git.sesse.net Git - ffmpeg/blob - 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
  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= ff_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 VLC ff_dc_lum_vlc;
 141 VLC ff_dc_chroma_vlc;
 142
 143 static VLC mv_vlc;
 144 static VLC mbincr_vlc;
 145 static VLC mb_ptype_vlc;
 146 static VLC mb_btype_vlc;
 147 static VLC mb_pat_vlc;
 148
 149 av_cold void ff_mpeg12_init_vlcs(void)
 150 {
 151     static int done = 0;
 152
 153     if (!done) {
 154         done = 1;
 155
 156         INIT_VLC_STATIC(&ff_dc_lum_vlc, DC_VLC_BITS, 12,
 157                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
 158                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
 159         INIT_VLC_STATIC(&ff_dc_chroma_vlc,  DC_VLC_BITS, 12,
 160                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
 161                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
 162         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
 163                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
 164                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
 165         INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 166                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
 167                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
 168         INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
 169                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
 170                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
 171
 172         INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 173                  &table_mb_ptype[0][1], 2, 1,
 174                  &table_mb_ptype[0][0], 2, 1, 64);
 175         INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 176                  &table_mb_btype[0][1], 2, 1,
 177                  &table_mb_btype[0][0], 2, 1, 64);
 178         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
 179         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
 180
 181         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
 182         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
 183     }
 184 }
 185
 186 static inline int get_dmv(MpegEncContext *s)
 187 {
 188     if(get_bits1(&s->gb))
 189         return 1 - (get_bits1(&s->gb) << 1);
 190     else
 191         return 0;
 192 }
 193
 194 static inline int get_qscale(MpegEncContext *s)
 195 {
 196     int qscale = get_bits(&s->gb, 5);
 197     if (s->q_scale_type) {
 198         return non_linear_qscale[qscale];
 199     } else {
 200         return qscale << 1;
 201     }
 202 }
 203
 204 /* motion type (for MPEG-2) */
 205 #define MT_FIELD 1
 206 #define MT_FRAME 2
 207 #define MT_16X8  2
 208 #define MT_DMV   3
 209
 210 static int mpeg_decode_mb(MpegEncContext *s,
 211                           DCTELEM block[12][64])
 212 {
 213     int i, j, k, cbp, val, mb_type, motion_type;
 214     const int mb_block_count = 4 + (1<< s->chroma_format);
 215
 216     av_dlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 217
 218     assert(s->mb_skipped==0);
 219
 220     if (s->mb_skip_run-- != 0) {
 221         if (s->pict_type == FF_P_TYPE) {
 222             s->mb_skipped = 1;
 223             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 224         } else {
 225             int mb_type;
 226
 227             if(s->mb_x)
 228                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
 229             else
 230                 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
 231             if(IS_INTRA(mb_type))
 232                 return -1;
 233
 234             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 235                 mb_type | MB_TYPE_SKIP;
 236 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 237
 238             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 239                 s->mb_skipped = 1;
 240         }
 241
 242         return 0;
 243     }
 244
 245     switch(s->pict_type) {
 246     default:
 247     case FF_I_TYPE:
 248         if (get_bits1(&s->gb) == 0) {
 249             if (get_bits1(&s->gb) == 0){
 250                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
 251                 return -1;
 252             }
 253             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 254         } else {
 255             mb_type = MB_TYPE_INTRA;
 256         }
 257         break;
 258     case FF_P_TYPE:
 259         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 260         if (mb_type < 0){
 261             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 262             return -1;
 263         }
 264         mb_type = ptype2mb_type[ mb_type ];
 265         break;
 266     case FF_B_TYPE:
 267         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 268         if (mb_type < 0){
 269             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 270             return -1;
 271         }
 272         mb_type = btype2mb_type[ mb_type ];
 273         break;
 274     }
 275     av_dlog(s->avctx, "mb_type=%x\n", mb_type);
 276 //    motion_type = 0; /* avoid warning */
 277     if (IS_INTRA(mb_type)) {
 278         s->dsp.clear_blocks(s->block[0]);
 279
 280         if(!s->chroma_y_shift){
 281             s->dsp.clear_blocks(s->block[6]);
 282         }
 283
 284         /* compute DCT type */
 285         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
 286             !s->frame_pred_frame_dct) {
 287             s->interlaced_dct = get_bits1(&s->gb);
 288         }
 289
 290         if (IS_QUANT(mb_type))
 291             s->qscale = get_qscale(s);
 292
 293         if (s->concealment_motion_vectors) {
 294             /* just parse them */
 295             if (s->picture_structure != PICT_FRAME)
 296                 skip_bits1(&s->gb); /* field select */
 297
 298             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 299                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 300             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 301                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 302
 303             skip_bits1(&s->gb); /* marker */
 304         }else
 305             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 306         s->mb_intra = 1;
 307         //if 1, we memcpy blocks in xvmcvideo
 308         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 309             ff_xvmc_pack_pblocks(s,-1);//inter are always full blocks
 310             if(s->swap_uv){
 311                 exchange_uv(s);
 312             }
 313         }
 314
 315         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 316             if(s->flags2 & CODEC_FLAG2_FAST){
 317                 for(i=0;i<6;i++) {
 318                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
 319                 }
 320             }else{
 321                 for(i=0;i<mb_block_count;i++) {
 322                     if (mpeg2_decode_block_intra(s, *s->pblocks[i], i) < 0)
 323                         return -1;
 324                 }
 325             }
 326         } else {
 327             for(i=0;i<6;i++) {
 328                 if (mpeg1_decode_block_intra(s, *s->pblocks[i], i) < 0)
 329                     return -1;
 330             }
 331         }
 332     } else {
 333         if (mb_type & MB_TYPE_ZERO_MV){
 334             assert(mb_type & MB_TYPE_CBP);
 335
 336             s->mv_dir = MV_DIR_FORWARD;
 337             if(s->picture_structure == PICT_FRAME){
 338                 if(!s->frame_pred_frame_dct)
 339                     s->interlaced_dct = get_bits1(&s->gb);
 340                 s->mv_type = MV_TYPE_16X16;
 341             }else{
 342                 s->mv_type = MV_TYPE_FIELD;
 343                 mb_type |= MB_TYPE_INTERLACED;
 344                 s->field_select[0][0]= s->picture_structure - 1;
 345             }
 346
 347             if (IS_QUANT(mb_type))
 348                 s->qscale = get_qscale(s);
 349
 350             s->last_mv[0][0][0] = 0;
 351             s->last_mv[0][0][1] = 0;
 352             s->last_mv[0][1][0] = 0;
 353             s->last_mv[0][1][1] = 0;
 354             s->mv[0][0][0] = 0;
 355             s->mv[0][0][1] = 0;
 356         }else{
 357             assert(mb_type & MB_TYPE_L0L1);
 358 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 359             /* get additional motion vector type */
 360             if (s->frame_pred_frame_dct)
 361                 motion_type = MT_FRAME;
 362             else{
 363                 motion_type = get_bits(&s->gb, 2);
 364                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 365                     s->interlaced_dct = get_bits1(&s->gb);
 366             }
 367
 368             if (IS_QUANT(mb_type))
 369                 s->qscale = get_qscale(s);
 370
 371             /* motion vectors */
 372             s->mv_dir= (mb_type>>13)&3;
 373             av_dlog(s->avctx, "motion_type=%d\n", motion_type);
 374             switch(motion_type) {
 375             case MT_FRAME: /* or MT_16X8 */
 376                 if (s->picture_structure == PICT_FRAME) {
 377                     mb_type |= MB_TYPE_16x16;
 378                     s->mv_type = MV_TYPE_16X16;
 379                     for(i=0;i<2;i++) {
 380                         if (USES_LIST(mb_type, i)) {
 381                             /* MT_FRAME */
 382                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
 383                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
 384                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
 385                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
 386                             /* full_pel: only for MPEG-1 */
 387                             if (s->full_pel[i]){
 388                                 s->mv[i][0][0] <<= 1;
 389                                 s->mv[i][0][1] <<= 1;
 390                             }
 391                         }
 392                     }
 393                 } else {
 394                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 395                     s->mv_type = MV_TYPE_16X8;
 396                     for(i=0;i<2;i++) {
 397                         if (USES_LIST(mb_type, i)) {
 398                             /* MT_16X8 */
 399                             for(j=0;j<2;j++) {
 400                                 s->field_select[i][j] = get_bits1(&s->gb);
 401                                 for(k=0;k<2;k++) {
 402                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 403                                                              s->last_mv[i][j][k]);
 404                                     s->last_mv[i][j][k] = val;
 405                                     s->mv[i][j][k] = val;
 406                                 }
 407                             }
 408                         }
 409                     }
 410                 }
 411                 break;
 412             case MT_FIELD:
 413                 s->mv_type = MV_TYPE_FIELD;
 414                 if (s->picture_structure == PICT_FRAME) {
 415                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 416                     for(i=0;i<2;i++) {
 417                         if (USES_LIST(mb_type, i)) {
 418                             for(j=0;j<2;j++) {
 419                                 s->field_select[i][j] = get_bits1(&s->gb);
 420                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 421                                                          s->last_mv[i][j][0]);
 422                                 s->last_mv[i][j][0] = val;
 423                                 s->mv[i][j][0] = val;
 424                                 av_dlog(s->avctx, "fmx=%d\n", val);
 425                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 426                                                          s->last_mv[i][j][1] >> 1);
 427                                 s->last_mv[i][j][1] = val << 1;
 428                                 s->mv[i][j][1] = val;
 429                                 av_dlog(s->avctx, "fmy=%d\n", val);
 430                             }
 431                         }
 432                     }
 433                 } else {
 434                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 435                     for(i=0;i<2;i++) {
 436                         if (USES_LIST(mb_type, i)) {
 437                             s->field_select[i][0] = get_bits1(&s->gb);
 438                             for(k=0;k<2;k++) {
 439                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 440                                                          s->last_mv[i][0][k]);
 441                                 s->last_mv[i][0][k] = val;
 442                                 s->last_mv[i][1][k] = val;
 443                                 s->mv[i][0][k] = val;
 444                             }
