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   1 /*
   2  * MPEG-1/2 decoder
   3  * Copyright (c) 2000,2001 Fabrice Bellard
   4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /**
  24  * @file libavcodec/mpeg12.c
  25  * MPEG-1/2 decoder
  26  */
  27
  28 //#define DEBUG
  29 #include "internal.h"
  30 #include "avcodec.h"
  31 #include "dsputil.h"
  32 #include "mpegvideo.h"
  33 #include "mpegvideo_common.h"
  34
  35 #include "mpeg12.h"
  36 #include "mpeg12data.h"
  37 #include "mpeg12decdata.h"
  38 #include "bytestream.h"
  39 #include "vdpau_internal.h"
  40 #include "xvmc_internal.h"
  41
  42 //#undef NDEBUG
  43 //#include <assert.h>
  44
  45
  46 #define MV_VLC_BITS 9
  47 #define MBINCR_VLC_BITS 9
  48 #define MB_PAT_VLC_BITS 9
  49 #define MB_PTYPE_VLC_BITS 6
  50 #define MB_BTYPE_VLC_BITS 6
  51
  52 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
  53                               DCTELEM *block,
  54                               int n);
  55 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
  56                               DCTELEM *block,
  57                               int n);
  58 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n);
  59 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
  60                                         DCTELEM *block,
  61                                         int n);
  62 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
  63                                     DCTELEM *block,
  64                                     int n);
  65 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n);
  66 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
  67 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
  68 static void exchange_uv(MpegEncContext *s);
  69
  70 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
  71                                            PIX_FMT_XVMC_MPEG2_IDCT,
  72                                            PIX_FMT_XVMC_MPEG2_MC,
  73                                            PIX_FMT_NONE};
  74
  75 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  76
  77
  78 #define INIT_2D_VLC_RL(rl, static_size)\
  79 {\
  80     static RL_VLC_ELEM rl_vlc_table[static_size];\
  81     INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
  82              &rl.table_vlc[0][1], 4, 2,\
  83              &rl.table_vlc[0][0], 4, 2, static_size);\
  84 \
  85     rl.rl_vlc[0]= rl_vlc_table;\
  86     init_2d_vlc_rl(&rl);\
  87 }
  88
  89 static void init_2d_vlc_rl(RLTable *rl)
  90 {
  91     int i;
  92
  93     for(i=0; i<rl->vlc.table_size; i++){
  94         int code= rl->vlc.table[i][0];
  95         int len = rl->vlc.table[i][1];
  96         int level, run;
  97
  98         if(len==0){ // illegal code
  99             run= 65;
 100             level= MAX_LEVEL;
 101         }else if(len<0){ //more bits needed
 102             run= 0;
 103             level= code;
 104         }else{
 105             if(code==rl->n){ //esc
 106                 run= 65;
 107                 level= 0;
 108             }else if(code==rl->n+1){ //eob
 109                 run= 0;
 110                 level= 127;
 111             }else{
 112                 run=   rl->table_run  [code] + 1;
 113                 level= rl->table_level[code];
 114             }
 115         }
 116         rl->rl_vlc[0][i].len= len;
 117         rl->rl_vlc[0][i].level= level;
 118         rl->rl_vlc[0][i].run= run;
 119     }
 120 }
 121
 122 void ff_mpeg12_common_init(MpegEncContext *s)
 123 {
 124
 125     s->y_dc_scale_table=
 126     s->c_dc_scale_table= mpeg2_dc_scale_table[s->intra_dc_precision];
 127
 128 }
 129
 130 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 131     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 132     s->last_dc[1] = s->last_dc[0];
 133     s->last_dc[2] = s->last_dc[0];
 134     memset(s->last_mv, 0, sizeof(s->last_mv));
 135 }
 136
 137
 138 /******************************************/
 139 /* decoding */
 140
 141 static VLC mv_vlc;
 142 static VLC mbincr_vlc;
 143 static VLC mb_ptype_vlc;
 144 static VLC mb_btype_vlc;
 145 static VLC mb_pat_vlc;
 146
 147 av_cold void ff_mpeg12_init_vlcs(void)
 148 {
 149     static int done = 0;
 150
 151     if (!done) {
 152         done = 1;
 153
 154         INIT_VLC_STATIC(&dc_lum_vlc, DC_VLC_BITS, 12,
 155                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
 156                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
 157         INIT_VLC_STATIC(&dc_chroma_vlc,  DC_VLC_BITS, 12,
 158                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
 159                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
 160         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
 161                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
 162                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
 163         INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 164                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
 165                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
 166         INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
 167                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
 168                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
 169
 170         INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 171                  &table_mb_ptype[0][1], 2, 1,
 172                  &table_mb_ptype[0][0], 2, 1, 64);
 173         INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 174                  &table_mb_btype[0][1], 2, 1,
 175                  &table_mb_btype[0][0], 2, 1, 64);
 176         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
 177         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
 178
 179         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
 180         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
 181     }
 182 }
 183
 184 static inline int get_dmv(MpegEncContext *s)
 185 {
 186     if(get_bits1(&s->gb))
 187         return 1 - (get_bits1(&s->gb) << 1);
 188     else
 189         return 0;
 190 }
 191
 192 static inline int get_qscale(MpegEncContext *s)
 193 {
 194     int qscale = get_bits(&s->gb, 5);
 195     if (s->q_scale_type) {
 196         return non_linear_qscale[qscale];
 197     } else {
 198         return qscale << 1;
 199     }
 200 }
 201
 202 /* motion type (for MPEG-2) */
 203 #define MT_FIELD 1
 204 #define MT_FRAME 2
 205 #define MT_16X8  2
 206 #define MT_DMV   3
 207
 208 static int mpeg_decode_mb(MpegEncContext *s,
 209                           DCTELEM block[12][64])
 210 {
 211     int i, j, k, cbp, val, mb_type, motion_type;
 212     const int mb_block_count = 4 + (1<< s->chroma_format);
 213
 214     dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 215
 216     assert(s->mb_skipped==0);
 217
 218     if (s->mb_skip_run-- != 0) {
 219         if (s->pict_type == FF_P_TYPE) {
 220             s->mb_skipped = 1;
 221             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 222         } else {
 223             int mb_type;
 224
 225             if(s->mb_x)
 226                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
 227             else
 228                 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
 229             if(IS_INTRA(mb_type))
 230                 return -1;
 231
 232             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 233                 mb_type | MB_TYPE_SKIP;
 234 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 235
 236             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 237                 s->mb_skipped = 1;
 238         }
 239
 240         return 0;
 241     }
 242
 243     switch(s->pict_type) {
 244     default:
 245     case FF_I_TYPE:
 246         if (get_bits1(&s->gb) == 0) {
 247             if (get_bits1(&s->gb) == 0){
 248                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
 249                 return -1;
 250             }
 251             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 252         } else {
 253             mb_type = MB_TYPE_INTRA;
 254         }
 255         break;
 256     case FF_P_TYPE:
 257         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 258         if (mb_type < 0){
 259             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 260             return -1;
 261         }
 262         mb_type = ptype2mb_type[ mb_type ];
 263         break;
 264     case FF_B_TYPE:
 265         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 266         if (mb_type < 0){
 267             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 268             return -1;
 269         }
 270         mb_type = btype2mb_type[ mb_type ];
 271         break;
 272     }
 273     dprintf(s->avctx, "mb_type=%x\n", mb_type);
 274 //    motion_type = 0; /* avoid warning */
 275     if (IS_INTRA(mb_type)) {
 276         s->dsp.clear_blocks(s->block[0]);
 277
 278         if(!s->chroma_y_shift){
 279             s->dsp.clear_blocks(s->block[6]);
 280         }
 281
 282         /* compute DCT type */
 283         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
 284             !s->frame_pred_frame_dct) {
 285             s->interlaced_dct = get_bits1(&s->gb);
 286         }
 287
 288         if (IS_QUANT(mb_type))
 289             s->qscale = get_qscale(s);
 290
 291         if (s->concealment_motion_vectors) {
 292             /* just parse them */
 293             if (s->picture_structure != PICT_FRAME)
 294                 skip_bits1(&s->gb); /* field select */
 295
 296             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 297                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 298             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 299                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 300
 301             skip_bits1(&s->gb); /* marker */
 302         }else
 303             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 304         s->mb_intra = 1;
 305         //if 1, we memcpy blocks in xvmcvideo
 306         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 307             ff_xvmc_pack_pblocks(s,-1);//inter are always full blocks
 308             if(s->swap_uv){
 309                 exchange_uv(s);
 310             }
 311         }
 312
 313         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 314             if(s->flags2 & CODEC_FLAG2_FAST){
 315                 for(i=0;i<6;i++) {
 316                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
 317                 }
 318             }else{
 319                 for(i=0;i<mb_block_count;i++) {
 320                     if (mpeg2_decode_block_intra(s, *s->pblocks[i], i) < 0)
 321                         return -1;
 322                 }
 323             }
 324         } else {
 325             for(i=0;i<6;i++) {
 326                 if (mpeg1_decode_block_intra(s, *s->pblocks[i], i) < 0)
 327                     return -1;
 328             }
 329         }
 330     } else {
 331         if (mb_type & MB_TYPE_ZERO_MV){
 332             assert(mb_type & MB_TYPE_CBP);
 333
 334             s->mv_dir = MV_DIR_FORWARD;
 335             if(s->picture_structure == PICT_FRAME){
 336                 if(!s->frame_pred_frame_dct)
 337                     s->interlaced_dct = get_bits1(&s->gb);
