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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 "mathops.h"
  40 #include "mpegutils.h"
  41 #include "unary.h"
  42 #include "flv.h"
  43 #include "mpeg4video.h"
  44
  45 // The defines below define the number of bits that are read at once for
  46 // reading vlc values. Changing these may improve speed and data cache needs
  47 // be aware though that decreasing them may need the number of stages that is
  48 // passed to get_vlc* to be increased.
  49 #define MV_VLC_BITS 9
  50 #define H263_MBTYPE_B_VLC_BITS 6
  51 #define CBPC_B_VLC_BITS 3
  52
  53 static const int h263_mb_type_b_map[15]= {
  54     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  55     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
  56     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
  57                       MB_TYPE_L0                                 | MB_TYPE_16x16,
  58                       MB_TYPE_L0   | MB_TYPE_CBP                 | MB_TYPE_16x16,
  59                       MB_TYPE_L0   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  60                       MB_TYPE_L1                                 | MB_TYPE_16x16,
  61                       MB_TYPE_L1   | MB_TYPE_CBP                 | MB_TYPE_16x16,
  62                       MB_TYPE_L1   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  63                       MB_TYPE_L0L1                               | MB_TYPE_16x16,
  64                       MB_TYPE_L0L1 | MB_TYPE_CBP                 | MB_TYPE_16x16,
  65                       MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  66     0, //stuffing
  67     MB_TYPE_INTRA4x4                | MB_TYPE_CBP,
  68     MB_TYPE_INTRA4x4                | MB_TYPE_CBP | MB_TYPE_QUANT,
  69 };
  70
  71 void ff_h263_show_pict_info(MpegEncContext *s){
  72     if(s->avctx->debug&FF_DEBUG_PICT_INFO){
  73     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",
  74          s->qscale, av_get_picture_type_char(s->pict_type),
  75          s->gb.size_in_bits, 1-s->no_rounding,
  76          s->obmc ? " AP" : "",
  77          s->umvplus ? " UMV" : "",
  78          s->h263_long_vectors ? " LONG" : "",
  79          s->h263_plus ? " +" : "",
  80          s->h263_aic ? " AIC" : "",
  81          s->alt_inter_vlc ? " AIV" : "",
  82          s->modified_quant ? " MQ" : "",
  83          s->loop_filter ? " LOOP" : "",
  84          s->h263_slice_structured ? " SS" : "",
  85          s->avctx->framerate.num, s->avctx->framerate.den
  86     );
  87     }
  88 }
  89
  90 /***********************************************/
  91 /* decoding */
  92
  93 VLC ff_h263_intra_MCBPC_vlc;
  94 VLC ff_h263_inter_MCBPC_vlc;
  95 VLC ff_h263_cbpy_vlc;
  96 static VLC mv_vlc;
  97 static VLC h263_mbtype_b_vlc;
  98 static VLC cbpc_b_vlc;
  99
 100 /* init vlcs */
 101
 102 /* XXX: find a better solution to handle static init */
 103 av_cold void ff_h263_decode_init_vlc(void)
 104 {
 105     static volatile int done = 0;
 106
 107     if (!done) {
 108         INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
 109                  ff_h263_intra_MCBPC_bits, 1, 1,
 110                  ff_h263_intra_MCBPC_code, 1, 1, 72);
 111         INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
 112                  ff_h263_inter_MCBPC_bits, 1, 1,
 113                  ff_h263_inter_MCBPC_code, 1, 1, 198);
 114         INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
 115                  &ff_h263_cbpy_tab[0][1], 2, 1,
 116                  &ff_h263_cbpy_tab[0][0], 2, 1, 64);
 117         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
 118                  &ff_mvtab[0][1], 2, 1,
 119                  &ff_mvtab[0][0], 2, 1, 538);
 120         ff_init_rl(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
 121         ff_init_rl(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
 122         INIT_VLC_RL(ff_h263_rl_inter, 554);
 123         INIT_VLC_RL(ff_rl_intra_aic, 554);
 124         INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
 125                  &ff_h263_mbtype_b_tab[0][1], 2, 1,
 126                  &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
 127         INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
 128                  &ff_cbpc_b_tab[0][1], 2, 1,
 129                  &ff_cbpc_b_tab[0][0], 2, 1, 8);
 130         done = 1;
 131     }
 132 }
 133
 134 int ff_h263_decode_mba(MpegEncContext *s)
 135 {
 136     int i, mb_pos;
 137
 138     for(i=0; i<6; i++){
 139         if(s->mb_num-1 <= ff_mba_max[i]) break;
 140     }
 141     mb_pos= get_bits(&s->gb, ff_mba_length[i]);
 142     s->mb_x= mb_pos % s->mb_width;
 143     s->mb_y= mb_pos / s->mb_width;
 144
 145     return mb_pos;
 146 }
 147
 148 /**
 149  * Decode the group of blocks header or slice header.
