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   1 /*
   2  * MPEG4 decoder.
   3  * Copyright (c) 2000,2001 Fabrice Bellard
   4  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "mpegvideo.h"
  24 #include "mpeg4video.h"
  25 #include "h263.h"
  26 #include "thread.h"
  27
  28 // The defines below define the number of bits that are read at once for
  29 // reading vlc values. Changing these may improve speed and data cache needs
  30 // be aware though that decreasing them may need the number of stages that is
  31 // passed to get_vlc* to be increased.
  32 #define SPRITE_TRAJ_VLC_BITS 6
  33 #define DC_VLC_BITS 9
  34 #define MB_TYPE_B_VLC_BITS 4
  35
  36
  37 static VLC dc_lum, dc_chrom;
  38 static VLC sprite_trajectory;
  39 static VLC mb_type_b_vlc;
  40
  41 static const int mb_type_b_map[4]= {
  42     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  43     MB_TYPE_L0L1 | MB_TYPE_16x16,
  44     MB_TYPE_L1 | MB_TYPE_16x16,
  45     MB_TYPE_L0 | MB_TYPE_16x16,
  46 };
  47
  48 /**
  49  * Predict the ac.
  50  * @param n block index (0-3 are luma, 4-5 are chroma)
  51  * @param dir the ac prediction direction
  52  */
  53 void ff_mpeg4_pred_ac(MpegEncContext * s, DCTELEM *block, int n,
  54                       int dir)
  55 {
  56     int i;
  57     int16_t *ac_val, *ac_val1;
  58     int8_t * const qscale_table = s->current_picture.f.qscale_table;
  59
  60     /* find prediction */
  61     ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
  62     ac_val1 = ac_val;
  63     if (s->ac_pred) {
  64         if (dir == 0) {
  65             const int xy= s->mb_x-1 + s->mb_y*s->mb_stride;
  66             /* left prediction */
  67             ac_val -= 16;
  68
  69             if(s->mb_x==0 || s->qscale == qscale_table[xy] || n==1 || n==3){
  70                 /* same qscale */
  71                 for(i=1;i<8;i++) {
  72                     block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
  73                 }
  74             }else{
  75                 /* different qscale, we must rescale */
  76                 for(i=1;i<8;i++) {
  77                     block[s->dsp.idct_permutation[i<<3]] += ROUNDED_DIV(ac_val[i]*qscale_table[xy], s->qscale);
  78                 }
  79             }
  80         } else {
  81             const int xy= s->mb_x + s->mb_y*s->mb_stride - s->mb_stride;
  82             /* top prediction */
  83             ac_val -= 16 * s->block_wrap[n];
  84
  85             if(s->mb_y==0 || s->qscale == qscale_table[xy] || n==2 || n==3){
  86                 /* same qscale */
  87                 for(i=1;i<8;i++) {
  88                     block[s->dsp.idct_permutation[i]] += ac_val[i + 8];
  89                 }
  90             }else{
  91                 /* different qscale, we must rescale */
  92                 for(i=1;i<8;i++) {
  93                     block[s->dsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8]*qscale_table[xy], s->qscale);
  94                 }
  95             }
  96         }
  97     }
  98     /* left copy */
  99     for(i=1;i<8;i++)
 100         ac_val1[i    ] = block[s->dsp.idct_permutation[i<<3]];
 101
 102     /* top copy */
 103     for(i=1;i<8;i++)
 104         ac_val1[8 + i] = block[s->dsp.idct_permutation[i   ]];
 105
 106 }
 107
 108 /**
 109  * check if the next stuff is a resync marker or the end.