 338                 s->mv_type = MV_TYPE_16X16;
 339             }else{
 340                 s->mv_type = MV_TYPE_FIELD;
 341                 mb_type |= MB_TYPE_INTERLACED;
 342                 s->field_select[0][0]= s->picture_structure - 1;
 343             }
 344
 345             if (IS_QUANT(mb_type))
 346                 s->qscale = get_qscale(s);
 347
 348             s->last_mv[0][0][0] = 0;
 349             s->last_mv[0][0][1] = 0;
 350             s->last_mv[0][1][0] = 0;
 351             s->last_mv[0][1][1] = 0;
 352             s->mv[0][0][0] = 0;
 353             s->mv[0][0][1] = 0;
 354         }else{
 355             assert(mb_type & MB_TYPE_L0L1);
 356 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 357             /* get additional motion vector type */
 358             if (s->frame_pred_frame_dct)
 359                 motion_type = MT_FRAME;
 360             else{
 361                 motion_type = get_bits(&s->gb, 2);
 362                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 363                     s->interlaced_dct = get_bits1(&s->gb);
 364             }
 365
 366             if (IS_QUANT(mb_type))
 367                 s->qscale = get_qscale(s);
 368
 369             /* motion vectors */
 370             s->mv_dir= (mb_type>>13)&3;
 371             dprintf(s->avctx, "motion_type=%d\n", motion_type);
 372             switch(motion_type) {
 373             case MT_FRAME: /* or MT_16X8 */
 374                 if (s->picture_structure == PICT_FRAME) {
 375                     mb_type |= MB_TYPE_16x16;
 376                     s->mv_type = MV_TYPE_16X16;
 377                     for(i=0;i<2;i++) {
 378                         if (USES_LIST(mb_type, i)) {
 379                             /* MT_FRAME */
 380                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
 381                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
 382                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
 383                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
 384                             /* full_pel: only for MPEG-1 */
 385                             if (s->full_pel[i]){
 386                                 s->mv[i][0][0] <<= 1;
 387                                 s->mv[i][0][1] <<= 1;
 388                             }
 389                         }
 390                     }
 391                 } else {
 392                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 393                     s->mv_type = MV_TYPE_16X8;
 394                     for(i=0;i<2;i++) {
 395                         if (USES_LIST(mb_type, i)) {
 396                             /* MT_16X8 */
 397                             for(j=0;j<2;j++) {
 398                                 s->field_select[i][j] = get_bits1(&s->gb);
 399                                 for(k=0;k<2;k++) {
 400                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 401                                                              s->last_mv[i][j][k]);
 402                                     s->last_mv[i][j][k] = val;
 403                                     s->mv[i][j][k] = val;
 404                                 }
 405                             }
 406                         }
 407                     }
 408                 }
 409                 break;
 410             case MT_FIELD:
 411                 s->mv_type = MV_TYPE_FIELD;
 412                 if (s->picture_structure == PICT_FRAME) {
 413                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 414                     for(i=0;i<2;i++) {
 415                         if (USES_LIST(mb_type, i)) {
 416                             for(j=0;j<2;j++) {
 417                                 s->field_select[i][j] = get_bits1(&s->gb);
 418                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 419                                                          s->last_mv[i][j][0]);
 420                                 s->last_mv[i][j][0] = val;
 421                                 s->mv[i][j][0] = val;
 422                                 dprintf(s->avctx, "fmx=%d\n", val);
 423                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 424                                                          s->last_mv[i][j][1] >> 1);
 425                                 s->last_mv[i][j][1] = val << 1;
 426                                 s->mv[i][j][1] = val;
 427                                 dprintf(s->avctx, "fmy=%d\n", val);
 428                             }
 429                         }
 430                     }
 431                 } else {
 432                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 433                     for(i=0;i<2;i++) {
 434                         if (USES_LIST(mb_type, i)) {
 435                             s->field_select[i][0] = get_bits1(&s->gb);
 436                             for(k=0;k<2;k++) {
 437                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 438                                                          s->last_mv[i][0][k]);
 439                                 s->last_mv[i][0][k] = val;
 440                                 s->last_mv[i][1][k] = val;
 441                                 s->mv[i][0][k] = val;
 442                             }
 443                         }
 444                     }
 445                 }
 446                 break;
 447             case MT_DMV:
 448                 s->mv_type = MV_TYPE_DMV;
 449                 for(i=0;i<2;i++) {
 450                     if (USES_LIST(mb_type, i)) {
 451                         int dmx, dmy, mx, my, m;
 452                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 453                                                 s->last_mv[i][0][0]);
 454                         s->last_mv[i][0][0] = mx;
 455                         s->last_mv[i][1][0] = mx;
 456                         dmx = get_dmv(s);
 457                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 458                                                 s->last_mv[i][0][1] >> 1);
 459                         dmy = get_dmv(s);
 460
 461
 462                         s->last_mv[i][0][1] = my<<1;
 463                         s->last_mv[i][1][1] = my<<1;
 464
 465                         s->mv[i][0][0] = mx;
 466                         s->mv[i][0][1] = my;
 467                         s->mv[i][1][0] = mx;//not used
 468                         s->mv[i][1][1] = my;//not used
 469
 470                         if (s->picture_structure == PICT_FRAME) {
 471                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 472
 473                             //m = 1 + 2 * s->top_field_first;
 474                             m = s->top_field_first ? 1 : 3;
 475
 476                             /* top -> top pred */
 477                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 478                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
 479                             m = 4 - m;
 480                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 481                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
 482                         } else {
 483                             mb_type |= MB_TYPE_16x16;
 484
 485                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
 486                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
 487                             if(s->picture_structure == PICT_TOP_FIELD)
 488                                 s->mv[i][2][1]--;
 489                             else
 490                                 s->mv[i][2][1]++;
 491                         }
 492                     }
 493                 }
 494                 break;
 495             default:
 496                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
 497                 return -1;
 498             }
 499         }
 500
 501         s->mb_intra = 0;
 502         if (HAS_CBP(mb_type)) {
 503             s->dsp.clear_blocks(s->block[0]);
 504
 505             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
 506             if(mb_block_count > 6){
 507                  cbp<<= mb_block_count-6;
 508                  cbp |= get_bits(&s->gb, mb_block_count-6);
 509                  s->dsp.clear_blocks(s->block[6]);
 510             }
 511             if (cbp <= 0){
 512                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
 513                 return -1;
 514             }
 515
 516             //if 1, we memcpy blocks in xvmcvideo
 517             if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 518                 ff_xvmc_pack_pblocks(s,cbp);
 519                 if(s->swap_uv){
 520                     exchange_uv(s);
 521                 }
 522             }
 523
 524             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 525                 if(s->flags2 & CODEC_FLAG2_FAST){
 526                     for(i=0;i<6;i++) {
 527                         if(cbp & 32) {
 528                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
 529                         } else {
 530                             s->block_last_index[i] = -1;
 531                         }
 532                         cbp+=cbp;
 533                     }
 534                 }else{
 535                     cbp<<= 12-mb_block_count;
 536
 537                     for(i=0;i<mb_block_count;i++) {
 538                         if ( cbp & (1<<11) ) {
 539                             if (mpeg2_decode_block_non_intra(s, *s->pblocks[i], i) < 0)
 540                                 return -1;
 541                         } else {
 542                             s->block_last_index[i] = -1;
 543                         }
 544                         cbp+=cbp;
 545                     }
 546                 }
 547             } else {
 548                 if(s->flags2 & CODEC_FLAG2_FAST){
 549                     for(i=0;i<6;i++) {
 550                         if (cbp & 32) {
 551                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
 552                         } else {
 553                             s->block_last_index[i] = -1;
 554                         }
 555                         cbp+=cbp;
 556                     }
 557                 }else{
 558                     for(i=0;i<6;i++) {
 559                         if (cbp & 32) {
 560                             if (mpeg1_decode_block_inter(s, *s->pblocks[i], i) < 0)
 561                                 return -1;
 562                         } else {
 563                             s->block_last_index[i] = -1;
 564                         }
 565                         cbp+=cbp;
 566                     }
 567                 }
 568             }
 569         }else{
 570             for(i=0;i<12;i++)
 571                 s->block_last_index[i] = -1;
 572         }
 573     }
 574
 575     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
 576
 577     return 0;
 578 }
 579
 580 /* as H.263, but only 17 codes */
 581 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 582 {
 583     int code, sign, val, l, shift;
 584
 585     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 586     if (code == 0) {
 587         return pred;
 588     }
 589     if (code < 0) {
 590         return 0xffff;
 591     }
 592
 593     sign = get_bits1(&s->gb);
 594     shift = fcode - 1;
 595     val = code;
 596     if (shift) {
