s1->mpeg_enc_ctx;
1686     AVCodecContext *avctx= s->avctx;
1687     const int field_pic= s->picture_structure != PICT_FRAME;
1688     const int lowres= s->avctx->lowres;
1689
1690     s->resync_mb_x=
1691     s->resync_mb_y= -1;
1692
1693     if (mb_y<<field_pic >= s->mb_height){
1694         av_log(s->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s->mb_height);
1695         return -1;
1696     }
1697
1698     init_get_bits(&s->gb, *buf, buf_size*8);
1699
1700     ff_mpeg1_clean_buffers(s);
1701     s->interlaced_dct = 0;
1702
1703     s->qscale = get_qscale(s);
1704
1705     if(s->qscale == 0){
1706         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1707         return -1;
1708     }
1709
1710     /* extra slice info */
1711     while (get_bits1(&s->gb) != 0) {
1712         skip_bits(&s->gb, 8);
1713     }
1714
1715     s->mb_x=0;
1716
1717     for(;;) {
1718         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1719         if (code < 0){
1720             av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1721             return -1;
1722         }
1723         if (code >= 33) {
1724             if (code == 33) {
1725                 s->mb_x += 33;
1726             }
1727             /* otherwise, stuffing, nothing to do */
1728         } else {
1729             s->mb_x += code;
1730             break;
1731         }
1732     }
1733     if(s->mb_x >= (unsigned)s->mb_width){
1734         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1735         return -1;
1736     }
1737
1738     if (avctx->hwaccel) {
1739         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1740         int start_code = -1;
1741         buf_end = ff_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1742         if (buf_end < *buf + buf_size)
1743             buf_end -= 4;
1744         s->mb_y = mb_y;
1745         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1746             return DECODE_SLICE_ERROR;
1747         *buf = buf_end;
1748         return DECODE_SLICE_OK;
1749     }
1750
1751     s->resync_mb_x= s->mb_x;
1752     s->resync_mb_y= s->mb_y= mb_y;
1753     s->mb_skip_run= 0;
1754     ff_init_block_index(s);
1755
1756     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1757         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1758              av_log(s->avctx, AV_LOG_DEBUG, "qp:%d fc:%2d%2d%2d%2d %s %s %s %s %s dc:%d pstruct:%d fdct:%d cmv:%d qtype:%d ivlc:%d rff:%d %s\n",
1759                  s->qscale, s->mpeg_f_code[0][0],s->mpeg_f_code[0][1],s->mpeg_f_code[1][0],s->mpeg_f_code[1][1],
1760                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1761                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1762                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1763                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1764         }
1765     }
1766
1767     for(;;) {
1768         //If 1, we memcpy blocks in xvmcvideo.
1769         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1)
1770             ff_xvmc_init_block(s);//set s->block
1771
1772         if(mpeg_decode_mb(s, s->block) < 0)
1773             return -1;
1774
1775         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1776             const int wrap = field_pic ? 2*s->b8_stride : s->b8_stride;
1777             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1778             int motion_x, motion_y, dir, i;
1779             if(field_pic && !s->first_field)
1780                 xy += wrap/2;
1781
1782             for(i=0; i<2; i++){
1783                 for(dir=0; dir<2; dir++){
1784                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1785                         motion_x = motion_y = 0;
1786                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1787                         motion_x = s->mv[dir][0][0];
1788                         motion_y = s->mv[dir][0][1];
1789                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1790                         motion_x = s->mv[dir][i][0];
1791                         motion_y = s->mv[dir][i][1];
1792                     }
1793
1794                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1795                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1796                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1797                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1798                     s->current_picture.ref_index [dir][xy    ]=
1799                     s->current_picture.ref_index [dir][xy + 1]= s->field_select[dir][i];
1800                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1801                 }
1802                 xy += wrap;
1803             }
1804         }
1805
1806         s->dest[0] += 16 >> lowres;
1807         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1808         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1809
1810         MPV_decode_mb(s, s->block);
1811
1812         if (++s->mb_x >= s->mb_width) {