 150  * @return <0 if an error occurred
 151  */
 152 static int h263_decode_gob_header(MpegEncContext *s)
 153 {
 154     unsigned int val, gob_number;
 155     int left;
 156
 157     /* Check for GOB Start Code */
 158     val = show_bits(&s->gb, 16);
 159     if(val)
 160         return -1;
 161
 162         /* We have a GBSC probably with GSTUFF */
 163     skip_bits(&s->gb, 16); /* Drop the zeros */
 164     left= get_bits_left(&s->gb);
 165     //MN: we must check the bits left or we might end in a infinite loop (or segfault)
 166     for(;left>13; left--){
 167         if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
 168     }
 169     if(left<=13)
 170         return -1;
 171
 172     if(s->h263_slice_structured){
 173         if(get_bits1(&s->gb)==0)
 174             return -1;
 175
 176         ff_h263_decode_mba(s);
 177
 178         if(s->mb_num > 1583)
 179             if(get_bits1(&s->gb)==0)
 180                 return -1;
 181
 182         s->qscale = get_bits(&s->gb, 5); /* SQUANT */
 183         if(get_bits1(&s->gb)==0)
 184             return -1;
 185         skip_bits(&s->gb, 2); /* GFID */
 186     }else{
 187         gob_number = get_bits(&s->gb, 5); /* GN */
 188         s->mb_x= 0;
 189         s->mb_y= s->gob_index* gob_number;
 190         skip_bits(&s->gb, 2); /* GFID */
 191         s->qscale = get_bits(&s->gb, 5); /* GQUANT */
 192     }
 193
 194     if(s->mb_y >= s->mb_height)
 195         return -1;
 196
 197     if(s->qscale==0)
 198         return -1;
 199
 200     return 0;
 201 }
 202
 203 /**
 204  * Decode the group of blocks / video packet header.
 205  * @return bit position of the resync_marker, or <0 if none was found
 206  */
 207 int ff_h263_resync(MpegEncContext *s){
 208     int left, pos, ret;
 209
 210     if(s->codec_id==AV_CODEC_ID_MPEG4){
 211         skip_bits1(&s->gb);
 212         align_get_bits(&s->gb);
 213     }
 214
 215     if(show_bits(&s->gb, 16)==0){
 216         pos= get_bits_count(&s->gb);
 217         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
 218             ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
 219         else
 220             ret= h263_decode_gob_header(s);
 221         if(ret>=0)
 222             return pos;
 223     }
 224     //OK, it's not where it is supposed to be ...
 225     s->gb= s->last_resync_gb;
 226     align_get_bits(&s->gb);
 227     left= get_bits_left(&s->gb);
 228
 229     for(;left>16+1+5+5; left-=8){
 230         if(show_bits(&s->gb, 16)==0){
 231             GetBitContext bak= s->gb;
 232
 233             pos= get_bits_count(&s->gb);
 234             if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
 235                 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
 236             else
 237                 ret= h263_decode_gob_header(s);
 238             if(ret>=0)
 239                 return pos;
 240
 241             s->gb= bak;
 242         }
 243         skip_bits(&s->gb, 8);
 244     }
 245
 246     return -1;
 247 }
 248
 249 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
 250 {
 251     int code, val, sign, shift;
 252     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 253
 254     if (code == 0)
 255         return pred;
 256     if (code < 0)
 257         return 0xffff;
 258
 259     sign = get_bits1(&s->gb);
 260     shift = f_code - 1;
 261     val = code;
 262     if (shift) {
 263         val = (val - 1) << shift;
 264         val |= get_bits(&s->gb, shift);
 265         val++;
 266     }
 267     if (sign)
 268         val = -val;
 269     val += pred;
 270
 271     /* modulo decoding */
 272     if (!s->h263_long_vectors) {
 273         val = sign_extend(val, 5 + f_code);
 274     } else {
 275         /* horrible h263 long vector mode */
 276         if (pred < -31 && val < -63)
 277             val += 64;
 278         if (pred > 32 && val > 63)
 279             val -= 64;
 280
 281     }
 282     return val;
 283 }
 284
 285
 286 /* Decode RVLC of H.263+ UMV */
 287 static int h263p_decode_umotion(MpegEncContext * s, int pred)
 288 {
 289    int code = 0, sign;
 290
 291    if (get_bits1(&s->gb)) /* Motion difference = 0 */
 292       return pred;
 293
 294    code = 2 + get_bits1(&s->gb);
 295
 296    while (get_bits1(&s->gb))
 297    {
 298       code <<= 1;
 299       code += get_bits1(&s->gb);
 300    }
 301    sign = code & 1;
 302    code >>= 1;
 303
 304    code = (sign) ? (pred - code) : (pred + code);
 305    av_dlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
 306    return code;
 307
 308 }
 309
 310 /**
 311  * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