 597         val = (val - 1) << shift;
 598         val |= get_bits(&s->gb, shift);
 599         val++;
 600     }
 601     if (sign)
 602         val = -val;
 603     val += pred;
 604
 605     /* modulo decoding */
 606     l= INT_BIT - 5 - shift;
 607     val = (val<<l)>>l;
 608     return val;
 609 }
 610
 611 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 612                                DCTELEM *block,
 613                                int n)
 614 {
 615     int level, dc, diff, i, j, run;
 616     int component;
 617     RLTable *rl = &ff_rl_mpeg1;
 618     uint8_t * const scantable= s->intra_scantable.permutated;
 619     const uint16_t *quant_matrix= s->intra_matrix;
 620     const int qscale= s->qscale;
 621
 622     /* DC coefficient */
 623     component = (n <= 3 ? 0 : n - 4 + 1);
 624     diff = decode_dc(&s->gb, component);
 625     if (diff >= 0xffff)
 626         return -1;
 627     dc = s->last_dc[component];
 628     dc += diff;
 629     s->last_dc[component] = dc;
 630     block[0] = dc*quant_matrix[0];
 631     dprintf(s->avctx, "dc=%d diff=%d\n", dc, diff);
 632     i = 0;
 633     {
 634         OPEN_READER(re, &s->gb);
 635         /* now quantify & encode AC coefficients */
 636         for(;;) {
 637             UPDATE_CACHE(re, &s->gb);
 638             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 639
 640             if(level == 127){
 641                 break;
 642             } else if(level != 0) {
 643                 i += run;
 644                 j = scantable[i];
 645                 level= (level*qscale*quant_matrix[j])>>4;
 646                 level= (level-1)|1;
 647                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 648                 LAST_SKIP_BITS(re, &s->gb, 1);
 649             } else {
 650                 /* escape */
 651                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 652                 UPDATE_CACHE(re, &s->gb);
 653                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 654                 if (level == -128) {
 655                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
 656                 } else if (level == 0) {
 657                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
 658                 }
 659                 i += run;
 660                 j = scantable[i];
 661                 if(level<0){
 662                     level= -level;
 663                     level= (level*qscale*quant_matrix[j])>>4;
 664                     level= (level-1)|1;
 665                     level= -level;
 666                 }else{
 667                     level= (level*qscale*quant_matrix[j])>>4;
 668                     level= (level-1)|1;
 669                 }
 670             }
 671             if (i > 63){
 672                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 673                 return -1;
 674             }
 675
 676             block[j] = level;
 677         }
 678         CLOSE_READER(re, &s->gb);
 679     }
 680     s->block_last_index[n] = i;
 681    return 0;
 682 }
 683
 684 int ff_mpeg1_decode_block_intra(MpegEncContext *s,
 685                                 DCTELEM *block,
 686                                 int n)
 687 {
 688     return mpeg1_decode_block_intra(s, block, n);
 689 }
 690
 691 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 692                                DCTELEM *block,
 693                                int n)
 694 {
 695     int level, i, j, run;
 696     RLTable *rl = &ff_rl_mpeg1;
 697     uint8_t * const scantable= s->intra_scantable.permutated;
 698     const uint16_t *quant_matrix= s->inter_matrix;
 699     const int qscale= s->qscale;
 700
 701     {
 702         OPEN_READER(re, &s->gb);
 703         i = -1;
 704         // special case for first coefficient, no need to add second VLC table
 705         UPDATE_CACHE(re, &s->gb);
 706         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 707             level= (3*qscale*quant_matrix[0])>>5;
 708             level= (level-1)|1;
 709             if(GET_CACHE(re, &s->gb)&0x40000000)
 710                 level= -level;
 711             block[0] = level;
 712             i++;
 713             SKIP_BITS(re, &s->gb, 2);
 714             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 715                 goto end;
 716         }
 717 #if MIN_CACHE_BITS < 19
 718         UPDATE_CACHE(re, &s->gb);
 719 #endif
 720         /* now quantify & encode AC coefficients */
 721         for(;;) {
 722             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 723
 724             if(level != 0) {
 725                 i += run;
 726                 j = scantable[i];
 727                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 728                 level= (level-1)|1;
 729                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 730                 SKIP_BITS(re, &s->gb, 1);
 731             } else {
 732                 /* escape */
 733                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 734                 UPDATE_CACHE(re, &s->gb);
 735                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 736                 if (level == -128) {
 737                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 738                 } else if (level == 0) {
 739                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 740                 }
 741                 i += run;
 742                 j = scantable[i];
 743                 if(level<0){
 744                     level= -level;
 745                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 746                     level= (level-1)|1;
 747                     level= -level;
 748                 }else{
 749                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 750                     level= (level-1)|1;
 751                 }
 752             }
 753             if (i > 63){
 754                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 755                 return -1;
 756             }
 757
 758             block[j] = level;
 759 #if MIN_CACHE_BITS < 19
 760             UPDATE_CACHE(re, &s->gb);
 761 #endif
 762             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 763                 break;
 764 #if MIN_CACHE_BITS >= 19
 765             UPDATE_CACHE(re, &s->gb);
 766 #endif
 767         }
 768 end:
 769         LAST_SKIP_BITS(re, &s->gb, 2);
 770         CLOSE_READER(re, &s->gb);
 771     }
 772     s->block_last_index[n] = i;
 773     return 0;
 774 }
 775
 776 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
 777 {
 778     int level, i, j, run;
 779     RLTable *rl = &ff_rl_mpeg1;
 780     uint8_t * const scantable= s->intra_scantable.permutated;
 781     const int qscale= s->qscale;
 782
 783     {
 784         OPEN_READER(re, &s->gb);
 785         i = -1;
 786         // special case for first coefficient, no need to add second VLC table
 787         UPDATE_CACHE(re, &s->gb);
 788         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 789             level= (3*qscale)>>1;
 790             level= (level-1)|1;
 791             if(GET_CACHE(re, &s->gb)&0x40000000)
 792                 level= -level;
 793             block[0] = level;
 794             i++;
 795             SKIP_BITS(re, &s->gb, 2);
 796             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 797                 goto end;
 798         }
 799 #if MIN_CACHE_BITS < 19
 800         UPDATE_CACHE(re, &s->gb);
 801 #endif
 802
 803         /* now quantify & encode AC coefficients */
 804         for(;;) {
 805             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 806
 807             if(level != 0) {
 808                 i += run;
 809                 j = scantable[i];
 810                 level= ((level*2+1)*qscale)>>1;
 811                 level= (level-1)|1;
 812                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 813                 SKIP_BITS(re, &s->gb, 1);
 814             } else {
 815                 /* escape */
 816                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 817                 UPDATE_CACHE(re, &s->gb);
 818                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 819                 if (level == -128) {
 820                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 821                 } else if (level == 0) {
 822                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 823                 }
 824                 i += run;
 825                 j = scantable[i];
 826                 if(level<0){
 827                     level= -level;
 828                     level= ((level*2+1)*qscale)>>1;
 829                     level= (level-1)|1;
 830                     level= -level;
 831                 }else{
 832                     level= ((level*2+1)*qscale)>>1;
 833                     level= (level-1)|1;
 834                 }
 835             }
 836
 837             block[j] = level;
 838 #if MIN_CACHE_BITS < 19
 839             UPDATE_CACHE(re, &s->gb);
 840 #endif
 841             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 842                 break;
 843 #if MIN_CACHE_BITS >= 19
 844             UPDATE_CACHE(re, &s->gb);
 845 #endif
 846         }
 847 end:
 848         LAST_SKIP_BITS(re, &s->gb, 2);
 849         CLOSE_READER(re, &s->gb);
 850     }
 851     s->block_last_index[n] = i;
 852     return 0;
 853 }
 854
 855
 856 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 857                                DCTELEM *block,
 858                                int n)
 859 {
 860     int level, i, j, run;
 861     RLTable *rl = &ff_rl_mpeg1;
 862     uint8_t * const scantable= s->intra_scantable.permutated;
 863     const uint16_t *quant_matrix;
 864     const int qscale= s->qscale;
 865     int mismatch;
 866
 867     mismatch = 1;
 868
 869     {
 870         OPEN_READER(re, &s->gb);
 871         i = -1;
 872         if (n < 4)
 873             quant_matrix = s->inter_matrix;
 874         else
 875             quant_matrix = s->chroma_inter_matrix;
 876
 877         // special case for first coefficient, no need to add second VLC table
 878         UPDATE_CACHE(re, &s->gb);
 879         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 880             level= (3*qscale*quant_matrix[0])>>5;
 881             if(GET_CACHE(re, &s->gb)&0x40000000)
 882                 level= -level;
 883             block[0] = level;
 884             mismatch ^= level;
 885             i++;
 886             SKIP_BITS(re, &s->gb, 2);
 887             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 888                 goto end;
 889         }
 890 #if MIN_CACHE_BITS < 19
 891         UPDATE_CACHE(re, &s->gb);
 892 #endif
 893
 894         /* now quantify & encode AC coefficients */
 895         for(;;) {
 896             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 897
 898             if(level != 0) {
 899                 i += run;
 900                 j = scantable[i];
 901                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 902                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 903                 SKIP_BITS(re, &s->gb, 1);
 904             } else {
 905                 /* escape */
 906                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 907                 UPDATE_CACHE(re, &s->gb);
 908                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 909