1813             const int mb_size= 16>>s->avctx->lowres;
1814
1815             ff_draw_horiz_band(s, mb_size*s->mb_y, mb_size);
1816
1817             s->mb_x = 0;
1818             s->mb_y++;
1819
1820             if(s->mb_y<<field_pic >= s->mb_height){
1821                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1822                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1823                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1824                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1825
1826                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1827                    || (avctx->error_recognition >= FF_ER_AGGRESSIVE && left>8)){
1828                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1829                     return -1;
1830                 }else
1831                     goto eos;
1832             }
1833
1834             ff_init_block_index(s);
1835         }
1836
1837         /* skip mb handling */
1838         if (s->mb_skip_run == -1) {
1839             /* read increment again */
1840             s->mb_skip_run = 0;
1841             for(;;) {
1842                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1843                 if (code < 0){
1844                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1845                     return -1;
1846                 }
1847                 if (code >= 33) {
1848                     if (code == 33) {
1849                         s->mb_skip_run += 33;
1850                     }else if(code == 35){
1851                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1852                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1853                             return -1;
1854                         }
1855                         goto eos; /* end of slice */
1856                     }
1857                     /* otherwise, stuffing, nothing to do */
1858                 } else {
1859                     s->mb_skip_run += code;
1860                     break;
1861                 }
1862             }
1863             if(s->mb_skip_run){
1864                 int i;
1865                 if(s->pict_type == FF_I_TYPE){
1866                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1867                     return -1;
1868                 }
1869
1870                 /* skip mb */
1871                 s->mb_intra = 0;
1872                 for(i=0;i<12;i++)
1873                     s->block_last_index[i] = -1;
1874                 if(s->picture_structure == PICT_FRAME)
1875                     s->mv_type = MV_TYPE_16X16;
1876                 else
1877                     s->mv_type = MV_TYPE_FIELD;
1878                 if (s->pict_type == FF_P_TYPE) {
1879                     /* if P type, zero motion vector is implied */
1880                     s->mv_dir = MV_DIR_FORWARD;
1881                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1882                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1883                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1884                     s->field_select[0][0]= s->picture_structure - 1;
1885                 } else {
1886                     /* if B type, reuse previous vectors and directions */
1887                     s->mv[0][0][0] = s->last_mv[0][0][0];
1888                     s->mv[0][0][1] = s->last_mv[0][0][1];
1889                     s->mv[1][0][0] = s->last_mv[1][0][0];
1890                     s->mv[1][0][1] = s->last_mv[1][0][1];
1891                 }
1892             }
1893         }
1894     }
1895 eos: // end of slice
1896     *buf += (get_bits_count(&s->gb)-1)/8;
1897 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1898     return 0;
1899 }
1900
1901 static int slice_decode_thread(AVCodecContext *c, void *arg){
1902     MpegEncContext *s= *(void**)arg;
1903     const uint8_t *buf= s->gb.buffer;
1904     int mb_y= s->start_mb_y;
1905
1906     s->error_count= 3*(s->end_mb_y - s->start_mb_y)*s->mb_width;
1907
1908     for(;;){
1909         uint32_t start_code;
1910         int ret;
1911
1912         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1913         emms_c();
1914 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1915 //ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, s->start_mb_y, s->end_mb_y, s->error_count);
1916         if(ret < 0){
1917             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1918                 ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, AC_ERROR|DC_ERROR|MV_ERROR);
1919         }else{
1920             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
1921         }
1922
1923         if(s->mb_y == s->end_mb_y)
1924             return 0;
1925
1926         start_code= -1;
1927         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1928         mb_y= start_code - SLICE_MIN_START_CODE;
1929         if(mb_y < 0 || mb_y >= s->end_mb_y)
1930             return -1;
1931     }
1932
1933     return 0; //not reached
1934 }
1935
1936 /**
1937  * Handles slice ends.
