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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 "avcodec.h"
  30 #include "dsputil.h"
  31 #include "mpegvideo.h"
  32
  33 #include "mpeg12.h"
  34 #include "mpeg12data.h"
  35 #include "mpeg12decdata.h"
  36 #include "bytestream.h"
  37 #include "vdpau_internal.h"
  38 #include "xvmc_internal.h"
  39
  40 //#undef NDEBUG
  41 //#include <assert.h>
  42
  43
  44 #define MV_VLC_BITS 9
  45 #define MBINCR_VLC_BITS 9
  46 #define MB_PAT_VLC_BITS 9
  47 #define MB_PTYPE_VLC_BITS 6
  48 #define MB_BTYPE_VLC_BITS 6
  49
  50 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
  51                               DCTELEM *block,
  52                               int n);
  53 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n);
  54 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
  55                                         DCTELEM *block,
  56                                         int n);
  57 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
  58                                     DCTELEM *block,
  59                                     int n);
  60 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n);
  61 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
  62 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
  63 static void exchange_uv(MpegEncContext *s);
  64
  65 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
  66                                            PIX_FMT_XVMC_MPEG2_IDCT,
  67                                            PIX_FMT_XVMC_MPEG2_MC,
  68                                            PIX_FMT_NONE};
  69
  70 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  71
  72
  73 #define INIT_2D_VLC_RL(rl, static_size)\
  74 {\
  75     static RL_VLC_ELEM rl_vlc_table[static_size];\
  76     INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
  77              &rl.table_vlc[0][1], 4, 2,\
  78              &rl.table_vlc[0][0], 4, 2, static_size);\
  79 \
  80     rl.rl_vlc[0]= rl_vlc_table;\
  81     init_2d_vlc_rl(&rl);\
  82 }
  83
  84 static void init_2d_vlc_rl(RLTable *rl)
  85 {
  86     int i;
  87
  88     for(i=0; i<rl->vlc.table_size; i++){
  89         int code= rl->vlc.table[i][0];
  90         int len = rl->vlc.table[i][1];
  91         int level, run;
  92
  93         if(len==0){ // illegal code
  94             run= 65;
  95             level= MAX_LEVEL;
  96         }else if(len<0){ //more bits needed
  97             run= 0;
  98             level= code;
  99         }else{
 100             if(code==rl->n){ //esc
 101                 run= 65;
 102                 level= 0;
 103             }else if(code==rl->n+1){ //eob
 104                 run= 0;
 105                 level= 127;
 106             }else{
 107                 run=   rl->table_run  [code] + 1;
 108                 level= rl->table_level[code];
 109             }
 110         }
 111         rl->rl_vlc[0][i].len= len;
 112         rl->rl_vlc[0][i].level= level;
 113         rl->rl_vlc[0][i].run= run;
 114     }
 115 }
 116
 117 void ff_mpeg12_common_init(MpegEncContext *s)
 118 {
 119
 120     s->y_dc_scale_table=
 121     s->c_dc_scale_table= mpeg2_dc_scale_table[s->intra_dc_precision];
 122
 123 }
 124
 125 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 126     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 127     s->last_dc[1] = s->last_dc[0];
 128     s->last_dc[2] = s->last_dc[0];
 129     memset(s->last_mv, 0, sizeof(s->last_mv));
 130 }
 131
 132
 133 /******************************************/
 134 /* decoding */
 135
 136 static VLC mv_vlc;
 137 static VLC mbincr_vlc;
 138 static VLC mb_ptype_vlc;
 139 static VLC mb_btype_vlc;
 140 static VLC mb_pat_vlc;
 141
 142 av_cold void ff_mpeg12_init_vlcs(void)
 143 {
 144     static int done = 0;
 145
 146     if (!done) {
 147         done = 1;
 148
 149         INIT_VLC_STATIC(&dc_lum_vlc, DC_VLC_BITS, 12,
 150                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
 151                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
 152         INIT_VLC_STATIC(&dc_chroma_vlc,  DC_VLC_BITS, 12,
 153                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
 154                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
 155         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
 156                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
 157                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
 158         INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 159                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
 160                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
 161         INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
 162                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
 163                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
 164
 165         INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 166                  &table_mb_ptype[0][1], 2, 1,
 167                  &table_mb_ptype[0][0], 2, 1, 64);
 168         INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 169                  &table_mb_btype[0][1], 2, 1,
 170                  &table_mb_btype[0][0], 2, 1, 64);
 171         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
 172         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
 173
 174         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
 175         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
 176     }
 177 }
 178
 179 static inline int get_dmv(MpegEncContext *s)
 180 {
 181     if(get_bits1(&s->gb))
 182         return 1 - (get_bits1(&s->gb) << 1);
 183     else
 184         return 0;
 185 }
 186
 187 static inline int get_qscale(MpegEncContext *s)
 188 {
 189     int qscale = get_bits(&s->gb, 5);
 190     if (s->q_scale_type) {
 191         return non_linear_qscale[qscale];
 192     } else {
 193         return qscale << 1;
 194     }
 195 }
 196
 197 /* motion type (for MPEG-2) */
 198 #define MT_FIELD 1
 199 #define MT_FRAME 2
 200 #define MT_16X8  2
 201 #define MT_DMV   3
 202
 203 static int mpeg_decode_mb(MpegEncContext *s,
 204                           DCTELEM block[12][64])
 205 {
 206     int i, j, k, cbp, val, mb_type, motion_type;
 207     const int mb_block_count = 4 + (1<< s->chroma_format);
 208
 209     dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 210
 211     assert(s->mb_skipped==0);
 212
 213     if (s->mb_skip_run-- != 0) {
 214         if (s->pict_type == FF_P_TYPE) {
 215             s->mb_skipped = 1;
 216             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 217         } else {
 218             int mb_type;
 219
 220             if(s->mb_x)
 221                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
 222             else
 223                 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
 224             if(IS_INTRA(mb_type))
 225                 return -1;
 226
 227             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 228                 mb_type | MB_TYPE_SKIP;
 229 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 230
 231             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 232                 s->mb_skipped = 1;
 233         }
 234
 235         return 0;
 236     }
 237
 238     switch(s->pict_type) {
 239     default:
 240     case FF_I_TYPE:
 241         if (get_bits1(&s->gb) == 0) {
 242             if (get_bits1(&s->gb) == 0){
 243                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
 244                 return -1;
 245             }
 246             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 247         } else {
 248             mb_type = MB_TYPE_INTRA;
 249         }
 250         break;
 251     case FF_P_TYPE:
 252         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 253         if (mb_type < 0){
 254             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 255             return -1;
 256         }
 257         mb_type = ptype2mb_type[ mb_type ];
 258         break;
 259     case FF_B_TYPE:
 260         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 261         if (mb_type < 0){
 262             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 263             return -1;
 264         }
 265         mb_type = btype2mb_type[ mb_type ];
 266         break;
 267     }
 268     dprintf(s->avctx, "mb_type=%x\n", mb_type);
 269 //    motion_type = 0; /* avoid warning */
 270     if (IS_INTRA(mb_type)) {
 271         s->dsp.clear_blocks(s->block[0]);
 272
 273         if(!s->chroma_y_shift){
 274             s->dsp.clear_blocks(s->block[6]);
 275         }
 276
 277         /* compute DCT type */
 278         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
 279             !s->frame_pred_frame_dct) {
 280             s->interlaced_dct = get_bits1(&s->gb);
 281         }
 282
 283         if (IS_QUANT(mb_type))
 284             s->qscale = get_qscale(s);
 285
 286         if (s->concealment_motion_vectors) {
 287             /* just parse them */
 288             if (s->picture_structure != PICT_FRAME)
 289                 skip_bits1(&s->gb); /* field select */
 290
 291             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 292                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 293             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 294                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 295
 296             skip_bits1(&s->gb); /* marker */
 297         }else
 298             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 299         s->mb_intra = 1;
 300         //if 1, we memcpy blocks in xvmcvideo
 301         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 302             ff_xvmc_pack_pblocks(s,-1);//inter are always full blocks
 303             if(s->swap_uv){
 304                 exchange_uv(s);
 305             }
 306         }
 307
 308         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 309             if(s->flags2 & CODEC_FLAG2_FAST){
 310                 for(i=0;i<6;i++) {
 311                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
 312                 }
 313             }else{
 314                 for(i=0;i<mb_block_count;i++) {
 315                     if (mpeg2_decode_block_intra(s, *s->pblocks[i], i) < 0)
 316                         return -1;
 317                 }
 318             }
 319         } else {
 320             for(i=0;i<6;i++) {
 321                 if (ff_mpeg1_decode_block_intra(s, *s->pblocks[i], i) < 0)
 322                     return -1;
 323             }
 324         }
 325     } else {
 326         if (mb_type & MB_TYPE_ZERO_MV){
 327             assert(mb_type & MB_TYPE_CBP);
 328
 329             s->mv_dir = MV_DIR_FORWARD;
 330             if(s->picture_structure == PICT_FRAME){
 331                 if(!s->frame_pred_frame_dct)
 332                     s->interlaced_dct = get_bits1(&s->gb);
 333                 s->mv_type = MV_TYPE_16X16;
 334             }else{
 335                 s->mv_type = MV_TYPE_FIELD;
 336                 mb_type |= MB_TYPE_INTERLACED;