 910                 i += run;
 911                 j = scantable[i];
 912                 if(level<0){
 913                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
 914                     level= -level;
 915                 }else{
 916                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 917                 }
 918             }
 919             if (i > 63){
 920                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 921                 return -1;
 922             }
 923
 924             mismatch ^= level;
 925             block[j] = level;
 926 #if MIN_CACHE_BITS < 19
 927             UPDATE_CACHE(re, &s->gb);
 928 #endif
 929             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 930                 break;
 931 #if MIN_CACHE_BITS >= 19
 932             UPDATE_CACHE(re, &s->gb);
 933 #endif
 934         }
 935 end:
 936         LAST_SKIP_BITS(re, &s->gb, 2);
 937         CLOSE_READER(re, &s->gb);
 938     }
 939     block[63] ^= (mismatch & 1);
 940
 941     s->block_last_index[n] = i;
 942     return 0;
 943 }
 944
 945 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 946                                DCTELEM *block,
 947                                int n)
 948 {
 949     int level, i, j, run;
 950     RLTable *rl = &ff_rl_mpeg1;
 951     uint8_t * const scantable= s->intra_scantable.permutated;
 952     const int qscale= s->qscale;
 953     OPEN_READER(re, &s->gb);
 954     i = -1;
 955
 956     // special case for first coefficient, no need to add second VLC table
 957     UPDATE_CACHE(re, &s->gb);
 958     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 959         level= (3*qscale)>>1;
 960         if(GET_CACHE(re, &s->gb)&0x40000000)
 961             level= -level;
 962         block[0] = level;
 963         i++;
 964         SKIP_BITS(re, &s->gb, 2);
 965         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 966             goto end;
 967     }
 968 #if MIN_CACHE_BITS < 19
 969     UPDATE_CACHE(re, &s->gb);
 970 #endif
 971
 972     /* now quantify & encode AC coefficients */
 973     for(;;) {
 974         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 975
 976         if(level != 0) {
 977             i += run;
 978             j = scantable[i];
 979             level= ((level*2+1)*qscale)>>1;
 980             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 981             SKIP_BITS(re, &s->gb, 1);
 982         } else {
 983             /* escape */
 984             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 985             UPDATE_CACHE(re, &s->gb);
 986             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 987
 988             i += run;
 989             j = scantable[i];
 990             if(level<0){
 991                 level= ((-level*2+1)*qscale)>>1;
 992                 level= -level;
 993             }else{
 994                 level= ((level*2+1)*qscale)>>1;
 995             }
 996         }
 997
 998         block[j] = level;
 999 #if MIN_CACHE_BITS < 19
1000         UPDATE_CACHE(re, &s->gb);
1001 #endif
1002         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
1003             break;
1004 #if MIN_CACHE_BITS >=19
1005         UPDATE_CACHE(re, &s->gb);
1006 #endif
1007     }
1008 end:
1009     LAST_SKIP_BITS(re, &s->gb, 2);
1010     CLOSE_READER(re, &s->gb);
1011     s->block_last_index[n] = i;
1012     return 0;
1013 }
1014
1015
1016 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1017                                DCTELEM *block,
1018                                int n)
1019 {
1020     int level, dc, diff, i, j, run;
1021     int component;
1022     RLTable *rl;
1023     uint8_t * const scantable= s->intra_scantable.permutated;
1024     const uint16_t *quant_matrix;
1025     const int qscale= s->qscale;
1026     int mismatch;
1027
1028     /* DC coefficient */
1029     if (n < 4){
1030         quant_matrix = s->intra_matrix;
1031         component = 0;
1032     }else{
1033         quant_matrix = s->chroma_intra_matrix;
1034         component = (n&1) + 1;
1035     }
1036     diff = decode_dc(&s->gb, component);
1037     if (diff >= 0xffff)
1038         return -1;
1039     dc = s->last_dc[component];
1040     dc += diff;
1041     s->last_dc[component] = dc;
1042     block[0] = dc << (3 - s->intra_dc_precision);
1043     dprintf(s->avctx, "dc=%d\n", block[0]);
1044     mismatch = block[0] ^ 1;
1045     i = 0;
1046     if (s->intra_vlc_format)
1047         rl = &ff_rl_mpeg2;
1048     else
1049         rl = &ff_rl_mpeg1;
1050
1051     {
1052         OPEN_READER(re, &s->gb);
1053         /* now quantify & encode AC coefficients */
1054         for(;;) {
1055             UPDATE_CACHE(re, &s->gb);
1056             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1057
1058             if(level == 127){
1059                 break;
1060             } else if(level != 0) {
1061                 i += run;
1062                 j = scantable[i];
1063                 level= (level*qscale*quant_matrix[j])>>4;
1064                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1065                 LAST_SKIP_BITS(re, &s->gb, 1);
1066             } else {
1067                 /* escape */
1068                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1069                 UPDATE_CACHE(re, &s->gb);
1070                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1071                 i += run;
1072                 j = scantable[i];
1073                 if(level<0){
1074                     level= (-level*qscale*quant_matrix[j])>>4;
1075                     level= -level;
1076                 }else{
1077                     level= (level*qscale*quant_matrix[j])>>4;
1078                 }
1079             }
1080             if (i > 63){
1081                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1082                 return -1;
1083             }
1084
1085             mismatch^= level;
1086             block[j] = level;
1087         }
1088         CLOSE_READER(re, &s->gb);
1089     }
1090     block[63]^= mismatch&1;
1091
1092     s->block_last_index[n] = i;
1093     return 0;
1094 }
1095
1096 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1097                                DCTELEM *block,
1098                                int n)
1099 {
1100     int level, dc, diff, j, run;
1101     int component;
1102     RLTable *rl;
1103     uint8_t * scantable= s->intra_scantable.permutated;
1104     const uint16_t *quant_matrix;
1105     const int qscale= s->qscale;
1106
1107     /* DC coefficient */
1108     if (n < 4){
1109         quant_matrix = s->intra_matrix;
1110         component = 0;
1111     }else{
1112         quant_matrix = s->chroma_intra_matrix;
1113         component = (n&1) + 1;
1114     }
1115     diff = decode_dc(&s->gb, component);
1116     if (diff >= 0xffff)
1117         return -1;
1118     dc = s->last_dc[component];
1119     dc += diff;
1120     s->last_dc[component] = dc;
1121     block[0] = dc << (3 - s->intra_dc_precision);
1122     if (s->intra_vlc_format)
1123         rl = &ff_rl_mpeg2;
1124     else
1125         rl = &ff_rl_mpeg1;
1126
1127     {
1128         OPEN_READER(re, &s->gb);
1129         /* now quantify & encode AC coefficients */
1130         for(;;) {
1131             UPDATE_CACHE(re, &s->gb);
1132             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1133
1134             if(level == 127){
1135                 break;
1136             } else if(level != 0) {
1137                 scantable += run;
1138                 j = *scantable;
1139                 level= (level*qscale*quant_matrix[j])>>4;
1140                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1141                 LAST_SKIP_BITS(re, &s->gb, 1);
1142             } else {
1143                 /* escape */
1144                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1145                 UPDATE_CACHE(re, &s->gb);
1146                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1147                 scantable += run;
1148                 j = *scantable;
1149                 if(level<0){
1150                     level= (-level*qscale*quant_matrix[j])>>4;
1151                     level= -level;
1152                 }else{
1153                     level= (level*qscale*quant_matrix[j])>>4;
1154                 }
1155             }
1156
1157             block[j] = level;
1158         }
1159         CLOSE_READER(re, &s->gb);
1160     }
1161
1162     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1163     return 0;
1164 }
1165
1166 typedef struct Mpeg1Context {
1167     MpegEncContext mpeg_enc_ctx;
1168     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1169     int repeat_field; /* true if we must repeat the field */
1170     AVPanScan pan_scan; /** some temporary storage for the panscan */
1171     int slice_count;
1172     int swap_uv;//indicate VCR2
1173     int save_aspect_info;
1174     int save_width, save_height, save_progressive_seq;
1175     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1176
1177 } Mpeg1Context;
1178
1179 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1180 {
1181     Mpeg1Context *s = avctx->priv_data;
1182     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1183     int i;
1184
1185     /* we need some permutation to store matrices,
1186      * until MPV_common_init() sets the real permutation. */
1187     for(i=0;i<64;i++)
1188        s2->dsp.idct_permutation[i]=i;
1189
1190     MPV_decode_defaults(s2);
1191
1192     s->mpeg_enc_ctx.avctx= avctx;
1193     s->mpeg_enc_ctx.flags= avctx->flags;
1194     s->mpeg_enc_ctx.flags2= avctx->flags2;
1195     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1196     ff_mpeg12_init_vlcs();
1197
1198     s->mpeg_enc_ctx_allocated = 0;
1199     s->mpeg_enc_ctx.picture_number = 0;
1200     s->repeat_field = 0;
1201     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1202     avctx->color_range= AVCOL_RANGE_MPEG;
1203     if (avctx->codec->id == CODEC_ID_MPEG1VIDEO)
1204         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1205     else
1206         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
1207     return 0;
1208 }
1209
1210 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1211                                      const uint8_t *new_perm){
1212     uint16_t temp_matrix[64];
1213     int i;
1214
1215     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1216
1217     for(i=0;i<64;i++){
1218         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1219     }
1220 }
1221
1222 static enum PixelFormat mpeg_get_pixelformat(AVCodecContext *avctx){
1223     Mpeg1Context *s1 = avctx->priv_data;
1224     MpegEncContext *s = &s1->mpeg_enc_ctx;
1225
1226     if(avctx->xvmc_acceleration)
1227         return avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1228     else if(avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU){
1229         if(avctx->codec_id == CODEC_ID_MPEG1VIDEO)
1230             return PIX_FMT_VDPAU_MPEG1;
1231         else
1232             return PIX_FMT_VDPAU_MPEG2;
1233     }else{
1234         if(s->chroma_format <  2)
1235             return avctx->get_format(avctx,ff_hwaccel_pixfmt_list_420);
1236         else if(s->chroma_format == 2)
1237             return PIX_FMT_YUV422P;
1238         else
1239             return PIX_FMT_YUV444P;
1240     }
1241 }
1242
1243 /* Call this function when we know all parameters.
