src/third_party/ffmpeg/libavcodec/ituh263dec.c

   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 #include <limits.h>
  31
  32 #include "libavutil/attributes.h"
  33 #include "libavutil/internal.h"
  34 #include "libavutil/mathematics.h"
  35 #include "avcodec.h"
  36 #include "mpegvideo.h"
  37 #include "h263.h"
  38 #include "mathops.h"
  39 #include "mpegutils.h"
  40 #include "unary.h"
  41 #include "flv.h"
  42 #include "mpeg4video.h"
  43
  44 // The defines below define the number of bits that are read at once for
  45 // reading vlc values. Changing these may improve speed and data cache needs
  46 // be aware though that decreasing them may need the number of stages that is
  47 // passed to get_vlc* to be increased.
  48 #define MV_VLC_BITS 9
  49 #define H263_MBTYPE_B_VLC_BITS 6
  50 #define CBPC_B_VLC_BITS 3
  51
  52 static const int h263_mb_type_b_map[15]= {
  53     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  54     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
  55     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
  56                       MB_TYPE_L0                                 | MB_TYPE_16x16,
  57                       MB_TYPE_L0   | MB_TYPE_CBP                 | MB_TYPE_16x16,
  58                       MB_TYPE_L0   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  59                       MB_TYPE_L1                                 | MB_TYPE_16x16,
  60                       MB_TYPE_L1   | MB_TYPE_CBP                 | MB_TYPE_16x16,
  61                       MB_TYPE_L1   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  62                       MB_TYPE_L0L1                               | MB_TYPE_16x16,
  63                       MB_TYPE_L0L1 | MB_TYPE_CBP                 | MB_TYPE_16x16,
  64                       MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
  65     0, //stuffing
  66     MB_TYPE_INTRA4x4                | MB_TYPE_CBP,
  67     MB_TYPE_INTRA4x4                | MB_TYPE_CBP | MB_TYPE_QUANT,
  68 };
  69
  70 void ff_h263_show_pict_info(MpegEncContext *s){
  71     if(s->avctx->debug&FF_DEBUG_PICT_INFO){
  72     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",
  73          s->qscale, av_get_picture_type_char(s->pict_type),
  74          s->gb.size_in_bits, 1-s->no_rounding,
  75          s->obmc ? " AP" : "",
  76          s->umvplus ? " UMV" : "",
  77          s->h263_long_vectors ? " LONG" : "",
  78          s->h263_plus ? " +" : "",
  79          s->h263_aic ? " AIC" : "",
  80          s->alt_inter_vlc ? " AIV" : "",
  81          s->modified_quant ? " MQ" : "",
  82          s->loop_filter ? " LOOP" : "",
  83          s->h263_slice_structured ? " SS" : "",
  84          s->avctx->time_base.den, s->avctx->time_base.num
  85     );
  86     }
  87 }
  88
  89 /***********************************************/
  90 /* decoding */
  91
  92 VLC ff_h263_intra_MCBPC_vlc;
  93 VLC ff_h263_inter_MCBPC_vlc;
  94 VLC ff_h263_cbpy_vlc;
  95 static VLC mv_vlc;
  96 static VLC h263_mbtype_b_vlc;
  97 static VLC cbpc_b_vlc;
  98
  99 /* init vlcs */
 100
 101 /* XXX: find a better solution to handle static init */
 102 av_cold void ff_h263_decode_init_vlc(void)
 103 {
 104     static volatile int done = 0;
 105
 106     if (!done) {
 107         INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
 108                  ff_h263_intra_MCBPC_bits, 1, 1,
 109                  ff_h263_intra_MCBPC_code, 1, 1, 72);
 110         INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
 111                  ff_h263_inter_MCBPC_bits, 1, 1,
 112                  ff_h263_inter_MCBPC_code, 1, 1, 198);
 113         INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
 114                  &ff_h263_cbpy_tab[0][1], 2, 1,
 115                  &ff_h263_cbpy_tab[0][0], 2, 1, 64);
 116         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
 117                  &ff_mvtab[0][1], 2, 1,
 118                  &ff_mvtab[0][0], 2, 1, 538);
 119         ff_init_rl(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
 120         ff_init_rl(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
 121         INIT_VLC_RL(ff_h263_rl_inter, 554);
 122         INIT_VLC_RL(ff_rl_intra_aic, 554);
 123         INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
 124                  &ff_h263_mbtype_b_tab[0][1], 2, 1,
 125                  &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
 126         INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
 127                  &ff_cbpc_b_tab[0][1], 2, 1,
 128                  &ff_cbpc_b_tab[0][0], 2, 1, 8);
 129         done = 1;
 130     }
 131 }
 132
 133 int ff_h263_decode_mba(MpegEncContext *s)
 134 {
 135     int i, mb_pos;
 136
 137     for(i=0; i<6; i++){
 138         if(s->mb_num-1 <= ff_mba_max[i]) break;
 139     }
 140     mb_pos= get_bits(&s->gb, ff_mba_length[i]);
 141     s->mb_x= mb_pos % s->mb_width;
 142     s->mb_y= mb_pos / s->mb_width;
 143
 144     return mb_pos;
 145 }
 146
 147 /**
 148  * Decode the group of blocks header or slice header.