 337                 s->field_select[0][0]= s->picture_structure - 1;
 338             }
 339
 340             if (IS_QUANT(mb_type))
 341                 s->qscale = get_qscale(s);
 342
 343             s->last_mv[0][0][0] = 0;
 344             s->last_mv[0][0][1] = 0;
 345             s->last_mv[0][1][0] = 0;
 346             s->last_mv[0][1][1] = 0;
 347             s->mv[0][0][0] = 0;
 348             s->mv[0][0][1] = 0;
 349         }else{
 350             assert(mb_type & MB_TYPE_L0L1);
 351 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 352             /* get additional motion vector type */
 353             if (s->frame_pred_frame_dct)
 354                 motion_type = MT_FRAME;
 355             else{
 356                 motion_type = get_bits(&s->gb, 2);
 357                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 358                     s->interlaced_dct = get_bits1(&s->gb);
 359             }
 360
 361             if (IS_QUANT(mb_type))
 362                 s->qscale = get_qscale(s);
 363
 364             /* motion vectors */
 365             s->mv_dir= (mb_type>>13)&3;
 366             dprintf(s->avctx, "motion_type=%d\n", motion_type);
 367             switch(motion_type) {
 368             case MT_FRAME: /* or MT_16X8 */
 369                 if (s->picture_structure == PICT_FRAME) {
 370                     mb_type |= MB_TYPE_16x16;
 371                     s->mv_type = MV_TYPE_16X16;
 372                     for(i=0;i<2;i++) {
 373                         if (USES_LIST(mb_type, i)) {
 374                             /* MT_FRAME */
 375                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
 376                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
 377                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
 378                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
 379                             /* full_pel: only for MPEG-1 */
 380                             if (s->full_pel[i]){
 381                                 s->mv[i][0][0] <<= 1;
 382                                 s->mv[i][0][1] <<= 1;
 383                             }
 384                         }
 385                     }
 386                 } else {
 387                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 388                     s->mv_type = MV_TYPE_16X8;
 389                     for(i=0;i<2;i++) {
 390                         if (USES_LIST(mb_type, i)) {
 391                             /* MT_16X8 */
 392                             for(j=0;j<2;j++) {
 393                                 s->field_select[i][j] = get_bits1(&s->gb);
 394                                 for(k=0;k<2;k++) {
 395                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 396                                                              s->last_mv[i][j][k]);
 397                                     s->last_mv[i][j][k] = val;
 398                                     s->mv[i][j][k] = val;
 399                                 }
 400                             }
 401                         }
 402                     }
 403                 }
 404                 break;
 405             case MT_FIELD:
 406                 s->mv_type = MV_TYPE_FIELD;
 407                 if (s->picture_structure == PICT_FRAME) {
 408                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 409                     for(i=0;i<2;i++) {
 410                         if (USES_LIST(mb_type, i)) {
 411                             for(j=0;j<2;j++) {
 412                                 s->field_select[i][j] = get_bits1(&s->gb);
 413                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 414                                                          s->last_mv[i][j][0]);
 415                                 s->last_mv[i][j][0] = val;
 416                                 s->mv[i][j][0] = val;
 417                                 dprintf(s->avctx, "fmx=%d\n", val);
 418                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 419                                                          s->last_mv[i][j][1] >> 1);
 420                                 s->last_mv[i][j][1] = val << 1;
 421                                 s->mv[i][j][1] = val;
 422                                 dprintf(s->avctx, "fmy=%d\n", val);
 423                             }
 424                         }
 425                     }
 426                 } else {
 427                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 428                     for(i=0;i<2;i++) {
 429                         if (USES_LIST(mb_type, i)) {
 430                             s->field_select[i][0] = get_bits1(&s->gb);
 431                             for(k=0;k<2;k++) {
 432                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 433                                                          s->last_mv[i][0][k]);
 434                                 s->last_mv[i][0][k] = val;
 435                                 s->last_mv[i][1][k] = val;
 436                                 s->mv[i][0][k] = val;
 437                             }
 438                         }
 439                     }
 440                 }
 441                 break;
 442             case MT_DMV:
 443                 s->mv_type = MV_TYPE_DMV;
 444                 for(i=0;i<2;i++) {
 445                     if (USES_LIST(mb_type, i)) {
 446                         int dmx, dmy, mx, my, m;
 447                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 448                                                 s->last_mv[i][0][0]);
 449                         s->last_mv[i][0][0] = mx;
 450                         s->last_mv[i][1][0] = mx;
 451                         dmx = get_dmv(s);
 452                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 453                                                 s->last_mv[i][0][1] >> 1);
 454                         dmy = get_dmv(s);
 455
 456
 457                         s->last_mv[i][0][1] = my<<1;
 458                         s->last_mv[i][1][1] = my<<1;
 459
 460                         s->mv[i][0][0] = mx;
 461                         s->mv[i][0][1] = my;
 462                         s->mv[i][1][0] = mx;//not used
 463                         s->mv[i][1][1] = my;//not used
 464
 465                         if (s->picture_structure == PICT_FRAME) {
 466                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 467
 468                             //m = 1 + 2 * s->top_field_first;
 469                             m = s->top_field_first ? 1 : 3;
 470
 471                             /* top -> top pred */
 472                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 473                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
 474                             m = 4 - m;
 475                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 476                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
 477                         } else {
 478                             mb_type |= MB_TYPE_16x16;
 479
 480                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
 481                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
 482                             if(s->picture_structure == PICT_TOP_FIELD)
 483                                 s->mv[i][2][1]--;
 484                             else
 485                                 s->mv[i][2][1]++;
 486                         }
 487                     }
 488                 }
 489                 break;
 490             default:
 491                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
 492                 return -1;
 493             }
 494         }
 495
 496         s->mb_intra = 0;
 497         if (HAS_CBP(mb_type)) {
 498             s->dsp.clear_blocks(s->block[0]);
 499
 500             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
 501             if(mb_block_count > 6){
 502                  cbp<<= mb_block_count-6;
 503                  cbp |= get_bits(&s->gb, mb_block_count-6);
 504                  s->dsp.clear_blocks(s->block[6]);
 505             }
 506             if (cbp <= 0){
 507                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
 508                 return -1;
 509             }
 510
 511             //if 1, we memcpy blocks in xvmcvideo
 512             if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 513                 ff_xvmc_pack_pblocks(s,cbp);
 514                 if(s->swap_uv){
 515                     exchange_uv(s);
 516                 }
 517             }
 518
 519             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 520                 if(s->flags2 & CODEC_FLAG2_FAST){
 521                     for(i=0;i<6;i++) {
 522                         if(cbp & 32) {
 523                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
 524                         } else {
 525                             s->block_last_index[i] = -1;
 526                         }
 527                         cbp+=cbp;
 528                     }
 529                 }else{
 530                     cbp<<= 12-mb_block_count;
 531
 532                     for(i=0;i<mb_block_count;i++) {
 533                         if ( cbp & (1<<11) ) {
 534                             if (mpeg2_decode_block_non_intra(s, *s->pblocks[i], i) < 0)
 535                                 return -1;
 536                         } else {
 537                             s->block_last_index[i] = -1;
 538                         }
 539                         cbp+=cbp;
 540                     }
 541                 }
 542             } else {
 543                 if(s->flags2 & CODEC_FLAG2_FAST){
 544                     for(i=0;i<6;i++) {
 545                         if (cbp & 32) {
 546                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
 547                         } else {
 548                             s->block_last_index[i] = -1;
 549                         }
 550                         cbp+=cbp;
 551                     }
 552                 }else{
 553                     for(i=0;i<6;i++) {
 554                         if (cbp & 32) {
 555                             if (mpeg1_decode_block_inter(s, *s->pblocks[i], i) < 0)
 556                                 return -1;
 557                         } else {
 558                             s->block_last_index[i] = -1;
 559                         }
 560                         cbp+=cbp;
 561                     }
 562                 }
 563             }
 564         }else{
 565             for(i=0;i<12;i++)
 566                 s->block_last_index[i] = -1;
 567         }
 568     }
 569
 570     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
 571
 572     return 0;
 573 }
 574
 575 /* as H.263, but only 17 codes */
 576 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 577 {
 578     int code, sign, val, l, shift;
 579
 580     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 581     if (code == 0) {
 582         return pred;
 583     }
 584     if (code < 0) {
 585         return 0xffff;
 586     }
 587
 588     sign = get_bits1(&s->gb);
 589     shift = fcode - 1;