1244  * It may be called in different places for MPEG-1 and MPEG-2. */
1245 static int mpeg_decode_postinit(AVCodecContext *avctx){
1246     Mpeg1Context *s1 = avctx->priv_data;
1247     MpegEncContext *s = &s1->mpeg_enc_ctx;
1248     uint8_t old_permutation[64];
1249
1250     if (
1251         (s1->mpeg_enc_ctx_allocated == 0)||
1252         avctx->coded_width  != s->width ||
1253         avctx->coded_height != s->height||
1254         s1->save_width != s->width ||
1255         s1->save_height != s->height ||
1256         s1->save_aspect_info != s->aspect_ratio_info||
1257         s1->save_progressive_seq != s->progressive_sequence ||
1258         0)
1259     {
1260
1261         if (s1->mpeg_enc_ctx_allocated) {
1262             ParseContext pc= s->parse_context;
1263             s->parse_context.buffer=0;
1264             MPV_common_end(s);
1265             s->parse_context= pc;
1266         }
1267
1268         if( (s->width == 0 )||(s->height == 0))
1269             return -2;
1270
1271         avcodec_set_dimensions(avctx, s->width, s->height);
1272         avctx->bit_rate = s->bit_rate;
1273         s1->save_aspect_info = s->aspect_ratio_info;
1274         s1->save_width = s->width;
1275         s1->save_height = s->height;
1276         s1->save_progressive_seq = s->progressive_sequence;
1277
1278         /* low_delay may be forced, in this case we will have B-frames
1279          * that behave like P-frames. */
1280         avctx->has_b_frames = !(s->low_delay);
1281
1282         assert((avctx->sub_id==1) == (avctx->codec_id==CODEC_ID_MPEG1VIDEO));
1283         if(avctx->codec_id==CODEC_ID_MPEG1VIDEO){
1284             //MPEG-1 fps
1285             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1286             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1287             //MPEG-1 aspect
1288             avctx->sample_aspect_ratio= av_d2q(
1289                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1290             avctx->ticks_per_frame=1;
1291         }else{//MPEG-2
1292         //MPEG-2 fps
1293             av_reduce(
1294                 &s->avctx->time_base.den,
1295                 &s->avctx->time_base.num,
1296                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num*2,
1297                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1298                 1<<30);
1299             avctx->ticks_per_frame=2;
1300         //MPEG-2 aspect
1301             if(s->aspect_ratio_info > 1){
1302                 //we ignore the spec here as reality does not match the spec, see for example
1303                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1304                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) || 1){
1305                     s->avctx->sample_aspect_ratio=
1306                         av_div_q(
1307                          ff_mpeg2_aspect[s->aspect_ratio_info],
1308                          (AVRational){s->width, s->height}
1309                          );
1310                 }else{
1311                     s->avctx->sample_aspect_ratio=
1312                         av_div_q(
1313                          ff_mpeg2_aspect[s->aspect_ratio_info],
1314                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1315                         );
1316                 }
1317             }else{
1318                 s->avctx->sample_aspect_ratio=
1319                     ff_mpeg2_aspect[s->aspect_ratio_info];
1320             }
1321         }//MPEG-2
1322
1323         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1324         avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
1325         //until then pix_fmt may be changed right after codec init
1326         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
1327             avctx->hwaccel ||
1328             s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
1329             if( avctx->idct_algo == FF_IDCT_AUTO )
1330                 avctx->idct_algo = FF_IDCT_SIMPLE;
1331
1332         /* Quantization matrices may need reordering
1333          * if DCT permutation is changed. */
1334         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1335
1336         if (MPV_common_init(s) < 0)
1337             return -2;
1338
1339         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1340         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1341         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1342         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1343
1344         s1->mpeg_enc_ctx_allocated = 1;
1345     }
1346     return 0;
1347 }
1348
1349 static int mpeg1_decode_picture(AVCodecContext *avctx,
1350                                 const uint8_t *buf, int buf_size)
1351 {
1352     Mpeg1Context *s1 = avctx->priv_data;
1353     MpegEncContext *s = &s1->mpeg_enc_ctx;
1354     int ref, f_code, vbv_delay;
1355
1356     if(mpeg_decode_postinit(s->avctx) < 0)
1357        return -2;
1358
1359     init_get_bits(&s->gb, buf, buf_size*8);
1360
1361     ref = get_bits(&s->gb, 10); /* temporal ref */
1362     s->pict_type = get_bits(&s->gb, 3);
1363     if(s->pict_type == 0 || s->pict_type > 3)
1364         return -1;
1365
1366     vbv_delay= get_bits(&s->gb, 16);
1367     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1368         s->full_pel[0] = get_bits1(&s->gb);
1369         f_code = get_bits(&s->gb, 3);
1370         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1371             return -1;
1372         s->mpeg_f_code[0][0] = f_code;
1373         s->mpeg_f_code[0][1] = f_code;
1374     }
1375     if (s->pict_type == FF_B_TYPE) {
1376         s->full_pel[1] = get_bits1(&s->gb);
1377         f_code = get_bits(&s->gb, 3);
1378         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1379             return -1;
1380         s->mpeg_f_code[1][0] = f_code;
1381         s->mpeg_f_code[1][1] = f_code;
1382     }
1383     s->current_picture.pict_type= s->pict_type;
1384     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1385
1386     if(avctx->debug & FF_DEBUG_PICT_INFO)
1387         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1388
1389     s->y_dc_scale = 8;
1390     s->c_dc_scale = 8;
1391     s->first_slice = 1;
1392     return 0;
1393 }
1394
1395 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1396 {
1397     MpegEncContext *s= &s1->mpeg_enc_ctx;
1398     int horiz_size_ext, vert_size_ext;
1399     int bit_rate_ext;
1400
1401     skip_bits(&s->gb, 1); /* profile and level esc*/
1402     s->avctx->profile= get_bits(&s->gb, 3);
1403     s->avctx->level= get_bits(&s->gb, 4);
1404     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1405     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1406     horiz_size_ext = get_bits(&s->gb, 2);
1407     vert_size_ext = get_bits(&s->gb, 2);
1408     s->width |= (horiz_size_ext << 12);
1409     s->height |= (vert_size_ext << 12);
1410     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1411     s->bit_rate += (bit_rate_ext << 18) * 400;
1412     skip_bits1(&s->gb); /* marker */
1413     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1414
1415     s->low_delay = get_bits1(&s->gb);
1416     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1417
1418     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1419     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1420
1421     dprintf(s->avctx, "sequence extension\n");
1422     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1423     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1424
1425     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1426         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1427                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1428
1429 }
1430
1431 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1432 {
1433     MpegEncContext *s= &s1->mpeg_enc_ctx;
1434     int color_description, w, h;
1435
1436     skip_bits(&s->gb, 3); /* video format */
1437     color_description= get_bits1(&s->gb);
1438     if(color_description){
1439         s->avctx->color_primaries= get_bits(&s->gb, 8);
1440         s->avctx->color_trc      = get_bits(&s->gb, 8);
1441         s->avctx->colorspace     = get_bits(&s->gb, 8);
1442     }
1443     w= get_bits(&s->gb, 14);
1444     skip_bits(&s->gb, 1); //marker
1445     h= get_bits(&s->gb, 14);
1446     skip_bits(&s->gb, 1); //marker
1447
1448     s1->pan_scan.width= 16*w;
1449     s1->pan_scan.height=16*h;
1450
1451     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1452         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1453 }
1454
1455 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1456 {
1457     MpegEncContext *s= &s1->mpeg_enc_ctx;
1458     int i,nofco;
1459
1460     nofco = 1;
1461     if(s->progressive_sequence){
1462         if(s->repeat_first_field){
1463             nofco++;
1464             if(s->top_field_first)
1465                 nofco++;
1466         }
1467     }else{
1468         if(s->picture_structure == PICT_FRAME){
1469             nofco++;
1470             if(s->repeat_first_field)
1471                 nofco++;
1472         }
1473     }
1474     for(i=0; i<nofco; i++){
1475         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1476         skip_bits(&s->gb, 1); //marker
1477         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1478         skip_bits(&s->gb, 1); //marker
1479     }
1480
1481     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1482         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1483             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1484             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1485             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1486         );
1487 }
1488
1489 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64], uint16_t matrix1[64], int intra){
1490     int i;
1491
1492     for(i=0; i<64; i++) {
1493         int j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1494         int v = get_bits(&s->gb, 8);
1495         if(v==0){
1496             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1497             return -1;
1498         }
1499         if(intra && i==0 && v!=8){
1500             av_log(s->avctx, AV_LOG_ERROR, "intra matrix invalid, ignoring\n");
1501             v= 8; // needed by pink.mpg / issue1046
1502         }
1503         matrix0[j] = v;
1504         if(matrix1)
1505             matrix1[j] = v;
1506     }
1507     return 0;
1508 }
1509
1510 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1511 {
1512     dprintf(s->avctx, "matrix extension\n");
1513
1514     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1515     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1516     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, NULL           , 1);
1517     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, NULL           , 0);
1518 }
1519
1520 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1521 {
1522     MpegEncContext *s= &s1->mpeg_enc_ctx;
1523
1524     s->full_pel[0] = s->full_pel[1] = 0;
1525     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1526     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1527     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1528     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1529     if(!s->pict_type && s1->mpeg_enc_ctx_allocated){
1530         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1531         if(s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1]==15){
1532             if(s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1533                 s->pict_type= FF_I_TYPE;
1534             else
1535                 s->pict_type= FF_P_TYPE;
1536         }else
1537             s->pict_type= FF_B_TYPE;
1538         s->current_picture.pict_type= s->pict_type;
1539         s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1540         s->first_slice= 1;
1541     }
1542     s->intra_dc_precision = get_bits(&s->gb, 2);
1543     s->picture_structure = get_bits(&s->gb, 2);
1544     s->top_field_first = get_bits1(&s->gb);
1545     s->frame_pred_frame_dct = get_bits1(&s->gb);
1546     s->concealment_motion_vectors = get_bits1(&s->gb);
1547     s->q_scale_type = get_bits1(&s->gb);
1548     s->intra_vlc_format = get_bits1(&s->gb);
1549     s->alternate_scan = get_bits1(&s->gb);
1550     s->repeat_first_field = get_bits1(&s->gb);
1551     s->chroma_420_type = get_bits1(&s->gb);
1552     s->progressive_frame = get_bits1(&s->gb);
1553
1554     if(s->picture_structure == PICT_FRAME){
1555         s->first_field=0;
1556         s->v_edge_pos= 16*s->mb_height;
1557     }else{
1558         s->first_field ^= 1;
1559         s->v_edge_pos=  8*s->mb_height;
1560         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1561     }
1562
1563     if(s->alternate_scan){
1564         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1565         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1566     }else{
1567         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1568         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1569     }
1570
1571     /* composite display not parsed */
1572     dprintf(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1573     dprintf(s->avctx, "picture_structure=%d\n", s->picture_structure);
1574     dprintf(s->avctx, "top field first=%d\n", s->top_field_first);