 110  * @return 0 if not
 111  */
 112 static inline int mpeg4_is_resync(MpegEncContext *s){
 113     int bits_count= get_bits_count(&s->gb);
 114     int v= show_bits(&s->gb, 16);
 115
 116     if(s->workaround_bugs&FF_BUG_NO_PADDING){
 117         return 0;
 118     }
 119
 120     while(v<=0xFF){
 121         if(s->pict_type==AV_PICTURE_TYPE_B || (v>>(8-s->pict_type)!=1) || s->partitioned_frame)
 122             break;
 123         skip_bits(&s->gb, 8+s->pict_type);
 124         bits_count+= 8+s->pict_type;
 125         v= show_bits(&s->gb, 16);
 126     }
 127
 128     if(bits_count + 8 >= s->gb.size_in_bits){
 129         v>>=8;
 130         v|= 0x7F >> (7-(bits_count&7));
 131
 132         if(v==0x7F)
 133             return 1;
 134     }else{
 135         if(v == ff_mpeg4_resync_prefix[bits_count&7]){
 136             int len;
 137             GetBitContext gb= s->gb;
 138
 139             skip_bits(&s->gb, 1);
 140             align_get_bits(&s->gb);
 141
 142             for(len=0; len<32; len++){
 143                 if(get_bits1(&s->gb)) break;
 144             }
 145
 146             s->gb= gb;
 147
 148             if(len>=ff_mpeg4_get_video_packet_prefix_length(s))
 149                 return 1;
 150         }
 151     }
 152     return 0;
 153 }
 154
 155 static void mpeg4_decode_sprite_trajectory(MpegEncContext * s, GetBitContext *gb)
 156 {
 157     int i;
 158     int a= 2<<s->sprite_warping_accuracy;
 159     int rho= 3-s->sprite_warping_accuracy;
 160     int r=16/a;
 161     const int vop_ref[4][2]= {{0,0}, {s->width,0}, {0, s->height}, {s->width, s->height}}; // only true for rectangle shapes
 162     int d[4][2]={{0,0}, {0,0}, {0,0}, {0,0}};
 163     int sprite_ref[4][2];
 164     int virtual_ref[2][2];
 165     int w2, h2, w3, h3;
 166     int alpha=0, beta=0;
 167     int w= s->width;
 168     int h= s->height;
 169     int min_ab;
 170
 171     for(i=0; i<s->num_sprite_warping_points; i++){
 172         int length;
 173         int x=0, y=0;
 174
 175         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 176         if(length){
 177             x= get_xbits(gb, length);
 178         }
 179         if(!(s->divx_version==500 && s->divx_build==413)) skip_bits1(gb); /* marker bit */
 180
 181         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 182         if(length){
 183             y=get_xbits(gb, length);
 184         }
 185         skip_bits1(gb); /* marker bit */
 186         s->sprite_traj[i][0]= d[i][0]= x;
 187         s->sprite_traj[i][1]= d[i][1]= y;
 188     }
 189     for(; i<4; i++)
 190         s->sprite_traj[i][0]= s->sprite_traj[i][1]= 0;
 191
 192     while((1<<alpha)<w) alpha++;
 193     while((1<<beta )<h) beta++; // there seems to be a typo in the mpeg4 std for the definition of w' and h'
 194     w2= 1<<alpha;
 195     h2= 1<<beta;
 196
 197 // Note, the 4th point isn't used for GMC
 198     if(s->divx_version==500 && s->divx_build==413){
 199         sprite_ref[0][0]= a*vop_ref[0][0] + d[0][0];
 200         sprite_ref[0][1]= a*vop_ref[0][1] + d[0][1];
 201         sprite_ref[1][0]= a*vop_ref[1][0] + d[0][0] + d[1][0];
 202         sprite_ref[1][1]= a*vop_ref[1][1] + d[0][1] + d[1][1];
 203         sprite_ref[2][0]= a*vop_ref[2][0] + d[0][0] + d[2][0];
 204         sprite_ref[2][1]= a*vop_ref[2][1] + d[0][1] + d[2][1];
 205     } else {
 206         sprite_ref[0][0]= (a>>1)*(2*vop_ref[0][0] + d[0][0]);
 207         sprite_ref[0][1]= (a>>1)*(2*vop_ref[0][1] + d[0][1]);
 208         sprite_ref[1][0]= (a>>1)*(2*vop_ref[1][0] + d[0][0] + d[1][0]);
 209         sprite_ref[1][1]= (a>>1)*(2*vop_ref[1][1] + d[0][1] + d[1][1]);
 210         sprite_ref[2][0]= (a>>1)*(2*vop_ref[2][0] + d[0][0] + d[2][0]);
 211         sprite_ref[2][1]= (a>>1)*(2*vop_ref[2][1] + d[0][1] + d[2][1]);
 212     }
 213 /*    sprite_ref[3][0]= (a>>1)*(2*vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
 214     sprite_ref[3][1]= (a>>1)*(2*vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
 215
 216 // this is mostly identical to the mpeg4 std (and is totally unreadable because of that ...)