 590     val = code;
 591     if (shift) {
 592         val = (val - 1) << shift;
 593         val |= get_bits(&s->gb, shift);
 594         val++;
 595     }
 596     if (sign)
 597         val = -val;
 598     val += pred;
 599
 600     /* modulo decoding */
 601     l= INT_BIT - 5 - shift;
 602     val = (val<<l)>>l;
 603     return val;
 604 }
 605
 606 inline int ff_mpeg1_decode_block_intra(MpegEncContext *s,
 607                                DCTELEM *block,
 608                                int n)
 609 {
 610     int level, dc, diff, i, j, run;
 611     int component;
 612     RLTable *rl = &ff_rl_mpeg1;
 613     uint8_t * const scantable= s->intra_scantable.permutated;
 614     const uint16_t *quant_matrix= s->intra_matrix;
 615     const int qscale= s->qscale;
 616
 617     /* DC coefficient */
 618     component = (n <= 3 ? 0 : n - 4 + 1);
 619     diff = decode_dc(&s->gb, component);
 620     if (diff >= 0xffff)
 621         return -1;
 622     dc = s->last_dc[component];
 623     dc += diff;
 624     s->last_dc[component] = dc;
 625     block[0] = dc*quant_matrix[0];
 626     dprintf(s->avctx, "dc=%d diff=%d\n", dc, diff);
 627     i = 0;
 628     {
 629         OPEN_READER(re, &s->gb);
 630         /* now quantify & encode AC coefficients */
 631         for(;;) {
 632             UPDATE_CACHE(re, &s->gb);
 633             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 634
 635             if(level == 127){
 636                 break;
 637             } else if(level != 0) {
 638                 i += run;
 639                 j = scantable[i];
 640                 level= (level*qscale*quant_matrix[j])>>4;
 641                 level= (level-1)|1;
 642                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 643                 LAST_SKIP_BITS(re, &s->gb, 1);
 644             } else {
 645                 /* escape */
 646                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 647                 UPDATE_CACHE(re, &s->gb);
 648                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 649                 if (level == -128) {
 650                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
 651                 } else if (level == 0) {
 652                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
 653                 }
 654                 i += run;
 655                 j = scantable[i];
 656                 if(level<0){
 657                     level= -level;
 658                     level= (level*qscale*quant_matrix[j])>>4;
 659                     level= (level-1)|1;
 660                     level= -level;
 661                 }else{
 662                     level= (level*qscale*quant_matrix[j])>>4;
 663                     level= (level-1)|1;
 664                 }
 665             }
 666             if (i > 63){
 667                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 668                 return -1;
 669             }
 670
 671             block[j] = level;
 672         }
 673         CLOSE_READER(re, &s->gb);
 674     }
 675     s->block_last_index[n] = i;
 676    return 0;
 677 }
 678
 679 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 680                                DCTELEM *block,
 681                                int n)
 682 {
 683     int level, i, j, run;
 684     RLTable *rl = &ff_rl_mpeg1;
 685     uint8_t * const scantable= s->intra_scantable.permutated;
 686     const uint16_t *quant_matrix= s->inter_matrix;
 687     const int qscale= s->qscale;
 688
 689     {
 690         OPEN_READER(re, &s->gb);
 691         i = -1;
 692         // special case for first coefficient, no need to add second VLC table
 693         UPDATE_CACHE(re, &s->gb);
 694         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 695             level= (3*qscale*quant_matrix[0])>>5;
 696             level= (level-1)|1;
 697             if(GET_CACHE(re, &s->gb)&0x40000000)
 698                 level= -level;
 699             block[0] = level;
 700             i++;
 701             SKIP_BITS(re, &s->gb, 2);
 702             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 703                 goto end;
 704         }
 705 #if MIN_CACHE_BITS < 19
 706         UPDATE_CACHE(re, &s->gb);
 707 #endif
 708         /* now quantify & encode AC coefficients */
 709         for(;;) {
 710             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 711
 712             if(level != 0) {
 713                 i += run;
 714                 j = scantable[i];
 715                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 716                 level= (level-1)|1;
 717                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 718                 SKIP_BITS(re, &s->gb, 1);
 719             } else {
 720                 /* escape */
 721                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 722                 UPDATE_CACHE(re, &s->gb);
 723                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 724                 if (level == -128) {
 725                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 726                 } else if (level == 0) {
 727                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 728                 }
 729                 i += run;
 730                 j = scantable[i];
 731                 if(level<0){
 732                     level= -level;
 733                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 734                     level= (level-1)|1;
 735                     level= -level;
 736                 }else{
 737                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 738                     level= (level-1)|1;
 739                 }
 740             }
 741             if (i > 63){
 742                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 743                 return -1;
 744             }
 745
 746             block[j] = level;
 747 #if MIN_CACHE_BITS < 19
 748             UPDATE_CACHE(re, &s->gb);
 749 #endif
 750             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 751                 break;
 752 #if MIN_CACHE_BITS >= 19
 753             UPDATE_CACHE(re, &s->gb);
 754 #endif
 755         }
 756 end:
 757         LAST_SKIP_BITS(re, &s->gb, 2);
 758         CLOSE_READER(re, &s->gb);
 759     }
 760     s->block_last_index[n] = i;
 761     return 0;
 762 }
 763
 764 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
 765 {
 766     int level, i, j, run;
 767     RLTable *rl = &ff_rl_mpeg1;
 768     uint8_t * const scantable= s->intra_scantable.permutated;
 769     const int qscale= s->qscale;
 770
 771     {
 772         OPEN_READER(re, &s->gb);
 773         i = -1;
 774         // special case for first coefficient, no need to add second VLC table
 775         UPDATE_CACHE(re, &s->gb);
 776         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 777             level= (3*qscale)>>1;
 778             level= (level-1)|1;
 779             if(GET_CACHE(re, &s->gb)&0x40000000)
 780                 level= -level;
 781             block[0] = level;
 782             i++;
 783             SKIP_BITS(re, &s->gb, 2);
 784             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 785                 goto end;
 786         }
 787 #if MIN_CACHE_BITS < 19
 788         UPDATE_CACHE(re, &s->gb);
 789 #endif
 790
 791         /* now quantify & encode AC coefficients */
 792         for(;;) {
 793             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 794
 795             if(level != 0) {
 796                 i += run;
 797                 j = scantable[i];
 798                 level= ((level*2+1)*qscale)>>1;
 799                 level= (level-1)|1;
 800                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 801                 SKIP_BITS(re, &s->gb, 1);
 802             } else {
 803                 /* escape */
 804                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 805                 UPDATE_CACHE(re, &s->gb);
 806                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 807                 if (level == -128) {
 808                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 809                 } else if (level == 0) {
 810                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 811                 }
 812                 i += run;
 813                 j = scantable[i];
 814                 if(level<0){
 815                     level= -level;
 816                     level= ((level*2+1)*qscale)>>1;
 817                     level= (level-1)|1;
 818                     level= -level;
 819                 }else{
 820                     level= ((level*2+1)*qscale)>>1;
 821                     level= (level-1)|1;
 822                 }
 823             }
 824
 825             block[j] = level;
 826 #if MIN_CACHE_BITS < 19
 827             UPDATE_CACHE(re, &s->gb);
 828 #endif
 829             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 830                 break;
 831 #if MIN_CACHE_BITS >= 19
 832             UPDATE_CACHE(re, &s->gb);
 833 #endif
 834         }
 835 end:
 836         LAST_SKIP_BITS(re, &s->gb, 2);
 837         CLOSE_READER(re, &s->gb);
 838     }
 839     s->block_last_index[n] = i;
 840     return 0;
 841 }
 842
 843
 844 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 845                                DCTELEM *block,
 846                                int n)
 847 {
 848     int level, i, j, run;
 849     RLTable *rl = &ff_rl_mpeg1;
 850     uint8_t * const scantable= s->intra_scantable.permutated;
 851     const uint16_t *quant_matrix;
 852     const int qscale= s->qscale;
 853     int mismatch;
 854
 855     mismatch = 1;
 856
 857     {
 858         OPEN_READER(re, &s->gb);
 859         i = -1;
 860         if (n < 4)
 861             quant_matrix = s->inter_matrix;
 862         else
 863             quant_matrix = s->chroma_inter_matrix;
 864
 865         // special case for first coefficient, no need to add second VLC table
 866         UPDATE_CACHE(re, &s->gb);
 867         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 868             level= (3*qscale*quant_matrix[0])>>5;
 869             if(GET_CACHE(re, &s->gb)&0x40000000)
 870                 level= -level;
 871             block[0] = level;
 872             mismatch ^= level;
 873             i++;
 874             SKIP_BITS(re, &s->gb, 2);
 875             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 876                 goto end;
 877         }
 878 #if MIN_CACHE_BITS < 19
 879         UPDATE_CACHE(re, &s->gb);
 880 #endif
 881
 882         /* now quantify & encode AC coefficients */
 883         for(;;) {
 884             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 885
 886             if(level != 0) {
 887                 i += run;
 888                 j = scantable[i];
 889                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 890                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 891                 SKIP_BITS(re, &s->gb, 1);
 892             } else {
 893                 /* escape */
 894                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 895                 UPDATE_CACHE(re, &s->gb);
