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   1 /*
   2  * ITU H263 bitstream decoder
   3  * Copyright (c) 2000,2001 Fabrice Bellard
   4  * H263+ support.
   5  * Copyright (c) 2001 Juan J. Sierralta P
   6  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
   7  *
   8  * This file is part of FFmpeg.
   9  *
  10  * FFmpeg is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * FFmpeg is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with FFmpeg; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 /**
  26  * @file
  27  * h263 decoder.
  28  */
  29
  30 #define UNCHECKED_BITSTREAM_READER 1
  31 #include <limits.h>
  32
  33 #include "libavutil/attributes.h"
  34 #include "libavutil/internal.h"
  35 #include "libavutil/mathematics.h"
  36 #include "avcodec.h"
  37 #include "mpegvideo.h"
  38 #include "h263.h"
  39 #include "internal.h"
  40 #include "mathops.h"
  41 #include "mpegutils.h"
  42 #include "unary.h"
  43 #include "flv.h"
  44 #include "mpeg4video.h"
  45 #include "mpegvideodata.h"
  46
  47 // The defines below define the number of bits that are read at once for
  48 // reading vlc values. Changing these may improve speed and data cache needs
  49 // be aware though that decreasing them may need the number of stages that is
  50 // passed to get_vlc* to be increased.
  51 #define MV_VLC_BITS 9
  52 #define H263_MBTYPE_B_VLC_BITS 6
  53 #define CBPC_B_VLC_BITS 3
  54
  55 static const int h263_mb_type_b_map[15]= {
  56     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  57     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
  58     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
  59                       MB_TYPE_L0                                 | MB_TYPE_16x16,
  60                       MB_TYPE_L0   | MB_TYPE_CBP                 | MB_TYPE_16x16,
  61                       MB_TYPE_L0   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  62                       MB_TYPE_L1                                 | MB_TYPE_16x16,
  63                       MB_TYPE_L1   | MB_TYPE_CBP                 | MB_TYPE_16x16,
  64                       MB_TYPE_L1   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  65                       MB_TYPE_L0L1                               | MB_TYPE_16x16,
  66                       MB_TYPE_L0L1 | MB_TYPE_CBP                 | MB_TYPE_16x16,
  67                       MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  68     0, //stuffing
  69     MB_TYPE_INTRA4x4                | MB_TYPE_CBP,
  70     MB_TYPE_INTRA4x4                | MB_TYPE_CBP | MB_TYPE_QUANT,
  71 };
  72
  73 void ff_h263_show_pict_info(MpegEncContext *s){
  74     if(s->avctx->debug&FF_DEBUG_PICT_INFO){
  75     av_log(s->avctx, AV_LOG_DEBUG, "qp:%d %c size:%d rnd:%d%s%s%s%s%s%s%s%s%s %d/%d\n",
  76          s->qscale, av_get_picture_type_char(s->pict_type),
  77          s->gb.size_in_bits, 1-s->no_rounding,
  78          s->obmc ? " AP" : "",
  79          s->umvplus ? " UMV" : "",
  80          s->h263_long_vectors ? " LONG" : "",
  81          s->h263_plus ? " +" : "",
  82          s->h263_aic ? " AIC" : "",
  83          s->alt_inter_vlc ? " AIV" : "",
  84          s->modified_quant ? " MQ" : "",
  85          s->loop_filter ? " LOOP" : "",
  86          s->h263_slice_structured ? " SS" : "",
  87          s->avctx->framerate.num, s->avctx->framerate.den
  88     );
  89     }
  90 }
  91
  92 /***********************************************/
  93 /* decoding */
  94
  95 VLC ff_h263_intra_MCBPC_vlc;
  96 VLC ff_h263_inter_MCBPC_vlc;
  97 VLC ff_h263_cbpy_vlc;
  98 static VLC mv_vlc;
  99 static VLC h263_mbtype_b_vlc;
 100 static VLC cbpc_b_vlc;
 101
 102 /* init vlcs */
 103
 104 /* XXX: find a better solution to handle static init */
 105 av_cold void ff_h263_decode_init_vlc(void)
 106 {
 107     static volatile int done = 0;
 108
 109     if (!done) {
 110         INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
 111                  ff_h263_intra_MCBPC_bits, 1, 1,
 112                  ff_h263_intra_MCBPC_code, 1, 1, 72);
 113         INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
 114                  ff_h263_inter_MCBPC_bits, 1, 1,
 115                  ff_h263_inter_MCBPC_code, 1, 1, 198);
 116         INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
 117                  &ff_h263_cbpy_tab[0][1], 2, 1,
 118                  &ff_h263_cbpy_tab[0][0], 2, 1, 64);
 119         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
 120                  &ff_mvtab[0][1], 2, 1,
 121                  &ff_mvtab[0][0], 2, 1, 538);
 122         ff_rl_init(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
 123         ff_rl_init(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
 124         INIT_VLC_RL(ff_h263_rl_inter, 554);
 125         INIT_VLC_RL(ff_rl_intra_aic, 554);
 126         INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
 127                  &ff_h263_mbtype_b_tab[0][1], 2, 1,
 128                  &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
 129         INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
 130                  &ff_cbpc_b_tab[0][1], 2, 1,
 131                  &ff_cbpc_b_tab[0][0], 2, 1, 8);
 132         done = 1;
 133     }
 134 }
 135
 136 int ff_h263_decode_mba(MpegEncContext *s)
 137 {
 138     int i, mb_pos;
 139
 140     for(i=0; i<6; i++){
 141         if(s->mb_num-1 <= ff_mba_max[i]) break;
 142     }
 143     mb_pos= get_bits(&s->gb, ff_mba_length[i]);
 144     s->mb_x= mb_pos % s->mb_width;
 145     s->mb_y= mb_pos / s->mb_width;
 146
 147     return mb_pos;
 148 }
 149
 150 /**
 151  * Decode the group of blocks header or slice header.