 312  */
 313 static void preview_obmc(MpegEncContext *s){
 314     GetBitContext gb= s->gb;
 315
 316     int cbpc, i, pred_x, pred_y, mx, my;
 317     int16_t *mot_val;
 318     const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
 319     const int stride= s->b8_stride*2;
 320
 321     for(i=0; i<4; i++)
 322         s->block_index[i]+= 2;
 323     for(i=4; i<6; i++)
 324         s->block_index[i]+= 1;
 325     s->mb_x++;
 326
 327     av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
 328
 329     do{
 330         if (get_bits1(&s->gb)) {
 331             /* skip mb */
 332             mot_val = s->current_picture.motion_val[0][s->block_index[0]];
 333             mot_val[0       ]= mot_val[2       ]=
 334             mot_val[0+stride]= mot_val[2+stride]= 0;
 335             mot_val[1       ]= mot_val[3       ]=
 336             mot_val[1+stride]= mot_val[3+stride]= 0;
 337
 338             s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 339             goto end;
 340         }
 341         cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 342     }while(cbpc == 20);
 343
 344     if(cbpc & 4){
 345         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 346     }else{
 347         get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 348         if (cbpc & 8) {
 349             if(s->modified_quant){
 350                 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
 351                 else                  skip_bits(&s->gb, 5);
 352             }else
 353                 skip_bits(&s->gb, 2);
 354         }
 355
 356         if ((cbpc & 16) == 0) {
 357                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 358                 /* 16x16 motion prediction */
 359                 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 360                 if (s->umvplus)
 361                    mx = h263p_decode_umotion(s, pred_x);
 362                 else
 363                    mx = ff_h263_decode_motion(s, pred_x, 1);
 364
 365                 if (s->umvplus)
 366                    my = h263p_decode_umotion(s, pred_y);
 367                 else
 368                    my = ff_h263_decode_motion(s, pred_y, 1);
 369
 370                 mot_val[0       ]= mot_val[2       ]=
 371                 mot_val[0+stride]= mot_val[2+stride]= mx;
 372                 mot_val[1       ]= mot_val[3       ]=
 373                 mot_val[1+stride]= mot_val[3+stride]= my;
 374         } else {
 375             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 376             for(i=0;i<4;i++) {
 377                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 378                 if (s->umvplus)
 379                   mx = h263p_decode_umotion(s, pred_x);
 380                 else
 381                   mx = ff_h263_decode_motion(s, pred_x, 1);
 382
 383                 if (s->umvplus)
 384                   my = h263p_decode_umotion(s, pred_y);
 385                 else
 386                   my = ff_h263_decode_motion(s, pred_y, 1);
 387                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 388                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 389                 mot_val[0] = mx;
 390                 mot_val[1] = my;
 391             }
 392         }
 393     }
 394 end:
 395
 396     for(i=0; i<4; i++)
 397         s->block_index[i]-= 2;
 398     for(i=4; i<6; i++)
 399         s->block_index[i]-= 1;
 400     s->mb_x--;
 401
 402     s->gb= gb;
 403 }
 404
 405 static void h263_decode_dquant(MpegEncContext *s){
 406     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 407
 408     if(s->modified_quant){
 409         if(get_bits1(&s->gb))
 410             s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
 411         else
 412             s->qscale= get_bits(&s->gb, 5);
 413     }else
 414         s->qscale += quant_tab[get_bits(&s->gb, 2)];
 415     ff_set_qscale(s, s->qscale);
 416 }
 417
 418 static int h263_decode_block(MpegEncContext * s, int16_t * block,
 419                              int n, int coded)
 420 {
 421     int level, i, j, run;
 422     RLTable *rl = &ff_h263_rl_inter;
 423     const uint8_t *scan_table;
 424     GetBitContext gb= s->gb;
 425
 426     scan_table = s->intra_scantable.permutated;
 427     if (s->h263_aic && s->mb_intra) {
 428         rl = &ff_rl_intra_aic;
 429         i = 0;
 430         if (s->ac_pred) {
 431             if (s->h263_aic_dir)
 432                 scan_table = s->intra_v_scantable.permutated; /* left */
 433             else
 434                 scan_table = s->intra_h_scantable.permutated; /* top */
