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   1 /*
   2  * ITU H.263 bitstream decoder
   3  * Copyright (c) 2000,2001 Fabrice Bellard
   4  * H.263+ 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  * H.263 decoder.
  28  */
  29
  30 #define UNCHECKED_BITSTREAM_READER 1
  31 #include <limits.h>
  32
  33 #include "libavutil/attributes.h"
  34 #include "libavutil/imgutils.h"
  35 #include "libavutil/internal.h"
  36 #include "libavutil/mathematics.h"
  37 #include "libavutil/mem_internal.h"
  38 #include "avcodec.h"
  39 #include "mpegvideo.h"
  40 #include "h263.h"
  41 #include "h263data.h"
  42 #include "internal.h"
  43 #include "mathops.h"
  44 #include "mpegutils.h"
  45 #include "unary.h"
  46 #include "flv.h"
  47 #include "rv10.h"
  48 #include "mpeg4video.h"
  49 #include "mpegvideodata.h"
  50
  51 // The defines below define the number of bits that are read at once for
  52 // reading vlc values. Changing these may improve speed and data cache needs
  53 // be aware though that decreasing them may need the number of stages that is
  54 // passed to get_vlc* to be increased.
  55 #define MV_VLC_BITS 9
  56 #define H263_MBTYPE_B_VLC_BITS 6
  57 #define CBPC_B_VLC_BITS 3
  58
  59 static const int h263_mb_type_b_map[15]= {
  60     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  61     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
  62     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
  63                       MB_TYPE_L0                                 | MB_TYPE_16x16,
  64                       MB_TYPE_L0   | MB_TYPE_CBP                 | MB_TYPE_16x16,
  65                       MB_TYPE_L0   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  66                       MB_TYPE_L1                                 | MB_TYPE_16x16,
  67                       MB_TYPE_L1   | MB_TYPE_CBP                 | MB_TYPE_16x16,
  68                       MB_TYPE_L1   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  69                       MB_TYPE_L0L1                               | MB_TYPE_16x16,
  70                       MB_TYPE_L0L1 | MB_TYPE_CBP                 | MB_TYPE_16x16,
  71                       MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  72     0, //stuffing
  73     MB_TYPE_INTRA4x4                | MB_TYPE_CBP,
  74     MB_TYPE_INTRA4x4                | MB_TYPE_CBP | MB_TYPE_QUANT,
  75 };
  76
  77 void ff_h263_show_pict_info(MpegEncContext *s){
  78     if(s->avctx->debug&FF_DEBUG_PICT_INFO){
  79     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",
  80          s->qscale, av_get_picture_type_char(s->pict_type),
  81          s->gb.size_in_bits, 1-s->no_rounding,
  82          s->obmc ? " AP" : "",
  83          s->umvplus ? " UMV" : "",
  84          s->h263_long_vectors ? " LONG" : "",
  85          s->h263_plus ? " +" : "",
  86          s->h263_aic ? " AIC" : "",
  87          s->alt_inter_vlc ? " AIV" : "",
  88          s->modified_quant ? " MQ" : "",
  89          s->loop_filter ? " LOOP" : "",
  90          s->h263_slice_structured ? " SS" : "",
  91          s->avctx->framerate.num, s->avctx->framerate.den
  92     );
  93     }
  94 }
  95
  96 /***********************************************/
  97 /* decoding */
  98
  99 VLC ff_h263_intra_MCBPC_vlc;
 100 VLC ff_h263_inter_MCBPC_vlc;
 101 VLC ff_h263_cbpy_vlc;
 102 static VLC mv_vlc;
 103 static VLC h263_mbtype_b_vlc;
 104 static VLC cbpc_b_vlc;
 105
 106 /* init vlcs */
 107
 108 /* XXX: find a better solution to handle static init */
 109 av_cold void ff_h263_decode_init_vlc(void)
 110 {
 111     static volatile int done = 0;
 112
 113     if (!done) {
 114         INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
 115                  ff_h263_intra_MCBPC_bits, 1, 1,
 116                  ff_h263_intra_MCBPC_code, 1, 1, 72);
 117         INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
 118                  ff_h263_inter_MCBPC_bits, 1, 1,
 119                  ff_h263_inter_MCBPC_code, 1, 1, 198);
 120         INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
 121                  &ff_h263_cbpy_tab[0][1], 2, 1,
 122                  &ff_h263_cbpy_tab[0][0], 2, 1, 64);
 123         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
 124                  &ff_mvtab[0][1], 2, 1,
 125                  &ff_mvtab[0][0], 2, 1, 538);
 126         ff_rl_init(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
 127         ff_rl_init(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
 128         INIT_VLC_RL(ff_h263_rl_inter, 554);
 129         INIT_VLC_RL(ff_rl_intra_aic, 554);
 130         INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
 131                  &ff_h263_mbtype_b_tab[0][1], 2, 1,
 132                  &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
 133         INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
 134                  &ff_cbpc_b_tab[0][1], 2, 1,
 135                  &ff_cbpc_b_tab[0][0], 2, 1, 8);
 136         done = 1;
 137     }
 138 }
 139
 140 int ff_h263_decode_mba(MpegEncContext *s)
 141 {
 142     int i, mb_pos;
 143
 144     for (i = 0; i < 6; i++)
 145         if (s->mb_num - 1 <= ff_mba_max[i])
 146             break;
 147     mb_pos  = get_bits(&s->gb, ff_mba_length[i]);
 148     s->mb_x = mb_pos % s->mb_width;
 149     s->mb_y = mb_pos / s->mb_width;
 150
 151     return mb_pos;
 152 }
 153
 154 /**
 155  * Decode the group of blocks header or slice header.