1575     dprintf(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1576     dprintf(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1577     dprintf(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1578     dprintf(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1579     dprintf(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1580     dprintf(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1581 }
1582
1583 static void mpeg_decode_extension(AVCodecContext *avctx,
1584                                   const uint8_t *buf, int buf_size)
1585 {
1586     Mpeg1Context *s1 = avctx->priv_data;
1587     MpegEncContext *s = &s1->mpeg_enc_ctx;
1588     int ext_type;
1589
1590     init_get_bits(&s->gb, buf, buf_size*8);
1591
1592     ext_type = get_bits(&s->gb, 4);
1593     switch(ext_type) {
1594     case 0x1:
1595         mpeg_decode_sequence_extension(s1);
1596         break;
1597     case 0x2:
1598         mpeg_decode_sequence_display_extension(s1);
1599         break;
1600     case 0x3:
1601         mpeg_decode_quant_matrix_extension(s);
1602         break;
1603     case 0x7:
1604         mpeg_decode_picture_display_extension(s1);
1605         break;
1606     case 0x8:
1607         mpeg_decode_picture_coding_extension(s1);
1608         break;
1609     }
1610 }
1611
1612 static void exchange_uv(MpegEncContext *s){
1613     DCTELEM (*tmp)[64];
1614
1615     tmp           = s->pblocks[4];
1616     s->pblocks[4] = s->pblocks[5];
1617     s->pblocks[5] = tmp;
1618 }
1619
1620 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size){
1621     AVCodecContext *avctx= s->avctx;
1622     Mpeg1Context *s1 = (Mpeg1Context*)s;
1623
1624     /* start frame decoding */
1625     if(s->first_field || s->picture_structure==PICT_FRAME){
1626         if(MPV_frame_start(s, avctx) < 0)
1627             return -1;
1628
1629         ff_er_frame_start(s);
1630
1631         /* first check if we must repeat the frame */
1632         s->current_picture_ptr->repeat_pict = 0;
1633         if (s->repeat_first_field) {
1634             if (s->progressive_sequence) {
1635                 if (s->top_field_first)
1636                     s->current_picture_ptr->repeat_pict = 4;
1637                 else
1638                     s->current_picture_ptr->repeat_pict = 2;
1639             } else if (s->progressive_frame) {
1640                 s->current_picture_ptr->repeat_pict = 1;
1641             }
1642         }
1643
1644         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1645     }else{ //second field
1646             int i;
1647
1648             if(!s->current_picture_ptr){
1649                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1650                 return -1;
1651             }
1652
1653             for(i=0; i<4; i++){
1654                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1655                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1656                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1657                 }
1658             }
1659     }
1660
1661     if (avctx->hwaccel) {
1662         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
1663             return -1;
1664     }
1665
1666 // MPV_frame_start will call this function too,
1667 // but we need to call it on every field
1668     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1669         if(ff_xvmc_field_start(s,avctx) < 0)
1670             return -1;
1671
1672     return 0;
1673 }
1674
1675 #define DECODE_SLICE_ERROR -1
1676 #define DECODE_SLICE_OK 0
1677
1678 /**
1679  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1680  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1681  *         DECODE_SLICE_OK if this slice is ok<br>
1682  */
1683 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1684                              const uint8_t **buf, int buf_size)
1685 {
1686     MpegEncContext *s = &s1->mpeg_enc_ctx;
1687     AVCodecContext *avctx= s->avctx;
1688     const int field_pic= s->picture_structure != PICT_FRAME;
1689     const int lowres= s->avctx->lowres;
1690
1691     s->resync_mb_x=
1692     s->resync_mb_y= -1;
1693
1694     if (mb_y<<field_pic >= s->mb_height){
1695         av_log(s->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s->mb_height);
1696         return -1;
1697     }
1698
1699     init_get_bits(&s->gb, *buf, buf_size*8);
1700
1701     ff_mpeg1_clean_buffers(s);
1702     s->interlaced_dct = 0;
1703
1704     s->qscale = get_qscale(s);
1705
1706     if(s->qscale == 0){
1707         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1708         return -1;
1709     }
1710
1711     /* extra slice info */
1712     while (get_bits1(&s->gb) != 0) {
1713         skip_bits(&s->gb, 8);
1714     }
1715
1716     s->mb_x=0;
1717
1718     if (avctx->hwaccel) {
1719         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1720         int start_code = -1;
1721         buf_end = ff_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1722         if (buf_end < *buf + buf_size)
1723             buf_end -= 4;
1724         s->mb_y = mb_y;
1725         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1726             return DECODE_SLICE_ERROR;
1727         *buf = buf_end;
1728         return DECODE_SLICE_OK;
1729     }
1730
1731     for(;;) {
1732         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1733         if (code < 0){
1734             av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1735             return -1;
1736         }
1737         if (code >= 33) {
1738             if (code == 33) {
1739                 s->mb_x += 33;
1740             }
1741             /* otherwise, stuffing, nothing to do */
1742         } else {
1743             s->mb_x += code;
1744             break;
1745         }
1746     }
1747     if(s->mb_x >= (unsigned)s->mb_width){
1748         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1749         return -1;
1750     }
1751
1752     s->resync_mb_x= s->mb_x;
1753     s->resync_mb_y= s->mb_y= mb_y;
1754     s->mb_skip_run= 0;
1755     ff_init_block_index(s);
1756
1757     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1758         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1759              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",
1760                  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],
1761                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1762                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1763                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1764                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1765         }
1766     }
1767
1768     for(;;) {
1769         //If 1, we memcpy blocks in xvmcvideo.
1770         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1)
1771             ff_xvmc_init_block(s);//set s->block
1772
1773         if(mpeg_decode_mb(s, s->block) < 0)
1774             return -1;
1775
1776         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1777             const int wrap = field_pic ? 2*s->b8_stride : s->b8_stride;
1778             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1779             int motion_x, motion_y, dir, i;
1780             if(field_pic && !s->first_field)
1781                 xy += wrap/2;
1782
1783             for(i=0; i<2; i++){
1784                 for(dir=0; dir<2; dir++){
1785                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1786                         motion_x = motion_y = 0;
1787                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1788                         motion_x = s->mv[dir][0][0];
1789                         motion_y = s->mv[dir][0][1];
1790                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1791                         motion_x = s->mv[dir][i][0];
1792                         motion_y = s->mv[dir][i][1];
1793                     }
1794
1795                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1796                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1797                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1798                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1799                     s->current_picture.ref_index [dir][xy    ]=
1800                     s->current_picture.ref_index [dir][xy + 1]= s->field_select[dir][i];
1801                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1802                 }
1803                 xy += wrap;
1804             }
1805         }
1806
1807         s->dest[0] += 16 >> lowres;
1808         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1809         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1810
1811         MPV_decode_mb(s, s->block);
1812
1813         if (++s->mb_x >= s->mb_width) {
1814             const int mb_size= 16>>s->avctx->lowres;
1815
1816             ff_draw_horiz_band(s, mb_size*s->mb_y, mb_size);
1817
1818             s->mb_x = 0;
1819             s->mb_y++;
1820
1821             if(s->mb_y<<field_pic >= s->mb_height){
1822                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1823                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1824                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1825                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1826
1827                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1828                    || (avctx->error_recognition >= FF_ER_AGGRESSIVE && left>8)){
1829                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1830                     return -1;
1831                 }else
1832                     goto eos;
1833             }
1834
1835             ff_init_block_index(s);
1836         }
1837
1838         /* skip mb handling */
1839         if (s->mb_skip_run == -1) {
1840             /* read increment again */
1841             s->mb_skip_run = 0;
1842             for(;;) {
1843                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1844                 if (code < 0){
1845                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1846                     return -1;
1847                 }
1848                 if (code >= 33) {
1849                     if (code == 33) {
1850                         s->mb_skip_run += 33;
1851                     }else if(code == 35){
1852                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1853                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1854                             return -1;
1855                         }
1856                         goto eos; /* end of slice */
1857                     }
1858                     /* otherwise, stuffing, nothing to do */
1859                 } else {
1860                     s->mb_skip_run += code;
1861                     break;
1862                 }
1863             }
1864             if(s->mb_skip_run){
1865                 int i;
1866                 if(s->pict_type == FF_I_TYPE){
1867                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1868                     return -1;
1869                 }
1870
1871                 /* skip mb */
1872                 s->mb_intra = 0;
1873                 for(i=0;i<12;i++)
1874                     s->block_last_index[i] = -1;
1875                 if(s->picture_structure == PICT_FRAME)
1876                     s->mv_type = MV_TYPE_16X16;
1877                 else
1878                     s->mv_type = MV_TYPE_FIELD;
1879                 if (s->pict_type == FF_P_TYPE) {
1880                     /* if P type, zero motion vector is implied */
1881                     s->mv_dir = MV_DIR_FORWARD;
1882                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1883                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1884                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1885                     s->field_select[0][0]= s->picture_structure - 1;
1886                 } else {
1887                     /* if B type, reuse previous vectors and directions */
1888                     s->mv[0][0][0] = s->last_mv[0][0][0];
1889                     s->mv[0][0][1] = s->last_mv[0][0][1];
1890                     s->mv[1][0][0] = s->last_mv[1][0][0];
1891                     s->mv[1][0][1] = s->last_mv[1][0][1];
1892                 }
1893             }
1894         }
1895     }
1896 eos: // end of slice
1897     *buf += (get_bits_count(&s->gb)-1)/8;
1898 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1899     return 0;
1900 }
1901
1902 static int slice_decode_thread(AVCodecContext *c, void *arg){
1903     MpegEncContext *s= *(void**)arg;
1904     const uint8_t *buf= s->gb.buffer;
1905     int mb_y= s->start_mb_y;
1906
1907     s->error_count= 3*(s->end_mb_y - s->start_mb_y)*s->mb_width;
1908
1909     for(;;){
1910         uint32_t start_code;
1911         int ret;
1912
1913         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1914         emms_c();
1915 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1916 //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);
1917         if(ret < 0){
1918             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1919                 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);
1920         }else{
1921             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);
1922         }
1923
1924         if(s->mb_y == s->end_mb_y)
1925             return 0;
1926
1927         start_code= -1;
1928         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1929         mb_y= start_code - SLICE_MIN_START_CODE;
1930         if(mb_y < 0 || mb_y >= s->end_mb_y)
1931             return -1;
1932     }
1933
1934     return 0; //not reached
1935 }
1936
1937 /**
1938  * Handles slice ends.