 445                         }
 446                     }
 447                 }
 448                 break;
 449             case MT_DMV:
 450                 s->mv_type = MV_TYPE_DMV;
 451                 for(i=0;i<2;i++) {
 452                     if (USES_LIST(mb_type, i)) {
 453                         int dmx, dmy, mx, my, m;
 454                         const int my_shift= s->picture_structure == PICT_FRAME;
 455
 456                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 457                                                 s->last_mv[i][0][0]);
 458                         s->last_mv[i][0][0] = mx;
 459                         s->last_mv[i][1][0] = mx;
 460                         dmx = get_dmv(s);
 461                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 462                                                 s->last_mv[i][0][1] >> my_shift);
 463                         dmy = get_dmv(s);
 464
 465
 466                         s->last_mv[i][0][1] = my<<my_shift;
 467                         s->last_mv[i][1][1] = my<<my_shift;
 468
 469                         s->mv[i][0][0] = mx;
 470                         s->mv[i][0][1] = my;
 471                         s->mv[i][1][0] = mx;//not used
 472                         s->mv[i][1][1] = my;//not used
 473
 474                         if (s->picture_structure == PICT_FRAME) {
 475                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 476
 477                             //m = 1 + 2 * s->top_field_first;
 478                             m = s->top_field_first ? 1 : 3;
 479
 480                             /* top -> top pred */
 481                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 482                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
 483                             m = 4 - m;
 484                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 485                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
 486                         } else {
 487                             mb_type |= MB_TYPE_16x16;
 488
 489                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
 490                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
 491                             if(s->picture_structure == PICT_TOP_FIELD)
 492                                 s->mv[i][2][1]--;
 493                             else
 494                                 s->mv[i][2][1]++;
 495                         }
 496                     }
 497                 }
 498                 break;
 499             default:
 500                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
 501                 return -1;
 502             }
 503         }
 504
 505         s->mb_intra = 0;
 506         if (HAS_CBP(mb_type)) {
 507             s->dsp.clear_blocks(s->block[0]);
 508
 509             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
 510             if(mb_block_count > 6){
 511                  cbp<<= mb_block_count-6;
 512                  cbp |= get_bits(&s->gb, mb_block_count-6);
 513                  s->dsp.clear_blocks(s->block[6]);
 514             }
 515             if (cbp <= 0){
 516                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
 517                 return -1;
 518             }
 519
 520             //if 1, we memcpy blocks in xvmcvideo
 521             if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 522                 ff_xvmc_pack_pblocks(s,cbp);
 523                 if(s->swap_uv){
 524                     exchange_uv(s);
 525                 }
 526             }
 527
 528             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 529                 if(s->flags2 & CODEC_FLAG2_FAST){
 530                     for(i=0;i<6;i++) {
 531                         if(cbp & 32) {
 532                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
 533                         } else {
 534                             s->block_last_index[i] = -1;
 535                         }
 536                         cbp+=cbp;
 537                     }
 538                 }else{
 539                     cbp<<= 12-mb_block_count;
 540
 541                     for(i=0;i<mb_block_count;i++) {
 542                         if ( cbp & (1<<11) ) {
 543                             if (mpeg2_decode_block_non_intra(s, *s->pblocks[i], i) < 0)
 544                                 return -1;
 545                         } else {
 546                             s->block_last_index[i] = -1;
 547                         }
 548                         cbp+=cbp;
 549                     }
 550                 }
 551             } else {
 552                 if(s->flags2 & CODEC_FLAG2_FAST){
 553                     for(i=0;i<6;i++) {
 554                         if (cbp & 32) {
 555                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
 556                         } else {
 557                             s->block_last_index[i] = -1;
 558                         }
 559                         cbp+=cbp;
 560                     }
 561                 }else{
 562                     for(i=0;i<6;i++) {
 563                         if (cbp & 32) {
 564                             if (mpeg1_decode_block_inter(s, *s->pblocks[i], i) < 0)
 565                                 return -1;
 566                         } else {
 567                             s->block_last_index[i] = -1;
 568                         }
 569                         cbp+=cbp;
 570                     }
 571                 }
 572             }
 573         }else{
 574             for(i=0;i<12;i++)
 575                 s->block_last_index[i] = -1;
 576         }
 577     }
 578
 579     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
 580
 581     return 0;
 582 }
 583
 584 /* as H.263, but only 17 codes */
 585 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 586 {
 587     int code, sign, val, l, shift;
 588
 589     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 590     if (code == 0) {
 591         return pred;
 592     }
 593     if (code < 0) {
 594         return 0xffff;
 595     }
 596
 597     sign = get_bits1(&s->gb);
 598     shift = fcode - 1;
 599     val = code;
 600     if (shift) {
 601         val = (val - 1) << shift;
 602         val |= get_bits(&s->gb, shift);
 603         val++;
 604     }
 605     if (sign)
 606         val = -val;
 607     val += pred;
 608
 609     /* modulo decoding */
 610     l= INT_BIT - 5 - shift;
 611     val = (val<<l)>>l;
 612     return val;
 613 }
 614
 615 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 616                                DCTELEM *block,
 617                                int n)
 618 {
 619     int level, dc, diff, i, j, run;
 620     int component;
 621     RLTable *rl = &ff_rl_mpeg1;
 622     uint8_t * const scantable= s->intra_scantable.permutated;
 623     const uint16_t *quant_matrix= s->intra_matrix;
 624     const int qscale= s->qscale;
 625
 626     /* DC coefficient */
 627     component = (n <= 3 ? 0 : n - 4 + 1);
 628     diff = decode_dc(&s->gb, component);
 629     if (diff >= 0xffff)
 630         return -1;
 631     dc = s->last_dc[component];
 632     dc += diff;
 633     s->last_dc[component] = dc;
 634     block[0] = dc*quant_matrix[0];
 635     av_dlog(s->avctx, "dc=%d diff=%d\n", dc, diff);
 636     i = 0;
 637     {
 638         OPEN_READER(re, &s->gb);
 639         /* now quantify & encode AC coefficients */
 640         for(;;) {
 641             UPDATE_CACHE(re, &s->gb);
 642             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 643
 644             if(level == 127){
 645                 break;
 646             } else if(level != 0) {
 647                 i += run;
 648                 j = scantable[i];
 649                 level= (level*qscale*quant_matrix[j])>>4;
 650                 level= (level-1)|1;
 651                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 652                 LAST_SKIP_BITS(re, &s->gb, 1);
 653             } else {
 654                 /* escape */
 655                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 656                 UPDATE_CACHE(re, &s->gb);
 657                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 658                 if (level == -128) {
 659                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
 660                 } else if (level == 0) {
 661                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
 662                 }
 663                 i += run;
 664                 j = scantable[i];
 665                 if(level<0){
 666                     level= -level;
 667                     level= (level*qscale*quant_matrix[j])>>4;
 668                     level= (level-1)|1;
 669                     level= -level;
 670                 }else{
 671                     level= (level*qscale*quant_matrix[j])>>4;
 672                     level= (level-1)|1;
 673                 }
 674             }
 675             if (i > 63){
 676                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 677                 return -1;
 678             }
 679
 680             block[j] = level;
 681         }
 682         CLOSE_READER(re, &s->gb);
 683     }
 684     s->block_last_index[n] = i;
 685    return 0;
 686 }
 687
 688 int ff_mpeg1_decode_block_intra(MpegEncContext *s,
 689                                 DCTELEM *block,
 690                                 int n)
 691 {
 692     return mpeg1_decode_block_intra(s, block, n);
 693 }
 694
 695 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 696                                DCTELEM *block,
 697                                int n)
 698 {
 699     int level, i, j, run;
 700     RLTable *rl = &ff_rl_mpeg1;
 701     uint8_t * const scantable= s->intra_scantable.permutated;
 702     const uint16_t *quant_matrix= s->inter_matrix;
 703     const int qscale= s->qscale;
 704
 705     {
 706         OPEN_READER(re, &s->gb);
 707         i = -1;
 708         // special case for first coefficient, no need to add second VLC table
 709         UPDATE_CACHE(re, &s->gb);
 710         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 711             level= (3*qscale*quant_matrix[0])>>5;
 712             level= (level-1)|1;
 713             if(GET_CACHE(re, &s->gb)&0x40000000)
 714                 level= -level;
 715             block[0] = level;
 716             i++;
 717             SKIP_BITS(re, &s->gb, 2);
 718             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 719                 goto end;
 720         }
 721         /* now quantify & encode AC coefficients */
 722         for(;;) {
 723             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 724
 725             if(level != 0) {
 726                 i += run;
 727                 j = scantable[i];
 728                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 729                 level= (level-1)|1;
 730                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 731                 SKIP_BITS(re, &s->gb, 1);
 732             } else {
 733                 /* escape */
 734                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 735                 UPDATE_CACHE(re, &s->gb);
 736                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 737                 if (level == -128) {
 738                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 739                 } else if (level == 0) {
 740                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 741                 }
 742                 i += run;
 743                 j = scantable[i];
 744                 if(level<0){
 745                     level= -level;
 746                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 747                     level= (level-1)|1;
 748                     level= -level;
 749                 }else{
 750                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 751                     level= (level-1)|1;
 752                 }
 753             }
 754             if (i > 63){
 755                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 756                 return -1;
 757             }
 758
 759             block[j] = level;
 760             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 761                 break;
 762             UPDATE_CACHE(re, &s->gb);
 763         }
 764 end:
 765         LAST_SKIP_BITS(re, &s->gb, 2);
 766         CLOSE_READER(re, &s->gb);
 767     }
 768     s->block_last_index[n] = i;
 769     return 0;
 770 }
 771
 772 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
 773 {
 774     int level, i, j, run;
 775     RLTable *rl = &ff_rl_mpeg1;
 776     uint8_t * const scantable= s->intra_scantable.permutated;
 777     const int qscale= s->qscale;
 778
 779     {
 780         OPEN_READER(re, &s->gb);
 781         i = -1;
 782         // special case for first coefficient, no need to add second VLC table
 783         UPDATE_CACHE(re, &s->gb);