 896                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 897
 898                 i += run;
 899                 j = scantable[i];
 900                 if(level<0){
 901                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
 902                     level= -level;
 903                 }else{
 904                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 905                 }
 906             }
 907             if (i > 63){
 908                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 909                 return -1;
 910             }
 911
 912             mismatch ^= level;
 913             block[j] = level;
 914 #if MIN_CACHE_BITS < 19
 915             UPDATE_CACHE(re, &s->gb);
 916 #endif
 917             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 918                 break;
 919 #if MIN_CACHE_BITS >= 19
 920             UPDATE_CACHE(re, &s->gb);
 921 #endif
 922         }
 923 end:
 924         LAST_SKIP_BITS(re, &s->gb, 2);
 925         CLOSE_READER(re, &s->gb);
 926     }
 927     block[63] ^= (mismatch & 1);
 928
 929     s->block_last_index[n] = i;
 930     return 0;
 931 }
 932
 933 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 934                                DCTELEM *block,
 935                                int n)
 936 {
 937     int level, i, j, run;
 938     RLTable *rl = &ff_rl_mpeg1;
 939     uint8_t * const scantable= s->intra_scantable.permutated;
 940     const int qscale= s->qscale;
 941     OPEN_READER(re, &s->gb);
 942     i = -1;
 943
 944     // special case for first coefficient, no need to add second VLC table
 945     UPDATE_CACHE(re, &s->gb);
 946     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 947         level= (3*qscale)>>1;
 948         if(GET_CACHE(re, &s->gb)&0x40000000)
 949             level= -level;
 950         block[0] = level;
 951         i++;
 952         SKIP_BITS(re, &s->gb, 2);
 953         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 954             goto end;
 955     }
 956 #if MIN_CACHE_BITS < 19
 957     UPDATE_CACHE(re, &s->gb);
 958 #endif
 959
 960     /* now quantify & encode AC coefficients */
 961     for(;;) {
 962         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 963
 964         if(level != 0) {
 965             i += run;
 966             j = scantable[i];
 967             level= ((level*2+1)*qscale)>>1;
 968             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 969             SKIP_BITS(re, &s->gb, 1);
 970         } else {
 971             /* escape */
 972             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 973             UPDATE_CACHE(re, &s->gb);
 974             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 975
 976             i += run;
 977             j = scantable[i];
 978             if(level<0){
 979                 level= ((-level*2+1)*qscale)>>1;
 980                 level= -level;
 981             }else{
 982                 level= ((level*2+1)*qscale)>>1;
 983             }
 984         }
 985
 986         block[j] = level;
 987 #if MIN_CACHE_BITS < 19
 988         UPDATE_CACHE(re, &s->gb);
 989 #endif
 990         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 991             break;
 992 #if MIN_CACHE_BITS >=19
 993         UPDATE_CACHE(re, &s->gb);
 994 #endif
 995     }
 996 end:
 997     LAST_SKIP_BITS(re, &s->gb, 2);
 998     CLOSE_READER(re, &s->gb);
 999     s->block_last_index[n] = i;
1000     return 0;
1001 }
1002
1003
1004 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1005                                DCTELEM *block,
1006                                int n)
1007 {
1008     int level, dc, diff, i, j, run;
1009     int component;
1010     RLTable *rl;
1011     uint8_t * const scantable= s->intra_scantable.permutated;
1012     const uint16_t *quant_matrix;
1013     const int qscale= s->qscale;
1014     int mismatch;
1015
1016     /* DC coefficient */
1017     if (n < 4){
1018         quant_matrix = s->intra_matrix;
1019         component = 0;
1020     }else{
1021         quant_matrix = s->chroma_intra_matrix;
1022         component = (n&1) + 1;
1023     }
1024     diff = decode_dc(&s->gb, component);
1025     if (diff >= 0xffff)
1026         return -1;
1027     dc = s->last_dc[component];
1028     dc += diff;
1029     s->last_dc[component] = dc;
1030     block[0] = dc << (3 - s->intra_dc_precision);
1031     dprintf(s->avctx, "dc=%d\n", block[0]);
1032     mismatch = block[0] ^ 1;
1033     i = 0;
1034     if (s->intra_vlc_format)
1035         rl = &ff_rl_mpeg2;
1036     else
1037         rl = &ff_rl_mpeg1;
1038
1039     {
1040         OPEN_READER(re, &s->gb);
1041         /* now quantify & encode AC coefficients */
1042         for(;;) {
1043             UPDATE_CACHE(re, &s->gb);
1044             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1045
1046             if(level == 127){
1047                 break;
1048             } else if(level != 0) {
1049                 i += run;
1050                 j = scantable[i];
1051                 level= (level*qscale*quant_matrix[j])>>4;
1052                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1053                 LAST_SKIP_BITS(re, &s->gb, 1);
1054             } else {
1055                 /* escape */
1056                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1057                 UPDATE_CACHE(re, &s->gb);
1058                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1059                 i += run;
1060                 j = scantable[i];
1061                 if(level<0){
1062                     level= (-level*qscale*quant_matrix[j])>>4;
1063                     level= -level;
1064                 }else{
1065                     level= (level*qscale*quant_matrix[j])>>4;
1066                 }
1067             }
1068             if (i > 63){
1069                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1070                 return -1;
1071             }
1072
1073             mismatch^= level;
1074             block[j] = level;
1075         }
1076         CLOSE_READER(re, &s->gb);
1077     }
1078     block[63]^= mismatch&1;
1079
1080     s->block_last_index[n] = i;
1081     return 0;
1082 }
1083
1084 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1085                                DCTELEM *block,
1086                                int n)
1087 {
1088     int level, dc, diff, j, run;
1089     int component;
1090     RLTable *rl;
1091     uint8_t * scantable= s->intra_scantable.permutated;
1092     const uint16_t *quant_matrix;
1093     const int qscale= s->qscale;
1094
1095     /* DC coefficient */
1096     if (n < 4){
1097         quant_matrix = s->intra_matrix;
1098         component = 0;
1099     }else{
1100         quant_matrix = s->chroma_intra_matrix;
1101         component = (n&1) + 1;
1102     }
1103     diff = decode_dc(&s->gb, component);
1104     if (diff >= 0xffff)
1105         return -1;
1106     dc = s->last_dc[component];
1107     dc += diff;
1108     s->last_dc[component] = dc;
1109     block[0] = dc << (3 - s->intra_dc_precision);
1110     if (s->intra_vlc_format)
1111         rl = &ff_rl_mpeg2;
1112     else
1113         rl = &ff_rl_mpeg1;
1114
1115     {
1116         OPEN_READER(re, &s->gb);
1117         /* now quantify & encode AC coefficients */
1118         for(;;) {
1119             UPDATE_CACHE(re, &s->gb);
1120             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1121
1122             if(level == 127){
1123                 break;
1124             } else if(level != 0) {
1125                 scantable += run;
1126                 j = *scantable;
1127                 level= (level*qscale*quant_matrix[j])>>4;
1128                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1129                 LAST_SKIP_BITS(re, &s->gb, 1);
1130             } else {
1131                 /* escape */
1132                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1133                 UPDATE_CACHE(re, &s->gb);
1134                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1135                 scantable += run;
1136                 j = *scantable;
1137                 if(level<0){
1138                     level= (-level*qscale*quant_matrix[j])>>4;
1139                     level= -level;
1140                 }else{
1141                     level= (level*qscale*quant_matrix[j])>>4;
1142                 }
1143             }
1144
1145             block[j] = level;
1146         }
1147         CLOSE_READER(re, &s->gb);
1148     }
1149
1150     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1151     return 0;
1152 }
1153
1154 typedef struct Mpeg1Context {
1155     MpegEncContext mpeg_enc_ctx;
1156     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1157     int repeat_field; /* true if we must repeat the field */
1158     AVPanScan pan_scan; /** some temporary storage for the panscan */
1159     int slice_count;
1160     int swap_uv;//indicate VCR2
1161     int save_aspect_info;
1162     int save_width, save_height;
1163     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1164
1165 } Mpeg1Context;
1166
1167 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1168 {
1169     Mpeg1Context *s = avctx->priv_data;
1170     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1171     int i;
1172
1173     /* we need some permutation to store matrices,
1174      * until MPV_common_init() sets the real permutation. */
1175     for(i=0;i<64;i++)
1176        s2->dsp.idct_permutation[i]=i;
1177
1178     MPV_decode_defaults(s2);
1179
1180     s->mpeg_enc_ctx.avctx= avctx;
1181     s->mpeg_enc_ctx.flags= avctx->flags;
1182     s->mpeg_enc_ctx.flags2= avctx->flags2;
1183     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1184     ff_mpeg12_init_vlcs();
1185
1186     s->mpeg_enc_ctx_allocated = 0;
1187     s->mpeg_enc_ctx.picture_number = 0;
1188     s->repeat_field = 0;
1189     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1190     return 0;
1191 }
1192
1193 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1194                                      const uint8_t *new_perm){
1195     uint16_t temp_matrix[64];
1196     int i;
1197
1198     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1199
1200     for(i=0;i<64;i++){
1201         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1202     }
1203 }
1204
1205 static enum PixelFormat mpeg_get_pixelformat(AVCodecContext *avctx){
1206     Mpeg1Context *s1 = avctx->priv_data;
1207     MpegEncContext *s = &s1->mpeg_enc_ctx;
1208
1209     if(avctx->xvmc_acceleration)
1210         return avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1211     else if(avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU){
1212         if(avctx->codec_id == CODEC_ID_MPEG1VIDEO)
1213             return PIX_FMT_VDPAU_MPEG1;
1214         else
1215             return PIX_FMT_VDPAU_MPEG2;
1216     }else{
1217         if(s->chroma_format <  2)
1218             return PIX_FMT_YUV420P;
1219         else if(s->chroma_format == 2)
1220             return PIX_FMT_YUV422P;
1221         else
1222             return PIX_FMT_YUV444P;
1223     }
1224 }
1225
1226 /* Call this function when we know all parameters.