1939  * @return 1 if it seems to be the last slice
1940  */
1941 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1942 {
1943     Mpeg1Context *s1 = avctx->priv_data;
1944     MpegEncContext *s = &s1->mpeg_enc_ctx;
1945
1946     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1947         return 0;
1948
1949     if (s->avctx->hwaccel) {
1950         if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
1951             av_log(avctx, AV_LOG_ERROR, "hardware accelerator failed to decode picture\n");
1952     }
1953
1954     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1955         ff_xvmc_field_end(s);
1956
1957     /* end of slice reached */
1958     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1959         /* end of image */
1960
1961         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1962
1963         ff_er_frame_end(s);
1964
1965         MPV_frame_end(s);
1966
1967         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1968             *pict= *(AVFrame*)s->current_picture_ptr;
1969             ff_print_debug_info(s, pict);
1970         } else {
1971             s->picture_number++;
1972             /* latency of 1 frame for I- and P-frames */
1973             /* XXX: use another variable than picture_number */
1974             if (s->last_picture_ptr != NULL) {
1975                 *pict= *(AVFrame*)s->last_picture_ptr;
1976                  ff_print_debug_info(s, pict);
1977             }
1978         }
1979
1980         return 1;
1981     } else {
1982         return 0;
1983     }
1984 }
1985
1986 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1987                                  const uint8_t *buf, int buf_size)
1988 {
1989     Mpeg1Context *s1 = avctx->priv_data;
1990     MpegEncContext *s = &s1->mpeg_enc_ctx;
1991     int width,height;
1992     int i, v, j;
1993
1994     init_get_bits(&s->gb, buf, buf_size*8);
1995
1996     width = get_bits(&s->gb, 12);
1997     height = get_bits(&s->gb, 12);
1998     if (width <= 0 || height <= 0)
1999         return -1;
2000     s->aspect_ratio_info= get_bits(&s->gb, 4);
2001     if (s->aspect_ratio_info == 0) {
2002         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2003         if (avctx->error_recognition >= FF_ER_COMPLIANT)
2004             return -1;
2005     }
2006     s->frame_rate_index = get_bits(&s->gb, 4);
2007     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
2008         return -1;
2009     s->bit_rate = get_bits(&s->gb, 18) * 400;
2010     if (get_bits1(&s->gb) == 0) /* marker */
2011         return -1;
2012     s->width = width;
2013     s->height = height;
2014
2015     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
2016     skip_bits(&s->gb, 1);
2017
2018     /* get matrix */
2019     if (get_bits1(&s->gb)) {
2020         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2021     } else {
2022         for(i=0;i<64;i++) {
2023             j = s->dsp.idct_permutation[i];
2024             v = ff_mpeg1_default_intra_matrix[i];
2025             s->intra_matrix[j] = v;
2026             s->chroma_intra_matrix[j] = v;
2027         }
2028     }
2029     if (get_bits1(&s->gb)) {
2030         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2031     } else {
2032         for(i=0;i<64;i++) {
2033             int j= s->dsp.idct_permutation[i];
2034             v = ff_mpeg1_default_non_intra_matrix[i];
2035             s->inter_matrix[j] = v;
2036             s->chroma_inter_matrix[j] = v;
2037         }
2038     }
2039
2040     if(show_bits(&s->gb, 23) != 0){
2041         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2042         return -1;
2043     }
2044
2045     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2046     s->progressive_sequence = 1;
2047     s->progressive_frame = 1;
2048     s->picture_structure = PICT_FRAME;
2049     s->frame_pred_frame_dct = 1;
2050     s->chroma_format = 1;
2051     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2052     avctx->sub_id = 1; /* indicates MPEG-1 */
2053     s->out_format = FMT_MPEG1;
2054     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2055     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2056
2057     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2058         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2059                s->avctx->rc_buffer_size, s->bit_rate);
2060
2061     return 0;
2062 }
2063
2064 static int vcr2_init_sequence(AVCodecContext *avctx)
2065 {
2066     Mpeg1Context *s1 = avctx->priv_data;
2067     MpegEncContext *s = &s1->mpeg_enc_ctx;
2068     int i, v;
2069
2070     /* start new MPEG-1 context decoding */
2071     s->out_format = FMT_MPEG1;
2072     if (s1->mpeg_enc_ctx_allocated) {
2073         MPV_common_end(s);
2074     }
2075     s->width  = avctx->coded_width;
2076     s->height = avctx->coded_height;
2077     avctx->has_b_frames= 0; //true?
2078     s->low_delay= 1;
2079
2080     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2081     avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
2082
2083     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT || avctx->hwaccel ||
2084         s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
2085         if( avctx->idct_algo == FF_IDCT_AUTO )
2086             avctx->idct_algo = FF_IDCT_SIMPLE;
2087
2088     if (MPV_common_init(s) < 0)
2089         return -1;
2090     exchange_uv(s);//common init reset pblocks, so we swap them here
2091     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2092     s1->mpeg_enc_ctx_allocated = 1;
2093
2094     for(i=0;i<64;i++) {
2095         int j= s->dsp.idct_permutation[i];
2096         v = ff_mpeg1_default_intra_matrix[i];
2097         s->intra_matrix[j] = v;
2098         s->chroma_intra_matrix[j] = v;
2099
2100         v = ff_mpeg1_default_non_intra_matrix[i];
2101         s->inter_matrix[j] = v;
2102         s->chroma_inter_matrix[j] = v;
2103     }
2104
2105     s->progressive_sequence = 1;
2106     s->progressive_frame = 1;
2107     s->picture_structure = PICT_FRAME;
2108     s->frame_pred_frame_dct = 1;
2109     s->chroma_format = 1;
2110     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2111     avctx->sub_id = 2; /* indicates MPEG-2 */
2112     return 0;
2113 }
2114
2115
2116 static void mpeg_decode_user_data(AVCodecContext *avctx,
2117                                   const uint8_t *buf, int buf_size)
2118 {
2119     const uint8_t *p;
2120     int len, flags;
2121     p = buf;
2122     len = buf_size;
2123
2124     /* we parse the DTG active format information */
2125     if (len >= 5 &&
2126         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2127         flags = p[4];
2128         p += 5;
2129         len -= 5;
2130         if (flags & 0x80) {
2131             /* skip event id */
2132             if (len < 2)
2133                 return;
2134             p += 2;
2135             len -= 2;
2136         }
2137         if (flags & 0x40) {
2138             if (len < 1)
2139                 return;
2140             avctx->dtg_active_format = p[0] & 0x0f;
2141         }
2142     }
2143 }
2144
2145 static void mpeg_decode_gop(AVCodecContext *avctx,
2146                             const uint8_t *buf, int buf_size){
2147     Mpeg1Context *s1 = avctx->priv_data;
2148     MpegEncContext *s = &s1->mpeg_enc_ctx;
2149
2150     int drop_frame_flag;
2151     int time_code_hours, time_code_minutes;
2152     int time_code_seconds, time_code_pictures;
2153     int broken_link;
2154
2155     init_get_bits(&s->gb, buf, buf_size*8);
2156
2157     drop_frame_flag = get_bits1(&s->gb);
2158
2159     time_code_hours=get_bits(&s->gb,5);
2160     time_code_minutes = get_bits(&s->gb,6);
2161     skip_bits1(&s->gb);//marker bit
2162     time_code_seconds = get_bits(&s->gb,6);
2163     time_code_pictures = get_bits(&s->gb,6);
2164
2165     s->closed_gop = get_bits1(&s->gb);
2166     /*broken_link indicate that after editing the
2167       reference frames of the first B-Frames after GOP I-Frame
2168       are missing (open gop)*/
2169     broken_link = get_bits1(&s->gb);
2170
2171     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2172         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2173             time_code_hours, time_code_minutes, time_code_seconds,
2174             time_code_pictures, s->closed_gop, broken_link);
2175 }
2176 /**
2177  * Finds the end of the current frame in the bitstream.