 784         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 785             level= (3*qscale)>>1;
 786             level= (level-1)|1;
 787             if(GET_CACHE(re, &s->gb)&0x40000000)
 788                 level= -level;
 789             block[0] = level;
 790             i++;
 791             SKIP_BITS(re, &s->gb, 2);
 792             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 793                 goto end;
 794         }
 795
 796         /* now quantify & encode AC coefficients */
 797         for(;;) {
 798             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 799
 800             if(level != 0) {
 801                 i += run;
 802                 j = scantable[i];
 803                 level= ((level*2+1)*qscale)>>1;
 804                 level= (level-1)|1;
 805                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 806                 SKIP_BITS(re, &s->gb, 1);
 807             } else {
 808                 /* escape */
 809                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 810                 UPDATE_CACHE(re, &s->gb);
 811                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 812                 if (level == -128) {
 813                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 814                 } else if (level == 0) {
 815                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 816                 }
 817                 i += run;
 818                 j = scantable[i];
 819                 if(level<0){
 820                     level= -level;
 821                     level= ((level*2+1)*qscale)>>1;
 822                     level= (level-1)|1;
 823                     level= -level;
 824                 }else{
 825                     level= ((level*2+1)*qscale)>>1;
 826                     level= (level-1)|1;
 827                 }
 828             }
 829
 830             block[j] = level;
 831             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 832                 break;
 833             UPDATE_CACHE(re, &s->gb);
 834         }
 835 end:
 836         LAST_SKIP_BITS(re, &s->gb, 2);
 837         CLOSE_READER(re, &s->gb);
 838     }
 839     s->block_last_index[n] = i;
 840     return 0;
 841 }
 842
 843
 844 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 845                                DCTELEM *block,
 846                                int n)
 847 {
 848     int level, i, j, run;
 849     RLTable *rl = &ff_rl_mpeg1;
 850     uint8_t * const scantable= s->intra_scantable.permutated;
 851     const uint16_t *quant_matrix;
 852     const int qscale= s->qscale;
 853     int mismatch;
 854
 855     mismatch = 1;
 856
 857     {
 858         OPEN_READER(re, &s->gb);
 859         i = -1;
 860         if (n < 4)
 861             quant_matrix = s->inter_matrix;
 862         else
 863             quant_matrix = s->chroma_inter_matrix;
 864
 865         // special case for first coefficient, no need to add second VLC table
 866         UPDATE_CACHE(re, &s->gb);
 867         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 868             level= (3*qscale*quant_matrix[0])>>5;
 869             if(GET_CACHE(re, &s->gb)&0x40000000)
 870                 level= -level;
 871             block[0] = level;
 872             mismatch ^= level;
 873             i++;
 874             SKIP_BITS(re, &s->gb, 2);
 875             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 876                 goto end;
 877         }
 878
 879         /* now quantify & encode AC coefficients */
 880         for(;;) {
 881             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 882
 883             if(level != 0) {
 884                 i += run;
 885                 j = scantable[i];
 886                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 887                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 888                 SKIP_BITS(re, &s->gb, 1);
 889             } else {
 890                 /* escape */
 891                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 892                 UPDATE_CACHE(re, &s->gb);
 893                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 894
 895                 i += run;
 896                 j = scantable[i];
 897                 if(level<0){
 898                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
 899                     level= -level;
 900                 }else{
 901                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 902                 }
 903             }
 904             if (i > 63){
 905                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 906                 return -1;
 907             }
 908
 909             mismatch ^= level;
 910             block[j] = level;
 911             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 912                 break;
 913             UPDATE_CACHE(re, &s->gb);
 914         }
 915 end:
 916         LAST_SKIP_BITS(re, &s->gb, 2);
 917         CLOSE_READER(re, &s->gb);
 918     }
 919     block[63] ^= (mismatch & 1);
 920
 921     s->block_last_index[n] = i;
 922     return 0;
 923 }
 924
 925 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 926                                DCTELEM *block,
 927                                int n)
 928 {
 929     int level, i, j, run;
 930     RLTable *rl = &ff_rl_mpeg1;
 931     uint8_t * const scantable= s->intra_scantable.permutated;
 932     const int qscale= s->qscale;
 933     OPEN_READER(re, &s->gb);
 934     i = -1;
 935
 936     // special case for first coefficient, no need to add second VLC table
 937     UPDATE_CACHE(re, &s->gb);
 938     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 939         level= (3*qscale)>>1;
 940         if(GET_CACHE(re, &s->gb)&0x40000000)
 941             level= -level;
 942         block[0] = level;
 943         i++;
 944         SKIP_BITS(re, &s->gb, 2);
 945         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 946             goto end;
 947     }
 948
 949     /* now quantify & encode AC coefficients */
 950     for(;;) {
 951         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 952
 953         if(level != 0) {
 954             i += run;
 955             j = scantable[i];
 956             level= ((level*2+1)*qscale)>>1;
 957             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 958             SKIP_BITS(re, &s->gb, 1);
 959         } else {
 960             /* escape */
 961             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 962             UPDATE_CACHE(re, &s->gb);
 963             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 964
 965             i += run;
 966             j = scantable[i];
 967             if(level<0){
 968                 level= ((-level*2+1)*qscale)>>1;
 969                 level= -level;
 970             }else{
 971                 level= ((level*2+1)*qscale)>>1;
 972             }
 973         }
 974
 975         block[j] = level;
 976         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 977             break;
 978         UPDATE_CACHE(re, &s->gb);
 979     }
 980 end:
 981     LAST_SKIP_BITS(re, &s->gb, 2);
 982     CLOSE_READER(re, &s->gb);
 983     s->block_last_index[n] = i;
 984     return 0;
 985 }
 986
 987
 988 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
 989                                DCTELEM *block,
 990                                int n)
 991 {
 992     int level, dc, diff, i, j, run;
 993     int component;
 994     RLTable *rl;
 995     uint8_t * const scantable= s->intra_scantable.permutated;
 996     const uint16_t *quant_matrix;
 997     const int qscale= s->qscale;
 998     int mismatch;
 999
1000     /* DC coefficient */
1001     if (n < 4){
1002         quant_matrix = s->intra_matrix;
1003         component = 0;
1004     }else{
1005         quant_matrix = s->chroma_intra_matrix;
1006         component = (n&1) + 1;
1007     }
1008     diff = decode_dc(&s->gb, component);
1009     if (diff >= 0xffff)
1010         return -1;
1011     dc = s->last_dc[component];
1012     dc += diff;
1013     s->last_dc[component] = dc;
1014     block[0] = dc << (3 - s->intra_dc_precision);
1015     av_dlog(s->avctx, "dc=%d\n", block[0]);
1016     mismatch = block[0] ^ 1;
1017     i = 0;
1018     if (s->intra_vlc_format)
1019         rl = &ff_rl_mpeg2;
1020     else
1021         rl = &ff_rl_mpeg1;
1022
1023     {
1024         OPEN_READER(re, &s->gb);
1025         /* now quantify & encode AC coefficients */
1026         for(;;) {
1027             UPDATE_CACHE(re, &s->gb);
1028             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1029
1030             if(level == 127){
1031                 break;
1032             } else if(level != 0) {
1033                 i += run;
1034                 j = scantable[i];
1035                 level= (level*qscale*quant_matrix[j])>>4;
1036                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1037                 LAST_SKIP_BITS(re, &s->gb, 1);
1038             } else {
1039                 /* escape */
1040                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1041                 UPDATE_CACHE(re, &s->gb);
1042                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1043                 i += run;
1044                 j = scantable[i];
1045                 if(level<0){
1046                     level= (-level*qscale*quant_matrix[j])>>4;
1047                     level= -level;
1048                 }else{
1049                     level= (level*qscale*quant_matrix[j])>>4;
1050                 }
1051             }
1052             if (i > 63){
1053                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1054                 return -1;
1055             }
1056
1057             mismatch^= level;
1058             block[j] = level;
1059         }
1060         CLOSE_READER(re, &s->gb);
1061     }
1062     block[63]^= mismatch&1;
1063
1064     s->block_last_index[n] = i;
1065     return 0;
1066 }
1067
1068 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1069                                DCTELEM *block,
1070                                int n)
1071 {
1072     int level, dc, diff, j, run;
1073     int component;
1074     RLTable *rl;
1075     uint8_t * scantable= s->intra_scantable.permutated;
1076     const uint16_t *quant_matrix;
1077     const int qscale= s->qscale;
1078
1079     /* DC coefficient */
1080     if (n < 4){
1081         quant_matrix = s->intra_matrix;
1082         component = 0;
1083     }else{
1084         quant_matrix = s->chroma_intra_matrix;
1085         component = (n&1) + 1;
1086     }
1087     diff = decode_dc(&s->gb, component);
1088     if (diff >= 0xffff)
1089         return -1;
1090     dc = s->last_dc[component];
1091     dc += diff;
1092     s->last_dc[component] = dc;
1093     block[0] = dc << (3 - s->intra_dc_precision);
1094     if (s->intra_vlc_format)
1095         rl = &ff_rl_mpeg2;
1096     else
1097         rl = &ff_rl_mpeg1;
1098
1099     {
1100         OPEN_READER(re, &s->gb);
1101         /* now quantify & encode AC coefficients */
1102         for(;;) {
1103             UPDATE_CACHE(re, &s->gb);
1104             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1105
1106             if(level == 127){
1107                 break;
1108             } else if(level != 0) {
1109                 scantable += run;
1110                 j = *scantable;
1111                 level= (level*qscale*quant_matrix[j])>>4;
1112                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1113                 LAST_SKIP_BITS(re, &s->gb, 1);
1114             } else {
1115                 /* escape */
1116                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1117                 UPDATE_CACHE(re, &s->gb);
1118                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1119                 scantable += run;
1120                 j = *scantable;
1121                 if(level<0){
1122                     level= (-level*qscale*quant_matrix[j])>>4;
1123                     level= -level;
1124                 }else{
1125                     level= (level*qscale*quant_matrix[j])>>4;
1126                 }
1127             }
1128
1129             block[j] = level;
1130         }
1131         CLOSE_READER(re, &s->gb);
1132     }
1133
1134     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1135     return 0;
1136 }
1137
1138 typedef struct Mpeg1Context {
1139     MpegEncContext mpeg_enc_ctx;
1140     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1141     int repeat_field; /* true if we must repeat the field */
1142     AVPanScan pan_scan;              /**< some temporary storage for the panscan */
1143     int slice_count;
1144     int swap_uv;//indicate VCR2
1145     int save_aspect_info;
1146     int save_width, save_height, save_progressive_seq;
1147     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1148     int sync;                        ///< Did we reach a sync point like a GOP/SEQ/KEYFrame?