 435         }
 436     } else if (s->mb_intra) {
 437         /* DC coef */
 438         if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
 439           if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
 440             int component, diff;
 441             component = (n <= 3 ? 0 : n - 4 + 1);
 442             level = s->last_dc[component];
 443             if (s->rv10_first_dc_coded[component]) {
 444                 diff = ff_rv_decode_dc(s, n);
 445                 if (diff == 0xffff)
 446                     return -1;
 447                 level += diff;
 448                 level = level & 0xff; /* handle wrap round */
 449                 s->last_dc[component] = level;
 450             } else {
 451                 s->rv10_first_dc_coded[component] = 1;
 452             }
 453           } else {
 454                 level = get_bits(&s->gb, 8);
 455                 if (level == 255)
 456                     level = 128;
 457           }
 458         }else{
 459             level = get_bits(&s->gb, 8);
 460             if((level&0x7F) == 0){
 461                 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
 462                 if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
 463                     return -1;
 464             }
 465             if (level == 255)
 466                 level = 128;
 467         }
 468         block[0] = level;
 469         i = 1;
 470     } else {
 471         i = 0;
 472     }
 473     if (!coded) {
 474         if (s->mb_intra && s->h263_aic)
 475             goto not_coded;
 476         s->block_last_index[n] = i - 1;
 477         return 0;
 478     }
 479 retry:
 480     {
 481     OPEN_READER(re, &s->gb);
 482     i--; // offset by -1 to allow direct indexing of scan_table
 483     for(;;) {
 484         UPDATE_CACHE(re, &s->gb);
 485         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 486         if (run == 66) {
 487             if (level){
 488                 CLOSE_READER(re, &s->gb);
 489                 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
 490                 return -1;
 491             }
 492             /* escape */
 493             if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
 494                 int is11 = SHOW_UBITS(re, &s->gb, 1);
 495                 SKIP_CACHE(re, &s->gb, 1);
 496                 run = SHOW_UBITS(re, &s->gb, 7) + 1;
 497                 if (is11) {
 498                     SKIP_COUNTER(re, &s->gb, 1 + 7);
 499                     UPDATE_CACHE(re, &s->gb);
 500                     level = SHOW_SBITS(re, &s->gb, 11);
 501                     SKIP_COUNTER(re, &s->gb, 11);
 502                 } else {
 503                     SKIP_CACHE(re, &s->gb, 7);
 504                     level = SHOW_SBITS(re, &s->gb, 7);
 505                     SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
 506                 }
 507             } else {
 508                 run = SHOW_UBITS(re, &s->gb, 7) + 1;
 509                 SKIP_CACHE(re, &s->gb, 7);
 510                 level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
 511                 SKIP_COUNTER(re, &s->gb, 7 + 8);
 512                 if(level == -128){
 513                     UPDATE_CACHE(re, &s->gb);
 514                     if (s->codec_id == AV_CODEC_ID_RV10) {
 515                         /* XXX: should patch encoder too */
 516                         level = SHOW_SBITS(re, &s->gb, 12);
 517                         SKIP_COUNTER(re, &s->gb, 12);
 518                     }else{
 519                         level = SHOW_UBITS(re, &s->gb, 5);
 520                         SKIP_CACHE(re, &s->gb, 5);
 521                         level |= SHOW_SBITS(re, &s->gb, 6)<<5;
 522                         SKIP_COUNTER(re, &s->gb, 5 + 6);
 523                     }
 524                 }
 525             }
 526         } else {
 527             if (SHOW_UBITS(re, &s->gb, 1))
 528                 level = -level;
 529             SKIP_COUNTER(re, &s->gb, 1);
 530         }
 531         i += run;
 532         if (i >= 64){
 533             CLOSE_READER(re, &s->gb);
 534             // redo update without last flag, revert -1 offset
 535             i = i - run + ((run-1)&63) + 1;
 536             if (i < 64) {
 537                 // only last marker, no overrun
 538                 block[scan_table[i]] = level;
 539                 break;
 540             }
 541             if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
 542                 //Looks like a hack but no, it's the way it is supposed to work ...