 217 // perhaps it should be reordered to be more readable ...
 218 // the idea behind this virtual_ref mess is to be able to use shifts later per pixel instead of divides
 219 // so the distance between points is converted from w&h based to w2&h2 based which are of the 2^x form
 220     virtual_ref[0][0]= 16*(vop_ref[0][0] + w2)
 221         + ROUNDED_DIV(((w - w2)*(r*sprite_ref[0][0] - 16*vop_ref[0][0]) + w2*(r*sprite_ref[1][0] - 16*vop_ref[1][0])),w);
 222     virtual_ref[0][1]= 16*vop_ref[0][1]
 223         + ROUNDED_DIV(((w - w2)*(r*sprite_ref[0][1] - 16*vop_ref[0][1]) + w2*(r*sprite_ref[1][1] - 16*vop_ref[1][1])),w);
 224     virtual_ref[1][0]= 16*vop_ref[0][0]
 225         + ROUNDED_DIV(((h - h2)*(r*sprite_ref[0][0] - 16*vop_ref[0][0]) + h2*(r*sprite_ref[2][0] - 16*vop_ref[2][0])),h);
 226     virtual_ref[1][1]= 16*(vop_ref[0][1] + h2)
 227         + ROUNDED_DIV(((h - h2)*(r*sprite_ref[0][1] - 16*vop_ref[0][1]) + h2*(r*sprite_ref[2][1] - 16*vop_ref[2][1])),h);
 228
 229     switch(s->num_sprite_warping_points)
 230     {
 231         case 0:
 232             s->sprite_offset[0][0]= 0;
 233             s->sprite_offset[0][1]= 0;
 234             s->sprite_offset[1][0]= 0;
 235             s->sprite_offset[1][1]= 0;
 236             s->sprite_delta[0][0]= a;
 237             s->sprite_delta[0][1]= 0;
 238             s->sprite_delta[1][0]= 0;
 239             s->sprite_delta[1][1]= a;
 240             s->sprite_shift[0]= 0;
 241             s->sprite_shift[1]= 0;
 242             break;
 243         case 1: //GMC only
 244             s->sprite_offset[0][0]= sprite_ref[0][0] - a*vop_ref[0][0];
 245             s->sprite_offset[0][1]= sprite_ref[0][1] - a*vop_ref[0][1];
 246             s->sprite_offset[1][0]= ((sprite_ref[0][0]>>1)|(sprite_ref[0][0]&1)) - a*(vop_ref[0][0]/2);
 247             s->sprite_offset[1][1]= ((sprite_ref[0][1]>>1)|(sprite_ref[0][1]&1)) - a*(vop_ref[0][1]/2);
 248             s->sprite_delta[0][0]= a;
 249             s->sprite_delta[0][1]= 0;
 250             s->sprite_delta[1][0]= 0;
 251             s->sprite_delta[1][1]= a;
 252             s->sprite_shift[0]= 0;
 253             s->sprite_shift[1]= 0;
 254             break;
 255         case 2:
 256             s->sprite_offset[0][0]= (sprite_ref[0][0]<<(alpha+rho))
 257                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][0])
 258                                                   + ( r*sprite_ref[0][1] - virtual_ref[0][1])*(-vop_ref[0][1])
 259                                                   + (1<<(alpha+rho-1));
 260             s->sprite_offset[0][1]= (sprite_ref[0][1]<<(alpha+rho))
 261                                                   + (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-vop_ref[0][0])
 262                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][1])
 263                                                   + (1<<(alpha+rho-1));
 264             s->sprite_offset[1][0]= ( (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][0] + 1)
 265                                      +( r*sprite_ref[0][1] - virtual_ref[0][1])*(-2*vop_ref[0][1] + 1)
 266                                      +2*w2*r*sprite_ref[0][0]
 267                                      - 16*w2
 268                                      + (1<<(alpha+rho+1)));
 269             s->sprite_offset[1][1]= ( (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-2*vop_ref[0][0] + 1)
 270                                      +(-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][1] + 1)
 271                                      +2*w2*r*sprite_ref[0][1]
 272                                      - 16*w2
 273                                      + (1<<(alpha+rho+1)));
 274             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 275             s->sprite_delta[0][1]=   (+r*sprite_ref[0][1] - virtual_ref[0][1]);