 156  * @return <0 if an error occurred
 157  */
 158 static int h263_decode_gob_header(MpegEncContext *s)
 159 {
 160     unsigned int val, gob_number;
 161     int left;
 162
 163     /* Check for GOB Start Code */
 164     val = show_bits(&s->gb, 16);
 165     if(val)
 166         return -1;
 167
 168         /* We have a GBSC probably with GSTUFF */
 169     skip_bits(&s->gb, 16); /* Drop the zeros */
 170     left= get_bits_left(&s->gb);
 171     left = FFMIN(left, 32);
 172     //MN: we must check the bits left or we might end in an infinite loop (or segfault)
 173     for(;left>13; left--){
 174         if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
 175     }
 176     if(left<=13)
 177         return -1;
 178
 179     if(s->h263_slice_structured){
 180         if(check_marker(s->avctx, &s->gb, "before MBA")==0)
 181             return -1;
 182
 183         ff_h263_decode_mba(s);
 184
 185         if(s->mb_num > 1583)
 186             if(check_marker(s->avctx, &s->gb, "after MBA")==0)
 187                 return -1;
 188
 189         s->qscale = get_bits(&s->gb, 5); /* SQUANT */
 190         if(check_marker(s->avctx, &s->gb, "after SQUANT")==0)
 191             return -1;
 192         skip_bits(&s->gb, 2); /* GFID */
 193     }else{
 194         gob_number = get_bits(&s->gb, 5); /* GN */
 195         s->mb_x= 0;
 196         s->mb_y= s->gob_index* gob_number;
 197         skip_bits(&s->gb, 2); /* GFID */
 198         s->qscale = get_bits(&s->gb, 5); /* GQUANT */
 199     }
 200
 201     if(s->mb_y >= s->mb_height)
 202         return -1;
 203
 204     if(s->qscale==0)
 205         return -1;
 206
 207     return 0;
 208 }
 209
 210 /**
 211  * Decode the group of blocks / video packet header / slice header (MPEG-4 Studio).
 212  * @return bit position of the resync_marker, or <0 if none was found
 213  */
 214 int ff_h263_resync(MpegEncContext *s){
 215     int left, pos, ret;
 216
 217     /* In MPEG-4 studio mode look for a new slice startcode
 218      * and decode slice header */
 219     if(s->codec_id==AV_CODEC_ID_MPEG4 && s->studio_profile) {
 220         align_get_bits(&s->gb);
 221
 222         while (get_bits_left(&s->gb) >= 32 && show_bits_long(&s->gb, 32) != SLICE_START_CODE) {
 223             get_bits(&s->gb, 8);
 224         }
 225
 226         if (get_bits_left(&s->gb) >= 32 && show_bits_long(&s->gb, 32) == SLICE_START_CODE)
 227             return get_bits_count(&s->gb);
 228         else
 229             return -1;
 230     }
 231
 232     if(s->codec_id==AV_CODEC_ID_MPEG4){
 233         skip_bits1(&s->gb);
 234         align_get_bits(&s->gb);
 235     }
 236
 237     if(show_bits(&s->gb, 16)==0){
 238         pos= get_bits_count(&s->gb);
 239         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
 240             ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
 241         else
 242             ret= h263_decode_gob_header(s);
 243         if(ret>=0)
 244             return pos;
 245     }
 246     //OK, it's not where it is supposed to be ...
 247     s->gb= s->last_resync_gb;
 248     align_get_bits(&s->gb);
 249     left= get_bits_left(&s->gb);
 250
 251     for(;left>16+1+5+5; left-=8){
 252         if(show_bits(&s->gb, 16)==0){
 253             GetBitContext bak= s->gb;
 254
 255             pos= get_bits_count(&s->gb);
 256             if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
 257                 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
 258             else
 259                 ret= h263_decode_gob_header(s);
 260             if(ret>=0)
 261                 return pos;
 262
 263             s->gb= bak;
 264         }
 265         skip_bits(&s->gb, 8);
 266     }
 267
 268     return -1;
 269 }
 270
 271 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
 272 {
 273     int code, val, sign, shift;
 274     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 275
 276     if (code == 0)
 277         return pred;
 278     if (code < 0)
 279         return 0xffff;
 280
 281     sign = get_bits1(&s->gb);
 282     shift = f_code - 1;
 283     val = code;
 284     if (shift) {
 285         val = (val - 1) << shift;
 286         val |= get_bits(&s->gb, shift);
 287         val++;
 288     }
 289     if (sign)
 290         val = -val;
 291     val += pred;
 292
 293     /* modulo decoding */
 294     if (!s->h263_long_vectors) {
 295         val = sign_extend(val, 5 + f_code);
 296     } else {
 297         /* horrible H.263 long vector mode */
 298         if (pred < -31 && val < -63)
 299             val += 64;
 300         if (pred > 32 && val > 63)
 301             val -= 64;
 302
 303     }
 304     return val;
 305 }
 306
 307
 308 /* Decode RVLC of H.263+ UMV */
 309 static int h263p_decode_umotion(MpegEncContext * s, int pred)
 310 {
 311    int code = 0, sign;
 312
 313    if (get_bits1(&s->gb)) /* Motion difference = 0 */
 314       return pred;
 315
 316    code = 2 + get_bits1(&s->gb);
 317
 318    while (get_bits1(&s->gb))
 319    {
 320       code <<= 1;
 321       code += get_bits1(&s->gb);
 322       if (code >= 32768) {
 323           avpriv_request_sample(s->avctx, "Huge DMV");
 324           return 0xffff;
 325       }
 326    }
 327    sign = code & 1;
 328    code >>= 1;
 329
 330    code = (sign) ? (pred - code) : (pred + code);
 331    ff_tlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
 332    return code;
 333
 334 }
 335
 336 /**
 337  * read the next MVs for OBMC. yes this is an ugly hack, feel free to send a patch :)
 338  */
 339 static void preview_obmc(MpegEncContext *s){
 340     GetBitContext gb= s->gb;
 341
 342     int cbpc, i, pred_x, pred_y, mx, my;
 343     int16_t *mot_val;
 344     const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
 345     const int stride= s->b8_stride*2;
 346
 347     for(i=0; i<4; i++)
 348         s->block_index[i]+= 2;
 349     for(i=4; i<6; i++)
 350         s->block_index[i]+= 1;
 351     s->mb_x++;
 352
 353     av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