 149  * @return <0 if an error occurred
 150  */
 151 static int h263_decode_gob_header(MpegEncContext *s)
 152 {
 153     unsigned int val, gob_number;
 154     int left;
 155
 156     /* Check for GOB Start Code */
 157     val = show_bits(&s->gb, 16);
 158     if(val)
 159         return -1;
 160
 161         /* We have a GBSC probably with GSTUFF */
 162     skip_bits(&s->gb, 16); /* Drop the zeros */
 163     left= get_bits_left(&s->gb);
 164     //MN: we must check the bits left or we might end in a infinite loop (or segfault)
 165     for(;left>13; left--){
 166         if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
 167     }
 168     if(left<=13)
 169         return -1;
 170
 171     if(s->h263_slice_structured){
 172         if(get_bits1(&s->gb)==0)
 173             return -1;
 174
 175         ff_h263_decode_mba(s);
 176
 177         if(s->mb_num > 1583)
 178             if(get_bits1(&s->gb)==0)
 179                 return -1;
 180
 181         s->qscale = get_bits(&s->gb, 5); /* SQUANT */
 182         if(get_bits1(&s->gb)==0)
 183             return -1;
 184         skip_bits(&s->gb, 2); /* GFID */
 185     }else{
 186         gob_number = get_bits(&s->gb, 5); /* GN */
 187         s->mb_x= 0;
 188         s->mb_y= s->gob_index* gob_number;
 189         skip_bits(&s->gb, 2); /* GFID */
 190         s->qscale = get_bits(&s->gb, 5); /* GQUANT */
 191     }
 192
 193     if(s->mb_y >= s->mb_height)
 194         return -1;
 195
 196     if(s->qscale==0)
 197         return -1;
 198
 199     return 0;
 200 }
 201
 202 /**
 203  * Decode the group of blocks / video packet header.
 204  * @return bit position of the resync_marker, or <0 if none was found
 205  */
 206 int ff_h263_resync(MpegEncContext *s){
 207     int left, pos, ret;
 208
 209     if(s->codec_id==AV_CODEC_ID_MPEG4){
 210         skip_bits1(&s->gb);
 211         align_get_bits(&s->gb);
 212     }
 213
 214     if(show_bits(&s->gb, 16)==0){
 215         pos= get_bits_count(&s->gb);
 216         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
 217             ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
 218         else
 219             ret= h263_decode_gob_header(s);
 220         if(ret>=0)
 221             return pos;
 222     }
 223     //OK, it's not where it is supposed to be ...