1149 } Mpeg1Context;
1150
1151 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1152 {
1153     Mpeg1Context *s = avctx->priv_data;
1154     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1155     int i;
1156
1157     /* we need some permutation to store matrices,
1158      * until MPV_common_init() sets the real permutation. */
1159     for(i=0;i<64;i++)
1160        s2->dsp.idct_permutation[i]=i;
1161
1162     MPV_decode_defaults(s2);
1163
1164     s->mpeg_enc_ctx.avctx= avctx;
1165     s->mpeg_enc_ctx.flags= avctx->flags;
1166     s->mpeg_enc_ctx.flags2= avctx->flags2;
1167     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1168     ff_mpeg12_init_vlcs();
1169
1170     s->mpeg_enc_ctx_allocated = 0;
1171     s->mpeg_enc_ctx.picture_number = 0;
1172     s->repeat_field = 0;
1173     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1174     avctx->color_range= AVCOL_RANGE_MPEG;
1175     if (avctx->codec->id == CODEC_ID_MPEG1VIDEO)
1176         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1177     else
1178         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
1179     return 0;
1180 }
1181
1182 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1183                                      const uint8_t *new_perm){
1184     uint16_t temp_matrix[64];
1185     int i;
1186
1187     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1188
1189     for(i=0;i<64;i++){
1190         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1191     }
1192 }
1193
1194 static enum PixelFormat mpeg_get_pixelformat(AVCodecContext *avctx){
1195     Mpeg1Context *s1 = avctx->priv_data;
1196     MpegEncContext *s = &s1->mpeg_enc_ctx;
1197
1198     if(avctx->xvmc_acceleration)
1199         return avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1200     else if(avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU){
1201         if(avctx->codec_id == CODEC_ID_MPEG1VIDEO)
1202             return PIX_FMT_VDPAU_MPEG1;
1203         else
1204             return PIX_FMT_VDPAU_MPEG2;
1205     }else{
1206         if(s->chroma_format <  2)
1207             return avctx->get_format(avctx,ff_hwaccel_pixfmt_list_420);
1208         else if(s->chroma_format == 2)
1209             return PIX_FMT_YUV422P;
1210         else
1211             return PIX_FMT_YUV444P;
1212     }
1213 }
1214
1215 /* Call this function when we know all parameters.
1216  * It may be called in different places for MPEG-1 and MPEG-2. */
1217 static int mpeg_decode_postinit(AVCodecContext *avctx){
1218     Mpeg1Context *s1 = avctx->priv_data;
1219     MpegEncContext *s = &s1->mpeg_enc_ctx;
1220     uint8_t old_permutation[64];
1221
1222     if (
1223         (s1->mpeg_enc_ctx_allocated == 0)||
1224         avctx->coded_width  != s->width ||
1225         avctx->coded_height != s->height||
1226         s1->save_width != s->width ||
1227         s1->save_height != s->height ||
1228         s1->save_aspect_info != s->aspect_ratio_info||
1229         s1->save_progressive_seq != s->progressive_sequence ||
1230         0)
1231     {
1232
1233         if (s1->mpeg_enc_ctx_allocated) {
1234             ParseContext pc= s->parse_context;
1235             s->parse_context.buffer=0;
1236             MPV_common_end(s);
1237             s->parse_context= pc;
1238         }
1239
1240         if( (s->width == 0 )||(s->height == 0))
1241             return -2;
1242
1243         avcodec_set_dimensions(avctx, s->width, s->height);
1244         avctx->bit_rate = s->bit_rate;
1245         s1->save_aspect_info = s->aspect_ratio_info;
1246         s1->save_width = s->width;
1247         s1->save_height = s->height;
1248         s1->save_progressive_seq = s->progressive_sequence;
1249
1250         /* low_delay may be forced, in this case we will have B-frames
1251          * that behave like P-frames. */
1252         avctx->has_b_frames = !(s->low_delay);
1253
1254         assert((avctx->sub_id==1) == (avctx->codec_id==CODEC_ID_MPEG1VIDEO));
1255         if(avctx->codec_id==CODEC_ID_MPEG1VIDEO){
1256             //MPEG-1 fps
1257             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1258             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1259             //MPEG-1 aspect
1260             avctx->sample_aspect_ratio= av_d2q(
1261                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1262             avctx->ticks_per_frame=1;
1263         }else{//MPEG-2
1264         //MPEG-2 fps
1265             av_reduce(
1266                 &s->avctx->time_base.den,
1267                 &s->avctx->time_base.num,
1268                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num*2,
1269                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1270                 1<<30);
1271             avctx->ticks_per_frame=2;
1272         //MPEG-2 aspect
1273             if(s->aspect_ratio_info > 1){
1274                 //we ignore the spec here as reality does not match the spec, see for example
1275                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1276                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) || 1){
1277                     s->avctx->sample_aspect_ratio=
1278                         av_div_q(
1279                          ff_mpeg2_aspect[s->aspect_ratio_info],
1280                          (AVRational){s->width, s->height}
1281                          );
1282                 }else{
1283                     s->avctx->sample_aspect_ratio=
1284                         av_div_q(
1285                          ff_mpeg2_aspect[s->aspect_ratio_info],
1286                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1287                         );
1288                 }
1289             }else{
1290                 s->avctx->sample_aspect_ratio=
1291                     ff_mpeg2_aspect[s->aspect_ratio_info];
1292             }
1293         }//MPEG-2
1294
1295         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1296         avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
1297         //until then pix_fmt may be changed right after codec init
1298         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
1299             avctx->hwaccel ||
1300             s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
1301             if( avctx->idct_algo == FF_IDCT_AUTO )
1302                 avctx->idct_algo = FF_IDCT_SIMPLE;
1303
1304         /* Quantization matrices may need reordering
1305          * if DCT permutation is changed. */
1306         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1307
1308         if (MPV_common_init(s) < 0)
1309             return -2;
1310
1311         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1312         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1313         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1314         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1315
1316         s1->mpeg_enc_ctx_allocated = 1;
1317     }
1318     return 0;
1319 }
1320
1321 static int mpeg1_decode_picture(AVCodecContext *avctx,
1322                                 const uint8_t *buf, int buf_size)
1323 {
1324     Mpeg1Context *s1 = avctx->priv_data;
1325     MpegEncContext *s = &s1->mpeg_enc_ctx;
1326     int ref, f_code, vbv_delay;
1327
1328     init_get_bits(&s->gb, buf, buf_size*8);
1329
1330     ref = get_bits(&s->gb, 10); /* temporal ref */
1331     s->pict_type = get_bits(&s->gb, 3);
1332     if(s->pict_type == 0 || s->pict_type > 3)
1333         return -1;
1334
1335     vbv_delay= get_bits(&s->gb, 16);
1336     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1337         s->full_pel[0] = get_bits1(&s->gb);
1338         f_code = get_bits(&s->gb, 3);
1339         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1340             return -1;
1341         s->mpeg_f_code[0][0] = f_code;
1342         s->mpeg_f_code[0][1] = f_code;
1343     }
1344     if (s->pict_type == FF_B_TYPE) {
1345         s->full_pel[1] = get_bits1(&s->gb);
1346         f_code = get_bits(&s->gb, 3);
1347         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1348             return -1;
1349         s->mpeg_f_code[1][0] = f_code;
1350         s->mpeg_f_code[1][1] = f_code;
1351     }
1352     s->current_picture.pict_type= s->pict_type;
1353     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1354
1355     if(avctx->debug & FF_DEBUG_PICT_INFO)
1356         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1357
1358     s->y_dc_scale = 8;
1359     s->c_dc_scale = 8;
1360     return 0;
1361 }
1362
1363 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1364 {
1365     MpegEncContext *s= &s1->mpeg_enc_ctx;
1366     int horiz_size_ext, vert_size_ext;
1367     int bit_rate_ext;
1368
1369     skip_bits(&s->gb, 1); /* profile and level esc*/
1370     s->avctx->profile= get_bits(&s->gb, 3);
1371     s->avctx->level= get_bits(&s->gb, 4);
1372     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1373     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1374     horiz_size_ext = get_bits(&s->gb, 2);
1375     vert_size_ext = get_bits(&s->gb, 2);
1376     s->width |= (horiz_size_ext << 12);
1377     s->height |= (vert_size_ext << 12);
1378     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1379     s->bit_rate += (bit_rate_ext << 18) * 400;
1380     skip_bits1(&s->gb); /* marker */
1381     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1382
1383     s->low_delay = get_bits1(&s->gb);
1384     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1385
1386     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1387     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1388
1389     av_dlog(s->avctx, "sequence extension\n");
1390     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1391     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1392
1393     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1394         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1395                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1396
1397 }
1398
1399 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1400 {
1401     MpegEncContext *s= &s1->mpeg_enc_ctx;
1402     int color_description, w, h;
1403
1404     skip_bits(&s->gb, 3); /* video format */
1405     color_description= get_bits1(&s->gb);
1406     if(color_description){
1407         s->avctx->color_primaries= get_bits(&s->gb, 8);
1408         s->avctx->color_trc      = get_bits(&s->gb, 8);
1409         s->avctx->colorspace     = get_bits(&s->gb, 8);
1410     }
1411     w= get_bits(&s->gb, 14);
1412     skip_bits(&s->gb, 1); //marker
1413     h= get_bits(&s->gb, 14);
1414     // remaining 3 bits are zero padding
1415
1416     s1->pan_scan.width= 16*w;
1417     s1->pan_scan.height=16*h;
1418
1419     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1420         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1421 }
1422
1423 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1424 {
1425     MpegEncContext *s= &s1->mpeg_enc_ctx;
1426     int i,nofco;
1427
1428     nofco = 1;
1429     if(s->progressive_sequence){
1430         if(s->repeat_first_field){