 354
 355     do{
 356         if (get_bits1(&s->gb)) {
 357             /* skip mb */
 358             mot_val = s->current_picture.motion_val[0][s->block_index[0]];
 359             mot_val[0       ]= mot_val[2       ]=
 360             mot_val[0+stride]= mot_val[2+stride]= 0;
 361             mot_val[1       ]= mot_val[3       ]=
 362             mot_val[1+stride]= mot_val[3+stride]= 0;
 363
 364             s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 365             goto end;
 366         }
 367         cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 368     }while(cbpc == 20);
 369
 370     if(cbpc & 4){
 371         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 372     }else{
 373         get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 374         if (cbpc & 8) {
 375             if(s->modified_quant){
 376                 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
 377                 else                  skip_bits(&s->gb, 5);
 378             }else
 379                 skip_bits(&s->gb, 2);
 380         }
 381
 382         if ((cbpc & 16) == 0) {
 383                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 384                 /* 16x16 motion prediction */
 385                 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 386                 if (s->umvplus)
 387                     mx = h263p_decode_umotion(s, pred_x);
 388                 else
 389                     mx = ff_h263_decode_motion(s, pred_x, 1);
 390
 391                 if (s->umvplus)
 392                     my = h263p_decode_umotion(s, pred_y);
 393                 else
 394                     my = ff_h263_decode_motion(s, pred_y, 1);
 395
 396                 mot_val[0       ]= mot_val[2       ]=
 397                 mot_val[0+stride]= mot_val[2+stride]= mx;
 398                 mot_val[1       ]= mot_val[3       ]=
 399                 mot_val[1+stride]= mot_val[3+stride]= my;
 400         } else {
 401             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 402             for(i=0;i<4;i++) {
 403                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 404                 if (s->umvplus)
 405                     mx = h263p_decode_umotion(s, pred_x);
 406                 else
 407                     mx = ff_h263_decode_motion(s, pred_x, 1);
 408
 409                 if (s->umvplus)
 410                     my = h263p_decode_umotion(s, pred_y);
 411                 else
 412                     my = ff_h263_decode_motion(s, pred_y, 1);
 413                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 414                     skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 415                 mot_val[0] = mx;
 416                 mot_val[1] = my;
 417             }
 418         }
 419     }
 420 end:
 421
 422     for(i=0; i<4; i++)
 423         s->block_index[i]-= 2;
 424     for(i=4; i<6; i++)
 425         s->block_index[i]-= 1;
 426     s->mb_x--;
 427
 428     s->gb= gb;
 429 }
 430
 431 static void h263_decode_dquant(MpegEncContext *s){
 432     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 433
 434     if(s->modified_quant){
 435         if(get_bits1(&s->gb))
 436             s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
 437         else
 438             s->qscale= get_bits(&s->gb, 5);
 439     }else
 440         s->qscale += quant_tab[get_bits(&s->gb, 2)];
 441     ff_set_qscale(s, s->qscale);
 442 }
 443
 444 static int h263_decode_block(MpegEncContext * s, int16_t * block,
 445                              int n, int coded)
 446 {
 447     int level, i, j, run;
 448     RLTable *rl = &ff_h263_rl_inter;
 449     const uint8_t *scan_table;
 450     GetBitContext gb= s->gb;
 451
 452     scan_table = s->intra_scantable.permutated;
 453     if (s->h263_aic && s->mb_intra) {
 454         rl = &ff_rl_intra_aic;
 455         i = 0;
 456         if (s->ac_pred) {
 457             if (s->h263_aic_dir)
 458                 scan_table = s->intra_v_scantable.permutated; /* left */
 459             else
 460                 scan_table = s->intra_h_scantable.permutated; /* top */
 461         }
 462     } else if (s->mb_intra) {
 463         /* DC coef */
 464         if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
 465           if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
 466             int component, diff;
 467             component = (n <= 3 ? 0 : n - 4 + 1);
 468             level = s->last_dc[component];
 469             if (s->rv10_first_dc_coded[component]) {
 470                 diff = ff_rv_decode_dc(s, n);
 471                 if (diff < 0)
 472                     return -1;
 473                 level += diff;
 474                 level = level & 0xff; /* handle wrap round */
 475                 s->last_dc[component] = level;
 476             } else {
 477                 s->rv10_first_dc_coded[component] = 1;
 478             }
 479           } else {
 480                 level = get_bits(&s->gb, 8);
 481                 if (level == 255)
 482                     level = 128;
 483           }
 484         }else{
 485             level = get_bits(&s->gb, 8);
 486             if((level&0x7F) == 0){
 487                 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
 488                 if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
 489                     return -1;
 490             }
 491             if (level == 255)
 492                 level = 128;
 493         }
 494         block[0] = level;
 495         i = 1;
 496     } else {
 497         i = 0;
 498     }
 499     if (!coded) {
 500         if (s->mb_intra && s->h263_aic)
 501             goto not_coded;
 502         s->block_last_index[n] = i - 1;
 503         return 0;
 504     }
 505 retry:
 506     {
 507     OPEN_READER(re, &s->gb);
 508     i--; // offset by -1 to allow direct indexing of scan_table
 509     for(;;) {
 510         UPDATE_CACHE(re, &s->gb);
 511         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 512         if (run == 66) {