1938  * @return 1 if it seems to be the last slice
1939  */
1940 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1941 {
1942     Mpeg1Context *s1 = avctx->priv_data;
1943     MpegEncContext *s = &s1->mpeg_enc_ctx;
1944
1945     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1946         return 0;
1947
1948     if (s->avctx->hwaccel) {
1949         if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
1950             av_log(avctx, AV_LOG_ERROR, "hardware accelerator failed to decode picture\n");
1951     }
1952
1953     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1954         ff_xvmc_field_end(s);
1955
1956     /* end of slice reached */
1957     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1958         /* end of image */
1959
1960         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1961
1962         ff_er_frame_end(s);
1963
1964         MPV_frame_end(s);
1965
1966         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1967             *pict= *(AVFrame*)s->current_picture_ptr;
1968             ff_print_debug_info(s, pict);
1969         } else {
1970             s->picture_number++;
1971             /* latency of 1 frame for I- and P-frames */
1972             /* XXX: use another variable than picture_number */
1973             if (s->last_picture_ptr != NULL) {
1974                 *pict= *(AVFrame*)s->last_picture_ptr;
1975                  ff_print_debug_info(s, pict);
1976             }
1977         }
1978
1979         return 1;
1980     } else {
1981         return 0;
1982     }
1983 }
1984
1985 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1986                                  const uint8_t *buf, int buf_size)
1987 {
1988     Mpeg1Context *s1 = avctx->priv_data;
1989     MpegEncContext *s = &s1->mpeg_enc_ctx;
1990     int width,height;
1991     int i, v, j;
1992
1993     init_get_bits(&s->gb, buf, buf_size*8);
1994
1995     width = get_bits(&s->gb, 12);
1996     height = get_bits(&s->gb, 12);
1997     if (width <= 0 || height <= 0)
1998         return -1;
1999     s->aspect_ratio_info= get_bits(&s->gb, 4);
2000     if (s->aspect_ratio_info == 0) {
2001         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2002         if (avctx->error_recognition >= FF_ER_COMPLIANT)
2003             return -1;
2004     }
2005     s->frame_rate_index = get_bits(&s->gb, 4);
2006     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
2007         return -1;
2008     s->bit_rate = get_bits(&s->gb, 18) * 400;
2009     if (get_bits1(&s->gb) == 0) /* marker */
2010         return -1;
2011     s->width = width;
2012     s->height = height;
2013
2014     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
2015     skip_bits(&s->gb, 1);
2016
2017     /* get matrix */
2018     if (get_bits1(&s->gb)) {
2019         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2020     } else {
2021         for(i=0;i<64;i++) {
2022             j = s->dsp.idct_permutation[i];
2023             v = ff_mpeg1_default_intra_matrix[i];
2024             s->intra_matrix[j] = v;
2025             s->chroma_intra_matrix[j] = v;
2026         }
2027     }
2028     if (get_bits1(&s->gb)) {
2029         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2030     } else {
2031         for(i=0;i<64;i++) {
2032             int j= s->dsp.idct_permutation[i];
2033             v = ff_mpeg1_default_non_intra_matrix[i];
2034             s->inter_matrix[j] = v;
2035             s->chroma_inter_matrix[j] = v;
2036         }
2037     }
2038
2039     if(show_bits(&s->gb, 23) != 0){
2040         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2041         return -1;
2042     }
2043
2044     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2045     s->progressive_sequence = 1;
2046     s->progressive_frame = 1;
2047     s->picture_structure = PICT_FRAME;
2048     s->frame_pred_frame_dct = 1;
2049     s->chroma_format = 1;
2050     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2051     avctx->sub_id = 1; /* indicates MPEG-1 */
2052     s->out_format = FMT_MPEG1;
2053     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2054     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2055
2056     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2057         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2058                s->avctx->rc_buffer_size, s->bit_rate);
2059
2060     return 0;
2061 }
2062
2063 static int vcr2_init_sequence(AVCodecContext *avctx)
2064 {
2065     Mpeg1Context *s1 = avctx->priv_data;
2066     MpegEncContext *s = &s1->mpeg_enc_ctx;
2067     int i, v;
2068
2069     /* start new MPEG-1 context decoding */
2070     s->out_format = FMT_MPEG1;
2071     if (s1->mpeg_enc_ctx_allocated) {
2072         MPV_common_end(s);
2073     }
2074     s->width  = avctx->coded_width;
2075     s->height = avctx->coded_height;
2076     avctx->has_b_frames= 0; //true?