 276             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1]);
 277             s->sprite_delta[1][1]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 278
 279             s->sprite_shift[0]= alpha+rho;
 280             s->sprite_shift[1]= alpha+rho+2;
 281             break;
 282         case 3:
 283             min_ab= FFMIN(alpha, beta);
 284             w3= w2>>min_ab;
 285             h3= h2>>min_ab;
 286             s->sprite_offset[0][0]=  (sprite_ref[0][0]<<(alpha+beta+rho-min_ab))
 287                                    + (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-vop_ref[0][0])
 288                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-vop_ref[0][1])
 289                                    + (1<<(alpha+beta+rho-min_ab-1));
 290             s->sprite_offset[0][1]=  (sprite_ref[0][1]<<(alpha+beta+rho-min_ab))
 291                                    + (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-vop_ref[0][0])
 292                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-vop_ref[0][1])
 293                                    + (1<<(alpha+beta+rho-min_ab-1));
 294             s->sprite_offset[1][0]=  (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-2*vop_ref[0][0] + 1)
 295                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-2*vop_ref[0][1] + 1)
 296                                    + 2*w2*h3*r*sprite_ref[0][0]
 297                                    - 16*w2*h3
 298                                    + (1<<(alpha+beta+rho-min_ab+1));
 299             s->sprite_offset[1][1]=  (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-2*vop_ref[0][0] + 1)
 300                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-2*vop_ref[0][1] + 1)
 301                                    + 2*w2*h3*r*sprite_ref[0][1]
 302                                    - 16*w2*h3
 303                                    + (1<<(alpha+beta+rho-min_ab+1));
 304             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3;
 305             s->sprite_delta[0][1]=   (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3;
 306             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3;
 307             s->sprite_delta[1][1]=   (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3;
 308
 309             s->sprite_shift[0]= alpha + beta + rho - min_ab;
 310             s->sprite_shift[1]= alpha + beta + rho - min_ab + 2;
 311             break;
 312     }
 313     /* try to simplify the situation */
 314     if(   s->sprite_delta[0][0] == a<<s->sprite_shift[0]
 315        && s->sprite_delta[0][1] == 0
 316        && s->sprite_delta[1][0] == 0
 317        && s->sprite_delta[1][1] == a<<s->sprite_shift[0])
 318     {
 319         s->sprite_offset[0][0]>>=s->sprite_shift[0];
 320         s->sprite_offset[0][1]>>=s->sprite_shift[0];
 321         s->sprite_offset[1][0]>>=s->sprite_shift[1];
 322         s->sprite_offset[1][1]>>=s->sprite_shift[1];
 323         s->sprite_delta[0][0]= a;
 324         s->sprite_delta[0][1]= 0;
 325         s->sprite_delta[1][0]= 0;
 326         s->sprite_delta[1][1]= a;
 327         s->sprite_shift[0]= 0;
 328         s->sprite_shift[1]= 0;
 329         s->real_sprite_warping_points=1;
 330     }
 331     else{
 332         int shift_y= 16 - s->sprite_shift[0];
 333         int shift_c= 16 - s->sprite_shift[1];
 334         for(i=0; i<2; i++){
 335             s->sprite_offset[0][i]<<= shift_y;
 336             s->sprite_offset[1][i]<<= shift_c;
 337             s->sprite_delta[0][i]<<= shift_y;
 338             s->sprite_delta[1][i]<<= shift_y;
 339             s->sprite_shift[i]= 16;
 340         }
 341         s->real_sprite_warping_points= s->num_sprite_warping_points;
 342     }
 343 }
 344
 345 /**
 346  * Decode the next video packet.