 513             if (level){
 514                 CLOSE_READER(re, &s->gb);
 515                 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
 516                 return -1;
 517             }
 518             /* escape */
 519             if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
 520                 int is11 = SHOW_UBITS(re, &s->gb, 1);
 521                 SKIP_CACHE(re, &s->gb, 1);
 522                 run = SHOW_UBITS(re, &s->gb, 7) + 1;
 523                 if (is11) {
 524                     SKIP_COUNTER(re, &s->gb, 1 + 7);
 525                     UPDATE_CACHE(re, &s->gb);
 526                     level = SHOW_SBITS(re, &s->gb, 11);
 527                     SKIP_COUNTER(re, &s->gb, 11);
 528                 } else {
 529                     SKIP_CACHE(re, &s->gb, 7);
 530                     level = SHOW_SBITS(re, &s->gb, 7);
 531                     SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
 532                 }
 533             } else {
 534                 run = SHOW_UBITS(re, &s->gb, 7) + 1;
 535                 SKIP_CACHE(re, &s->gb, 7);
 536                 level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
 537                 SKIP_COUNTER(re, &s->gb, 7 + 8);
 538                 if(level == -128){
 539                     UPDATE_CACHE(re, &s->gb);
 540                     if (s->codec_id == AV_CODEC_ID_RV10) {
 541                         /* XXX: should patch encoder too */
 542                         level = SHOW_SBITS(re, &s->gb, 12);
 543                         SKIP_COUNTER(re, &s->gb, 12);
 544                     }else{
 545                         level = SHOW_UBITS(re, &s->gb, 5);
 546                         SKIP_CACHE(re, &s->gb, 5);
 547                         level |= SHOW_SBITS(re, &s->gb, 6) * (1<<5);
 548                         SKIP_COUNTER(re, &s->gb, 5 + 6);
 549                     }
 550                 }
 551             }
 552         } else {
 553             if (SHOW_UBITS(re, &s->gb, 1))
 554                 level = -level;
 555             SKIP_COUNTER(re, &s->gb, 1);
 556         }
 557         i += run;
 558         if (i >= 64){
 559             CLOSE_READER(re, &s->gb);
 560             // redo update without last flag, revert -1 offset
 561             i = i - run + ((run-1)&63) + 1;
 562             if (i < 64) {
 563                 // only last marker, no overrun
 564                 block[scan_table[i]] = level;
 565                 break;
 566             }
 567             if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
 568                 //Looks like a hack but no, it's the way it is supposed to work ...
 569                 rl = &ff_rl_intra_aic;
 570                 i = 0;
 571                 s->gb= gb;
 572                 s->bdsp.clear_block(block);
 573                 goto retry;
 574             }
 575             av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
 576             return -1;
 577         }
 578         j = scan_table[i];
 579         block[j] = level;
 580     }
 581     }
 582 not_coded:
 583     if (s->mb_intra && s->h263_aic) {
 584         ff_h263_pred_acdc(s, block, n);
 585         i = 63;
 586     }
 587     s->block_last_index[n] = i;
 588     return 0;
 589 }
 590
 591 static int h263_skip_b_part(MpegEncContext *s, int cbp)
 592 {
 593     LOCAL_ALIGNED_32(int16_t, dblock, [64]);
 594     int i, mbi;
 595     int bli[6];
 596
 597     /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
 598      * but real value should be restored in order to be used later (in OBMC condition)
 599      */
 600     mbi = s->mb_intra;
 601     memcpy(bli, s->block_last_index, sizeof(bli));
 602     s->mb_intra = 0;
 603     for (i = 0; i < 6; i++) {
 604         if (h263_decode_block(s, dblock, i, cbp&32) < 0)
 605             return -1;
 606         cbp+=cbp;
 607     }
 608     s->mb_intra = mbi;
 609     memcpy(s->block_last_index, bli, sizeof(bli));
 610     return 0;
 611 }
 612
 613 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
 614 {
 615     int c, mv = 1;
 616
 617     if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
 618         c = get_bits1(gb);
 619         if (pb_frame == 2 && c)
 620             mv = !get_bits1(gb);
 621     } else { // h.263 Annex M improved PB-frame
 622         mv = get_unary(gb, 0, 4) + 1;
 623         c = mv & 1;
 624         mv = !!(mv & 2);
 625     }
 626     if(c)
 627         *cbpb = get_bits(gb, 6);
 628     return mv;
 629 }
 630
 631 #define tab_size ((signed)FF_ARRAY_ELEMS(s->direct_scale_mv[0]))
 632 #define tab_bias (tab_size / 2)
 633 static inline void set_one_direct_mv(MpegEncContext *s, Picture *p, int i)
 634 {
 635     int xy           = s->block_index[i];
 636     uint16_t time_pp = s->pp_time;
 637     uint16_t time_pb = s->pb_time;
 638     int p_mx, p_my;
 639
 640     p_mx = p->motion_val[0][xy][0];
 641     if ((unsigned)(p_mx + tab_bias) < tab_size) {
 642         s->mv[0][i][0] = s->direct_scale_mv[0][p_mx + tab_bias];
 643         s->mv[1][i][0] = s->direct_scale_mv[1][p_mx + tab_bias];
 644     } else {
 645         s->mv[0][i][0] = p_mx * time_pb / time_pp;
 646         s->mv[1][i][0] = p_mx * (time_pb - time_pp) / time_pp;
 647     }
 648     p_my = p->motion_val[0][xy][1];
 649     if ((unsigned)(p_my + tab_bias) < tab_size) {
 650         s->mv[0][i][1] = s->direct_scale_mv[0][p_my + tab_bias];
 651         s->mv[1][i][1] = s->direct_scale_mv[1][p_my + tab_bias];
 652     } else {
 653         s->mv[0][i][1] = p_my * time_pb / time_pp;
 654         s->mv[1][i][1] = p_my * (time_pb - time_pp) / time_pp;
 655     }
 656 }
 657
 658 /**
 659  * @return the mb_type
 660  */
 661 static int set_direct_mv(MpegEncContext *s)
 662 {
 663     const int mb_index = s->mb_x + s->mb_y * s->mb_stride;
 664     Picture *p = &s->next_picture;
 665     int colocated_mb_type = p->mb_type[mb_index];
 666     int i;
 667
 668     if (s->codec_tag == AV_RL32("U263") && p->f->pict_type == AV_PICTURE_TYPE_I) {