1227  * It may be called in different places for MPEG-1 and MPEG-2. */
1228 static int mpeg_decode_postinit(AVCodecContext *avctx){
1229     Mpeg1Context *s1 = avctx->priv_data;
1230     MpegEncContext *s = &s1->mpeg_enc_ctx;
1231     uint8_t old_permutation[64];
1232
1233     if (
1234         (s1->mpeg_enc_ctx_allocated == 0)||
1235         avctx->coded_width  != s->width ||
1236         avctx->coded_height != s->height||
1237         s1->save_width != s->width ||
1238         s1->save_height != s->height ||
1239         s1->save_aspect_info != s->aspect_ratio_info||
1240         0)
1241     {
1242
1243         if (s1->mpeg_enc_ctx_allocated) {
1244             ParseContext pc= s->parse_context;
1245             s->parse_context.buffer=0;
1246             MPV_common_end(s);
1247             s->parse_context= pc;
1248         }
1249
1250         if( (s->width == 0 )||(s->height == 0))
1251             return -2;
1252
1253         avcodec_set_dimensions(avctx, s->width, s->height);
1254         avctx->bit_rate = s->bit_rate;
1255         s1->save_aspect_info = s->aspect_ratio_info;
1256         s1->save_width = s->width;
1257         s1->save_height = s->height;
1258
1259         /* low_delay may be forced, in this case we will have B-frames
1260          * that behave like P-frames. */
1261         avctx->has_b_frames = !(s->low_delay);
1262
1263         assert((avctx->sub_id==1) == (avctx->codec_id==CODEC_ID_MPEG1VIDEO));
1264         if(avctx->codec_id==CODEC_ID_MPEG1VIDEO){
1265             //MPEG-1 fps
1266             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1267             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1268             //MPEG-1 aspect
1269             avctx->sample_aspect_ratio= av_d2q(
1270                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1271
1272         }else{//MPEG-2
1273         //MPEG-2 fps
1274             av_reduce(
1275                 &s->avctx->time_base.den,
1276                 &s->avctx->time_base.num,
1277                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1278                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1279                 1<<30);
1280         //MPEG-2 aspect
1281             if(s->aspect_ratio_info > 1){
1282                 //we ignore the spec here as reality does not match the spec, see for example
1283                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1284                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) || 1){
1285                     s->avctx->sample_aspect_ratio=
1286                         av_div_q(
1287                          ff_mpeg2_aspect[s->aspect_ratio_info],
1288                          (AVRational){s->width, s->height}
1289                          );
1290                 }else{
1291                     s->avctx->sample_aspect_ratio=
1292                         av_div_q(
1293                          ff_mpeg2_aspect[s->aspect_ratio_info],
1294                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1295                         );
1296                 }
1297             }else{
1298                 s->avctx->sample_aspect_ratio=
1299                     ff_mpeg2_aspect[s->aspect_ratio_info];
1300             }
1301         }//MPEG-2
1302
1303         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1304         //until then pix_fmt may be changed right after codec init
1305         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
1306             s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
1307             if( avctx->idct_algo == FF_IDCT_AUTO )
1308                 avctx->idct_algo = FF_IDCT_SIMPLE;
1309
1310         /* Quantization matrices may need reordering
1311          * if DCT permutation is changed. */
1312         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1313
1314         if (MPV_common_init(s) < 0)
1315             return -2;
1316
1317         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1318         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1319         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1320         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1321
1322         s1->mpeg_enc_ctx_allocated = 1;
1323     }
1324     return 0;
1325 }
1326
1327 static int mpeg1_decode_picture(AVCodecContext *avctx,
1328                                 const uint8_t *buf, int buf_size)
1329 {
1330     Mpeg1Context *s1 = avctx->priv_data;
1331     MpegEncContext *s = &s1->mpeg_enc_ctx;
1332     int ref, f_code, vbv_delay;
1333
1334     if(mpeg_decode_postinit(s->avctx) < 0)
1335        return -2;
1336
1337     init_get_bits(&s->gb, buf, buf_size*8);
1338
1339     ref = get_bits(&s->gb, 10); /* temporal ref */
1340     s->pict_type = get_bits(&s->gb, 3);
1341     if(s->pict_type == 0 || s->pict_type > 3)
1342         return -1;
1343
1344     vbv_delay= get_bits(&s->gb, 16);
1345     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1346         s->full_pel[0] = get_bits1(&s->gb);
1347         f_code = get_bits(&s->gb, 3);
1348         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1349             return -1;
1350         s->mpeg_f_code[0][0] = f_code;
1351         s->mpeg_f_code[0][1] = f_code;
1352     }
1353     if (s->pict_type == FF_B_TYPE) {
1354         s->full_pel[1] = get_bits1(&s->gb);
1355         f_code = get_bits(&s->gb, 3);
1356         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1357             return -1;
1358         s->mpeg_f_code[1][0] = f_code;
1359         s->mpeg_f_code[1][1] = f_code;
1360     }
1361     s->current_picture.pict_type= s->pict_type;
1362     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1363
1364     if(avctx->debug & FF_DEBUG_PICT_INFO)
1365         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1366
1367     s->y_dc_scale = 8;
1368     s->c_dc_scale = 8;
1369     s->first_slice = 1;
1370     return 0;
1371 }
1372
1373 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1374 {
1375     MpegEncContext *s= &s1->mpeg_enc_ctx;
1376     int horiz_size_ext, vert_size_ext;
1377     int bit_rate_ext;
1378
1379     skip_bits(&s->gb, 1); /* profile and level esc*/
1380     s->avctx->profile= get_bits(&s->gb, 3);
1381     s->avctx->level= get_bits(&s->gb, 4);
1382     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1383     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1384     horiz_size_ext = get_bits(&s->gb, 2);
1385     vert_size_ext = get_bits(&s->gb, 2);
1386     s->width |= (horiz_size_ext << 12);
1387     s->height |= (vert_size_ext << 12);
1388     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1389     s->bit_rate += (bit_rate_ext << 18) * 400;
1390     skip_bits1(&s->gb); /* marker */
1391     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1392
1393     s->low_delay = get_bits1(&s->gb);
1394     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1395
1396     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1397     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1398
1399     dprintf(s->avctx, "sequence extension\n");
1400     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1401     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1402
1403     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1404         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1405                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1406
1407 }
1408
1409 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1410 {
1411     MpegEncContext *s= &s1->mpeg_enc_ctx;
1412     int color_description, w, h;
1413
1414     skip_bits(&s->gb, 3); /* video format */
1415     color_description= get_bits1(&s->gb);
1416     if(color_description){
1417         skip_bits(&s->gb, 8); /* color primaries */
1418         skip_bits(&s->gb, 8); /* transfer_characteristics */
1419         skip_bits(&s->gb, 8); /* matrix_coefficients */
1420     }
1421     w= get_bits(&s->gb, 14);
1422     skip_bits(&s->gb, 1); //marker
1423     h= get_bits(&s->gb, 14);
1424     skip_bits(&s->gb, 1); //marker
1425
1426     s1->pan_scan.width= 16*w;
1427     s1->pan_scan.height=16*h;
1428
1429     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1430         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1431 }
1432
1433 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1434 {
1435     MpegEncContext *s= &s1->mpeg_enc_ctx;
1436     int i,nofco;
1437
1438     nofco = 1;
1439     if(s->progressive_sequence){
1440         if(s->repeat_first_field){
1441             nofco++;
1442             if(s->top_field_first)
1443                 nofco++;
1444         }
1445     }else{
1446         if(s->picture_structure == PICT_FRAME){
1447             nofco++;
1448             if(s->repeat_first_field)
1449                 nofco++;
1450         }
1451     }
1452     for(i=0; i<nofco; i++){
1453         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1454         skip_bits(&s->gb, 1); //marker
1455         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1456         skip_bits(&s->gb, 1); //marker
1457     }
1458
1459     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1460         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1461             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1462             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1463             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1464         );
1465 }
1466
1467 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1468 {
1469     int i, v, j;
1470
1471     dprintf(s->avctx, "matrix extension\n");
1472
1473     if (get_bits1(&s->gb)) {
1474         for(i=0;i<64;i++) {
1475             v = get_bits(&s->gb, 8);
1476             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1477             s->intra_matrix[j] = v;
1478             s->chroma_intra_matrix[j] = v;
1479         }
1480     }
1481     if (get_bits1(&s->gb)) {
1482         for(i=0;i<64;i++) {
1483             v = get_bits(&s->gb, 8);
1484             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1485             s->inter_matrix[j] = v;
1486             s->chroma_inter_matrix[j] = v;
1487         }
1488     }
1489     if (get_bits1(&s->gb)) {
1490         for(i=0;i<64;i++) {
1491             v = get_bits(&s->gb, 8);
1492             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1493             s->chroma_intra_matrix[j] = v;
1494         }
1495     }
1496     if (get_bits1(&s->gb)) {
1497         for(i=0;i<64;i++) {
1498             v = get_bits(&s->gb, 8);
1499             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1500             s->chroma_inter_matrix[j] = v;
1501         }
1502     }
1503 }
1504
1505 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1506 {
1507     MpegEncContext *s= &s1->mpeg_enc_ctx;
1508
1509     s->full_pel[0] = s->full_pel[1] = 0;
1510     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1511     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1512     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1513     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1514     if(!s->pict_type && s1->mpeg_enc_ctx_allocated){
1515         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1516         if(s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1]==15){
1517             if(s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1518                 s->pict_type= FF_I_TYPE;
1519             else
1520                 s->pict_type= FF_P_TYPE;
1521         }else
1522             s->pict_type= FF_B_TYPE;
1523         s->current_picture.pict_type= s->pict_type;
1524         s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1525         s->first_slice= 1;
1526     }
1527     s->intra_dc_precision = get_bits(&s->gb, 2);
1528     s->picture_structure = get_bits(&s->gb, 2);
1529     s->top_field_first = get_bits1(&s->gb);
1530     s->frame_pred_frame_dct = get_bits1(&s->gb);
1531     s->concealment_motion_vectors = get_bits1(&s->gb);
1532     s->q_scale_type = get_bits1(&s->gb);
1533     s->intra_vlc_format = get_bits1(&s->gb);
1534     s->alternate_scan = get_bits1(&s->gb);
1535     s->repeat_first_field = get_bits1(&s->gb);
1536     s->chroma_420_type = get_bits1(&s->gb);
1537     s->progressive_frame = get_bits1(&s->gb);
1538
1539     if(s->picture_structure == PICT_FRAME){
1540         s->first_field=0;
1541         s->v_edge_pos= 16*s->mb_height;
1542     }else{
1543         s->first_field ^= 1;
1544         s->v_edge_pos=  8*s->mb_height;
1545         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1546     }
1547
1548     if(s->alternate_scan){
1549         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1550         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1551     }else{
1552         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1553         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1554     }
1555
1556     /* composite display not parsed */
1557     dprintf(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1558     dprintf(s->avctx, "picture_structure=%d\n", s->picture_structure);
1559     dprintf(s->avctx, "top field first=%d\n", s->top_field_first);