 152  * @return <0 if an error occurred
 153  */
 154 static int h263_decode_gob_header(MpegEncContext *s)
 155 {
 156     unsigned int val, gob_number;
 157     int left;
 158
 159     /* Check for GOB Start Code */
 160     val = show_bits(&s->gb, 16);
 161     if(val)
 162         return -1;
 163
 164         /* We have a GBSC probably with GSTUFF */
 165     skip_bits(&s->gb, 16); /* Drop the zeros */
 166     left= get_bits_left(&s->gb);
 167     //MN: we must check the bits left or we might end in a infinite loop (or segfault)
 168     for(;left>13; left--){
 169         if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
 170     }
 171     if(left<=13)
 172         return -1;
 173
 174     if(s->h263_slice_structured){
 175         if(check_marker(&s->gb, "before MBA")==0)
 176             return -1;
 177
 178         ff_h263_decode_mba(s);
 179
 180         if(s->mb_num > 1583)
 181             if(check_marker(&s->gb, "after MBA")==0)
 182                 return -1;
 183
 184         s->qscale = get_bits(&s->gb, 5); /* SQUANT */
 185         if(check_marker(&s->gb, "after SQUANT")==0)
 186             return -1;
 187         skip_bits(&s->gb, 2); /* GFID */
 188     }else{
 189         gob_number = get_bits(&s->gb, 5); /* GN */
 190         s->mb_x= 0;
 191         s->mb_y= s->gob_index* gob_number;
 192         skip_bits(&s->gb, 2); /* GFID */
 193         s->qscale = get_bits(&s->gb, 5); /* GQUANT */
 194     }
 195
 196     if(s->mb_y >= s->mb_height)
 197         return -1;
 198
 199     if(s->qscale==0)
 200         return -1;
 201
 202     return 0;
 203 }
 204
 205 /**
 206  * Decode the group of blocks / video packet header.
 207  * @return bit position of the resync_marker, or <0 if none was found
 208  */
 209 int ff_h263_resync(MpegEncContext *s){
 210     int left, pos, ret;
 211
 212     if(s->codec_id==AV_CODEC_ID_MPEG4){
 213         skip_bits1(&s->gb);
 214         align_get_bits(&s->gb);
 215     }
 216
 217     if(show_bits(&s->gb, 16)==0){
 218         pos= get_bits_count(&s->gb);
 219         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
 220             ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
 221         else
 222             ret= h263_decode_gob_header(s);
 223         if(ret>=0)
 224             return pos;
 225     }
 226     //OK, it's not where it is supposed to be ...