 543                 rl = &ff_rl_intra_aic;
 544                 i = 0;
 545                 s->gb= gb;
 546                 s->bdsp.clear_block(block);
 547                 goto retry;
 548             }
 549             av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
 550             return -1;
 551         }
 552         j = scan_table[i];
 553         block[j] = level;
 554     }
 555     }
 556 not_coded:
 557     if (s->mb_intra && s->h263_aic) {
 558         ff_h263_pred_acdc(s, block, n);
 559         i = 63;
 560     }
 561     s->block_last_index[n] = i;
 562     return 0;
 563 }
 564
 565 static int h263_skip_b_part(MpegEncContext *s, int cbp)
 566 {
 567     LOCAL_ALIGNED_16(int16_t, dblock, [64]);
 568     int i, mbi;
 569     int bli[6];
 570
 571     /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
 572      * but real value should be restored in order to be used later (in OBMC condition)
 573      */
 574     mbi = s->mb_intra;
 575     memcpy(bli, s->block_last_index, sizeof(bli));
 576     s->mb_intra = 0;
 577     for (i = 0; i < 6; i++) {
 578         if (h263_decode_block(s, dblock, i, cbp&32) < 0)
 579             return -1;
 580         cbp+=cbp;
 581     }
 582     s->mb_intra = mbi;
 583     memcpy(s->block_last_index, bli, sizeof(bli));
 584     return 0;
 585 }
 586
 587 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
 588 {
 589     int c, mv = 1;
 590
 591     if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
 592         c = get_bits1(gb);
 593         if (pb_frame == 2 && c)
 594             mv = !get_bits1(gb);
 595     } else { // h.263 Annex M improved PB-frame
 596         mv = get_unary(gb, 0, 4) + 1;
 597         c = mv & 1;
 598         mv = !!(mv & 2);
 599     }
 600     if(c)
 601         *cbpb = get_bits(gb, 6);
 602     return mv;
 603 }
 604
 605 int ff_h263_decode_mb(MpegEncContext *s,
 606                       int16_t block[6][64])
 607 {
 608     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
 609     int16_t *mot_val;
 610     const int xy= s->mb_x + s->mb_y * s->mb_stride;
 611     int cbpb = 0, pb_mv_count = 0;
 612
 613     av_assert2(!s->h263_pred);
 614
 615     if (s->pict_type == AV_PICTURE_TYPE_P) {
 616         do{
 617             if (get_bits1(&s->gb)) {
 618                 /* skip mb */
 619                 s->mb_intra = 0;
 620                 for(i=0;i<6;i++)
 621                     s->block_last_index[i] = -1;
 622                 s->mv_dir = MV_DIR_FORWARD;
 623                 s->mv_type = MV_TYPE_16X16;
 624                 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 625                 s->mv[0][0][0] = 0;
 626                 s->mv[0][0][1] = 0;
 627                 s->mb_skipped = !(s->obmc | s->loop_filter);
 628                 goto end;
 629             }
 630             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 631             if (cbpc < 0){
 632                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
 633                 return -1;
 634             }
 635         }while(cbpc == 20);
 636
 637         s->bdsp.clear_blocks(s->block[0]);
 638
 639         dquant = cbpc & 8;
 640         s->mb_intra = ((cbpc & 4) != 0);
 641         if (s->mb_intra) goto intra;
 642
 643         if(s->pb_frame && get_bits1(&s->gb))
 644             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
 645         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 646
 647         if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
 648             cbpy ^= 0xF;
 649
 650         cbp = (cbpc & 3) | (cbpy << 2);
 651         if (dquant) {
 652             h263_decode_dquant(s);
 653         }
 654
 655         s->mv_dir = MV_DIR_FORWARD;
 656         if ((cbpc & 16) == 0) {
 657             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 658             /* 16x16 motion prediction */
 659             s->mv_type = MV_TYPE_16X16;
 660             ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 661             if (s->umvplus)
 662                mx = h263p_decode_umotion(s, pred_x);
 663             else
 664                mx = ff_h263_decode_motion(s, pred_x, 1);
 665
 666             if (mx >= 0xffff)
 667                 return -1;
 668
 669             if (s->umvplus)
 670                my = h263p_decode_umotion(s, pred_y);
 671             else
 672                my = ff_h263_decode_motion(s, pred_y, 1);
 673
 674             if (my >= 0xffff)
 675                 return -1;
 676             s->mv[0][0][0] = mx;
 677             s->mv[0][0][1] = my;
 678
 679             if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 680                skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 681         } else {
 682             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 683             s->mv_type = MV_TYPE_8X8;