 224     s->gb= s->last_resync_gb;
 225     align_get_bits(&s->gb);
 226     left= get_bits_left(&s->gb);
 227
 228     for(;left>16+1+5+5; left-=8){
 229         if(show_bits(&s->gb, 16)==0){
 230             GetBitContext bak= s->gb;
 231
 232             pos= get_bits_count(&s->gb);
 233             if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
 234                 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
 235             else
 236                 ret= h263_decode_gob_header(s);
 237             if(ret>=0)
 238                 return pos;
 239
 240             s->gb= bak;
 241         }
 242         skip_bits(&s->gb, 8);
 243     }
 244
 245     return -1;
 246 }
 247
 248 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
 249 {
 250     int code, val, sign, shift;
 251     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 252
 253     if (code == 0)
 254         return pred;
 255     if (code < 0)
 256         return 0xffff;
 257
 258     sign = get_bits1(&s->gb);
 259     shift = f_code - 1;
 260     val = code;
 261     if (shift) {
 262         val = (val - 1) << shift;
 263         val |= get_bits(&s->gb, shift);
 264         val++;
 265     }
 266     if (sign)
 267         val = -val;
 268     val += pred;
 269
 270     /* modulo decoding */
 271     if (!s->h263_long_vectors) {
 272         val = sign_extend(val, 5 + f_code);
 273     } else {
 274         /* horrible h263 long vector mode */
 275         if (pred < -31 && val < -63)
 276             val += 64;
 277         if (pred > 32 && val > 63)
 278             val -= 64;
 279
 280     }
 281     return val;
 282 }
 283
 284
 285 /* Decode RVLC of H.263+ UMV */
 286 static int h263p_decode_umotion(MpegEncContext * s, int pred)
 287 {
 288    int code = 0, sign;
 289
 290    if (get_bits1(&s->gb)) /* Motion difference = 0 */
 291       return pred;
 292
 293    code = 2 + get_bits1(&s->gb);
 294
 295    while (get_bits1(&s->gb))
 296    {
 297       code <<= 1;
 298       code += get_bits1(&s->gb);
 299    }
 300    sign = code & 1;
 301    code >>= 1;
 302
 303    code = (sign) ? (pred - code) : (pred + code);
 304    av_dlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
 305    return code;
 306
 307 }
 308
 309 /**
 310  * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
 311  */
 312 static void preview_obmc(MpegEncContext *s){
 313     GetBitContext gb= s->gb;
 314
 315     int cbpc, i, pred_x, pred_y, mx, my;
 316     int16_t *mot_val;
 317     const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
 318     const int stride= s->b8_stride*2;
 319
 320     for(i=0; i<4; i++)
 321         s->block_index[i]+= 2;
 322     for(i=4; i<6; i++)
 323         s->block_index[i]+= 1;
 324     s->mb_x++;
 325
 326     av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
 327
 328     do{
 329         if (get_bits1(&s->gb)) {
 330             /* skip mb */
 331             mot_val = s->current_picture.motion_val[0][s->block_index[0]];
 332             mot_val[0       ]= mot_val[2       ]=
 333             mot_val[0+stride]= mot_val[2+stride]= 0;
 334             mot_val[1       ]= mot_val[3       ]=
 335             mot_val[1+stride]= mot_val[3+stride]= 0;
 336
 337             s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 338             goto end;
 339         }
 340         cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 341     }while(cbpc == 20);
 342
 343     if(cbpc & 4){
 344         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 345     }else{
 346         get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 347         if (cbpc & 8) {
 348             if(s->modified_quant){
 349                 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
 350                 else                  skip_bits(&s->gb, 5);
 351             }else
 352                 skip_bits(&s->gb, 2);
 353         }
 354
 355         if ((cbpc & 16) == 0) {
 356                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 357                 /* 16x16 motion prediction */
 358                 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 359                 if (s->umvplus)
 360                    mx = h263p_decode_umotion(s, pred_x);
 361                 else
 362                    mx = ff_h263_decode_motion(s, pred_x, 1);
 363
 364                 if (s->umvplus)
 365                    my = h263p_decode_umotion(s, pred_y);
 366                 else
 367                    my = ff_h263_decode_motion(s, pred_y, 1);
 368
 369                 mot_val[0       ]= mot_val[2       ]=
 370                 mot_val[0+stride]= mot_val[2+stride]= mx;
 371                 mot_val[1       ]= mot_val[3       ]=
 372                 mot_val[1+stride]= mot_val[3+stride]= my;
 373         } else {
 374             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 375             for(i=0;i<4;i++) {
 376                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 377                 if (s->umvplus)
 378                   mx = h263p_decode_umotion(s, pred_x);
 379                 else
 380                   mx = ff_h263_decode_motion(s, pred_x, 1);
 381
 382                 if (s->umvplus)
 383                   my = h263p_decode_umotion(s, pred_y);
 384                 else
 385                   my = ff_h263_decode_motion(s, pred_y, 1);