 227     s->gb= s->last_resync_gb;
 228     align_get_bits(&s->gb);
 229     left= get_bits_left(&s->gb);
 230
 231     for(;left>16+1+5+5; left-=8){
 232         if(show_bits(&s->gb, 16)==0){
 233             GetBitContext bak= s->gb;
 234
 235             pos= get_bits_count(&s->gb);
 236             if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
 237                 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
 238             else
 239                 ret= h263_decode_gob_header(s);
 240             if(ret>=0)
 241                 return pos;
 242
 243             s->gb= bak;
 244         }
 245         skip_bits(&s->gb, 8);
 246     }
 247
 248     return -1;
 249 }
 250
 251 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
 252 {
 253     int code, val, sign, shift;
 254     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 255
 256     if (code == 0)
 257         return pred;
 258     if (code < 0)
 259         return 0xffff;
 260
 261     sign = get_bits1(&s->gb);
 262     shift = f_code - 1;
 263     val = code;
 264     if (shift) {
 265         val = (val - 1) << shift;
 266         val |= get_bits(&s->gb, shift);
 267         val++;
 268     }
 269     if (sign)
 270         val = -val;
 271     val += pred;
 272
 273     /* modulo decoding */
 274     if (!s->h263_long_vectors) {
 275         val = sign_extend(val, 5 + f_code);
 276     } else {
 277         /* horrible h263 long vector mode */
 278         if (pred < -31 && val < -63)
 279             val += 64;
 280         if (pred > 32 && val > 63)
 281             val -= 64;
 282
 283     }
 284     return val;
 285 }
 286
 287
 288 /* Decode RVLC of H.263+ UMV */
 289 static int h263p_decode_umotion(MpegEncContext * s, int pred)
 290 {
 291    int code = 0, sign;
 292
 293    if (get_bits1(&s->gb)) /* Motion difference = 0 */
 294       return pred;
 295
 296    code = 2 + get_bits1(&s->gb);
 297
 298    while (get_bits1(&s->gb))
 299    {
 300       code <<= 1;
 301       code += get_bits1(&s->gb);
 302    }
 303    sign = code & 1;
 304    code >>= 1;
 305
 306    code = (sign) ? (pred - code) : (pred + code);
 307    ff_tlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
 308    return code;
 309
 310 }
 311
 312 /**
 313  * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
 314  */
 315 static void preview_obmc(MpegEncContext *s){
 316     GetBitContext gb= s->gb;
 317
 318     int cbpc, i, pred_x, pred_y, mx, my;
 319     int16_t *mot_val;
 320     const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
 321     const int stride= s->b8_stride*2;
 322
 323     for(i=0; i<4; i++)
 324         s->block_index[i]+= 2;
 325     for(i=4; i<6; i++)
 326         s->block_index[i]+= 1;
 327     s->mb_x++;
 328
 329     av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
 330
 331     do{
 332         if (get_bits1(&s->gb)) {
 333             /* skip mb */
 334             mot_val = s->current_picture.motion_val[0][s->block_index[0]];
 335             mot_val[0       ]= mot_val[2       ]=
 336             mot_val[0+stride]= mot_val[2+stride]= 0;
 337             mot_val[1       ]= mot_val[3       ]=
 338             mot_val[1+stride]= mot_val[3+stride]= 0;
 339
 340             s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 341             goto end;
 342         }
 343         cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 344     }while(cbpc == 20);
 345
 346     if(cbpc & 4){
 347         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 348     }else{
 349         get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 350         if (cbpc & 8) {
 351             if(s->modified_quant){
 352                 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
 353                 else                  skip_bits(&s->gb, 5);
 354             }else
 355                 skip_bits(&s->gb, 2);
 356         }
 357
 358         if ((cbpc & 16) == 0) {
 359                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 360                 /* 16x16 motion prediction */
 361                 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 362                 if (s->umvplus)
 363                    mx = h263p_decode_umotion(s, pred_x);
 364                 else
 365                    mx = ff_h263_decode_motion(s, pred_x, 1);
 366
 367                 if (s->umvplus)
 368                    my = h263p_decode_umotion(s, pred_y);
 369                 else
 370                    my = ff_h263_decode_motion(s, pred_y, 1);
 371
 372                 mot_val[0       ]= mot_val[2       ]=
 373                 mot_val[0+stride]= mot_val[2+stride]= mx;
 374                 mot_val[1       ]= mot_val[3       ]=
 375                 mot_val[1+stride]= mot_val[3+stride]= my;
 376         } else {
 377             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 378             for(i=0;i<4;i++) {
 379                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 380                 if (s->umvplus)
 381                   mx = h263p_decode_umotion(s, pred_x);
 382                 else
 383                   mx = ff_h263_decode_motion(s, pred_x, 1);
 384
 385                 if (s->umvplus)
 386                   my = h263p_decode_umotion(s, pred_y);
 387                 else
 388                   my = ff_h263_decode_motion(s, pred_y, 1);
 389                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 390                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 391                 mot_val[0] = mx;
 392                 mot_val[1] = my;
 393             }
 394         }
 395     }
 396 end:
 397
 398     for(i=0; i<4; i++)
 399         s->block_index[i]-= 2;
 400     for(i=4; i<6; i++)
 401         s->block_index[i]-= 1;