 669         p = &s->last_picture;
 670         colocated_mb_type = p->mb_type[mb_index];
 671     }
 672
 673     if (IS_8X8(colocated_mb_type)) {
 674         s->mv_type = MV_TYPE_8X8;
 675         for (i = 0; i < 4; i++)
 676             set_one_direct_mv(s, p, i);
 677         return MB_TYPE_DIRECT2 | MB_TYPE_8x8 | MB_TYPE_L0L1;
 678     } else {
 679         set_one_direct_mv(s, p, 0);
 680         s->mv[0][1][0] =
 681         s->mv[0][2][0] =
 682         s->mv[0][3][0] = s->mv[0][0][0];
 683         s->mv[0][1][1] =
 684         s->mv[0][2][1] =
 685         s->mv[0][3][1] = s->mv[0][0][1];
 686         s->mv[1][1][0] =
 687         s->mv[1][2][0] =
 688         s->mv[1][3][0] = s->mv[1][0][0];
 689         s->mv[1][1][1] =
 690         s->mv[1][2][1] =
 691         s->mv[1][3][1] = s->mv[1][0][1];
 692         s->mv_type = MV_TYPE_8X8;
 693         // Note see prev line
 694         return MB_TYPE_DIRECT2 | MB_TYPE_16x16 | MB_TYPE_L0L1;
 695     }
 696 }
 697
 698 int ff_h263_decode_mb(MpegEncContext *s,
 699                       int16_t block[6][64])
 700 {
 701     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
 702     int16_t *mot_val;
 703     const int xy= s->mb_x + s->mb_y * s->mb_stride;
 704     int cbpb = 0, pb_mv_count = 0;
 705
 706     av_assert2(!s->h263_pred);
 707
 708     if (s->pict_type == AV_PICTURE_TYPE_P) {
 709         do{
 710             if (get_bits1(&s->gb)) {
 711                 /* skip mb */
 712                 s->mb_intra = 0;
 713                 for(i=0;i<6;i++)
 714                     s->block_last_index[i] = -1;
 715                 s->mv_dir = MV_DIR_FORWARD;
 716                 s->mv_type = MV_TYPE_16X16;
 717                 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 718                 s->mv[0][0][0] = 0;
 719                 s->mv[0][0][1] = 0;
 720                 s->mb_skipped = !(s->obmc | s->loop_filter);
 721                 goto end;
 722             }
 723             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 724             if (cbpc < 0){
 725                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
 726                 return SLICE_ERROR;
 727             }
 728         }while(cbpc == 20);
 729
 730         s->bdsp.clear_blocks(s->block[0]);
 731
 732         dquant = cbpc & 8;
 733         s->mb_intra = ((cbpc & 4) != 0);
 734         if (s->mb_intra) goto intra;
 735
 736         if(s->pb_frame && get_bits1(&s->gb))
 737             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
 738         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 739
 740         if (cbpy < 0) {
 741             av_log(s->avctx, AV_LOG_ERROR, "cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
 742             return SLICE_ERROR;
 743         }
 744
 745         if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
 746             cbpy ^= 0xF;
 747
 748         cbp = (cbpc & 3) | (cbpy << 2);
 749         if (dquant) {
 750             h263_decode_dquant(s);
 751         }
 752
 753         s->mv_dir = MV_DIR_FORWARD;
 754         if ((cbpc & 16) == 0) {
 755             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 756             /* 16x16 motion prediction */
 757             s->mv_type = MV_TYPE_16X16;
 758             ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 759             if (s->umvplus)
 760                mx = h263p_decode_umotion(s, pred_x);
 761             else
 762                mx = ff_h263_decode_motion(s, pred_x, 1);
 763
 764             if (mx >= 0xffff)
 765                 return SLICE_ERROR;
 766
 767             if (s->umvplus)
 768                my = h263p_decode_umotion(s, pred_y);
 769             else
 770                my = ff_h263_decode_motion(s, pred_y, 1);
 771
 772             if (my >= 0xffff)
 773                 return SLICE_ERROR;
 774             s->mv[0][0][0] = mx;
 775             s->mv[0][0][1] = my;
 776
 777             if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 778                skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 779         } else {
 780             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 781             s->mv_type = MV_TYPE_8X8;
 782             for(i=0;i<4;i++) {
 783                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 784                 if (s->umvplus)
 785                     mx = h263p_decode_umotion(s, pred_x);
 786                 else
 787                     mx = ff_h263_decode_motion(s, pred_x, 1);
 788                 if (mx >= 0xffff)
 789                     return SLICE_ERROR;
 790
 791                 if (s->umvplus)
 792                     my = h263p_decode_umotion(s, pred_y);
 793                 else
 794                     my = ff_h263_decode_motion(s, pred_y, 1);
 795                 if (my >= 0xffff)
 796                     return SLICE_ERROR;
 797                 s->mv[0][i][0] = mx;
 798                 s->mv[0][i][1] = my;
 799                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 800                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 801                 mot_val[0] = mx;
 802                 mot_val[1] = my;
 803             }
 804         }
 805     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
 806         int mb_type;
 807         const int stride= s->b8_stride;
 808         int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
 809         int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
 810 //        const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
 811
 812         //FIXME ugly
 813         mot_val0[0       ]= mot_val0[2       ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
 814         mot_val0[1       ]= mot_val0[3       ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
 815         mot_val1[0       ]= mot_val1[2       ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
 816         mot_val1[1       ]= mot_val1[3       ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