 386                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 387                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 388                 mot_val[0] = mx;
 389                 mot_val[1] = my;
 390             }
 391         }
 392     }
 393 end:
 394
 395     for(i=0; i<4; i++)
 396         s->block_index[i]-= 2;
 397     for(i=4; i<6; i++)
 398         s->block_index[i]-= 1;
 399     s->mb_x--;
 400
 401     s->gb= gb;
 402 }
 403
 404 static void h263_decode_dquant(MpegEncContext *s){
 405     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 406
 407     if(s->modified_quant){
 408         if(get_bits1(&s->gb))
 409             s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
 410         else
 411             s->qscale= get_bits(&s->gb, 5);
 412     }else
 413         s->qscale += quant_tab[get_bits(&s->gb, 2)];
 414     ff_set_qscale(s, s->qscale);
 415 }
 416
 417 static int h263_decode_block(MpegEncContext * s, int16_t * block,
 418                              int n, int coded)
 419 {
 420     int code, level, i, j, last, run;
 421     RLTable *rl = &ff_h263_rl_inter;
 422     const uint8_t *scan_table;
 423     GetBitContext gb= s->gb;
 424
 425     scan_table = s->intra_scantable.permutated;
 426     if (s->h263_aic && s->mb_intra) {
 427         rl = &ff_rl_intra_aic;
 428         i = 0;
 429         if (s->ac_pred) {
 430             if (s->h263_aic_dir)
 431                 scan_table = s->intra_v_scantable.permutated; /* left */
 432             else
 433                 scan_table = s->intra_h_scantable.permutated; /* top */
 434         }
 435     } else if (s->mb_intra) {
 436         /* DC coef */
 437         if(s->codec_id == AV_CODEC_ID_RV10){
 438 #if CONFIG_RV10_DECODER
 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 #endif
 459         }else{
 460             level = get_bits(&s->gb, 8);
 461             if((level&0x7F) == 0){
 462                 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
 463                 if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
 464                     return -1;
 465             }
 466             if (level == 255)
 467                 level = 128;
 468         }
 469         block[0] = level;
 470         i = 1;
 471     } else {
 472         i = 0;
 473     }
 474     if (!coded) {
 475         if (s->mb_intra && s->h263_aic)
 476             goto not_coded;
 477         s->block_last_index[n] = i - 1;
 478         return 0;
 479     }
 480 retry:
 481     for(;;) {
 482         code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
 483         if (code < 0){
 484             av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
 485             return -1;
 486         }
 487         if (code == rl->n) {
 488             /* escape */
 489             if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
 490                 ff_flv2_decode_ac_esc(&s->gb, &level, &run, &last);
 491             } else {
 492                 last = get_bits1(&s->gb);
 493                 run = get_bits(&s->gb, 6);
 494                 level = (int8_t)get_bits(&s->gb, 8);
 495                 if(level == -128){
 496                     if (s->codec_id == AV_CODEC_ID_RV10) {
 497                         /* XXX: should patch encoder too */
 498                         level = get_sbits(&s->gb, 12);
 499                     }else{
 500                         level = get_bits(&s->gb, 5);
 501                         level |= get_sbits(&s->gb, 6)<<5;
 502                     }
 503                 }
 504             }
 505         } else {
 506             run = rl->table_run[code];
 507             level = rl->table_level[code];
 508             last = code >= rl->last;
 509             if (get_bits1(&s->gb))
 510                 level = -level;
 511         }
 512         i += run;
 513         if (i >= 64){
 514             if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
 515                 //Looks like a hack but no, it's the way it is supposed to work ...
 516                 rl = &ff_rl_intra_aic;
 517                 i = 0;
 518                 s->gb= gb;
 519                 s->bdsp.clear_block(block);
 520                 goto retry;
 521             }
 522             av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
 523             return -1;
 524         }
 525         j = scan_table[i];
 526         block[j] = level;
 527         if (last)
 528             break;
 529         i++;
 530     }
 531 not_coded:
 532     if (s->mb_intra && s->h263_aic) {
 533         ff_h263_pred_acdc(s, block, n);
 534         i = 63;
 535     }
 536     s->block_last_index[n] = i;
 537     return 0;
 538 }
 539
 540 static int h263_skip_b_part(MpegEncContext *s, int cbp)
 541 {
 542     LOCAL_ALIGNED_16(int16_t, dblock, [64]);
 543     int i, mbi;
 544     int bli[6];
 545
 546     /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
 547      * but real value should be restored in order to be used later (in OBMC condition)
 548      */
 549     mbi = s->mb_intra;
 550     memcpy(bli, s->block_last_index, sizeof(bli));
 551     s->mb_intra = 0;
 552     for (i = 0; i < 6; i++) {
 553         if (h263_decode_block(s, dblock, i, cbp&32) < 0)
 554             return -1;
 555         cbp+=cbp;
 556     }
 557     s->mb_intra = mbi;
 558     memcpy(s->block_last_index, bli, sizeof(bli));
 559     return 0;
 560 }
 561