 402     s->mb_x--;
 403
 404     s->gb= gb;
 405 }
 406
 407 static void h263_decode_dquant(MpegEncContext *s){
 408     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 409
 410     if(s->modified_quant){
 411         if(get_bits1(&s->gb))
 412             s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
 413         else
 414             s->qscale= get_bits(&s->gb, 5);
 415     }else
 416         s->qscale += quant_tab[get_bits(&s->gb, 2)];
 417     ff_set_qscale(s, s->qscale);
 418 }
 419
 420 static int h263_decode_block(MpegEncContext * s, int16_t * block,
 421                              int n, int coded)
 422 {
 423     int level, i, j, run;
 424     RLTable *rl = &ff_h263_rl_inter;
 425     const uint8_t *scan_table;
 426     GetBitContext gb= s->gb;
 427
 428     scan_table = s->intra_scantable.permutated;
 429     if (s->h263_aic && s->mb_intra) {
 430         rl = &ff_rl_intra_aic;
 431         i = 0;
 432         if (s->ac_pred) {
 433             if (s->h263_aic_dir)
 434                 scan_table = s->intra_v_scantable.permutated; /* left */
 435             else
 436                 scan_table = s->intra_h_scantable.permutated; /* top */
 437         }
 438     } else if (s->mb_intra) {
 439         /* DC coef */
 440         if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
 441           if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
 442             int component, diff;
 443             component = (n <= 3 ? 0 : n - 4 + 1);
 444             level = s->last_dc[component];
 445             if (s->rv10_first_dc_coded[component]) {
 446                 diff = ff_rv_decode_dc(s, n);
 447                 if (diff == 0xffff)
 448                     return -1;
 449                 level += diff;
 450                 level = level & 0xff; /* handle wrap round */
 451                 s->last_dc[component] = level;
 452             } else {
 453                 s->rv10_first_dc_coded[component] = 1;
 454             }
 455           } else {
 456                 level = get_bits(&s->gb, 8);
 457                 if (level == 255)
 458                     level = 128;
 459           }
 460         }else{
 461             level = get_bits(&s->gb, 8);
 462             if((level&0x7F) == 0){
 463                 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
 464                 if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
 465                     return -1;
 466             }
 467             if (level == 255)
 468                 level = 128;
 469         }
 470         block[0] = level;
 471         i = 1;
 472     } else {
 473         i = 0;
 474     }
 475     if (!coded) {
 476         if (s->mb_intra && s->h263_aic)
 477             goto not_coded;
 478         s->block_last_index[n] = i - 1;
 479         return 0;
 480     }
 481 retry:
 482     {
 483     OPEN_READER(re, &s->gb);
 484     i--; // offset by -1 to allow direct indexing of scan_table
 485     for(;;) {
 486         UPDATE_CACHE(re, &s->gb);
 487         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 488         if (run == 66) {
 489             if (level){
 490                 CLOSE_READER(re, &s->gb);
 491                 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
 492                 return -1;
 493             }
 494             /* escape */
 495             if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
 496                 int is11 = SHOW_UBITS(re, &s->gb, 1);
 497                 SKIP_CACHE(re, &s->gb, 1);
 498                 run = SHOW_UBITS(re, &s->gb, 7) + 1;
 499                 if (is11) {
 500                     SKIP_COUNTER(re, &s->gb, 1 + 7);
 501                     UPDATE_CACHE(re, &s->gb);
 502                     level = SHOW_SBITS(re, &s->gb, 11);
 503                     SKIP_COUNTER(re, &s->gb, 11);
 504                 } else {
 505                     SKIP_CACHE(re, &s->gb, 7);
 506                     level = SHOW_SBITS(re, &s->gb, 7);
 507                     SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
 508                 }
 509             } else {
 510                 run = SHOW_UBITS(re, &s->gb, 7) + 1;
 511                 SKIP_CACHE(re, &s->gb, 7);
 512                 level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
 513                 SKIP_COUNTER(re, &s->gb, 7 + 8);
 514                 if(level == -128){
 515                     UPDATE_CACHE(re, &s->gb);
 516                     if (s->codec_id == AV_CODEC_ID_RV10) {
 517                         /* XXX: should patch encoder too */
 518                         level = SHOW_SBITS(re, &s->gb, 12);
 519                         SKIP_COUNTER(re, &s->gb, 12);
 520                     }else{
 521                         level = SHOW_UBITS(re, &s->gb, 5);
 522                         SKIP_CACHE(re, &s->gb, 5);
 523                         level |= SHOW_SBITS(re, &s->gb, 6)<<5;
 524                         SKIP_COUNTER(re, &s->gb, 5 + 6);
 525                     }
 526                 }
 527             }
 528         } else {
 529             if (SHOW_UBITS(re, &s->gb, 1))
 530                 level = -level;
 531             SKIP_COUNTER(re, &s->gb, 1);
 532         }
 533         i += run;
 534         if (i >= 64){
 535             CLOSE_READER(re, &s->gb);
 536             // redo update without last flag, revert -1 offset
 537             i = i - run + ((run-1)&63) + 1;
 538             if (i < 64) {
 539                 // only last marker, no overrun
 540                 block[scan_table[i]] = level;
 541                 break;
 542             }
 543             if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
 544                 //Looks like a hack but no, it's the way it is supposed to work ...