2077     s->low_delay= 1;
2078
2079     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2080     avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
2081
2082     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT || avctx->hwaccel ||
2083         s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
2084         if( avctx->idct_algo == FF_IDCT_AUTO )
2085             avctx->idct_algo = FF_IDCT_SIMPLE;
2086
2087     if (MPV_common_init(s) < 0)
2088         return -1;
2089     exchange_uv(s);//common init reset pblocks, so we swap them here
2090     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2091     s1->mpeg_enc_ctx_allocated = 1;
2092
2093     for(i=0;i<64;i++) {
2094         int j= s->dsp.idct_permutation[i];
2095         v = ff_mpeg1_default_intra_matrix[i];
2096         s->intra_matrix[j] = v;
2097         s->chroma_intra_matrix[j] = v;
2098
2099         v = ff_mpeg1_default_non_intra_matrix[i];
2100         s->inter_matrix[j] = v;
2101         s->chroma_inter_matrix[j] = v;
2102     }
2103
2104     s->progressive_sequence = 1;
2105     s->progressive_frame = 1;
2106     s->picture_structure = PICT_FRAME;
2107     s->frame_pred_frame_dct = 1;
2108     s->chroma_format = 1;
2109     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2110     avctx->sub_id = 2; /* indicates MPEG-2 */
2111     return 0;
2112 }
2113
2114
2115 static void mpeg_decode_user_data(AVCodecContext *avctx,
2116                                   const uint8_t *buf, int buf_size)
2117 {
2118     const uint8_t *p;
2119     int len, flags;
2120     p = buf;
2121     len = buf_size;
2122
2123     /* we parse the DTG active format information */
2124     if (len >= 5 &&
2125         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2126         flags = p[4];
2127         p += 5;
2128         len -= 5;
2129         if (flags & 0x80) {
2130             /* skip event id */
2131             if (len < 2)
2132                 return;
2133             p += 2;
2134             len -= 2;
2135         }
2136         if (flags & 0x40) {
2137             if (len < 1)
2138                 return;
2139             avctx->dtg_active_format = p[0] & 0x0f;
2140         }
2141     }
2142 }
2143
2144 static void mpeg_decode_gop(AVCodecContext *avctx,
2145                             const uint8_t *buf, int buf_size){
2146     Mpeg1Context *s1 = avctx->priv_data;
2147     MpegEncContext *s = &s1->mpeg_enc_ctx;
2148
2149     int drop_frame_flag;
2150     int time_code_hours, time_code_minutes;
2151     int time_code_seconds, time_code_pictures;
2152     int broken_link;
2153
2154     init_get_bits(&s->gb, buf, buf_size*8);
2155
2156     drop_frame_flag = get_bits1(&s->gb);
2157
2158     time_code_hours=get_bits(&s->gb,5);
2159     time_code_minutes = get_bits(&s->gb,6);
2160     skip_bits1(&s->gb);//marker bit
2161     time_code_seconds = get_bits(&s->gb,6);
2162     time_code_pictures = get_bits(&s->gb,6);
2163
2164     s->closed_gop = get_bits1(&s->gb);
2165     /*broken_link indicate that after editing the
2166       reference frames of the first B-Frames after GOP I-Frame
2167       are missing (open gop)*/
2168     broken_link = get_bits1(&s->gb);
2169
2170     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2171         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2172             time_code_hours, time_code_minutes, time_code_seconds,
2173             time_code_pictures, s->closed_gop, broken_link);
2174 }
2175 /**
2176  * Finds the end of the current frame in the bitstream.