 562 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
 563 {
 564     int c, mv = 1;
 565
 566     if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
 567         c = get_bits1(gb);
 568         if (pb_frame == 2 && c)
 569             mv = !get_bits1(gb);
 570     } else { // h.263 Annex M improved PB-frame
 571         mv = get_unary(gb, 0, 4) + 1;
 572         c = mv & 1;
 573         mv = !!(mv & 2);
 574     }
 575     if(c)
 576         *cbpb = get_bits(gb, 6);
 577     return mv;
 578 }
 579
 580 int ff_h263_decode_mb(MpegEncContext *s,
 581                       int16_t block[6][64])
 582 {
 583     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
 584     int16_t *mot_val;
 585     const int xy= s->mb_x + s->mb_y * s->mb_stride;
 586     int cbpb = 0, pb_mv_count = 0;
 587
 588     av_assert2(!s->h263_pred);
 589
 590     if (s->pict_type == AV_PICTURE_TYPE_P) {
 591         do{
 592             if (get_bits1(&s->gb)) {
 593                 /* skip mb */
 594                 s->mb_intra = 0;
 595                 for(i=0;i<6;i++)
 596                     s->block_last_index[i] = -1;
 597                 s->mv_dir = MV_DIR_FORWARD;
 598                 s->mv_type = MV_TYPE_16X16;
 599                 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 600                 s->mv[0][0][0] = 0;
 601                 s->mv[0][0][1] = 0;
 602                 s->mb_skipped = !(s->obmc | s->loop_filter);
 603                 goto end;
 604             }
 605             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 606             if (cbpc < 0){
 607                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
 608                 return -1;
 609             }
 610         }while(cbpc == 20);
 611
 612         s->bdsp.clear_blocks(s->block[0]);
 613
 614         dquant = cbpc & 8;
 615         s->mb_intra = ((cbpc & 4) != 0);
 616         if (s->mb_intra) goto intra;
 617
 618         if(s->pb_frame && get_bits1(&s->gb))
 619             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
 620         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 621
 622         if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
 623             cbpy ^= 0xF;
 624
 625         cbp = (cbpc & 3) | (cbpy << 2);
 626         if (dquant) {
 627             h263_decode_dquant(s);
 628         }
 629
 630         s->mv_dir = MV_DIR_FORWARD;
 631         if ((cbpc & 16) == 0) {
 632             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 633             /* 16x16 motion prediction */
 634             s->mv_type = MV_TYPE_16X16;
 635             ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 636             if (s->umvplus)
 637                mx = h263p_decode_umotion(s, pred_x);
 638             else
 639                mx = ff_h263_decode_motion(s, pred_x, 1);
 640
 641             if (mx >= 0xffff)
 642                 return -1;
 643
 644             if (s->umvplus)
 645                my = h263p_decode_umotion(s, pred_y);
 646             else
 647                my = ff_h263_decode_motion(s, pred_y, 1);
 648
 649             if (my >= 0xffff)
 650                 return -1;
 651             s->mv[0][0][0] = mx;
 652             s->mv[0][0][1] = my;
 653
 654             if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 655                skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 656         } else {
 657             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 658             s->mv_type = MV_TYPE_8X8;
 659             for(i=0;i<4;i++) {
 660                 mot_val = ff_h263_pred_motion(s, i, 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                 if (mx >= 0xffff)
 666                     return -1;
 667
 668                 if (s->umvplus)
 669                   my = h263p_decode_umotion(s, pred_y);
 670                 else
 671                   my = ff_h263_decode_motion(s, pred_y, 1);
 672                 if (my >= 0xffff)
 673                     return -1;
 674                 s->mv[0][i][0] = mx;
 675                 s->mv[0][i][1] = my;
 676                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
 677                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
 678                 mot_val[0] = mx;
 679                 mot_val[1] = my;
 680             }
 681         }
 682     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
 683         int mb_type;
 684         const int stride= s->b8_stride;
 685         int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
 686         int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
 687 //        const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
 688
 689         //FIXME ugly
 690         mot_val0[0       ]= mot_val0[2       ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
 691         mot_val0[1       ]= mot_val0[3       ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
 692         mot_val1[0       ]= mot_val1[2       ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
 693         mot_val1[1       ]= mot_val1[3       ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
 694
 695         do{
 696             mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
 697             if (mb_type < 0){
 698                 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
 699                 return -1;
 700             }