 545                 rl = &ff_rl_intra_aic;
 546                 i = 0;
 547                 s->gb= gb;
 548                 s->bdsp.clear_block(block);
 549                 goto retry;
 550             }
 551             av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
 552             return -1;
 553         }
 554         j = scan_table[i];
 555         block[j] = level;
 556     }
 557     }
 558 not_coded:
 559     if (s->mb_intra && s->h263_aic) {
 560         ff_h263_pred_acdc(s, block, n);
 561         i = 63;
 562     }
 563     s->block_last_index[n] = i;
 564     return 0;
 565 }
 566
 567 static int h263_skip_b_part(MpegEncContext *s, int cbp)
 568 {
 569     LOCAL_ALIGNED_16(int16_t, dblock, [64]);
 570     int i, mbi;
 571     int bli[6];
 572
 573     /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
 574      * but real value should be restored in order to be used later (in OBMC condition)
 575      */
 576     mbi = s->mb_intra;
 577     memcpy(bli, s->block_last_index, sizeof(bli));
 578     s->mb_intra = 0;
 579     for (i = 0; i < 6; i++) {
 580         if (h263_decode_block(s, dblock, i, cbp&32) < 0)
 581             return -1;
 582         cbp+=cbp;
 583     }
 584     s->mb_intra = mbi;
 585     memcpy(s->block_last_index, bli, sizeof(bli));
 586     return 0;
 587 }
 588
 589 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
 590 {
 591     int c, mv = 1;
 592
 593     if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
 594         c = get_bits1(gb);
 595         if (pb_frame == 2 && c)
 596             mv = !get_bits1(gb);
 597     } else { // h.263 Annex M improved PB-frame
 598         mv = get_unary(gb, 0, 4) + 1;
 599         c = mv & 1;
 600         mv = !!(mv & 2);
 601     }
 602     if(c)
 603         *cbpb = get_bits(gb, 6);
 604     return mv;
 605 }
 606
 607 int ff_h263_decode_mb(MpegEncContext *s,
 608                       int16_t block[6][64])
 609 {
 610     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
 611     int16_t *mot_val;
 612     const int xy= s->mb_x + s->mb_y * s->mb_stride;
 613     int cbpb = 0, pb_mv_count = 0;
 614
 615     av_assert2(!s->h263_pred);
 616
 617     if (s->pict_type == AV_PICTURE_TYPE_P) {
 618         do{
 619             if (get_bits1(&s->gb)) {
 620                 /* skip mb */
 621                 s->mb_intra = 0;
 622                 for(i=0;i<6;i++)
 623                     s->block_last_index[i] = -1;
 624                 s->mv_dir = MV_DIR_FORWARD;
 625                 s->mv_type = MV_TYPE_16X16;
 626                 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 627                 s->mv[0][0][0] = 0;
 628                 s->mv[0][0][1] = 0;
 629                 s->mb_skipped = !(s->obmc | s->loop_filter);
 630                 goto end;
 631             }
 632             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 633             if (cbpc < 0){
 634                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
 635                 return -1;
 636             }
 637         }while(cbpc == 20);
 638
 639         s->bdsp.clear_blocks(s->block[0]);
 640
 641         dquant = cbpc & 8;
 642         s->mb_intra = ((cbpc & 4) != 0);
 643         if (s->mb_intra) goto intra;
 644
 645         if(s->pb_frame && get_bits1(&s->gb))
 646             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
 647         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 648
 649         if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
 650             cbpy ^= 0xF;
 651
 652         cbp = (cbpc & 3) | (cbpy << 2);
 653         if (dquant) {
 654             h263_decode_dquant(s);
 655         }
 656
 657         s->mv_dir = MV_DIR_FORWARD;
 658         if ((cbpc & 16) == 0) {
 659             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 660             /* 16x16 motion prediction */
 661             s->mv_type = MV_TYPE_16X16;
 662             ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 663             if (s->umvplus)
 664                mx = h263p_decode_umotion(s, pred_x);
 665             else
 666                mx = ff_h263_decode_motion(s, pred_x, 1);
 667
 668             if (mx >= 0xffff)
 669                 return -1;
 670
 671             if (s->umvplus)
 672                my = h263p_decode_umotion(s, pred_y);
 673             else
 674                my = ff_h263_decode_motion(s, pred_y, 1);
 675
 676             if (my >= 0xffff)
 677                 return -1;
 678             s->mv[0][0][0] = mx;
 679             s->mv[0][0][1] = my;
 680
 681             if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 682                skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 683         } else {
 684             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 685             s->mv_type = MV_TYPE_8X8;
 686             for(i=0;i<4;i++) {
 687                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 688                 if (s->umvplus)
 689                   mx = h263p_decode_umotion(s, pred_x);
 690                 else
 691                   mx = ff_h263_decode_motion(s, pred_x, 1);
 692                 if (mx >= 0xffff)
 693                     return -1;
 694
 695                 if (s->umvplus)
 696                   my = h263p_decode_umotion(s, pred_y);
 697                 else
 698                   my = ff_h263_decode_motion(s, pred_y, 1);
 699                 if (my >= 0xffff)
 700                     return -1;
 701                 s->mv[0][i][0] = mx;
 702                 s->mv[0][i][1] = my;
 703                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 704                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 705                 mot_val[0] = mx;