2177  * @return the position of the first byte of the next frame, or -1
2178  */
2179 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
2180 {
2181     int i;
2182     uint32_t state= pc->state;
2183
2184     /* EOF considered as end of frame */
2185     if (buf_size == 0)
2186         return 0;
2187
2188 /*
2189  0  frame start         -> 1/4
2190  1  first_SEQEXT        -> 0/2
2191  2  first field start   -> 3/0
2192  3  second_SEQEXT       -> 2/0
2193  4  searching end
2194 */
2195
2196     for(i=0; i<buf_size; i++){
2197         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2198         if(pc->frame_start_found&1){
2199             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2200                 pc->frame_start_found--;
2201             else if(state == EXT_START_CODE+2){
2202                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2203                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2204             }
2205             state++;
2206         }else{
2207             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2208             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2209                 i++;
2210                 pc->frame_start_found=4;
2211             }
2212             if(state == SEQ_END_CODE){
2213                 pc->state=-1;
2214                 return i+1;
2215             }
2216             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2217                 pc->frame_start_found= 0;
2218             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2219                 pc->frame_start_found++;
2220             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2221                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2222                     pc->frame_start_found=0;
2223                     pc->state=-1;
2224                     return i-3;
2225                 }
2226             }
2227             if(s && state == PICTURE_START_CODE){
2228                 ff_fetch_timestamp(s, i-3, 1);
2229             }
2230         }
2231     }
2232     pc->state= state;
2233     return END_NOT_FOUND;
2234 }
2235
2236 static int decode_chunks(AVCodecContext *avctx,
2237                              AVFrame *picture, int *data_size,
2238                              const uint8_t *buf, int buf_size);
2239
2240 /* handle buffering and image synchronisation */
2241 static int mpeg_decode_frame(AVCodecContext *avctx,
2242                              void *data, int *data_size,
2243                              AVPacket *avpkt)
2244 {
2245     const uint8_t *buf = avpkt->data;
2246     int buf_size = avpkt->size;
2247     Mpeg1Context *s = avctx->priv_data;
2248     AVFrame *picture = data;
2249     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2250     dprintf(avctx, "fill_buffer\n");
2251
2252     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2253         /* special case for last picture */
2254         if (s2->low_delay==0 && s2->next_picture_ptr) {
2255             *picture= *(AVFrame*)s2->next_picture_ptr;
2256             s2->next_picture_ptr= NULL;
2257
2258             *data_size = sizeof(AVFrame);
2259         }
2260         return buf_size;
2261     }
2262
2263     if(s2->flags&CODEC_FLAG_TRUNCATED){
2264         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size, NULL);
2265
2266         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2267             return buf_size;
2268     }
2269
2270 #if 0
2271     if (s->repeat_field % 2 == 1) {
2272         s->repeat_field++;
2273         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2274         //        s2->picture_number, s->repeat_field);
2275         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2276             *data_size = sizeof(AVPicture);
2277             goto the_end;
2278         }
2279     }
2280 #endif
2281
2282     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == AV_RL32("VCR2"))
2283         vcr2_init_sequence(avctx);
2284
2285     s->slice_count= 0;
2286
2287     if(avctx->extradata && !avctx->frame_number)
2288         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2289
2290     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2291 }
2292
2293 static int decode_chunks(AVCodecContext *avctx,
2294                              AVFrame *picture, int *data_size,
2295                              const uint8_t *buf, int buf_size)
2296 {
2297     Mpeg1Context *s = avctx->priv_data;
2298     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2299     const uint8_t *buf_ptr = buf;
2300     const uint8_t *buf_end = buf + buf_size;
2301     int ret, input_size;
2302
2303     for(;;) {
2304         /* find next start code */
2305         uint32_t start_code = -1;
2306         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2307         if (start_code > 0x1ff){
2308             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2309                 if(avctx->thread_count > 1){