1560     dprintf(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1561     dprintf(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1562     dprintf(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1563     dprintf(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1564     dprintf(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1565     dprintf(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1566 }
1567
1568 static void mpeg_decode_extension(AVCodecContext *avctx,
1569                                   const uint8_t *buf, int buf_size)
1570 {
1571     Mpeg1Context *s1 = avctx->priv_data;
1572     MpegEncContext *s = &s1->mpeg_enc_ctx;
1573     int ext_type;
1574
1575     init_get_bits(&s->gb, buf, buf_size*8);
1576
1577     ext_type = get_bits(&s->gb, 4);
1578     switch(ext_type) {
1579     case 0x1:
1580         mpeg_decode_sequence_extension(s1);
1581         break;
1582     case 0x2:
1583         mpeg_decode_sequence_display_extension(s1);
1584         break;
1585     case 0x3:
1586         mpeg_decode_quant_matrix_extension(s);
1587         break;
1588     case 0x7:
1589         mpeg_decode_picture_display_extension(s1);
1590         break;
1591     case 0x8:
1592         mpeg_decode_picture_coding_extension(s1);
1593         break;
1594     }
1595 }
1596
1597 static void exchange_uv(MpegEncContext *s){
1598     DCTELEM (*tmp)[64];
1599
1600     tmp           = s->pblocks[4];
1601     s->pblocks[4] = s->pblocks[5];
1602     s->pblocks[5] = tmp;
1603 }
1604
1605 static int mpeg_field_start(MpegEncContext *s){
1606     AVCodecContext *avctx= s->avctx;
1607     Mpeg1Context *s1 = (Mpeg1Context*)s;
1608
1609     /* start frame decoding */
1610     if(s->first_field || s->picture_structure==PICT_FRAME){
1611         if(MPV_frame_start(s, avctx) < 0)
1612             return -1;
1613
1614         ff_er_frame_start(s);
1615
1616         /* first check if we must repeat the frame */
1617         s->current_picture_ptr->repeat_pict = 0;
1618         if (s->repeat_first_field) {
1619             if (s->progressive_sequence) {
1620                 if (s->top_field_first)
1621                     s->current_picture_ptr->repeat_pict = 4;
1622                 else
1623                     s->current_picture_ptr->repeat_pict = 2;
1624             } else if (s->progressive_frame) {
1625                 s->current_picture_ptr->repeat_pict = 1;
1626             }
1627         }
1628
1629         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1630     }else{ //second field
1631             int i;
1632
1633             if(!s->current_picture_ptr){
1634                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1635                 return -1;
1636             }
1637
1638             for(i=0; i<4; i++){
1639                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1640                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1641                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1642                 }
1643             }
1644     }
1645 // MPV_frame_start will call this function too,
1646 // but we need to call it on every field
1647     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1648         if(ff_xvmc_field_start(s,avctx) < 0)
1649             return -1;
1650
1651     return 0;
1652 }
1653
1654 #define DECODE_SLICE_ERROR -1
1655 #define DECODE_SLICE_OK 0
1656
1657 /**
1658  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1659  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1660  *         DECODE_SLICE_OK if this slice is ok<br>
1661  */
1662 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1663                              const uint8_t **buf, int buf_size)
1664 {
1665     MpegEncContext *s = &s1->mpeg_enc_ctx;
1666     AVCodecContext *avctx= s->avctx;
1667     const int field_pic= s->picture_structure != PICT_FRAME;
1668     const int lowres= s->avctx->lowres;
1669
1670     s->resync_mb_x=
1671     s->resync_mb_y= -1;
1672
1673     if (mb_y<<field_pic >= s->mb_height){
1674         av_log(s->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s->mb_height);
1675         return -1;
1676     }
1677
1678     init_get_bits(&s->gb, *buf, buf_size*8);
1679
1680     ff_mpeg1_clean_buffers(s);
1681     s->interlaced_dct = 0;
1682
1683     s->qscale = get_qscale(s);
1684
1685     if(s->qscale == 0){
1686         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1687         return -1;
1688     }
1689
1690     /* extra slice info */
1691     while (get_bits1(&s->gb) != 0) {
1692         skip_bits(&s->gb, 8);
1693     }
1694
1695     s->mb_x=0;
1696
1697     for(;;) {
1698         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1699         if (code < 0){
1700             av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1701             return -1;
1702         }
1703         if (code >= 33) {
1704             if (code == 33) {
1705                 s->mb_x += 33;
1706             }
1707             /* otherwise, stuffing, nothing to do */
1708         } else {
1709             s->mb_x += code;
1710             break;
1711         }
1712     }
1713     if(s->mb_x >= (unsigned)s->mb_width){
1714         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1715         return -1;
1716     }
1717
1718     s->resync_mb_x= s->mb_x;
1719     s->resync_mb_y= s->mb_y= mb_y;
1720     s->mb_skip_run= 0;
1721     ff_init_block_index(s);
1722
1723     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1724         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1725              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",
1726                  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],
1727                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1728                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1729                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1730                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1731         }
1732     }
1733
1734     for(;;) {
1735         //If 1, we memcpy blocks in xvmcvideo.
1736         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1)
1737             ff_xvmc_init_block(s);//set s->block
1738
1739         if(mpeg_decode_mb(s, s->block) < 0)
1740             return -1;
1741
1742         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1743             const int wrap = field_pic ? 2*s->b8_stride : s->b8_stride;
1744             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1745             int motion_x, motion_y, dir, i;
1746             if(field_pic && !s->first_field)
1747                 xy += wrap/2;
1748
1749             for(i=0; i<2; i++){
1750                 for(dir=0; dir<2; dir++){
1751                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1752                         motion_x = motion_y = 0;
1753                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1754                         motion_x = s->mv[dir][0][0];
1755                         motion_y = s->mv[dir][0][1];
1756                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1757                         motion_x = s->mv[dir][i][0];
1758                         motion_y = s->mv[dir][i][1];
1759                     }
1760
1761                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1762                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1763                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1764                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1765                     s->current_picture.ref_index [dir][xy    ]=
1766                     s->current_picture.ref_index [dir][xy + 1]= s->field_select[dir][i];
1767                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1768                 }
1769                 xy += wrap;
1770             }
1771         }
1772
1773         s->dest[0] += 16 >> lowres;
1774         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1775         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1776
1777         MPV_decode_mb(s, s->block);
1778
1779         if (++s->mb_x >= s->mb_width) {
1780             const int mb_size= 16>>s->avctx->lowres;
1781
1782             ff_draw_horiz_band(s, mb_size*s->mb_y, mb_size);
1783
1784             s->mb_x = 0;
1785             s->mb_y++;
1786
1787             if(s->mb_y<<field_pic >= s->mb_height){
1788                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1789                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1790                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1791                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1792
1793                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1794                    || (avctx->error_recognition >= FF_ER_AGGRESSIVE && left>8)){
1795                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1796                     return -1;
1797                 }else
1798                     goto eos;
1799             }
1800
1801             ff_init_block_index(s);
1802         }
1803
1804         /* skip mb handling */
1805         if (s->mb_skip_run == -1) {
1806             /* read increment again */
1807             s->mb_skip_run = 0;
1808             for(;;) {
1809                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1810                 if (code < 0){
1811                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1812                     return -1;
1813                 }
1814                 if (code >= 33) {
1815                     if (code == 33) {
1816                         s->mb_skip_run += 33;
1817                     }else if(code == 35){
1818                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1819                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1820                             return -1;
1821                         }
1822                         goto eos; /* end of slice */
1823                     }
1824                     /* otherwise, stuffing, nothing to do */
1825                 } else {
1826                     s->mb_skip_run += code;
1827                     break;
1828                 }
1829             }
1830             if(s->mb_skip_run){
1831                 int i;
1832                 if(s->pict_type == FF_I_TYPE){
1833                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1834                     return -1;
1835                 }
1836
1837                 /* skip mb */
1838                 s->mb_intra = 0;
1839                 for(i=0;i<12;i++)
1840                     s->block_last_index[i] = -1;
1841                 if(s->picture_structure == PICT_FRAME)
1842                     s->mv_type = MV_TYPE_16X16;
1843                 else
1844                     s->mv_type = MV_TYPE_FIELD;
1845                 if (s->pict_type == FF_P_TYPE) {
1846                     /* if P type, zero motion vector is implied */
1847                     s->mv_dir = MV_DIR_FORWARD;
1848                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1849                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1850                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1851                     s->field_select[0][0]= s->picture_structure - 1;
1852                 } else {
1853                     /* if B type, reuse previous vectors and directions */
1854                     s->mv[0][0][0] = s->last_mv[0][0][0];
1855                     s->mv[0][0][1] = s->last_mv[0][0][1];
1856                     s->mv[1][0][0] = s->last_mv[1][0][0];
1857                     s->mv[1][0][1] = s->last_mv[1][0][1];
1858                 }
1859             }
1860         }
1861     }
1862 eos: // end of slice
1863     *buf += (get_bits_count(&s->gb)-1)/8;
1864 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1865     return 0;
1866 }
1867
1868 static int slice_decode_thread(AVCodecContext *c, void *arg){
1869     MpegEncContext *s= *(void**)arg;
1870     const uint8_t *buf= s->gb.buffer;
1871     int mb_y= s->start_mb_y;
1872
1873     s->error_count= 3*(s->end_mb_y - s->start_mb_y)*s->mb_width;
1874
1875     for(;;){
1876         uint32_t start_code;
1877         int ret;
1878
1879         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1880         emms_c();
1881 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1882 //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);
1883         if(ret < 0){
1884             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1885                 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);
1886         }else{
1887             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);
1888         }
1889
1890         if(s->mb_y == s->end_mb_y)
1891             return 0;
1892
1893         start_code= -1;
1894         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1895         mb_y= start_code - SLICE_MIN_START_CODE;
1896         if(mb_y < 0 || mb_y >= s->end_mb_y)
1897             return -1;
1898     }
1899
1900     return 0; //not reached
1901 }
1902
1903 /**
1904  * Handles slice ends.