 706                 mot_val[1] = my;
 707             }
 708         }
 709     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
 710         int mb_type;
 711         const int stride= s->b8_stride;
 712         int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
 713         int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
 714 //        const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
 715
 716         //FIXME ugly
 717         mot_val0[0       ]= mot_val0[2       ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
 718         mot_val0[1       ]= mot_val0[3       ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
 719         mot_val1[0       ]= mot_val1[2       ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
 720         mot_val1[1       ]= mot_val1[3       ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
 721
 722         do{
 723             mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
 724             if (mb_type < 0){
 725                 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
 726                 return -1;
 727             }
 728
 729             mb_type= h263_mb_type_b_map[ mb_type ];
 730         }while(!mb_type);
 731
 732         s->mb_intra = IS_INTRA(mb_type);
 733         if(HAS_CBP(mb_type)){
 734             s->bdsp.clear_blocks(s->block[0]);
 735             cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
 736             if(s->mb_intra){
 737                 dquant = IS_QUANT(mb_type);
 738                 goto intra;
 739             }
 740
 741             cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 742
 743             if (cbpy < 0){
 744                 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
 745                 return -1;
 746             }
 747
 748             if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
 749                 cbpy ^= 0xF;
 750
 751             cbp = (cbpc & 3) | (cbpy << 2);
 752         }else
 753             cbp=0;
 754
 755         av_assert2(!s->mb_intra);
 756
 757         if(IS_QUANT(mb_type)){
 758             h263_decode_dquant(s);
 759         }
 760
 761         if(IS_DIRECT(mb_type)){
 762             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
 763             mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0);
 764         }else{
 765             s->mv_dir = 0;
 766             s->mv_type= MV_TYPE_16X16;
 767 //FIXME UMV
 768
 769             if(USES_LIST(mb_type, 0)){
 770                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &mx, &my);
 771                 s->mv_dir = MV_DIR_FORWARD;
 772
 773                 mx = ff_h263_decode_motion(s, mx, 1);
 774                 my = ff_h263_decode_motion(s, my, 1);
 775
 776                 s->mv[0][0][0] = mx;
 777                 s->mv[0][0][1] = my;
 778                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
 779                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
 780             }
 781
 782             if(USES_LIST(mb_type, 1)){
 783                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &mx, &my);
 784                 s->mv_dir |= MV_DIR_BACKWARD;
 785
 786                 mx = ff_h263_decode_motion(s, mx, 1);
 787                 my = ff_h263_decode_motion(s, my, 1);
 788
 789                 s->mv[1][0][0] = mx;
 790                 s->mv[1][0][1] = my;
 791                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
 792                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
 793             }
 794         }
 795
 796         s->current_picture.mb_type[xy] = mb_type;
 797     } else { /* I-Frame */
 798         do{
 799             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 800             if (cbpc < 0){
 801                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
 802                 return -1;
 803             }
 804         }while(cbpc == 8);
 805
 806         s->bdsp.clear_blocks(s->block[0]);
 807
 808         dquant = cbpc & 4;
 809         s->mb_intra = 1;
 810 intra:
 811         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 812         if (s->h263_aic) {
 813             s->ac_pred = get_bits1(&s->gb);
 814             if(s->ac_pred){
 815                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
 816
 817                 s->h263_aic_dir = get_bits1(&s->gb);
 818             }
 819         }else
 820             s->ac_pred = 0;
 821
 822         if(s->pb_frame && get_bits1(&s->gb))
 823             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
 824         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 825         if(cbpy<0){
 826             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
 827             return -1;
 828         }
 829         cbp = (cbpc & 3) | (cbpy << 2);
 830         if (dquant) {
 831             h263_decode_dquant(s);
 832         }
 833
 834         pb_mv_count += !!s->pb_frame;
 835     }
 836
 837     while(pb_mv_count--){
 838         ff_h263_decode_motion(s, 0, 1);
 839         ff_h263_decode_motion(s, 0, 1);
 840     }
 841
 842     /* decode each block */
 843     for (i = 0; i < 6; i++) {
 844         if (h263_decode_block(s, block[i], i, cbp&32) < 0)
 845             return -1;
 846         cbp+=cbp;
 847     }
 848
 849     if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
 850         return -1;
 851     if(s->obmc && !s->mb_intra){
 852         if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
 853             preview_obmc(s);
 854     }
 855 end:
 856
 857         /* per-MB end of slice check */
 858     {
 859         int v= show_bits(&s->gb, 16);