2310                     int i;
2311
2312                     avctx->execute(avctx, slice_decode_thread,  &s2->thread_context[0], NULL, s->slice_count, sizeof(void*));
2313                     for(i=0; i<s->slice_count; i++)
2314                         s2->error_count += s2->thread_context[i]->error_count;
2315                 }
2316
2317                 if (CONFIG_MPEG_VDPAU_DECODER && avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
2318                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2319
2320                 if (slice_end(avctx, picture)) {
2321                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2322                         *data_size = sizeof(AVPicture);
2323                 }
2324             }
2325             s2->pict_type= 0;
2326             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2327         }
2328
2329         input_size = buf_end - buf_ptr;
2330
2331         if(avctx->debug & FF_DEBUG_STARTCODE){
2332             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2333         }
2334
2335         /* prepare data for next start code */
2336         switch(start_code) {
2337         case SEQ_START_CODE:
2338             mpeg1_decode_sequence(avctx, buf_ptr,
2339                                     input_size);
2340             break;
2341
2342         case PICTURE_START_CODE:
2343             /* we have a complete image: we try to decompress it */
2344             if(mpeg1_decode_picture(avctx,
2345                                     buf_ptr, input_size) < 0)
2346                 s2->pict_type=0;
2347             break;
2348         case EXT_START_CODE:
2349             mpeg_decode_extension(avctx,
2350                                     buf_ptr, input_size);
2351             break;
2352         case USER_START_CODE:
2353             mpeg_decode_user_data(avctx,
2354                                     buf_ptr, input_size);
2355             break;
2356         case GOP_START_CODE:
2357             s2->first_field=0;
2358             mpeg_decode_gop(avctx,
2359                                     buf_ptr, input_size);
2360             break;
2361         default:
2362             if (start_code >= SLICE_MIN_START_CODE &&
2363                 start_code <= SLICE_MAX_START_CODE) {
2364                 int mb_y= start_code - SLICE_MIN_START_CODE;
2365
2366                 if(s2->last_picture_ptr==NULL){
2367                 /* Skip B-frames if we do not have reference frames and gop is not closed */
2368                     if(s2->pict_type==FF_B_TYPE){
2369                         int i;
2370                         if(!s2->closed_gop)
2371                             break;
2372                         /* Allocate a dummy frame */
2373                         i= ff_find_unused_picture(s2, 0);
2374                         s2->last_picture_ptr= &s2->picture[i];
2375                         if(ff_alloc_picture(s2, s2->last_picture_ptr, 0) < 0)
2376                             return -1;
2377                     }
2378                 }
2379                 if(s2->next_picture_ptr==NULL){
2380                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2381                     if(s2->pict_type==FF_P_TYPE && (s2->first_field || s2->picture_structure==PICT_FRAME)) break;
2382                 }
2383                 /* Skip B-frames if we are in a hurry. */
2384                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2385                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2386                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2387                     || avctx->skip_frame >= AVDISCARD_ALL)
2388                     break;
2389                 /* Skip everything if we are in a hurry>=5. */
2390                 if(avctx->hurry_up>=5) break;
2391
2392                 if (!s->mpeg_enc_ctx_allocated) break;
2393
2394                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2395                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2396                         break;
2397                 }
2398
2399                 if(!s2->pict_type){
2400                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2401                     break;
2402                 }
2403
2404                 if(s2->first_slice){
2405                     s2->first_slice=0;
2406                     if(mpeg_field_start(s2, buf, buf_size) < 0)
2407                         return -1;
2408                 }
2409                 if(!s2->current_picture_ptr){
2410                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2411                     return -1;
2412                 }
2413
2414                 if (avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
2415                     s->slice_count++;
2416                     break;
2417                 }
2418