1431             nofco++;
1432             if(s->top_field_first)
1433                 nofco++;
1434         }
1435     }else{
1436         if(s->picture_structure == PICT_FRAME){
1437             nofco++;
1438             if(s->repeat_first_field)
1439                 nofco++;
1440         }
1441     }
1442     for(i=0; i<nofco; i++){
1443         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1444         skip_bits(&s->gb, 1); //marker
1445         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1446         skip_bits(&s->gb, 1); //marker
1447     }
1448
1449     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1450         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1451             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1452             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1453             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1454         );
1455 }
1456
1457 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64], uint16_t matrix1[64], int intra){
1458     int i;
1459
1460     for(i=0; i<64; i++) {
1461         int j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1462         int v = get_bits(&s->gb, 8);
1463         if(v==0){
1464             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1465             return -1;
1466         }
1467         if(intra && i==0 && v!=8){
1468             av_log(s->avctx, AV_LOG_ERROR, "intra matrix invalid, ignoring\n");
1469             v= 8; // needed by pink.mpg / issue1046
1470         }
1471         matrix0[j] = v;
1472         if(matrix1)
1473             matrix1[j] = v;
1474     }
1475     return 0;
1476 }
1477
1478 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1479 {
1480     av_dlog(s->avctx, "matrix extension\n");
1481
1482     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1483     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1484     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, NULL           , 1);
1485     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, NULL           , 0);
1486 }
1487
1488 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1489 {
1490     MpegEncContext *s= &s1->mpeg_enc_ctx;
1491
1492     s->full_pel[0] = s->full_pel[1] = 0;
1493     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1494     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1495     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1496     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1497     if(!s->pict_type && s1->mpeg_enc_ctx_allocated){
1498         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1499         if(s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1]==15){
1500             if(s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1501                 s->pict_type= FF_I_TYPE;
1502             else
1503                 s->pict_type= FF_P_TYPE;
1504         }else
1505             s->pict_type= FF_B_TYPE;
1506         s->current_picture.pict_type= s->pict_type;
1507         s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1508     }
1509     s->intra_dc_precision = get_bits(&s->gb, 2);
1510     s->picture_structure = get_bits(&s->gb, 2);
1511     s->top_field_first = get_bits1(&s->gb);
1512     s->frame_pred_frame_dct = get_bits1(&s->gb);
1513     s->concealment_motion_vectors = get_bits1(&s->gb);
1514     s->q_scale_type = get_bits1(&s->gb);
1515     s->intra_vlc_format = get_bits1(&s->gb);
1516     s->alternate_scan = get_bits1(&s->gb);
1517     s->repeat_first_field = get_bits1(&s->gb);
1518     s->chroma_420_type = get_bits1(&s->gb);
1519     s->progressive_frame = get_bits1(&s->gb);
1520
1521     if(s->progressive_sequence && !s->progressive_frame){
1522         s->progressive_frame= 1;
1523         av_log(s->avctx, AV_LOG_ERROR, "interlaced frame in progressive sequence, ignoring\n");
1524     }
1525
1526     if(s->picture_structure==0 || (s->progressive_frame && s->picture_structure!=PICT_FRAME)){
1527         av_log(s->avctx, AV_LOG_ERROR, "picture_structure %d invalid, ignoring\n", s->picture_structure);
1528         s->picture_structure= PICT_FRAME;
1529     }
1530
1531     if(s->progressive_sequence && !s->frame_pred_frame_dct){
1532         av_log(s->avctx, AV_LOG_ERROR, "invalid frame_pred_frame_dct\n");
1533         s->frame_pred_frame_dct= 1;
1534     }
1535
1536     if(s->picture_structure == PICT_FRAME){
1537         s->first_field=0;
1538         s->v_edge_pos= 16*s->mb_height;
1539     }else{
1540         s->first_field ^= 1;
1541         s->v_edge_pos=  8*s->mb_height;
1542         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1543     }
1544
1545     if(s->alternate_scan){
1546         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1547         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1548     }else{
1549         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1550         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1551     }
1552
1553     /* composite display not parsed */
1554     av_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1555     av_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1556     av_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1557     av_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1558     av_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1559     av_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1560     av_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1561     av_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1562     av_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1563 }
1564
1565 static void exchange_uv(MpegEncContext *s){
1566     DCTELEM (*tmp)[64];
1567
1568     tmp           = s->pblocks[4];
1569     s->pblocks[4] = s->pblocks[5];
1570     s->pblocks[5] = tmp;
1571 }
1572
1573 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size){
1574     AVCodecContext *avctx= s->avctx;
1575     Mpeg1Context *s1 = (Mpeg1Context*)s;
1576
1577     /* start frame decoding */
1578     if(s->first_field || s->picture_structure==PICT_FRAME){
1579         if(MPV_frame_start(s, avctx) < 0)
1580             return -1;
1581
1582         ff_er_frame_start(s);
1583
1584         /* first check if we must repeat the frame */
1585         s->current_picture_ptr->repeat_pict = 0;
1586         if (s->repeat_first_field) {
1587             if (s->progressive_sequence) {
1588                 if (s->top_field_first)
1589                     s->current_picture_ptr->repeat_pict = 4;
1590                 else
1591                     s->current_picture_ptr->repeat_pict = 2;
1592             } else if (s->progressive_frame) {
1593                 s->current_picture_ptr->repeat_pict = 1;
1594             }
1595         }
1596
1597         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1598     }else{ //second field
1599             int i;
1600
1601             if(!s->current_picture_ptr){
1602                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1603                 return -1;
1604             }
1605
1606             for(i=0; i<4; i++){
1607                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1608                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1609                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1610                 }
1611             }
1612     }
1613
1614     if (avctx->hwaccel) {
1615         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
1616             return -1;
1617     }
1618
1619 // MPV_frame_start will call this function too,
1620 // but we need to call it on every field
1621     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1622         if(ff_xvmc_field_start(s,avctx) < 0)
1623             return -1;
1624
1625     return 0;
1626 }
1627
1628 #define DECODE_SLICE_ERROR -1
1629 #define DECODE_SLICE_OK 0
1630
1631 /**
1632  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1633  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1634  *         DECODE_SLICE_OK if this slice is ok<br>
1635  */
1636 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1637                              const uint8_t **buf, int buf_size)
1638 {
1639     MpegEncContext *s = &s1->mpeg_enc_ctx;
1640     AVCodecContext *avctx= s->avctx;
1641     const int field_pic= s->picture_structure != PICT_FRAME;
1642     const int lowres= s->avctx->lowres;
1643
1644     s->resync_mb_x=
1645     s->resync_mb_y= -1;
1646
1647     assert(mb_y < s->mb_height);
1648
1649     init_get_bits(&s->gb, *buf, buf_size*8);
1650
1651     ff_mpeg1_clean_buffers(s);
1652     s->interlaced_dct = 0;
1653
1654     s->qscale = get_qscale(s);
1655
1656     if(s->qscale == 0){
1657         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1658         return -1;
1659     }
1660
1661     /* extra slice info */
1662     while (get_bits1(&s->gb) != 0) {
1663         skip_bits(&s->gb, 8);
1664     }
1665
1666     s->mb_x=0;
1667
1668     if(mb_y==0 && s->codec_tag == AV_RL32("SLIF")){
1669         skip_bits1(&s->gb);
1670     }else{
1671         for(;;) {
1672             int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1673             if (code < 0){
1674                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1675                 return -1;
1676             }
1677             if (code >= 33) {
1678                 if (code == 33) {
1679                     s->mb_x += 33;
1680                 }
1681                 /* otherwise, stuffing, nothing to do */
1682             } else {
1683                 s->mb_x += code;
1684                 break;
1685             }
1686         }
1687     }
1688
1689     if(s->mb_x >= (unsigned)s->mb_width){
1690         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1691         return -1;
1692     }
1693
1694     if (avctx->hwaccel) {
1695         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1696         int start_code = -1;
1697         buf_end = ff_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1698         if (buf_end < *buf + buf_size)
1699             buf_end -= 4;
1700         s->mb_y = mb_y;
1701         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1702             return DECODE_SLICE_ERROR;
1703         *buf = buf_end;
1704         return DECODE_SLICE_OK;
1705     }
1706
1707     s->resync_mb_x= s->mb_x;
1708     s->resync_mb_y= s->mb_y= mb_y;
1709     s->mb_skip_run= 0;
1710     ff_init_block_index(s);
1711
1712     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1713         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1714              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",
1715                  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],
1716                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1717                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1718                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1719                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1720         }
1721     }
1722
1723     for(;;) {
1724         //If 1, we memcpy blocks in xvmcvideo.