 701
 702             mb_type= h263_mb_type_b_map[ mb_type ];
 703         }while(!mb_type);
 704
 705         s->mb_intra = IS_INTRA(mb_type);
 706         if(HAS_CBP(mb_type)){
 707             s->bdsp.clear_blocks(s->block[0]);
 708             cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
 709             if(s->mb_intra){
 710                 dquant = IS_QUANT(mb_type);
 711                 goto intra;
 712             }
 713
 714             cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 715
 716             if (cbpy < 0){
 717                 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
 718                 return -1;
 719             }
 720
 721             if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
 722                 cbpy ^= 0xF;
 723
 724             cbp = (cbpc & 3) | (cbpy << 2);
 725         }else
 726             cbp=0;
 727
 728         av_assert2(!s->mb_intra);
 729
 730         if(IS_QUANT(mb_type)){
 731             h263_decode_dquant(s);
 732         }
 733
 734         if(IS_DIRECT(mb_type)){
 735             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
 736             mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0);
 737         }else{
 738             s->mv_dir = 0;
 739             s->mv_type= MV_TYPE_16X16;
 740 //FIXME UMV
 741
 742             if(USES_LIST(mb_type, 0)){
 743                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &mx, &my);
 744                 s->mv_dir = MV_DIR_FORWARD;
 745
 746                 mx = ff_h263_decode_motion(s, mx, 1);
 747                 my = ff_h263_decode_motion(s, my, 1);
 748
 749                 s->mv[0][0][0] = mx;
 750                 s->mv[0][0][1] = my;
 751                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
 752                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
 753             }
 754
 755             if(USES_LIST(mb_type, 1)){
 756                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &mx, &my);
 757                 s->mv_dir |= MV_DIR_BACKWARD;
 758
 759                 mx = ff_h263_decode_motion(s, mx, 1);
 760                 my = ff_h263_decode_motion(s, my, 1);
 761
 762                 s->mv[1][0][0] = mx;
 763                 s->mv[1][0][1] = my;
 764                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
 765                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
 766             }
 767         }
 768
 769         s->current_picture.mb_type[xy] = mb_type;
 770     } else { /* I-Frame */
 771         do{
 772             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 773             if (cbpc < 0){
 774                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
 775                 return -1;
 776             }
 777         }while(cbpc == 8);
 778
 779         s->bdsp.clear_blocks(s->block[0]);
 780
 781         dquant = cbpc & 4;
 782         s->mb_intra = 1;
 783 intra:
 784         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 785         if (s->h263_aic) {
 786             s->ac_pred = get_bits1(&s->gb);
 787             if(s->ac_pred){
 788                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
 789
 790                 s->h263_aic_dir = get_bits1(&s->gb);
 791             }
 792         }else
 793             s->ac_pred = 0;
 794
 795         if(s->pb_frame && get_bits1(&s->gb))
 796             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
 797         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 798         if(cbpy<0){
 799             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
 800             return -1;
 801         }
 802         cbp = (cbpc & 3) | (cbpy << 2);
 803         if (dquant) {
 804             h263_decode_dquant(s);
 805         }
 806
 807         pb_mv_count += !!s->pb_frame;
 808     }
 809
 810     while(pb_mv_count--){
 811         ff_h263_decode_motion(s, 0, 1);
 812         ff_h263_decode_motion(s, 0, 1);
 813     }
 814
 815     /* decode each block */
 816     for (i = 0; i < 6; i++) {
 817         if (h263_decode_block(s, block[i], i, cbp&32) < 0)
 818             return -1;
 819         cbp+=cbp;
 820     }
 821
 822     if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
 823         return -1;
 824     if(s->obmc && !s->mb_intra){
 825         if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
 826             preview_obmc(s);
 827     }
 828 end:
 829
 830         /* per-MB end of slice check */
 831     {
 832         int v= show_bits(&s->gb, 16);
 833
 834         if (get_bits_left(&s->gb) < 16) {
 835             v >>= 16 - get_bits_left(&s->gb);
 836         }
 837
 838         if(v==0)
 839             return SLICE_END;
 840     }
 841
 842     return SLICE_OK;
 843 }
 844
 845 /* most is hardcoded. should extend to handle all h263 streams */
 846 int ff_h263_decode_picture_header(MpegEncContext *s)
 847 {
 848     int format, width, height, i;
 849     uint32_t startcode;
 850
 851     align_get_bits(&s->gb);
 852
 853     if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
 854          av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
 855     }
 856
 857     startcode= get_bits(&s->gb, 22-8);
 858
 859     for(i= get_bits_left(&s->gb); i>24; i-=8) {
 860         startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
 861
