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