 817
 818         do{
 819             mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
 820             if (mb_type < 0){
 821                 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
 822                 return SLICE_ERROR;
 823             }
 824
 825             mb_type= h263_mb_type_b_map[ mb_type ];
 826         }while(!mb_type);
 827
 828         s->mb_intra = IS_INTRA(mb_type);
 829         if(HAS_CBP(mb_type)){
 830             s->bdsp.clear_blocks(s->block[0]);
 831             cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
 832             if(s->mb_intra){
 833                 dquant = IS_QUANT(mb_type);
 834                 goto intra;
 835             }
 836
 837             cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 838
 839             if (cbpy < 0){
 840                 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
 841                 return SLICE_ERROR;
 842             }
 843
 844             if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
 845                 cbpy ^= 0xF;
 846
 847             cbp = (cbpc & 3) | (cbpy << 2);
 848         }else
 849             cbp=0;
 850
 851         av_assert2(!s->mb_intra);
 852
 853         if(IS_QUANT(mb_type)){
 854             h263_decode_dquant(s);
 855         }
 856
 857         if(IS_DIRECT(mb_type)){
 858             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
 859             mb_type |= set_direct_mv(s);
 860         }else{
 861             s->mv_dir = 0;
 862             s->mv_type= MV_TYPE_16X16;
 863 //FIXME UMV
 864
 865             if(USES_LIST(mb_type, 0)){
 866                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 867                 s->mv_dir = MV_DIR_FORWARD;
 868
 869                 if (s->umvplus)
 870                     mx = h263p_decode_umotion(s, pred_x);
 871                 else
 872                     mx = ff_h263_decode_motion(s, pred_x, 1);
 873                 if (mx >= 0xffff)
 874                     return SLICE_ERROR;
 875
 876                 if (s->umvplus)
 877                     my = h263p_decode_umotion(s, pred_y);
 878                 else
 879                     my = ff_h263_decode_motion(s, pred_y, 1);
 880                 if (my >= 0xffff)
 881                     return SLICE_ERROR;
 882
 883                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 884                     skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 885
 886                 s->mv[0][0][0] = mx;
 887                 s->mv[0][0][1] = my;
 888                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
 889                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
 890             }
 891
 892             if(USES_LIST(mb_type, 1)){
 893                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &pred_x, &pred_y);
 894                 s->mv_dir |= MV_DIR_BACKWARD;
 895
 896                 if (s->umvplus)
 897                     mx = h263p_decode_umotion(s, pred_x);
 898                 else
 899                     mx = ff_h263_decode_motion(s, pred_x, 1);
 900                 if (mx >= 0xffff)
 901                     return SLICE_ERROR;
 902
 903                 if (s->umvplus)
 904                     my = h263p_decode_umotion(s, pred_y);
 905                 else
 906                     my = ff_h263_decode_motion(s, pred_y, 1);
 907                 if (my >= 0xffff)
 908                     return SLICE_ERROR;
 909
 910                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 911                     skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 912
 913                 s->mv[1][0][0] = mx;
 914                 s->mv[1][0][1] = my;
 915                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
 916                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
 917             }
 918         }
 919
 920         s->current_picture.mb_type[xy] = mb_type;
 921     } else { /* I-Frame */
 922         do{
 923             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 924             if (cbpc < 0){
 925                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
 926                 return SLICE_ERROR;
 927             }
 928         }while(cbpc == 8);
 929
 930         s->bdsp.clear_blocks(s->block[0]);
 931
 932         dquant = cbpc & 4;
 933         s->mb_intra = 1;
 934 intra:
 935         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 936         if (s->h263_aic) {
 937             s->ac_pred = get_bits1(&s->gb);
 938             if(s->ac_pred){
 939                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
 940
 941                 s->h263_aic_dir = get_bits1(&s->gb);
 942             }
 943         }else
 944             s->ac_pred = 0;
 945
 946         if(s->pb_frame && get_bits1(&s->gb))
 947             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
 948         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 949         if(cbpy<0){
 950             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
 951             return SLICE_ERROR;
 952         }
 953         cbp = (cbpc & 3) | (cbpy << 2);
 954         if (dquant) {
 955             h263_decode_dquant(s);
 956         }
 957
 958         pb_mv_count += !!s->pb_frame;
 959     }
 960
 961     while(pb_mv_count--){
 962         ff_h263_decode_motion(s, 0, 1);
 963         ff_h263_decode_motion(s, 0, 1);
 964     }
 965
 966     /* decode each block */
 967     for (i = 0; i < 6; i++) {
 968         if (h263_decode_block(s, block[i], i, cbp&32) < 0)
 969             return -1;
 970         cbp+=cbp;
 971     }
 972
 973     if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
 974         return -1;
 975     if(s->obmc && !s->mb_intra){
 976         if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
 977             preview_obmc(s);
 978     }
 979 end:
 980
 981     if (get_bits_left(&s->gb) < 0)
 982         return AVERROR_INVALIDDATA;
 983