 862         if(startcode == 0x20)
 863             break;
 864     }
 865
 866     if (startcode != 0x20) {
 867         av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
 868         return -1;
 869     }
 870     /* temporal reference */
 871     i = get_bits(&s->gb, 8); /* picture timestamp */
 872     if( (s->picture_number&~0xFF)+i < s->picture_number)
 873         i+= 256;
 874     s->picture_number= (s->picture_number&~0xFF) + i;
 875
 876     /* PTYPE starts here */
 877     if (get_bits1(&s->gb) != 1) {
 878         /* marker */
 879         av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
 880         return -1;
 881     }
 882     if (get_bits1(&s->gb) != 0) {
 883         av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
 884         return -1;      /* h263 id */
 885     }
 886     skip_bits1(&s->gb);         /* split screen off */
 887     skip_bits1(&s->gb);         /* camera  off */
 888     skip_bits1(&s->gb);         /* freeze picture release off */
 889
 890     format = get_bits(&s->gb, 3);
 891     /*
 892         0    forbidden
 893         1    sub-QCIF
 894         10   QCIF
 895         7       extended PTYPE (PLUSPTYPE)
 896     */
 897
 898     if (format != 7 && format != 6) {
 899         s->h263_plus = 0;
 900         /* H.263v1 */
 901         width = ff_h263_format[format][0];
 902         height = ff_h263_format[format][1];
 903         if (!width)
 904             return -1;
 905
 906         s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
 907
 908         s->h263_long_vectors = get_bits1(&s->gb);
 909
 910         if (get_bits1(&s->gb) != 0) {
 911             av_log(s->avctx, AV_LOG_ERROR, "H263 SAC not supported\n");
 912             return -1; /* SAC: off */
 913         }
 914         s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
 915         s->unrestricted_mv = s->h263_long_vectors || s->obmc;
 916
 917         s->pb_frame = get_bits1(&s->gb);
 918         s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
 919         skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
 920
 921         s->width = width;
 922         s->height = height;
 923         s->avctx->sample_aspect_ratio= (AVRational){12,11};
 924         s->avctx->time_base= (AVRational){1001, 30000};
 925     } else {
 926         int ufep;
 927
 928         /* H.263v2 */
 929         s->h263_plus = 1;
 930         ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
 931
 932         /* ufep other than 0 and 1 are reserved */
 933         if (ufep == 1) {
 934             /* OPPTYPE */
 935             format = get_bits(&s->gb, 3);
 936             av_dlog(s->avctx, "ufep=1, format: %d\n", format);
 937             s->custom_pcf= get_bits1(&s->gb);
 938             s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
 939             if (get_bits1(&s->gb) != 0) {
 940                 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
 941             }
 942             s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
 943             s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
 944             s->loop_filter= get_bits1(&s->gb);
 945             s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
 946             if(s->avctx->lowres)
 947                 s->loop_filter = 0;
 948
 949             s->h263_slice_structured= get_bits1(&s->gb);
 950             if (get_bits1(&s->gb) != 0) {
 951                 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
 952             }
 953             if (get_bits1(&s->gb) != 0) {
 954                 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
 955             }
 956             s->alt_inter_vlc= get_bits1(&s->gb);
 957             s->modified_quant= get_bits1(&s->gb);
 958             if(s->modified_quant)
 959                 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
 960
 961             skip_bits(&s->gb, 1); /* Prevent start code emulation */
 962
 963             skip_bits(&s->gb, 3); /* Reserved */
 964         } else if (ufep != 0) {
 965             av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
 966             return -1;
 967         }
 968
 969         /* MPPTYPE */
 970         s->pict_type = get_bits(&s->gb, 3);
 971         switch(s->pict_type){
 972         case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
 973         case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
 974         case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
 975         case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
 976         case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
 977         default:
 978             return -1;
 979         }
 980         skip_bits(&s->gb, 2);
 981         s->no_rounding = get_bits1(&s->gb);
 982         skip_bits(&s->gb, 4);
 983
 984         /* Get the picture dimensions */
 985         if (ufep) {
 986             if (format == 6) {
 987                 /* Custom Picture Format (CPFMT) */
 988                 s->aspect_ratio_info = get_bits(&s->gb, 4);
 989                 av_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
 990                 /* aspect ratios:
 991                 0 - forbidden
 992                 1 - 1:1
 993                 2 - 12:11 (CIF 4:3)
 994                 3 - 10:11 (525-type 4:3)
 995                 4 - 16:11 (CIF 16:9)
 996                 5 - 40:33 (525-type 16:9)