 347  * @return <0 if something went wrong
 348  */
 349 int ff_mpeg4_decode_video_packet_header(MpegEncContext *s)
 350 {
 351     int mb_num_bits= av_log2(s->mb_num - 1) + 1;
 352     int header_extension=0, mb_num, len;
 353
 354     /* is there enough space left for a video packet + header */
 355     if( get_bits_count(&s->gb) > s->gb.size_in_bits-20) return -1;
 356
 357     for(len=0; len<32; len++){
 358         if(get_bits1(&s->gb)) break;
 359     }
 360
 361     if(len!=ff_mpeg4_get_video_packet_prefix_length(s)){
 362         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
 363         return -1;
 364     }
 365
 366     if(s->shape != RECT_SHAPE){
 367         header_extension= get_bits1(&s->gb);
 368         //FIXME more stuff here
 369     }
 370
 371     mb_num= get_bits(&s->gb, mb_num_bits);
 372     if(mb_num>=s->mb_num){
 373         av_log(s->avctx, AV_LOG_ERROR, "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
 374         return -1;
 375     }
 376     if(s->pict_type == AV_PICTURE_TYPE_B){
 377         int mb_x = 0, mb_y = 0;
 378
 379         while (s->next_picture.f.mbskip_table[s->mb_index2xy[mb_num]]) {
 380             if (!mb_x)
 381                 ff_thread_await_progress(&s->next_picture_ptr->f, mb_y++, 0);
 382             mb_num++;
 383             if (++mb_x == s->mb_width) mb_x = 0;
 384         }
 385         if(mb_num >= s->mb_num) return -1; // slice contains just skipped MBs which where already decoded
 386     }
 387
 388     s->mb_x= mb_num % s->mb_width;
 389     s->mb_y= mb_num / s->mb_width;
 390
 391     if(s->shape != BIN_ONLY_SHAPE){
 392         int qscale= get_bits(&s->gb, s->quant_precision);
 393         if(qscale)
 394             s->chroma_qscale=s->qscale= qscale;
 395     }
 396
 397     if(s->shape == RECT_SHAPE){
 398         header_extension= get_bits1(&s->gb);
 399     }
 400     if(header_extension){
 401         int time_incr=0;
 402
 403         while (get_bits1(&s->gb) != 0)
 404             time_incr++;
 405
 406         check_marker(&s->gb, "before time_increment in video packed header");
 407         skip_bits(&s->gb, s->time_increment_bits); /* time_increment */
 408         check_marker(&s->gb, "before vop_coding_type in video packed header");
 409
 410         skip_bits(&s->gb, 2); /* vop coding type */
 411         //FIXME not rect stuff here
 412
 413         if(s->shape != BIN_ONLY_SHAPE){
 414             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
 415 //FIXME don't just ignore everything
 416             if(s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 417                 mpeg4_decode_sprite_trajectory(s, &s->gb);
 418                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
 419             }
 420
 421             //FIXME reduced res stuff here
 422
 423             if (s->pict_type != AV_PICTURE_TYPE_I) {
 424                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
 425                 if(f_code==0){
 426                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (f_code=0)\n");
 427                 }
 428             }
 429             if (s->pict_type == AV_PICTURE_TYPE_B) {
 430                 int b_code = get_bits(&s->gb, 3);
 431                 if(b_code==0){
 432                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (b_code=0)\n");
 433                 }
 434             }
 435         }
 436     }
 437     //FIXME new-pred stuff
 438
 439     return 0;
 440 }
 441
 442 /**
 443  * Get the average motion vector for a GMC MB.