1725         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1)
1726             ff_xvmc_init_block(s);//set s->block
1727
1728         if(mpeg_decode_mb(s, s->block) < 0)
1729             return -1;
1730
1731         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1732             const int wrap = s->b8_stride;
1733             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1734             int b8_xy= 4*(s->mb_x + s->mb_y*s->mb_stride);
1735             int motion_x, motion_y, dir, i;
1736
1737             for(i=0; i<2; i++){
1738                 for(dir=0; dir<2; dir++){
1739                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1740                         motion_x = motion_y = 0;
1741                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1742                         motion_x = s->mv[dir][0][0];
1743                         motion_y = s->mv[dir][0][1];
1744                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1745                         motion_x = s->mv[dir][i][0];
1746                         motion_y = s->mv[dir][i][1];
1747                     }
1748
1749                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1750                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1751                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1752                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1753                     s->current_picture.ref_index [dir][b8_xy    ]=
1754                     s->current_picture.ref_index [dir][b8_xy + 1]= s->field_select[dir][i];
1755                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1756                 }
1757                 xy += wrap;
1758                 b8_xy +=2;
1759             }
1760         }
1761
1762         s->dest[0] += 16 >> lowres;
1763         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1764         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1765
1766         MPV_decode_mb(s, s->block);
1767
1768         if (++s->mb_x >= s->mb_width) {
1769             const int mb_size= 16>>s->avctx->lowres;
1770
1771             ff_draw_horiz_band(s, mb_size*(s->mb_y>>field_pic), mb_size);
1772
1773             s->mb_x = 0;
1774             s->mb_y += 1<<field_pic;
1775
1776             if(s->mb_y >= s->mb_height){
1777                 int left= get_bits_left(&s->gb);
1778                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1779                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1780                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1781
1782                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1783                    || (avctx->error_recognition >= FF_ER_AGGRESSIVE && left>8)){
1784                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1785                     return -1;
1786                 }else
1787                     goto eos;
1788             }
1789
1790             ff_init_block_index(s);
1791         }
1792
1793         /* skip mb handling */
1794         if (s->mb_skip_run == -1) {
1795             /* read increment again */
1796             s->mb_skip_run = 0;
1797             for(;;) {
1798                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1799                 if (code < 0){
1800                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1801                     return -1;
1802                 }
1803                 if (code >= 33) {
1804                     if (code == 33) {
1805                         s->mb_skip_run += 33;
1806                     }else if(code == 35){
1807                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1808                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1809                             return -1;
1810                         }
1811                         goto eos; /* end of slice */
1812                     }
1813                     /* otherwise, stuffing, nothing to do */
1814                 } else {
1815                     s->mb_skip_run += code;
1816                     break;
1817                 }
1818             }
1819             if(s->mb_skip_run){
1820                 int i;
1821                 if(s->pict_type == FF_I_TYPE){
1822                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1823                     return -1;
1824                 }
1825
1826                 /* skip mb */
1827                 s->mb_intra = 0;
1828                 for(i=0;i<12;i++)
1829                     s->block_last_index[i] = -1;
1830                 if(s->picture_structure == PICT_FRAME)
1831                     s->mv_type = MV_TYPE_16X16;
1832                 else
1833                     s->mv_type = MV_TYPE_FIELD;
1834                 if (s->pict_type == FF_P_TYPE) {
1835                     /* if P type, zero motion vector is implied */
1836                     s->mv_dir = MV_DIR_FORWARD;
1837                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1838                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1839                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1840                     s->field_select[0][0]= (s->picture_structure - 1) & 1;
1841                 } else {
1842                     /* if B type, reuse previous vectors and directions */
1843                     s->mv[0][0][0] = s->last_mv[0][0][0];
1844                     s->mv[0][0][1] = s->last_mv[0][0][1];
1845                     s->mv[1][0][0] = s->last_mv[1][0][0];
1846                     s->mv[1][0][1] = s->last_mv[1][0][1];
1847                 }
1848             }
1849         }
1850     }
1851 eos: // end of slice
1852     *buf += (get_bits_count(&s->gb)-1)/8;
1853 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1854     return 0;
1855 }
1856
1857 static int slice_decode_thread(AVCodecContext *c, void *arg){
1858     MpegEncContext *s= *(void**)arg;
1859     const uint8_t *buf= s->gb.buffer;
1860     int mb_y= s->start_mb_y;
1861     const int field_pic= s->picture_structure != PICT_FRAME;
1862
1863     s->error_count= (3*(s->end_mb_y - s->start_mb_y)*s->mb_width) >> field_pic;
1864
1865     for(;;){
1866         uint32_t start_code;
1867         int ret;
1868
1869         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1870         emms_c();
1871 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1872 //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);
1873         if(ret < 0){
1874             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1875                 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);
1876         }else{
1877             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);
1878         }
1879
1880         if(s->mb_y == s->end_mb_y)
1881             return 0;
1882
1883         start_code= -1;
1884         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1885         mb_y= start_code - SLICE_MIN_START_CODE;
1886         if(mb_y < 0 || mb_y >= s->end_mb_y)
1887             return -1;
1888     }
1889
1890     return 0; //not reached
1891 }
1892
1893 /**
1894  * Handle slice ends.
1895  * @return 1 if it seems to be the last slice
1896  */
1897 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1898 {
1899     Mpeg1Context *s1 = avctx->priv_data;
1900     MpegEncContext *s = &s1->mpeg_enc_ctx;
1901
1902     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1903         return 0;
1904
1905     if (s->avctx->hwaccel) {
1906         if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
1907             av_log(avctx, AV_LOG_ERROR, "hardware accelerator failed to decode picture\n");
1908     }
1909
1910     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1911         ff_xvmc_field_end(s);
1912
1913     /* end of slice reached */
1914     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1915         /* end of image */
1916
1917         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1918
1919         ff_er_frame_end(s);
1920
1921         MPV_frame_end(s);
1922
1923         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1924             *pict= *(AVFrame*)s->current_picture_ptr;
1925             ff_print_debug_info(s, pict);
1926         } else {
1927             s->picture_number++;
1928             /* latency of 1 frame for I- and P-frames */
1929             /* XXX: use another variable than picture_number */
1930             if (s->last_picture_ptr != NULL) {
1931                 *pict= *(AVFrame*)s->last_picture_ptr;
1932                  ff_print_debug_info(s, pict);
1933             }
1934         }
1935
1936         return 1;
1937     } else {
1938         return 0;
1939     }
1940 }
1941
1942 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1943                                  const uint8_t *buf, int buf_size)
1944 {
1945     Mpeg1Context *s1 = avctx->priv_data;
1946     MpegEncContext *s = &s1->mpeg_enc_ctx;
1947     int width,height;
1948     int i, v, j;
1949
1950     init_get_bits(&s->gb, buf, buf_size*8);
1951
1952     width = get_bits(&s->gb, 12);
1953     height = get_bits(&s->gb, 12);
1954     if (width <= 0 || height <= 0)
1955         return -1;
1956     s->aspect_ratio_info= get_bits(&s->gb, 4);
1957     if (s->aspect_ratio_info == 0) {
1958         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
1959         if (avctx->error_recognition >= FF_ER_COMPLIANT)
1960             return -1;
1961     }
1962     s->frame_rate_index = get_bits(&s->gb, 4);
1963     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1964         return -1;
1965     s->bit_rate = get_bits(&s->gb, 18) * 400;
1966     if (get_bits1(&s->gb) == 0) /* marker */
1967         return -1;
1968     s->width = width;
1969     s->height = height;
1970
1971     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
1972     skip_bits(&s->gb, 1);
1973
1974     /* get matrix */
1975     if (get_bits1(&s->gb)) {
1976         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1977     } else {
1978         for(i=0;i<64;i++) {
1979             j = s->dsp.idct_permutation[i];
1980             v = ff_mpeg1_default_intra_matrix[i];
1981             s->intra_matrix[j] = v;
1982             s->chroma_intra_matrix[j] = v;
1983         }
1984     }
1985     if (get_bits1(&s->gb)) {
1986         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1987     } else {
1988         for(i=0;i<64;i++) {
1989             int j= s->dsp.idct_permutation[i];
1990             v = ff_mpeg1_default_non_intra_matrix[i];
1991             s->inter_matrix[j] = v;
1992             s->chroma_inter_matrix[j] = v;
1993         }
1994     }
1995
1996     if(show_bits(&s->gb, 23) != 0){
1997         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
1998         return -1;
1999     }
2000
2001     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2002     s->progressive_sequence = 1;
2003     s->progressive_frame = 1;
2004     s->picture_structure = PICT_FRAME;
2005     s->frame_pred_frame_dct = 1;
2006     s->chroma_format = 1;
2007     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2008     avctx->sub_id = 1; /* indicates MPEG-1 */
2009     s->out_format = FMT_MPEG1;
2010     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2011     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2012
2013     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2014         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2015                s->avctx->rc_buffer_size, s->bit_rate);
2016
2017     return 0;
2018 }
2019
2020 static int vcr2_init_sequence(AVCodecContext *avctx)
2021 {
2022     Mpeg1Context *s1 = avctx->priv_data;
2023     MpegEncContext *s = &s1->mpeg_enc_ctx;
2024     int i, v;
2025
2026     /* start new MPEG-1 context decoding */
2027     s->out_format = FMT_MPEG1;
2028     if (s1->mpeg_enc_ctx_allocated) {
2029         MPV_common_end(s);
2030     }
2031     s->width  = avctx->coded_width;
2032     s->height = avctx->coded_height;
2033     avctx->has_b_frames= 0; //true?