 984         /* per-MB end of slice check */
 985     {
 986         int v= show_bits(&s->gb, 16);
 987
 988         if (get_bits_left(&s->gb) < 16) {
 989             v >>= 16 - get_bits_left(&s->gb);
 990         }
 991
 992         if(v==0)
 993             return SLICE_END;
 994     }
 995
 996     return SLICE_OK;
 997 }
 998
 999 /* Most is hardcoded; should extend to handle all H.263 streams. */
1000 int ff_h263_decode_picture_header(MpegEncContext *s)
1001 {
1002     int format, width, height, i, ret;
1003     uint32_t startcode;
1004
1005     align_get_bits(&s->gb);
1006
1007     if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
1008          av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
1009     }
1010
1011     startcode= get_bits(&s->gb, 22-8);
1012
1013     for(i= get_bits_left(&s->gb); i>24; i-=8) {
1014         startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
1015
1016         if(startcode == 0x20)
1017             break;
1018     }
1019
1020     if (startcode != 0x20) {
1021         av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
1022         return -1;
1023     }
1024     /* temporal reference */
1025     i = get_bits(&s->gb, 8); /* picture timestamp */
1026
1027     i -= (i - (s->picture_number & 0xFF) + 128) & ~0xFF;
1028
1029     s->picture_number= (s->picture_number&~0xFF) + i;
1030
1031     /* PTYPE starts here */
1032     if (check_marker(s->avctx, &s->gb, "in PTYPE") != 1) {
1033         return -1;
1034     }
1035     if (get_bits1(&s->gb) != 0) {
1036         av_log(s->avctx, AV_LOG_ERROR, "Bad H.263 id\n");
1037         return -1;      /* H.263 id */
1038     }
1039     skip_bits1(&s->gb);         /* split screen off */
1040     skip_bits1(&s->gb);         /* camera  off */
1041     skip_bits1(&s->gb);         /* freeze picture release off */
1042
1043     format = get_bits(&s->gb, 3);
1044     /*
1045         0    forbidden
1046         1    sub-QCIF
1047         10   QCIF
1048         7       extended PTYPE (PLUSPTYPE)
1049     */
1050
1051     if (format != 7 && format != 6) {
1052         s->h263_plus = 0;
1053         /* H.263v1 */
1054         width = ff_h263_format[format][0];
1055         height = ff_h263_format[format][1];
1056         if (!width)
1057             return -1;
1058
1059         s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
1060
1061         s->h263_long_vectors = get_bits1(&s->gb);
1062
1063         if (get_bits1(&s->gb) != 0) {
1064             av_log(s->avctx, AV_LOG_ERROR, "H.263 SAC not supported\n");
1065             return -1; /* SAC: off */
1066         }
1067         s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
1068         s->unrestricted_mv = s->h263_long_vectors || s->obmc;
1069
1070         s->pb_frame = get_bits1(&s->gb);
1071         s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
1072         skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
1073
1074         s->width = width;
1075         s->height = height;
1076         s->avctx->sample_aspect_ratio= (AVRational){12,11};
1077         s->avctx->framerate = (AVRational){ 30000, 1001 };
1078     } else {
1079         int ufep;
1080
1081         /* H.263v2 */
1082         s->h263_plus = 1;
1083         ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
1084
1085         /* ufep other than 0 and 1 are reserved */
1086         if (ufep == 1) {
1087             /* OPPTYPE */
1088             format = get_bits(&s->gb, 3);
1089             ff_dlog(s->avctx, "ufep=1, format: %d\n", format);
1090             s->custom_pcf= get_bits1(&s->gb);
1091             s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
1092             if (get_bits1(&s->gb) != 0) {
1093                 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
1094             }
1095             s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
1096             s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
1097             s->loop_filter= get_bits1(&s->gb);
1098             s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
1099             if(s->avctx->lowres)
1100                 s->loop_filter = 0;
1101
1102             s->h263_slice_structured= get_bits1(&s->gb);
1103             if (get_bits1(&s->gb) != 0) {
1104                 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
1105             }
1106             if (get_bits1(&s->gb) != 0) {
1107                 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
1108             }
1109             s->alt_inter_vlc= get_bits1(&s->gb);
1110             s->modified_quant= get_bits1(&s->gb);
1111             if(s->modified_quant)
1112                 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
1113
1114             skip_bits(&s->gb, 1); /* Prevent start code emulation */
1115
1116             skip_bits(&s->gb, 3); /* Reserved */
1117         } else if (ufep != 0) {
1118             av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
1119             return -1;
1120         }
1121
1122         /* MPPTYPE */
1123         s->pict_type = get_bits(&s->gb, 3);
1124         switch(s->pict_type){
1125         case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
1126         case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
1127         case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
1128         case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
1129         case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
1130         default:
1131             return -1;
1132         }
1133         skip_bits(&s->gb, 2);
1134         s->no_rounding = get_bits1(&s->gb);
1135         skip_bits(&s->gb, 4);
1136
1137         /* Get the picture dimensions */
1138         if (ufep) {
1139             if (format == 6) {
1140                 /* Custom Picture Format (CPFMT) */
1141                 s->aspect_ratio_info = get_bits(&s->gb, 4);
1142                 ff_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
1143                 /* aspect ratios:
1144                 0 - forbidden