 684             for(i=0;i<4;i++) {
 685                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 686                 if (s->umvplus)
 687                   mx = h263p_decode_umotion(s, pred_x);
 688                 else
 689                   mx = ff_h263_decode_motion(s, pred_x, 1);
 690                 if (mx >= 0xffff)
 691                     return -1;
 692
 693                 if (s->umvplus)
 694                   my = h263p_decode_umotion(s, pred_y);
 695                 else
 696                   my = ff_h263_decode_motion(s, pred_y, 1);
 697                 if (my >= 0xffff)
 698                     return -1;
 699                 s->mv[0][i][0] = mx;
 700                 s->mv[0][i][1] = my;
 701                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 702                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 703                 mot_val[0] = mx;
 704                 mot_val[1] = my;
 705             }
 706         }
 707     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
 708         int mb_type;
 709         const int stride= s->b8_stride;
 710         int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
 711         int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
 712 //        const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
 713
 714         //FIXME ugly
 715         mot_val0[0       ]= mot_val0[2       ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
 716         mot_val0[1       ]= mot_val0[3       ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
 717         mot_val1[0       ]= mot_val1[2       ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
 718         mot_val1[1       ]= mot_val1[3       ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
 719
 720         do{
 721             mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
 722             if (mb_type < 0){
 723                 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
 724                 return -1;
 725             }
 726
 727             mb_type= h263_mb_type_b_map[ mb_type ];
 728         }while(!mb_type);
 729
 730         s->mb_intra = IS_INTRA(mb_type);
 731         if(HAS_CBP(mb_type)){
 732             s->bdsp.clear_blocks(s->block[0]);
 733             cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
 734             if(s->mb_intra){
 735                 dquant = IS_QUANT(mb_type);
 736                 goto intra;
 737             }
 738
 739             cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 740
 741             if (cbpy < 0){
 742                 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
 743                 return -1;
 744             }
 745
 746             if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
 747                 cbpy ^= 0xF;
 748
 749             cbp = (cbpc & 3) | (cbpy << 2);
 750         }else
 751             cbp=0;
 752
 753         av_assert2(!s->mb_intra);
 754
 755         if(IS_QUANT(mb_type)){
 756             h263_decode_dquant(s);
 757         }
 758
 759         if(IS_DIRECT(mb_type)){
 760             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
 761             mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0);
 762         }else{
 763             s->mv_dir = 0;
 764             s->mv_type= MV_TYPE_16X16;
 765 //FIXME UMV
 766
 767             if(USES_LIST(mb_type, 0)){
 768                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &mx, &my);
 769                 s->mv_dir = MV_DIR_FORWARD;
 770
 771                 mx = ff_h263_decode_motion(s, mx, 1);
 772                 my = ff_h263_decode_motion(s, my, 1);
 773
 774                 s->mv[0][0][0] = mx;
 775                 s->mv[0][0][1] = my;
 776                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
 777                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
 778             }
 779
 780             if(USES_LIST(mb_type, 1)){
 781                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &mx, &my);
 782                 s->mv_dir |= MV_DIR_BACKWARD;
 783
 784                 mx = ff_h263_decode_motion(s, mx, 1);
 785                 my = ff_h263_decode_motion(s, my, 1);
 786
 787                 s->mv[1][0][0] = mx;
 788                 s->mv[1][0][1] = my;
 789                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
 790                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
 791             }
 792         }
 793
 794         s->current_picture.mb_type[xy] = mb_type;
 795     } else { /* I-Frame */
 796         do{
 797             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 798             if (cbpc < 0){
 799                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
 800                 return -1;
 801             }
 802         }while(cbpc == 8);