2034     s->low_delay= 1;
2035
2036     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2037     avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
2038
2039     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT || avctx->hwaccel ||
2040         s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
2041         if( avctx->idct_algo == FF_IDCT_AUTO )
2042             avctx->idct_algo = FF_IDCT_SIMPLE;
2043
2044     if (MPV_common_init(s) < 0)
2045         return -1;
2046     exchange_uv(s);//common init reset pblocks, so we swap them here
2047     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2048     s1->mpeg_enc_ctx_allocated = 1;
2049
2050     for(i=0;i<64;i++) {
2051         int j= s->dsp.idct_permutation[i];
2052         v = ff_mpeg1_default_intra_matrix[i];
2053         s->intra_matrix[j] = v;
2054         s->chroma_intra_matrix[j] = v;
2055
2056         v = ff_mpeg1_default_non_intra_matrix[i];
2057         s->inter_matrix[j] = v;
2058         s->chroma_inter_matrix[j] = v;
2059     }
2060
2061     s->progressive_sequence = 1;
2062     s->progressive_frame = 1;
2063     s->picture_structure = PICT_FRAME;
2064     s->frame_pred_frame_dct = 1;
2065     s->chroma_format = 1;
2066     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2067     avctx->sub_id = 2; /* indicates MPEG-2 */
2068     s1->save_width           = s->width;
2069     s1->save_height          = s->height;
2070     s1->save_progressive_seq = s->progressive_sequence;
2071     return 0;
2072 }
2073
2074
2075 static void mpeg_decode_user_data(AVCodecContext *avctx,
2076                                   const uint8_t *p, int buf_size)
2077 {
2078     const uint8_t *buf_end = p+buf_size;
2079
2080     /* we parse the DTG active format information */
2081     if (buf_end - p >= 5 &&
2082         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2083         int flags = p[4];
2084         p += 5;
2085         if (flags & 0x80) {
2086             /* skip event id */
2087             p += 2;
2088         }
2089         if (flags & 0x40) {
2090             if (buf_end - p < 1)
2091                 return;
2092             avctx->dtg_active_format = p[0] & 0x0f;
2093         }
2094     }
2095 }
2096
2097 static void mpeg_decode_gop(AVCodecContext *avctx,
2098                             const uint8_t *buf, int buf_size){
2099     Mpeg1Context *s1 = avctx->priv_data;
2100     MpegEncContext *s = &s1->mpeg_enc_ctx;
2101
2102     int drop_frame_flag;
2103     int time_code_hours, time_code_minutes;
2104     int time_code_seconds, time_code_pictures;
2105     int broken_link;
2106
2107     init_get_bits(&s->gb, buf, buf_size*8);
2108
2109     drop_frame_flag = get_bits1(&s->gb);
2110
2111     time_code_hours=get_bits(&s->gb,5);
2112     time_code_minutes = get_bits(&s->gb,6);
2113     skip_bits1(&s->gb);//marker bit
2114     time_code_seconds = get_bits(&s->gb,6);
2115     time_code_pictures = get_bits(&s->gb,6);
2116
2117     s->closed_gop = get_bits1(&s->gb);
2118     /*broken_link indicate that after editing the
2119       reference frames of the first B-Frames after GOP I-Frame
2120       are missing (open gop)*/
2121     broken_link = get_bits1(&s->gb);
2122
2123     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2124         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2125             time_code_hours, time_code_minutes, time_code_seconds,
2126             time_code_pictures, s->closed_gop, broken_link);
2127 }
2128 /**
2129  * Find the end of the current frame in the bitstream.
2130  * @return the position of the first byte of the next frame, or -1
2131  */
2132 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
2133 {
2134     int i;
2135     uint32_t state= pc->state;
2136
2137     /* EOF considered as end of frame */
2138     if (buf_size == 0)
2139         return 0;
2140
2141 /*
2142  0  frame start         -> 1/4
2143  1  first_SEQEXT        -> 0/2
2144  2  first field start   -> 3/0
2145  3  second_SEQEXT       -> 2/0
2146  4  searching end
2147 */
2148
2149     for(i=0; i<buf_size; i++){
2150         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2151         if(pc->frame_start_found&1){
2152             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2153                 pc->frame_start_found--;
2154             else if(state == EXT_START_CODE+2){
2155                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2156                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2157             }
2158             state++;
2159         }else{
2160             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2161             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2162                 i++;
2163                 pc->frame_start_found=4;
2164             }
2165             if(state == SEQ_END_CODE){
2166                 pc->state=-1;
2167                 return i+1;
2168             }
2169             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2170                 pc->frame_start_found= 0;
2171             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2172                 pc->frame_start_found++;
2173             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2174                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2175                     pc->frame_start_found=0;
2176                     pc->state=-1;
2177                     return i-3;
2178                 }
2179             }
2180             if(pc->frame_start_found == 0 && s && state == PICTURE_START_CODE){
2181                 ff_fetch_timestamp(s, i-3, 1);
2182             }
2183         }
2184     }
2185     pc->state= state;
2186     return END_NOT_FOUND;
2187 }
2188
2189 static int decode_chunks(AVCodecContext *avctx,
2190                              AVFrame *picture, int *data_size,
2191                              const uint8_t *buf, int buf_size);
2192
2193 /* handle buffering and image synchronisation */
2194 static int mpeg_decode_frame(AVCodecContext *avctx,
2195                              void *data, int *data_size,
2196                              AVPacket *avpkt)
2197 {
2198     const uint8_t *buf = avpkt->data;
2199     int buf_size = avpkt->size;
2200     Mpeg1Context *s = avctx->priv_data;
2201     AVFrame *picture = data;
2202     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2203     av_dlog(avctx, "fill_buffer\n");
2204
2205     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2206         /* special case for last picture */
2207         if (s2->low_delay==0 && s2->next_picture_ptr) {
2208             *picture= *(AVFrame*)s2->next_picture_ptr;
2209             s2->next_picture_ptr= NULL;
2210
2211             *data_size = sizeof(AVFrame);
2212         }
2213         return buf_size;
2214     }
2215
2216     if(s2->flags&CODEC_FLAG_TRUNCATED){
2217         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size, NULL);
2218
2219         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2220             return buf_size;
2221     }
2222
2223 #if 0
2224     if (s->repeat_field % 2 == 1) {
2225         s->repeat_field++;
2226         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2227         //        s2->picture_number, s->repeat_field);
2228         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2229             *data_size = sizeof(AVPicture);
2230             goto the_end;
2231         }
2232     }
2233 #endif
2234
2235     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == AV_RL32("VCR2"))
2236         vcr2_init_sequence(avctx);
2237
2238     s->slice_count= 0;
2239
2240     if(avctx->extradata && !avctx->frame_number)
2241         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2242
2243     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2244 }
2245
2246 static int decode_chunks(AVCodecContext *avctx,
2247                              AVFrame *picture, int *data_size,
2248                              const uint8_t *buf, int buf_size)
2249 {
2250     Mpeg1Context *s = avctx->priv_data;
2251     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2252     const uint8_t *buf_ptr = buf;
2253     const uint8_t *buf_end = buf + buf_size;
2254     int ret, input_size;
2255     int last_code= 0;
2256
2257     for(;;) {
2258         /* find next start code */
2259         uint32_t start_code = -1;
2260         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2261         if (start_code > 0x1ff){
2262             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2263                 if(avctx->thread_count > 1){
2264                     int i;
2265
2266                     avctx->execute(avctx, slice_decode_thread,  &s2->thread_context[0], NULL, s->slice_count, sizeof(void*));
2267                     for(i=0; i<s->slice_count; i++)
2268                         s2->error_count += s2->thread_context[i]->error_count;
2269                 }
2270
2271                 if (CONFIG_MPEG_VDPAU_DECODER && avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
2272                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2273
2274                 if (slice_end(avctx, picture)) {
2275                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2276                         *data_size = sizeof(AVPicture);
2277                 }
2278             }
2279             s2->pict_type= 0;
2280             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2281         }
2282
2283         input_size = buf_end - buf_ptr;
2284
2285         if(avctx->debug & FF_DEBUG_STARTCODE){
2286             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2287         }
2288
2289         /* prepare data for next start code */
2290         switch(start_code) {
2291         case SEQ_START_CODE:
2292             if(last_code == 0){
2293             mpeg1_decode_sequence(avctx, buf_ptr,
2294                                     input_size);
2295                 s->sync=1;
2296             }else{
2297                 av_log(avctx, AV_LOG_ERROR, "ignoring SEQ_START_CODE after %X\n", last_code);
2298             }
2299             break;
2300