1905  * @return 1 if it seems to be the last slice
1906  */
1907 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1908 {
1909     Mpeg1Context *s1 = avctx->priv_data;
1910     MpegEncContext *s = &s1->mpeg_enc_ctx;
1911
1912     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1913         return 0;
1914
1915     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1916         ff_xvmc_field_end(s);
1917
1918     /* end of slice reached */
1919     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1920         /* end of image */
1921
1922         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1923
1924         ff_er_frame_end(s);
1925
1926         MPV_frame_end(s);
1927
1928         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1929             *pict= *(AVFrame*)s->current_picture_ptr;
1930             ff_print_debug_info(s, pict);
1931         } else {
1932             s->picture_number++;
1933             /* latency of 1 frame for I- and P-frames */
1934             /* XXX: use another variable than picture_number */
1935             if (s->last_picture_ptr != NULL) {
1936                 *pict= *(AVFrame*)s->last_picture_ptr;
1937                  ff_print_debug_info(s, pict);
1938             }
1939         }
1940
1941         return 1;
1942     } else {
1943         return 0;
1944     }
1945 }
1946
1947 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1948                                  const uint8_t *buf, int buf_size)
1949 {
1950     Mpeg1Context *s1 = avctx->priv_data;
1951     MpegEncContext *s = &s1->mpeg_enc_ctx;
1952     int width,height;
1953     int i, v, j;
1954
1955     init_get_bits(&s->gb, buf, buf_size*8);
1956
1957     width = get_bits(&s->gb, 12);
1958     height = get_bits(&s->gb, 12);
1959     if (width <= 0 || height <= 0)
1960         return -1;
1961     s->aspect_ratio_info= get_bits(&s->gb, 4);
1962     if (s->aspect_ratio_info == 0) {
1963         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
1964         if (avctx->error_recognition >= FF_ER_COMPLIANT)
1965             return -1;
1966     }
1967     s->frame_rate_index = get_bits(&s->gb, 4);
1968     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1969         return -1;
1970     s->bit_rate = get_bits(&s->gb, 18) * 400;
1971     if (get_bits1(&s->gb) == 0) /* marker */
1972         return -1;
1973     s->width = width;
1974     s->height = height;
1975
1976     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
1977     skip_bits(&s->gb, 1);
1978
1979     /* get matrix */
1980     if (get_bits1(&s->gb)) {
1981         for(i=0;i<64;i++) {
1982             v = get_bits(&s->gb, 8);
1983             if(v==0){
1984                 av_log(s->avctx, AV_LOG_ERROR, "intra matrix damaged\n");
1985                 return -1;
1986             }
1987             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1988             s->intra_matrix[j] = v;
1989             s->chroma_intra_matrix[j] = v;
1990         }
1991 #ifdef DEBUG
1992         dprintf(s->avctx, "intra matrix present\n");
1993         for(i=0;i<64;i++)
1994             dprintf(s->avctx, " %d", s->intra_matrix[s->dsp.idct_permutation[i]]);
1995         dprintf(s->avctx, "\n");
1996 #endif
1997     } else {
1998         for(i=0;i<64;i++) {
1999             j = s->dsp.idct_permutation[i];
2000             v = ff_mpeg1_default_intra_matrix[i];
2001             s->intra_matrix[j] = v;
2002             s->chroma_intra_matrix[j] = v;
2003         }
2004     }
2005     if (get_bits1(&s->gb)) {
2006         for(i=0;i<64;i++) {
2007             v = get_bits(&s->gb, 8);
2008             if(v==0){
2009                 av_log(s->avctx, AV_LOG_ERROR, "inter matrix damaged\n");
2010                 return -1;
2011             }
2012             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
2013             s->inter_matrix[j] = v;
2014             s->chroma_inter_matrix[j] = v;
2015         }
2016 #ifdef DEBUG
2017         dprintf(s->avctx, "non-intra matrix present\n");
2018         for(i=0;i<64;i++)
2019             dprintf(s->avctx, " %d", s->inter_matrix[s->dsp.idct_permutation[i]]);
2020         dprintf(s->avctx, "\n");
2021 #endif
2022     } else {
2023         for(i=0;i<64;i++) {
2024             int j= s->dsp.idct_permutation[i];
2025             v = ff_mpeg1_default_non_intra_matrix[i];
2026             s->inter_matrix[j] = v;
2027             s->chroma_inter_matrix[j] = v;
2028         }
2029     }
2030
2031     if(show_bits(&s->gb, 23) != 0){
2032         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2033         return -1;
2034     }
2035
2036     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2037     s->progressive_sequence = 1;
2038     s->progressive_frame = 1;
2039     s->picture_structure = PICT_FRAME;
2040     s->frame_pred_frame_dct = 1;
2041     s->chroma_format = 1;
2042     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2043     avctx->sub_id = 1; /* indicates MPEG-1 */
2044     s->out_format = FMT_MPEG1;
2045     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2046     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2047
2048     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2049         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2050                s->avctx->rc_buffer_size, s->bit_rate);
2051
2052     return 0;
2053 }
2054
2055 static int vcr2_init_sequence(AVCodecContext *avctx)
2056 {
2057     Mpeg1Context *s1 = avctx->priv_data;
2058     MpegEncContext *s = &s1->mpeg_enc_ctx;
2059     int i, v;
2060
2061     /* start new MPEG-1 context decoding */
2062     s->out_format = FMT_MPEG1;
2063     if (s1->mpeg_enc_ctx_allocated) {
2064         MPV_common_end(s);
2065     }
2066     s->width  = avctx->coded_width;
2067     s->height = avctx->coded_height;
2068     avctx->has_b_frames= 0; //true?
2069     s->low_delay= 1;
2070
2071     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2072
2073     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
2074         s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
2075         if( avctx->idct_algo == FF_IDCT_AUTO )
2076             avctx->idct_algo = FF_IDCT_SIMPLE;
2077
2078     if (MPV_common_init(s) < 0)
2079         return -1;
2080     exchange_uv(s);//common init reset pblocks, so we swap them here
2081     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2082     s1->mpeg_enc_ctx_allocated = 1;
2083
2084     for(i=0;i<64;i++) {
2085         int j= s->dsp.idct_permutation[i];
2086         v = ff_mpeg1_default_intra_matrix[i];
2087         s->intra_matrix[j] = v;
2088         s->chroma_intra_matrix[j] = v;
2089
2090         v = ff_mpeg1_default_non_intra_matrix[i];
2091         s->inter_matrix[j] = v;
2092         s->chroma_inter_matrix[j] = v;
2093     }
2094
2095     s->progressive_sequence = 1;
2096     s->progressive_frame = 1;
2097     s->picture_structure = PICT_FRAME;
2098     s->frame_pred_frame_dct = 1;
2099     s->chroma_format = 1;
2100     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2101     avctx->sub_id = 2; /* indicates MPEG-2 */
2102     return 0;
2103 }
2104
2105
2106 static void mpeg_decode_user_data(AVCodecContext *avctx,
2107                                   const uint8_t *buf, int buf_size)
2108 {
2109     const uint8_t *p;
2110     int len, flags;
2111     p = buf;
2112     len = buf_size;
2113
2114     /* we parse the DTG active format information */
2115     if (len >= 5 &&
2116         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2117         flags = p[4];
2118         p += 5;
2119         len -= 5;
2120         if (flags & 0x80) {
2121             /* skip event id */
2122             if (len < 2)
2123                 return;
2124             p += 2;
2125             len -= 2;
2126         }
2127         if (flags & 0x40) {
2128             if (len < 1)
2129                 return;
2130             avctx->dtg_active_format = p[0] & 0x0f;
2131         }
2132     }
2133 }
2134
2135 static void mpeg_decode_gop(AVCodecContext *avctx,
2136                             const uint8_t *buf, int buf_size){
2137     Mpeg1Context *s1 = avctx->priv_data;
2138     MpegEncContext *s = &s1->mpeg_enc_ctx;
2139
2140     int drop_frame_flag;
2141     int time_code_hours, time_code_minutes;
2142     int time_code_seconds, time_code_pictures;
2143     int closed_gop, broken_link;
2144
2145     init_get_bits(&s->gb, buf, buf_size*8);
2146
2147     drop_frame_flag = get_bits1(&s->gb);
2148
2149     time_code_hours=get_bits(&s->gb,5);
2150     time_code_minutes = get_bits(&s->gb,6);
2151     skip_bits1(&s->gb);//marker bit
2152     time_code_seconds = get_bits(&s->gb,6);
2153     time_code_pictures = get_bits(&s->gb,6);
2154
2155     closed_gop  = get_bits1(&s->gb);
2156     /*broken_link indicate that after editing the
2157       reference frames of the first B-Frames after GOP I-Frame
2158       are missing (open gop)*/
2159     broken_link = get_bits1(&s->gb);
2160
2161     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2162         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2163             time_code_hours, time_code_minutes, time_code_seconds,
2164             time_code_pictures, closed_gop, broken_link);
2165 }
2166 /**
2167  * Finds the end of the current frame in the bitstream.