 803
 804         s->bdsp.clear_blocks(s->block[0]);
 805
 806         dquant = cbpc & 4;
 807         s->mb_intra = 1;
 808 intra:
 809         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 810         if (s->h263_aic) {
 811             s->ac_pred = get_bits1(&s->gb);
 812             if(s->ac_pred){
 813                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
 814
 815                 s->h263_aic_dir = get_bits1(&s->gb);
 816             }
 817         }else
 818             s->ac_pred = 0;
 819
 820         if(s->pb_frame && get_bits1(&s->gb))
 821             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
 822         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 823         if(cbpy<0){
 824             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
 825             return -1;
 826         }
 827         cbp = (cbpc & 3) | (cbpy << 2);
 828         if (dquant) {
 829             h263_decode_dquant(s);
 830         }
 831
 832         pb_mv_count += !!s->pb_frame;
 833     }
 834
 835     while(pb_mv_count--){
 836         ff_h263_decode_motion(s, 0, 1);
 837         ff_h263_decode_motion(s, 0, 1);
 838     }
 839
 840     /* decode each block */
 841     for (i = 0; i < 6; i++) {
 842         if (h263_decode_block(s, block[i], i, cbp&32) < 0)
 843             return -1;
 844         cbp+=cbp;
 845     }
 846
 847     if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
 848         return -1;
 849     if(s->obmc && !s->mb_intra){
 850         if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
 851             preview_obmc(s);
 852     }
 853 end:
 854
 855         /* per-MB end of slice check */
 856     {
 857         int v= show_bits(&s->gb, 16);
 858
 859         if (get_bits_left(&s->gb) < 16) {
 860             v >>= 16 - get_bits_left(&s->gb);
 861         }
 862
 863         if(v==0)
 864             return SLICE_END;
 865     }
 866
 867     return SLICE_OK;
 868 }
 869
 870 /* most is hardcoded. should extend to handle all h263 streams */
 871 int ff_h263_decode_picture_header(MpegEncContext *s)
 872 {
 873     int format, width, height, i;
 874     uint32_t startcode;
 875
 876     align_get_bits(&s->gb);
 877
 878     if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
 879          av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
 880     }
 881
 882     startcode= get_bits(&s->gb, 22-8);
 883
 884     for(i= get_bits_left(&s->gb); i>24; i-=8) {
 885         startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
 886
 887         if(startcode == 0x20)
 888             break;
 889     }
 890
 891     if (startcode != 0x20) {
 892         av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
 893         return -1;
 894     }
 895     /* temporal reference */
 896     i = get_bits(&s->gb, 8); /* picture timestamp */
 897     if( (s->picture_number&~0xFF)+i < s->picture_number)
 898         i+= 256;
 899     s->picture_number= (s->picture_number&~0xFF) + i;
 900
 901     /* PTYPE starts here */
 902     if (get_bits1(&s->gb) != 1) {
 903         /* marker */
 904         av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
 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             av_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                 av_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                 skip_bits1(&s->gb);
1026                 height = get_bits(&s->gb, 9) * 4;
1027                 av_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 (get_bits1(&s->gb) != 1) {
1122             av_log(s->avctx, AV_LOG_ERROR, "SEPB1 marker missing\n");
1123             return -1;
1124         }
1125
1126         ff_h263_decode_mba(s);
1127
1128         if (get_bits1(&s->gb) != 1) {
1129             av_log(s->avctx, AV_LOG_ERROR, "SEPB2 marker missing\n");
1130             return -1;
1131         }
1132     }
1133     s->f_code = 1;
1134
1135     if(s->h263_aic){
1136          s->y_dc_scale_table=
1137          s->c_dc_scale_table= ff_aic_dc_scale_table;
1138     }else{
1139         s->y_dc_scale_table=
1140         s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1141     }
1142
1143         ff_h263_show_pict_info(s);
1144     if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1145         int i,j;
1146         for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1147         av_log(s->avctx, AV_LOG_DEBUG, "\n");
1148         for(i=0; i<13; i++){
1149             for(j=0; j<3; j++){
1150                 int v= get_bits(&s->gb, 8);
1151                 v |= get_sbits(&s->gb, 8)<<8;
1152                 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1153             }
1154             av_log(s->avctx, AV_LOG_DEBUG, "\n");
1155         }
1156         for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1157     }
1158
1159     return 0;
1160 }