 444  * @param n either 0 for the x component or 1 for y
 445  * @return the average MV for a GMC MB
 446  */
 447 static inline int get_amv(MpegEncContext *s, int n){
 448     int x, y, mb_v, sum, dx, dy, shift;
 449     int len = 1 << (s->f_code + 4);
 450     const int a= s->sprite_warping_accuracy;
 451
 452     if(s->workaround_bugs & FF_BUG_AMV)
 453         len >>= s->quarter_sample;
 454
 455     if(s->real_sprite_warping_points==1){
 456         if(s->divx_version==500 && s->divx_build==413)
 457             sum= s->sprite_offset[0][n] / (1<<(a - s->quarter_sample));
 458         else
 459             sum= RSHIFT(s->sprite_offset[0][n]<<s->quarter_sample, a);
 460     }else{
 461         dx= s->sprite_delta[n][0];
 462         dy= s->sprite_delta[n][1];
 463         shift= s->sprite_shift[0];
 464         if(n) dy -= 1<<(shift + a + 1);
 465         else  dx -= 1<<(shift + a + 1);
 466         mb_v= s->sprite_offset[0][n] + dx*s->mb_x*16 + dy*s->mb_y*16;
 467
 468         sum=0;
 469         for(y=0; y<16; y++){
 470             int v;
 471
 472             v= mb_v + dy*y;
 473             //XXX FIXME optimize
 474             for(x=0; x<16; x++){
 475                 sum+= v>>shift;
 476                 v+= dx;
 477             }
 478         }
 479         sum= RSHIFT(sum, a+8-s->quarter_sample);
 480     }
 481
 482     if      (sum < -len) sum= -len;
 483     else if (sum >= len) sum= len-1;
 484
 485     return sum;
 486 }
 487
 488 /**
 489  * Decode the dc value.
 490  * @param n block index (0-3 are luma, 4-5 are chroma)
 491  * @param dir_ptr the prediction direction will be stored here
 492  * @return the quantized dc
 493  */
 494 static inline int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
 495 {
 496     int level, code;
 497
 498     if (n < 4)
 499         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
 500     else
 501         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
 502     if (code < 0 || code > 9 /* && s->nbit<9 */){
 503         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
 504         return -1;
 505     }
 506     if (code == 0) {
 507         level = 0;
 508     } else {
 509         if(IS_3IV1){
 510             if(code==1)
 511                 level= 2*get_bits1(&s->gb)-1;
 512             else{
 513                 if(get_bits1(&s->gb))
 514                     level = get_bits(&s->gb, code-1) + (1<<(code-1));
 515                 else
 516                     level = -get_bits(&s->gb, code-1) - (1<<(code-1));
 517             }
 518         }else{
 519             level = get_xbits(&s->gb, code);
 520         }
 521
 522         if (code > 8){
 523             if(get_bits1(&s->gb)==0){ /* marker */
 524                 if(s->err_recognition&AV_EF_BITSTREAM){
 525                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
 526                     return -1;
 527                 }
 528             }
 529         }
 530     }
 531
 532     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
 533 }
 534
 535 /**
 536  * Decode first partition.