2168  * @return the position of the first byte of the next frame, or -1
2169  */
2170 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
2171 {
2172     int i;
2173     uint32_t state= pc->state;
2174
2175     /* EOF considered as end of frame */
2176     if (buf_size == 0)
2177         return 0;
2178
2179 /*
2180  0  frame start         -> 1/4
2181  1  first_SEQEXT        -> 0/2
2182  2  first field start   -> 3/0
2183  3  second_SEQEXT       -> 2/0
2184  4  searching end
2185 */
2186
2187     for(i=0; i<buf_size; i++){
2188         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2189         if(pc->frame_start_found&1){
2190             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2191                 pc->frame_start_found--;
2192             else if(state == EXT_START_CODE+2){
2193                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2194                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2195             }
2196             state++;
2197         }else{
2198             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2199             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2200                 i++;
2201                 pc->frame_start_found=4;
2202             }
2203             if(state == SEQ_END_CODE){
2204                 pc->state=-1;
2205                 return i+1;
2206             }
2207             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2208                 pc->frame_start_found= 0;
2209             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2210                 pc->frame_start_found++;
2211             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2212                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2213                     pc->frame_start_found=0;
2214                     pc->state=-1;
2215                     return i-3;
2216                 }
2217             }
2218         }
2219     }
2220     pc->state= state;
2221     return END_NOT_FOUND;
2222 }
2223
2224 static int decode_chunks(AVCodecContext *avctx,
2225                              AVFrame *picture, int *data_size,
2226                              const uint8_t *buf, int buf_size);
2227
2228 /* handle buffering and image synchronisation */
2229 static int mpeg_decode_frame(AVCodecContext *avctx,
2230                              void *data, int *data_size,
2231                              const uint8_t *buf, int buf_size)
2232 {
2233     Mpeg1Context *s = avctx->priv_data;
2234     AVFrame *picture = data;
2235     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2236     dprintf(avctx, "fill_buffer\n");
2237
2238     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2239         /* special case for last picture */
2240         if (s2->low_delay==0 && s2->next_picture_ptr) {
2241             *picture= *(AVFrame*)s2->next_picture_ptr;
2242             s2->next_picture_ptr= NULL;
2243
2244             *data_size = sizeof(AVFrame);
2245         }
2246         return buf_size;
2247     }
2248
2249     if(s2->flags&CODEC_FLAG_TRUNCATED){
2250         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size);
2251
2252         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2253             return buf_size;
2254     }
2255
2256 #if 0
2257     if (s->repeat_field % 2 == 1) {
2258         s->repeat_field++;
2259         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2260         //        s2->picture_number, s->repeat_field);
2261         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2262             *data_size = sizeof(AVPicture);
2263             goto the_end;
2264         }
2265     }
2266 #endif
2267
2268     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == AV_RL32("VCR2"))
2269         vcr2_init_sequence(avctx);
2270
2271     s->slice_count= 0;
2272
2273     if(avctx->extradata && !avctx->frame_number)
2274         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2275
2276     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2277 }
2278
2279 static int decode_chunks(AVCodecContext *avctx,
2280                              AVFrame *picture, int *data_size,
2281                              const uint8_t *buf, int buf_size)
2282 {
2283     Mpeg1Context *s = avctx->priv_data;
2284     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2285     const uint8_t *buf_ptr = buf;
2286     const uint8_t *buf_end = buf + buf_size;
2287     int ret, input_size;
2288
2289     for(;;) {
2290         /* find next start code */
2291         uint32_t start_code = -1;
2292         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2293         if (start_code > 0x1ff){
2294             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2295                 if(avctx->thread_count > 1){
2296                     int i;
2297
2298                     avctx->execute(avctx, slice_decode_thread,  (void**)&(s2->thread_context[0]), NULL, s->slice_count, sizeof(void*));
2299                     for(i=0; i<s->slice_count; i++)
2300                         s2->error_count += s2->thread_context[i]->error_count;
2301                 }
2302
2303                 if (CONFIG_MPEG_VDPAU_DECODER && avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
2304                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2305
2306                 if (slice_end(avctx, picture)) {
2307                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2308                         *data_size = sizeof(AVPicture);
2309                 }
2310             }
2311             s2->pict_type= 0;
2312             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2313         }
2314
2315         input_size = buf_end - buf_ptr;
2316
2317         if(avctx->debug & FF_DEBUG_STARTCODE){
2318             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2319         }
2320
2321         /* prepare data for next start code */
2322         switch(start_code) {
2323         case SEQ_START_CODE:
2324             mpeg1_decode_sequence(avctx, buf_ptr,
2325                                     input_size);
2326             break;
2327
2328         case PICTURE_START_CODE:
2329             /* we have a complete image: we try to decompress it */
2330             if(mpeg1_decode_picture(avctx,
2331                                     buf_ptr, input_size) < 0)
2332                 s2->pict_type=0;
2333             break;
2334         case EXT_START_CODE:
2335             mpeg_decode_extension(avctx,
2336                                     buf_ptr, input_size);
2337             break;
2338         case USER_START_CODE:
2339             mpeg_decode_user_data(avctx,
2340                                     buf_ptr, input_size);
2341             break;
2342         case GOP_START_CODE:
2343             s2->first_field=0;
2344             mpeg_decode_gop(avctx,
2345                                     buf_ptr, input_size);
2346             break;
2347         default:
2348             if (start_code >= SLICE_MIN_START_CODE &&
2349                 start_code <= SLICE_MAX_START_CODE) {
2350                 int mb_y= start_code - SLICE_MIN_START_CODE;
2351
2352                 if(s2->last_picture_ptr==NULL){
2353                 /* Skip B-frames if we do not have reference frames. */
2354                     if(s2->pict_type==FF_B_TYPE) break;
2355                 }
2356                 if(s2->next_picture_ptr==NULL){
2357                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2358                     if(s2->pict_type==FF_P_TYPE && (s2->first_field || s2->picture_structure==PICT_FRAME)) break;
2359                 }
2360                 /* Skip B-frames if we are in a hurry. */
2361                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2362                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2363                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2364                     || avctx->skip_frame >= AVDISCARD_ALL)
2365                     break;
2366                 /* Skip everything if we are in a hurry>=5. */
2367                 if(avctx->hurry_up>=5) break;
2368
2369                 if (!s->mpeg_enc_ctx_allocated) break;
2370
2371                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2372                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2373                         break;
2374                 }
2375
2376                 if(!s2->pict_type){
2377                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2378                     break;
2379                 }
2380
2381                 if(s2->first_slice){
2382                     s2->first_slice=0;
2383                     if(mpeg_field_start(s2) < 0)
2384                         return -1;
2385                 }
2386                 if(!s2->current_picture_ptr){
2387                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2388                     return -1;
2389                 }
2390
2391                 if (avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
2392                     s->slice_count++;
2393                     break;
2394                 }
2395
2396                 if(avctx->thread_count > 1){
2397                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2398                     if(threshold <= mb_y){
2399                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2400
2401                         thread_context->start_mb_y= mb_y;
2402                         thread_context->end_mb_y  = s2->mb_height;
2403                         if(s->slice_count){
2404                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2405                             ff_update_duplicate_context(thread_context, s2);
2406                         }
2407                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2408                         s->slice_count++;
2409                     }
2410                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2411                 }else{
2412                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2413                     emms_c();
2414
2415                     if(ret < 0){
2416                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2417                             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);
2418                     }else{
2419                         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);
2420                     }
2421                 }
2422             }
2423             break;
2424         }
2425     }
2426 }
2427
2428 static int mpeg_decode_end(AVCodecContext *avctx)
2429 {
2430     Mpeg1Context *s = avctx->priv_data;
2431
2432     if (s->mpeg_enc_ctx_allocated)
2433         MPV_common_end(&s->mpeg_enc_ctx);
2434     return 0;
2435 }
2436
2437 AVCodec mpeg1video_decoder = {
2438     "mpeg1video",
2439     CODEC_TYPE_VIDEO,
2440     CODEC_ID_MPEG1VIDEO,
2441     sizeof(Mpeg1Context),
2442     mpeg_decode_init,
2443     NULL,
2444     mpeg_decode_end,
2445     mpeg_decode_frame,
2446     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2447     .flush= ff_mpeg_flush,
2448     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2449 };
2450
2451 AVCodec mpeg2video_decoder = {
2452     "mpeg2video",
2453     CODEC_TYPE_VIDEO,
2454     CODEC_ID_MPEG2VIDEO,
2455     sizeof(Mpeg1Context),
2456     mpeg_decode_init,
2457     NULL,
2458     mpeg_decode_end,
2459     mpeg_decode_frame,
2460     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2461     .flush= ff_mpeg_flush,
2462     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2463 };
2464
2465 //legacy decoder
2466 AVCodec mpegvideo_decoder = {
2467     "mpegvideo",
2468     CODEC_TYPE_VIDEO,
2469     CODEC_ID_MPEG2VIDEO,
2470     sizeof(Mpeg1Context),
2471     mpeg_decode_init,
2472     NULL,
2473     mpeg_decode_end,
2474     mpeg_decode_frame,
2475     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2476     .flush= ff_mpeg_flush,
2477     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2478 };
2479
2480 #if CONFIG_MPEG_XVMC_DECODER
2481 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2482     Mpeg1Context *s;
2483
2484     if( avctx->thread_count > 1)
2485         return -1;
2486     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2487         return -1;
2488     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2489         dprintf(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2490     }
2491     mpeg_decode_init(avctx);
2492     s = avctx->priv_data;
2493
2494     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2495     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2496
2497     return 0;
2498 }
2499
2500 AVCodec mpeg_xvmc_decoder = {
2501     "mpegvideo_xvmc",
2502     CODEC_TYPE_VIDEO,
2503     CODEC_ID_MPEG2VIDEO_XVMC,
2504     sizeof(Mpeg1Context),
2505     mpeg_mc_decode_init,
2506     NULL,
2507     mpeg_decode_end,
2508     mpeg_decode_frame,
2509     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2510     .flush= ff_mpeg_flush,
2511     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video XvMC (X-Video Motion Compensation)"),
2512 };
2513
2514 #endif
2515
2516 #if CONFIG_MPEG_VDPAU_DECODER
2517 AVCodec mpeg_vdpau_decoder = {
2518     "mpegvideo_vdpau",
2519     CODEC_TYPE_VIDEO,
2520     CODEC_ID_MPEG2VIDEO,
2521     sizeof(Mpeg1Context),
2522     mpeg_decode_init,
2523     NULL,
2524     mpeg_decode_end,
2525     mpeg_decode_frame,
2526     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2527     .flush= ff_mpeg_flush,
2528     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2529 };
2530 #endif
2531
2532 #if CONFIG_MPEG1_VDPAU_DECODER
2533 AVCodec mpeg1_vdpau_decoder = {
2534     "mpeg1video_vdpau",
2535     CODEC_TYPE_VIDEO,
2536     CODEC_ID_MPEG1VIDEO,
2537     sizeof(Mpeg1Context),
2538     mpeg_decode_init,
2539     NULL,
2540     mpeg_decode_end,
2541     mpeg_decode_frame,
2542     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2543     .flush= ff_mpeg_flush,
2544     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2545 };
2546 #endif
2547