 860
 861         if (get_bits_left(&s->gb) < 16) {
 862             v >>= 16 - get_bits_left(&s->gb);
 863         }
 864
 865         if(v==0)
 866             return SLICE_END;
 867     }
 868
 869     return SLICE_OK;
 870 }
 871
 872 /* most is hardcoded. should extend to handle all h263 streams */
 873 int ff_h263_decode_picture_header(MpegEncContext *s)
 874 {
 875     int format, width, height, i;
 876     uint32_t startcode;
 877
 878     align_get_bits(&s->gb);
 879
 880     if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
 881          av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
 882     }
 883
 884     startcode= get_bits(&s->gb, 22-8);
 885
 886     for(i= get_bits_left(&s->gb); i>24; i-=8) {
 887         startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
 888
 889         if(startcode == 0x20)
 890             break;
 891     }
 892
 893     if (startcode != 0x20) {
 894         av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
 895         return -1;
 896     }
 897     /* temporal reference */
 898     i = get_bits(&s->gb, 8); /* picture timestamp */
 899     if( (s->picture_number&~0xFF)+i < s->picture_number)
 900         i+= 256;
 901     s->picture_number= (s->picture_number&~0xFF) + i;
 902
 903     /* PTYPE starts here */
 904     if (check_marker(&s->gb, "in PTYPE") != 1) {
 905         return -1;
 906     }
 907     if (get_bits1(&s->gb) != 0) {
 908         av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
 909         return -1;      /* h263 id */
 910     }
 911     skip_bits1(&s->gb);         /* split screen off */
 912     skip_bits1(&s->gb);         /* camera  off */
 913     skip_bits1(&s->gb);         /* freeze picture release off */
 914
 915     format = get_bits(&s->gb, 3);
 916     /*
 917         0    forbidden
 918         1    sub-QCIF
 919         10   QCIF
 920         7       extended PTYPE (PLUSPTYPE)
 921     */
 922
 923     if (format != 7 && format != 6) {
 924         s->h263_plus = 0;
 925         /* H.263v1 */
 926         width = ff_h263_format[format][0];
 927         height = ff_h263_format[format][1];
 928         if (!width)
 929             return -1;
 930
 931         s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
 932
 933         s->h263_long_vectors = get_bits1(&s->gb);
 934
 935         if (get_bits1(&s->gb) != 0) {
 936             av_log(s->avctx, AV_LOG_ERROR, "H263 SAC not supported\n");
 937             return -1; /* SAC: off */
 938         }
 939         s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
 940         s->unrestricted_mv = s->h263_long_vectors || s->obmc;
 941
 942         s->pb_frame = get_bits1(&s->gb);
 943         s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
 944         skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
 945
 946         s->width = width;
 947         s->height = height;
 948         s->avctx->sample_aspect_ratio= (AVRational){12,11};
 949         s->avctx->framerate = (AVRational){ 30000, 1001 };
 950     } else {
 951         int ufep;
 952
 953         /* H.263v2 */
 954         s->h263_plus = 1;
 955         ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
 956
 957         /* ufep other than 0 and 1 are reserved */
 958         if (ufep == 1) {
 959             /* OPPTYPE */
 960             format = get_bits(&s->gb, 3);
 961             ff_dlog(s->avctx, "ufep=1, format: %d\n", format);
 962             s->custom_pcf= get_bits1(&s->gb);
 963             s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
 964             if (get_bits1(&s->gb) != 0) {
 965                 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
 966             }
 967             s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
 968             s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
 969             s->loop_filter= get_bits1(&s->gb);
 970             s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
 971             if(s->avctx->lowres)
 972                 s->loop_filter = 0;
 973
 974             s->h263_slice_structured= get_bits1(&s->gb);
 975             if (get_bits1(&s->gb) != 0) {
 976                 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
 977             }
 978             if (get_bits1(&s->gb) != 0) {
 979                 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
 980             }
 981             s->alt_inter_vlc= get_bits1(&s->gb);
 982             s->modified_quant= get_bits1(&s->gb);
 983             if(s->modified_quant)
 984                 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
 985
 986             skip_bits(&s->gb, 1); /* Prevent start code emulation */
 987
 988             skip_bits(&s->gb, 3); /* Reserved */
 989         } else if (ufep != 0) {
 990             av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
 991             return -1;
 992         }
 993
 994         /* MPPTYPE */
 995         s->pict_type = get_bits(&s->gb, 3);
 996         switch(s->pict_type){
 997         case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
 998         case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
 999         case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
1000         case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
1001         case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
1002         default:
1003             return -1;
1004         }
1005         skip_bits(&s->gb, 2);
1006         s->no_rounding = get_bits1(&s->gb);
1007         skip_bits(&s->gb, 4);
1008
1009         /* Get the picture dimensions */
1010         if (ufep) {
1011             if (format == 6) {
1012                 /* Custom Picture Format (CPFMT) */