2301         case PICTURE_START_CODE:
2302             if(last_code == 0 || last_code == SLICE_MIN_START_CODE){
2303             if(mpeg_decode_postinit(avctx) < 0){
2304                 av_log(avctx, AV_LOG_ERROR, "mpeg_decode_postinit() failure\n");
2305                 return -1;
2306             }
2307
2308             /* we have a complete image: we try to decompress it */
2309             if(mpeg1_decode_picture(avctx,
2310                                     buf_ptr, input_size) < 0)
2311                 s2->pict_type=0;
2312                 s2->first_slice = 1;
2313             last_code= PICTURE_START_CODE;
2314             }else{
2315                 av_log(avctx, AV_LOG_ERROR, "ignoring pic after %X\n", last_code);
2316             }
2317             break;
2318         case EXT_START_CODE:
2319             init_get_bits(&s2->gb, buf_ptr, input_size*8);
2320
2321             switch(get_bits(&s2->gb, 4)) {
2322             case 0x1:
2323                 if(last_code == 0){
2324                 mpeg_decode_sequence_extension(s);
2325                 }else{
2326                     av_log(avctx, AV_LOG_ERROR, "ignoring seq ext after %X\n", last_code);
2327                 }
2328                 break;
2329             case 0x2:
2330                 mpeg_decode_sequence_display_extension(s);
2331                 break;
2332             case 0x3:
2333                 mpeg_decode_quant_matrix_extension(s2);
2334                 break;
2335             case 0x7:
2336                 mpeg_decode_picture_display_extension(s);
2337                 break;
2338             case 0x8:
2339                 if(last_code == PICTURE_START_CODE){
2340                 mpeg_decode_picture_coding_extension(s);
2341                 }else{
2342                     av_log(avctx, AV_LOG_ERROR, "ignoring pic cod ext after %X\n", last_code);
2343                 }
2344                 break;
2345             }
2346             break;
2347         case USER_START_CODE:
2348             mpeg_decode_user_data(avctx,
2349                                     buf_ptr, input_size);
2350             break;
2351         case GOP_START_CODE:
2352             if(last_code == 0){
2353             s2->first_field=0;
2354             mpeg_decode_gop(avctx,
2355                                     buf_ptr, input_size);
2356                 s->sync=1;
2357             }else{
2358                 av_log(avctx, AV_LOG_ERROR, "ignoring GOP_START_CODE after %X\n", last_code);
2359             }
2360             break;
2361         default:
2362             if (start_code >= SLICE_MIN_START_CODE &&
2363                 start_code <= SLICE_MAX_START_CODE && last_code!=0) {
2364                 const int field_pic= s2->picture_structure != PICT_FRAME;
2365                 int mb_y= (start_code - SLICE_MIN_START_CODE) << field_pic;
2366                 last_code= SLICE_MIN_START_CODE;
2367
2368                 if(s2->picture_structure == PICT_BOTTOM_FIELD)
2369                     mb_y++;
2370
2371                 if (mb_y >= s2->mb_height){
2372                     av_log(s2->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2373                     return -1;
2374                 }
2375
2376                 if(s2->last_picture_ptr==NULL){
2377                 /* Skip B-frames if we do not have reference frames and gop is not closed */
2378                     if(s2->pict_type==FF_B_TYPE){
2379                         if(!s2->closed_gop)
2380                             break;
2381                     }
2382                 }
2383                 if(s2->pict_type==FF_I_TYPE)
2384                     s->sync=1;
2385                 if(s2->next_picture_ptr==NULL){
2386                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2387                     if(s2->pict_type==FF_P_TYPE && !s->sync) break;
2388                 }
2389                 /* Skip B-frames if we are in a hurry. */
2390                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2391                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2392                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2393                     || avctx->skip_frame >= AVDISCARD_ALL)
2394                     break;
2395                 /* Skip everything if we are in a hurry>=5. */
2396                 if(avctx->hurry_up>=5) break;
2397
2398                 if (!s->mpeg_enc_ctx_allocated) break;
2399
2400                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2401                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2402                         break;
2403                 }
2404
2405                 if(!s2->pict_type){
2406                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2407                     break;
2408                 }
2409
2410                 if(s2->first_slice){
2411                     s2->first_slice=0;
2412                     if(mpeg_field_start(s2, buf, buf_size) < 0)
2413                         return -1;
2414                 }
2415                 if(!s2->current_picture_ptr){
2416                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2417                     return -1;
2418                 }
2419
2420                 if (avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
2421                     s->slice_count++;
2422                     break;
2423                 }
2424
2425                 if(avctx->thread_count > 1){
2426                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2427                     if(threshold <= mb_y){
2428                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2429
2430                         thread_context->start_mb_y= mb_y;
2431                         thread_context->end_mb_y  = s2->mb_height;
2432                         if(s->slice_count){
2433                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2434                             ff_update_duplicate_context(thread_context, s2);
2435                         }
2436                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2437                         s->slice_count++;
2438                     }
2439                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2440                 }else{
2441                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2442                     emms_c();
2443
2444                     if(ret < 0){
2445                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2446                             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);
2447                     }else{
2448                         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);
2449                     }
2450                 }
2451             }
2452             break;
2453         }
2454     }
2455 }
2456
2457 static void flush(AVCodecContext *avctx){
2458     Mpeg1Context *s = avctx->priv_data;
2459
2460     s->sync=0;
2461
2462     ff_mpeg_flush(avctx);
2463 }
2464
2465 static int mpeg_decode_end(AVCodecContext *avctx)
2466 {
2467     Mpeg1Context *s = avctx->priv_data;
2468
2469     if (s->mpeg_enc_ctx_allocated)
2470         MPV_common_end(&s->mpeg_enc_ctx);
2471     return 0;
2472 }
2473
2474 AVCodec ff_mpeg1video_decoder = {
2475     "mpeg1video",
2476     AVMEDIA_TYPE_VIDEO,
2477     CODEC_ID_MPEG1VIDEO,
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= flush,
2485     .max_lowres= 3,
2486     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2487 };
2488
2489 AVCodec ff_mpeg2video_decoder = {
2490     "mpeg2video",
2491     AVMEDIA_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= flush,
2500     .max_lowres= 3,
2501     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2502 };
2503
2504 //legacy decoder
2505 AVCodec ff_mpegvideo_decoder = {
2506     "mpegvideo",
2507     AVMEDIA_TYPE_VIDEO,
2508     CODEC_ID_MPEG2VIDEO,
2509     sizeof(Mpeg1Context),
2510     mpeg_decode_init,
2511     NULL,
2512     mpeg_decode_end,
2513     mpeg_decode_frame,
2514     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2515     .flush= flush,
2516     .max_lowres= 3,
2517     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2518 };
2519
2520 #if CONFIG_MPEG_XVMC_DECODER
2521 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2522     if( avctx->thread_count > 1)
2523         return -1;
2524     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2525         return -1;
2526     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2527         av_dlog(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2528     }
2529     mpeg_decode_init(avctx);
2530
2531     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2532     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2533
2534     return 0;
2535 }
2536
2537 AVCodec ff_mpeg_xvmc_decoder = {
2538     "mpegvideo_xvmc",
2539     AVMEDIA_TYPE_VIDEO,
2540     CODEC_ID_MPEG2VIDEO_XVMC,
2541     sizeof(Mpeg1Context),
2542     mpeg_mc_decode_init,
2543     NULL,
2544     mpeg_decode_end,
2545     mpeg_decode_frame,
2546     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2547     .flush= flush,
2548     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2549 };
2550
2551 #endif
2552
2553 #if CONFIG_MPEG_VDPAU_DECODER
2554 AVCodec ff_mpeg_vdpau_decoder = {
2555     "mpegvideo_vdpau",
2556     AVMEDIA_TYPE_VIDEO,
2557     CODEC_ID_MPEG2VIDEO,
2558     sizeof(Mpeg1Context),
2559     mpeg_decode_init,
2560     NULL,
2561     mpeg_decode_end,
2562     mpeg_decode_frame,
2563     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2564     .flush= flush,
2565     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2566 };
2567 #endif
2568
2569 #if CONFIG_MPEG1_VDPAU_DECODER
2570 AVCodec ff_mpeg1_vdpau_decoder = {
2571     "mpeg1video_vdpau",
2572     AVMEDIA_TYPE_VIDEO,
2573     CODEC_ID_MPEG1VIDEO,
2574     sizeof(Mpeg1Context),
2575     mpeg_decode_init,
2576     NULL,
2577     mpeg_decode_end,
2578     mpeg_decode_frame,
2579     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2580     .flush= flush,
2581     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2582 };
2583 #endif
2584