 997                 6-14 - reserved
 998                 */
 999                 width = (get_bits(&s->gb, 9) + 1) * 4;
1000                 skip_bits1(&s->gb);
1001                 height = get_bits(&s->gb, 9) * 4;
1002                 av_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1003                 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1004                     /* aspected dimensions */
1005                     s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1006                     s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1007                 }else{
1008                     s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1009                 }
1010             } else {
1011                 width = ff_h263_format[format][0];
1012                 height = ff_h263_format[format][1];
1013                 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1014             }
1015             s->avctx->sample_aspect_ratio.den <<= s->ehc_mode;
1016             if ((width == 0) || (height == 0))
1017                 return -1;
1018             s->width = width;
1019             s->height = height;
1020
1021             if(s->custom_pcf){
1022                 int gcd;
1023                 s->avctx->time_base.den= 1800000;
1024                 s->avctx->time_base.num= 1000 + get_bits1(&s->gb);
1025                 s->avctx->time_base.num*= get_bits(&s->gb, 7);
1026                 if(s->avctx->time_base.num == 0){
1027                     av_log(s, AV_LOG_ERROR, "zero framerate\n");
1028                     return -1;
1029                 }
1030                 gcd= av_gcd(s->avctx->time_base.den, s->avctx->time_base.num);
1031                 s->avctx->time_base.den /= gcd;
1032                 s->avctx->time_base.num /= gcd;
1033             }else{
1034                 s->avctx->time_base= (AVRational){1001, 30000};
1035             }
1036         }
1037
1038         if(s->custom_pcf){
1039             skip_bits(&s->gb, 2); //extended Temporal reference
1040         }
1041
1042         if (ufep) {
1043             if (s->umvplus) {
1044                 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1045                     skip_bits1(&s->gb);
1046             }
1047             if(s->h263_slice_structured){
1048                 if (get_bits1(&s->gb) != 0) {
1049                     av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1050                 }
1051                 if (get_bits1(&s->gb) != 0) {
1052                     av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1053                 }
1054             }
1055         }
1056
1057         s->qscale = get_bits(&s->gb, 5);
1058     }
1059
1060     if (s->width == 0 || s->height == 0) {
1061         av_log(s->avctx, AV_LOG_ERROR, "dimensions 0\n");
1062         return -1;
1063     }
1064     s->mb_width = (s->width  + 15) / 16;
1065     s->mb_height = (s->height  + 15) / 16;
1066     s->mb_num = s->mb_width * s->mb_height;
1067
1068     if (s->pb_frame) {
1069         skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1070         if (s->custom_pcf)
1071             skip_bits(&s->gb, 2); //extended Temporal reference
1072         skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1073     }
1074
1075     if (s->pict_type!=AV_PICTURE_TYPE_B) {
1076         s->time            = s->picture_number;
1077         s->pp_time         = s->time - s->last_non_b_time;
1078         s->last_non_b_time = s->time;
1079     }else{
1080         s->time    = s->picture_number;
1081         s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1082         if (s->pp_time <=s->pb_time ||
1083             s->pp_time <= s->pp_time - s->pb_time ||
1084             s->pp_time <= 0){
1085             s->pp_time = 2;
1086             s->pb_time = 1;
1087         }
1088         ff_mpeg4_init_direct_mv(s);
1089     }
1090
1091     /* PEI */
1092     if (skip_1stop_8data_bits(&s->gb) < 0)
1093         return AVERROR_INVALIDDATA;
1094
1095     if(s->h263_slice_structured){
1096         if (get_bits1(&s->gb) != 1) {
1097             av_log(s->avctx, AV_LOG_ERROR, "SEPB1 marker missing\n");
1098             return -1;
1099         }
1100
1101         ff_h263_decode_mba(s);
1102
1103         if (get_bits1(&s->gb) != 1) {
1104             av_log(s->avctx, AV_LOG_ERROR, "SEPB2 marker missing\n");
1105             return -1;
1106         }
1107     }
1108     s->f_code = 1;
1109
1110     if(s->h263_aic){
1111          s->y_dc_scale_table=
1112          s->c_dc_scale_table= ff_aic_dc_scale_table;
1113     }else{
1114         s->y_dc_scale_table=
1115         s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1116     }
1117
1118         ff_h263_show_pict_info(s);
1119     if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1120         int i,j;
1121         for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1122         av_log(s->avctx, AV_LOG_DEBUG, "\n");
1123         for(i=0; i<13; i++){
1124             for(j=0; j<3; j++){
1125                 int v= get_bits(&s->gb, 8);
1126                 v |= get_sbits(&s->gb, 8)<<8;
1127                 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1128             }
1129             av_log(s->avctx, AV_LOG_DEBUG, "\n");
1130         }
1131         for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1132     }
1133
1134     return 0;
1135 }