1013                 s->aspect_ratio_info = get_bits(&s->gb, 4);
1014                 ff_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
1015                 /* aspect ratios:
1016                 0 - forbidden
1017                 1 - 1:1
1018                 2 - 12:11 (CIF 4:3)
1019                 3 - 10:11 (525-type 4:3)
1020                 4 - 16:11 (CIF 16:9)
1021                 5 - 40:33 (525-type 16:9)
1022                 6-14 - reserved
1023                 */
1024                 width = (get_bits(&s->gb, 9) + 1) * 4;
1025                 check_marker(&s->gb, "in dimensions");
1026                 height = get_bits(&s->gb, 9) * 4;
1027                 ff_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1028                 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1029                     /* aspected dimensions */
1030                     s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1031                     s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1032                 }else{
1033                     s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1034                 }
1035             } else {
1036                 width = ff_h263_format[format][0];
1037                 height = ff_h263_format[format][1];
1038                 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1039             }
1040             s->avctx->sample_aspect_ratio.den <<= s->ehc_mode;
1041             if ((width == 0) || (height == 0))
1042                 return -1;
1043             s->width = width;
1044             s->height = height;
1045
1046             if(s->custom_pcf){
1047                 int gcd;
1048                 s->avctx->framerate.num  = 1800000;
1049                 s->avctx->framerate.den  = 1000 + get_bits1(&s->gb);
1050                 s->avctx->framerate.den *= get_bits(&s->gb, 7);
1051                 if(s->avctx->framerate.den == 0){
1052                     av_log(s, AV_LOG_ERROR, "zero framerate\n");
1053                     return -1;
1054                 }
1055                 gcd= av_gcd(s->avctx->framerate.den, s->avctx->framerate.num);
1056                 s->avctx->framerate.den /= gcd;
1057                 s->avctx->framerate.num /= gcd;
1058             }else{
1059                 s->avctx->framerate = (AVRational){ 30000, 1001 };
1060             }
1061         }
1062
1063         if(s->custom_pcf){
1064             skip_bits(&s->gb, 2); //extended Temporal reference
1065         }
1066
1067         if (ufep) {
1068             if (s->umvplus) {
1069                 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1070                     skip_bits1(&s->gb);
1071             }
1072             if(s->h263_slice_structured){
1073                 if (get_bits1(&s->gb) != 0) {
1074                     av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1075                 }
1076                 if (get_bits1(&s->gb) != 0) {
1077                     av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1078                 }
1079             }
1080         }
1081
1082         s->qscale = get_bits(&s->gb, 5);
1083     }
1084
1085     if (s->width == 0 || s->height == 0) {
1086         av_log(s->avctx, AV_LOG_ERROR, "dimensions 0\n");
1087         return -1;
1088     }
1089     s->mb_width = (s->width  + 15) / 16;
1090     s->mb_height = (s->height  + 15) / 16;
1091     s->mb_num = s->mb_width * s->mb_height;
1092
1093     if (s->pb_frame) {
1094         skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1095         if (s->custom_pcf)
1096             skip_bits(&s->gb, 2); //extended Temporal reference
1097         skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1098     }
1099
1100     if (s->pict_type!=AV_PICTURE_TYPE_B) {
1101         s->time            = s->picture_number;
1102         s->pp_time         = s->time - s->last_non_b_time;
1103         s->last_non_b_time = s->time;
1104     }else{
1105         s->time    = s->picture_number;
1106         s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1107         if (s->pp_time <=s->pb_time ||
1108             s->pp_time <= s->pp_time - s->pb_time ||
1109             s->pp_time <= 0){
1110             s->pp_time = 2;
1111             s->pb_time = 1;
1112         }
1113         ff_mpeg4_init_direct_mv(s);
1114     }
1115
1116     /* PEI */
1117     if (skip_1stop_8data_bits(&s->gb) < 0)
1118         return AVERROR_INVALIDDATA;
1119
1120     if(s->h263_slice_structured){
1121         if (check_marker(&s->gb, "SEPB1") != 1) {
1122             return -1;
1123         }
1124
1125         ff_h263_decode_mba(s);
1126
1127         if (check_marker(&s->gb, "SEPB2") != 1) {
1128             return -1;
1129         }
1130     }
1131     s->f_code = 1;
1132
1133     if(s->h263_aic){
1134          s->y_dc_scale_table=
1135          s->c_dc_scale_table= ff_aic_dc_scale_table;
1136     }else{
1137         s->y_dc_scale_table=
1138         s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1139     }
1140
1141         ff_h263_show_pict_info(s);
1142     if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1143         int i,j;
1144         for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1145         av_log(s->avctx, AV_LOG_DEBUG, "\n");
1146         for(i=0; i<13; i++){
1147             for(j=0; j<3; j++){
1148                 int v= get_bits(&s->gb, 8);
1149                 v |= get_sbits(&s->gb, 8)<<8;
1150                 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1151             }
1152             av_log(s->avctx, AV_LOG_DEBUG, "\n");
1153         }
1154         for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1155     }
1156
1157     return 0;
1158 }