1145                 1 - 1:1
1146                 2 - 12:11 (CIF 4:3)
1147                 3 - 10:11 (525-type 4:3)
1148                 4 - 16:11 (CIF 16:9)
1149                 5 - 40:33 (525-type 16:9)
1150                 6-14 - reserved
1151                 */
1152                 width = (get_bits(&s->gb, 9) + 1) * 4;
1153                 check_marker(s->avctx, &s->gb, "in dimensions");
1154                 height = get_bits(&s->gb, 9) * 4;
1155                 ff_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1156                 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1157                     /* expected dimensions */
1158                     s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1159                     s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1160                 }else{
1161                     s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1162                 }
1163             } else {
1164                 width = ff_h263_format[format][0];
1165                 height = ff_h263_format[format][1];
1166                 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1167             }
1168             s->avctx->sample_aspect_ratio.den <<= s->ehc_mode;
1169             if ((width == 0) || (height == 0))
1170                 return -1;
1171             s->width = width;
1172             s->height = height;
1173
1174             if(s->custom_pcf){
1175                 int gcd;
1176                 s->avctx->framerate.num  = 1800000;
1177                 s->avctx->framerate.den  = 1000 + get_bits1(&s->gb);
1178                 s->avctx->framerate.den *= get_bits(&s->gb, 7);
1179                 if(s->avctx->framerate.den == 0){
1180                     av_log(s, AV_LOG_ERROR, "zero framerate\n");
1181                     return -1;
1182                 }
1183                 gcd= av_gcd(s->avctx->framerate.den, s->avctx->framerate.num);
1184                 s->avctx->framerate.den /= gcd;
1185                 s->avctx->framerate.num /= gcd;
1186             }else{
1187                 s->avctx->framerate = (AVRational){ 30000, 1001 };
1188             }
1189         }
1190
1191         if(s->custom_pcf){
1192             skip_bits(&s->gb, 2); //extended Temporal reference
1193         }
1194
1195         if (ufep) {
1196             if (s->umvplus) {
1197                 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1198                     skip_bits1(&s->gb);
1199             }
1200             if(s->h263_slice_structured){
1201                 if (get_bits1(&s->gb) != 0) {
1202                     av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1203                 }
1204                 if (get_bits1(&s->gb) != 0) {
1205                     av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1206                 }
1207             }
1208             if (s->pict_type == AV_PICTURE_TYPE_B) {
1209                 skip_bits(&s->gb, 4); //ELNUM
1210                 if (ufep == 1) {
1211                     skip_bits(&s->gb, 4); // RLNUM
1212                 }
1213             }
1214         }
1215
1216         s->qscale = get_bits(&s->gb, 5);
1217     }
1218
1219     if ((ret = av_image_check_size(s->width, s->height, 0, s)) < 0)
1220         return ret;
1221
1222     if (!(s->avctx->flags2 & AV_CODEC_FLAG2_CHUNKS)) {
1223         if ((s->width * s->height / 256 / 8) > get_bits_left(&s->gb))
1224             return AVERROR_INVALIDDATA;
1225     }
1226
1227     s->mb_width = (s->width  + 15) / 16;
1228     s->mb_height = (s->height  + 15) / 16;
1229     s->mb_num = s->mb_width * s->mb_height;
1230
1231     if (s->pb_frame) {
1232         skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1233         if (s->custom_pcf)
1234             skip_bits(&s->gb, 2); //extended Temporal reference
1235         skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1236     }
1237
1238     if (s->pict_type!=AV_PICTURE_TYPE_B) {
1239         s->time            = s->picture_number;
1240         s->pp_time         = s->time - s->last_non_b_time;
1241         s->last_non_b_time = s->time;
1242     }else{
1243         s->time    = s->picture_number;
1244         s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1245         if (s->pp_time <=s->pb_time ||
1246             s->pp_time <= s->pp_time - s->pb_time ||
1247             s->pp_time <= 0){
1248             s->pp_time = 2;
1249             s->pb_time = 1;
1250         }
1251         ff_mpeg4_init_direct_mv(s);
1252     }
1253
1254     /* PEI */
1255     if (skip_1stop_8data_bits(&s->gb) < 0)
1256         return AVERROR_INVALIDDATA;
1257
1258     if(s->h263_slice_structured){
1259         if (check_marker(s->avctx, &s->gb, "SEPB1") != 1) {
1260             return -1;
1261         }
1262
1263         ff_h263_decode_mba(s);
1264
1265         if (check_marker(s->avctx, &s->gb, "SEPB2") != 1) {
1266             return -1;
1267         }
1268     }
1269     s->f_code = 1;
1270
1271     if (s->pict_type == AV_PICTURE_TYPE_B)
1272         s->low_delay = 0;
1273
1274     if(s->h263_aic){
1275          s->y_dc_scale_table=
1276          s->c_dc_scale_table= ff_aic_dc_scale_table;
1277     }else{
1278         s->y_dc_scale_table=
1279         s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1280     }
1281
1282         ff_h263_show_pict_info(s);
1283     if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1284         int i,j;
1285         for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1286         av_log(s->avctx, AV_LOG_DEBUG, "\n");
1287         for(i=0; i<13; i++){
1288             for(j=0; j<3; j++){
1289                 int v= get_bits(&s->gb, 8);
1290                 v |= get_sbits(&s->gb, 8) * (1 << 8);
1291                 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1292             }
1293             av_log(s->avctx, AV_LOG_DEBUG, "\n");
1294         }
1295         for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1296     }
1297
1298     return 0;
1299 }