2178  * @return the position of the first byte of the next frame, or -1
2179  */
2180 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
2181 {
2182     int i;
2183     uint32_t state= pc->state;
2184
2185     /* EOF considered as end of frame */
2186     if (buf_size == 0)
2187         return 0;
2188
2189 /*
2190  0  frame start         -> 1/4
2191  1  first_SEQEXT        -> 0/2
2192  2  first field start   -> 3/0
2193  3  second_SEQEXT       -> 2/0
2194  4  searching end
2195 */
2196
2197     for(i=0; i<buf_size; i++){
2198         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2199         if(pc->frame_start_found&1){
2200             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2201                 pc->frame_start_found--;
2202             else if(state == EXT_START_CODE+2){
2203                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2204                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2205             }
2206             state++;
2207         }else{
2208             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2209             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2210                 i++;
2211                 pc->frame_start_found=4;
2212             }
2213             if(state == SEQ_END_CODE){
2214                 pc->state=-1;
2215                 return i+1;
2216             }
2217             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2218                 pc->frame_start_found= 0;
2219             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2220                 pc->frame_start_found++;
2221             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2222                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2223                     pc->frame_start_found=0;
2224                     pc->state=-1;
2225                     return i-3;
2226                 }
2227             }
2228             if(s && state == PICTURE_START_CODE){
2229                 ff_fetch_timestamp(s, i-4, 1);
2230             }
2231         }
2232     }
2233     pc->state= state;
2234     return END_NOT_FOUND;
2235 }
2236
2237 static int decode_chunks(AVCodecContext *avctx,
2238                              AVFrame *picture, int *data_size,
2239                              const uint8_t *buf, int buf_size);
2240
2241 /* handle buffering and image synchronisation */
2242 static int mpeg_decode_frame(AVCodecContext *avctx,
2243                              void *data, int *data_size,
2244                              AVPacket *avpkt)
2245 {
2246     const uint8_t *buf = avpkt->data;
2247     int buf_size = avpkt->size;
2248     Mpeg1Context *s = avctx->priv_data;
2249     AVFrame *picture = data;
2250     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2251     dprintf(avctx, "fill_buffer\n");
2252
2253     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2254         /* special case for last picture */
2255         if (s2->low_delay==0 && s2->next_picture_ptr) {
2256             *picture= *(AVFrame*)s2->next_picture_ptr;
2257             s2->next_picture_ptr= NULL;
2258
2259             *data_size = sizeof(AVFrame);
2260         }
2261         return buf_size;
2262     }
2263
2264     if(s2->flags&CODEC_FLAG_TRUNCATED){
2265         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size, NULL);
2266
2267         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2268             return buf_size;
2269     }
2270
2271 #if 0
2272     if (s->repeat_field % 2 == 1) {
2273         s->repeat_field++;
2274         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2275         //        s2->picture_number, s->repeat_field);
2276         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2277             *data_size = sizeof(AVPicture);
2278             goto the_end;
2279         }
2280     }
2281 #endif
2282
2283     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == AV_RL32("VCR2"))
2284         vcr2_init_sequence(avctx);
2285
2286     s->slice_count= 0;
2287
2288     if(avctx->extradata && !avctx->frame_number)
2289         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2290
2291     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2292 }
2293
2294 static int decode_chunks(AVCodecContext *avctx,
2295                              AVFrame *picture, int *data_size,
2296                              const uint8_t *buf, int buf_size)
2297 {
2298     Mpeg1Context *s = avctx->priv_data;
2299     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2300     const uint8_t *buf_ptr = buf;
2301     const uint8_t *buf_end = buf + buf_size;
2302     int ret, input_size;
2303
2304     for(;;) {
2305         /* find next start code */
2306         uint32_t start_code = -1;
2307         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2308         if (start_code > 0x1ff){
2309             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2310                 if(avctx->thread_count > 1){
2311                     int i;
2312
2313                     avctx->execute(avctx, slice_decode_thread,  (void**)&(s2->thread_context[0]), NULL, s->slice_count, sizeof(void*));
2314                     for(i=0; i<s->slice_count; i++)
2315                         s2->error_count += s2->thread_context[i]->error_count;
2316                 }
2317
2318                 if (CONFIG_MPEG_VDPAU_DECODER && avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
2319                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2320
2321                 if (slice_end(avctx, picture)) {
2322                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2323                         *data_size = sizeof(AVPicture);
2324                 }
2325             }
2326             s2->pict_type= 0;
2327             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2328         }
2329
2330         input_size = buf_end - buf_ptr;
2331
2332         if(avctx->debug & FF_DEBUG_STARTCODE){
2333             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2334         }
2335
2336         /* prepare data for next start code */
2337         switch(start_code) {
2338         case SEQ_START_CODE:
2339             mpeg1_decode_sequence(avctx, buf_ptr,
2340                                     input_size);
2341             break;
2342
2343         case PICTURE_START_CODE:
2344             /* we have a complete image: we try to decompress it */
2345             if(mpeg1_decode_picture(avctx,
2346                                     buf_ptr, input_size) < 0)
2347                 s2->pict_type=0;
2348             break;
2349         case EXT_START_CODE:
2350             mpeg_decode_extension(avctx,
2351                                     buf_ptr, input_size);
2352             break;
2353         case USER_START_CODE:
2354             mpeg_decode_user_data(avctx,
2355                                     buf_ptr, input_size);
2356             break;
2357         case GOP_START_CODE:
2358             s2->first_field=0;
2359             mpeg_decode_gop(avctx,
2360                                     buf_ptr, input_size);
2361             break;
2362         default:
2363             if (start_code >= SLICE_MIN_START_CODE &&
2364                 start_code <= SLICE_MAX_START_CODE) {
2365                 int mb_y= start_code - SLICE_MIN_START_CODE;
2366
2367                 if(s2->last_picture_ptr==NULL){
2368                 /* Skip B-frames if we do not have reference frames and gop is not closed */
2369                     if(s2->pict_type==FF_B_TYPE){
2370                         int i;
2371                         if(!s2->closed_gop)
2372                             break;
2373                         /* Allocate a dummy frame */
2374                         i= ff_find_unused_picture(s2, 0);
2375                         s2->last_picture_ptr= &s2->picture[i];
2376                         if(alloc_picture(s2, s2->last_picture_ptr, 0) < 0)
2377                             return -1;
2378                     }
2379                 }
2380                 if(s2->next_picture_ptr==NULL){
2381                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2382                     if(s2->pict_type==FF_P_TYPE && (s2->first_field || s2->picture_structure==PICT_FRAME)) break;
2383                 }
2384                 /* Skip B-frames if we are in a hurry. */
2385                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2386                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2387                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2388                     || avctx->skip_frame >= AVDISCARD_ALL)
2389                     break;
2390                 /* Skip everything if we are in a hurry>=5. */
2391                 if(avctx->hurry_up>=5) break;
2392
2393                 if (!s->mpeg_enc_ctx_allocated) break;
2394
2395                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2396                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2397                         break;
2398                 }
2399
2400                 if(!s2->pict_type){
2401                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2402                     break;
2403                 }
2404
2405                 if(s2->first_slice){
2406                     s2->first_slice=0;
2407                     if(mpeg_field_start(s2, buf, buf_size) < 0)
2408                         return -1;
2409                 }
2410                 if(!s2->current_picture_ptr){
2411                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2412                     return -1;
2413                 }
2414
2415                 if (avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
2416                     s->slice_count++;
2417                     break;
2418                 }
2419
2420                 if(avctx->thread_count > 1){
2421                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2422                     if(threshold <= mb_y){
2423                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2424
2425                         thread_context->start_mb_y= mb_y;
2426                         thread_context->end_mb_y  = s2->mb_height;
2427                         if(s->slice_count){
2428                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2429                             ff_update_duplicate_context(thread_context, s2);
2430                         }
2431                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2432                         s->slice_count++;
2433                     }
2434                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2435                 }else{
2436                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2437                     emms_c();
2438
2439                     if(ret < 0){
2440                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2441                             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);
2442                     }else{
2443                         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);
2444                     }
2445                 }
2446             }
2447             break;
2448         }
2449     }
2450 }
2451
2452 static int mpeg_decode_end(AVCodecContext *avctx)
2453 {
2454     Mpeg1Context *s = avctx->priv_data;
2455
2456     if (s->mpeg_enc_ctx_allocated)
2457         MPV_common_end(&s->mpeg_enc_ctx);
2458     return 0;
2459 }
2460
2461 AVCodec mpeg1video_decoder = {
2462     "mpeg1video",
2463     CODEC_TYPE_VIDEO,
2464     CODEC_ID_MPEG1VIDEO,
2465     sizeof(Mpeg1Context),
2466     mpeg_decode_init,
2467     NULL,
2468     mpeg_decode_end,
2469     mpeg_decode_frame,
2470     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2471     .flush= ff_mpeg_flush,
2472     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2473 };
2474
2475 AVCodec mpeg2video_decoder = {
2476     "mpeg2video",
2477     CODEC_TYPE_VIDEO,
2478     CODEC_ID_MPEG2VIDEO,
2479     sizeof(Mpeg1Context),
2480     mpeg_decode_init,
2481     NULL,
2482     mpeg_decode_end,
2483     mpeg_decode_frame,
2484     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2485     .flush= ff_mpeg_flush,
2486     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2487 };
2488
2489 //legacy decoder
2490 AVCodec mpegvideo_decoder = {
2491     "mpegvideo",
2492     CODEC_TYPE_VIDEO,
2493     CODEC_ID_MPEG2VIDEO,
2494     sizeof(Mpeg1Context),
2495     mpeg_decode_init,
2496     NULL,
2497     mpeg_decode_end,
2498     mpeg_decode_frame,
2499     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2500     .flush= ff_mpeg_flush,
2501     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2502 };
2503
2504 #if CONFIG_MPEG_XVMC_DECODER
2505 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2506     if( avctx->thread_count > 1)
2507         return -1;
2508     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2509         return -1;
2510     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2511         dprintf(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2512     }
2513     mpeg_decode_init(avctx);
2514
2515     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2516     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2517
2518     return 0;
2519 }
2520
2521 AVCodec mpeg_xvmc_decoder = {
2522     "mpegvideo_xvmc",
2523     CODEC_TYPE_VIDEO,
2524     CODEC_ID_MPEG2VIDEO_XVMC,
2525     sizeof(Mpeg1Context),
2526     mpeg_mc_decode_init,
2527     NULL,
2528     mpeg_decode_end,
2529     mpeg_decode_frame,
2530     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2531     .flush= ff_mpeg_flush,
2532     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2533 };
2534
2535 #endif
2536
2537 #if CONFIG_MPEG_VDPAU_DECODER
2538 AVCodec mpeg_vdpau_decoder = {
2539     "mpegvideo_vdpau",
2540     CODEC_TYPE_VIDEO,
2541     CODEC_ID_MPEG2VIDEO,
2542     sizeof(Mpeg1Context),
2543     mpeg_decode_init,
2544     NULL,
2545     mpeg_decode_end,
2546     mpeg_decode_frame,
2547     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2548     .flush= ff_mpeg_flush,
2549     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2550 };
2551 #endif
2552
2553 #if CONFIG_MPEG1_VDPAU_DECODER
2554 AVCodec mpeg1_vdpau_decoder = {
2555     "mpeg1video_vdpau",
2556     CODEC_TYPE_VIDEO,
2557     CODEC_ID_MPEG1VIDEO,
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= ff_mpeg_flush,
2565     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2566 };
2567 #endif
2568