2419                 if(avctx->thread_count > 1){
2420                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2421                     if(threshold <= mb_y){
2422                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2423
2424                         thread_context->start_mb_y= mb_y;
2425                         thread_context->end_mb_y  = s2->mb_height;
2426                         if(s->slice_count){
2427                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2428                             ff_update_duplicate_context(thread_context, s2);
2429                         }
2430                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2431                         s->slice_count++;
2432                     }
2433                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2434                 }else{
2435                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2436                     emms_c();
2437
2438                     if(ret < 0){
2439                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2440                             ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x, s2->mb_y, AC_ERROR|DC_ERROR|MV_ERROR);
2441                     }else{
2442                         ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x-1, s2->mb_y, AC_END|DC_END|MV_END);
2443                     }
2444                 }
2445             }
2446             break;
2447         }
2448     }
2449 }
2450
2451 static int mpeg_decode_end(AVCodecContext *avctx)
2452 {
2453     Mpeg1Context *s = avctx->priv_data;
2454
2455     if (s->mpeg_enc_ctx_allocated)
2456         MPV_common_end(&s->mpeg_enc_ctx);
2457     return 0;
2458 }
2459
2460 AVCodec mpeg1video_decoder = {
2461     "mpeg1video",
2462     CODEC_TYPE_VIDEO,
2463     CODEC_ID_MPEG1VIDEO,
2464     sizeof(Mpeg1Context),
2465     mpeg_decode_init,
2466     NULL,
2467     mpeg_decode_end,
2468     mpeg_decode_frame,
2469     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2470     .flush= ff_mpeg_flush,
2471     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2472 };
2473
2474 AVCodec mpeg2video_decoder = {
2475     "mpeg2video",
2476     CODEC_TYPE_VIDEO,
2477     CODEC_ID_MPEG2VIDEO,
2478     sizeof(Mpeg1Context),
2479     mpeg_decode_init,
2480     NULL,
2481     mpeg_decode_end,
2482     mpeg_decode_frame,
2483     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2484     .flush= ff_mpeg_flush,
2485     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2486 };
2487
2488 //legacy decoder
2489 AVCodec mpegvideo_decoder = {
2490     "mpegvideo",
2491     CODEC_TYPE_VIDEO,
2492     CODEC_ID_MPEG2VIDEO,
2493     sizeof(Mpeg1Context),
2494     mpeg_decode_init,
2495     NULL,
2496     mpeg_decode_end,
2497     mpeg_decode_frame,
2498     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2499     .flush= ff_mpeg_flush,
2500     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2501 };
2502
2503 #if CONFIG_MPEG_XVMC_DECODER
2504 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2505     if( avctx->thread_count > 1)
2506         return -1;
2507     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2508         return -1;
2509     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2510         dprintf(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2511     }
2512     mpeg_decode_init(avctx);
2513
2514     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2515     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2516
2517     return 0;
2518 }
2519
2520 AVCodec mpeg_xvmc_decoder = {
2521     "mpegvideo_xvmc",
2522     CODEC_TYPE_VIDEO,
2523     CODEC_ID_MPEG2VIDEO_XVMC,
2524     sizeof(Mpeg1Context),
2525     mpeg_mc_decode_init,
2526     NULL,
2527     mpeg_decode_end,
2528     mpeg_decode_frame,
2529     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2530     .flush= ff_mpeg_flush,
2531     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2532 };
2533
2534 #endif
2535
2536 #if CONFIG_MPEG_VDPAU_DECODER
2537 AVCodec mpeg_vdpau_decoder = {
2538     "mpegvideo_vdpau",
2539     CODEC_TYPE_VIDEO,
2540     CODEC_ID_MPEG2VIDEO,
2541     sizeof(Mpeg1Context),
2542     mpeg_decode_init,
2543     NULL,
2544     mpeg_decode_end,
2545     mpeg_decode_frame,
2546     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2547     .flush= ff_mpeg_flush,
2548     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2549 };
2550 #endif
2551
2552 #if CONFIG_MPEG1_VDPAU_DECODER
2553 AVCodec mpeg1_vdpau_decoder = {
2554     "mpeg1video_vdpau",
2555     CODEC_TYPE_VIDEO,
2556     CODEC_ID_MPEG1VIDEO,
2557     sizeof(Mpeg1Context),
2558     mpeg_decode_init,
2559     NULL,
2560     mpeg_decode_end,
2561     mpeg_decode_frame,
2562     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2563     .flush= ff_mpeg_flush,
2564     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2565 };
2566 #endif
2567