 537  * @return number of MBs decoded or <0 if an error occurred
 538  */
 539 static int mpeg4_decode_partition_a(MpegEncContext *s){
 540     int mb_num;
 541     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 542
 543     /* decode first partition */
 544     mb_num=0;
 545     s->first_slice_line=1;
 546     for(; s->mb_y<s->mb_height; s->mb_y++){
 547         ff_init_block_index(s);
 548         for(; s->mb_x<s->mb_width; s->mb_x++){
 549             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 550             int cbpc;
 551             int dir=0;
 552
 553             mb_num++;
 554             ff_update_block_index(s);
 555             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 556                 s->first_slice_line=0;
 557
 558             if(s->pict_type==AV_PICTURE_TYPE_I){
 559                 int i;
 560
 561                 do{
 562                     if(show_bits_long(&s->gb, 19)==DC_MARKER){
 563                         return mb_num-1;
 564                     }
 565
 566                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 567                     if (cbpc < 0){
 568                         av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 569                         return -1;
 570                     }
 571                 }while(cbpc == 8);
 572
 573                 s->cbp_table[xy]= cbpc & 3;
 574                 s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
 575                 s->mb_intra = 1;
 576
 577                 if(cbpc & 4) {
 578                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 579                 }
 580                 s->current_picture.f.qscale_table[xy]= s->qscale;
 581
 582                 s->mbintra_table[xy]= 1;
 583                 for(i=0; i<6; i++){
 584                     int dc_pred_dir;
 585                     int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 586                     if(dc < 0){
 587                         av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 588                         return -1;
 589                     }
 590                     dir<<=1;
 591                     if(dc_pred_dir) dir|=1;
 592                 }
 593                 s->pred_dir_table[xy]= dir;
 594             }else{ /* P/S_TYPE */
 595                 int mx, my, pred_x, pred_y, bits;
 596                 int16_t * const mot_val = s->current_picture.f.motion_val[0][s->block_index[0]];
 597                 const int stride= s->b8_stride*2;
 598
 599 try_again:
 600                 bits= show_bits(&s->gb, 17);
 601                 if(bits==MOTION_MARKER){
 602                     return mb_num-1;
 603                 }
 604                 skip_bits1(&s->gb);
 605                 if(bits&0x10000){
 606                     /* skip mb */
 607                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 608                         s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 609                         mx= get_amv(s, 0);
 610                         my= get_amv(s, 1);
 611                     }else{
 612                         s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 613                         mx=my=0;
 614                     }
 615                     mot_val[0       ]= mot_val[2       ]=
 616                     mot_val[0+stride]= mot_val[2+stride]= mx;
 617                     mot_val[1       ]= mot_val[3       ]=
 618                     mot_val[1+stride]= mot_val[3+stride]= my;
 619
 620                     if(s->mbintra_table[xy])
 621                         ff_clean_intra_table_entries(s);
 622                     continue;
 623                 }
 624
 625                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 626                 if (cbpc < 0){
 627                     av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 628                     return -1;
 629                 }
 630                 if(cbpc == 20)
 631                     goto try_again;
 632
 633                 s->cbp_table[xy]= cbpc&(8+3); //8 is dquant
 634
 635                 s->mb_intra = ((cbpc & 4) != 0);
 636
 637                 if(s->mb_intra){
 638                     s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
 639                     s->mbintra_table[xy]= 1;
 640                     mot_val[0       ]= mot_val[2       ]=
 641                     mot_val[0+stride]= mot_val[2+stride]= 0;
 642                     mot_val[1       ]= mot_val[3       ]=
 643                     mot_val[1+stride]= mot_val[3+stride]= 0;
 644                 }else{
 645                     if(s->mbintra_table[xy])
 646                         ff_clean_intra_table_entries(s);
 647
 648                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
 649                         s->mcsel= get_bits1(&s->gb);
 650                     else s->mcsel= 0;
 651
 652                     if ((cbpc & 16) == 0) {
 653                         /* 16x16 motion prediction */
 654
 655                         ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 656                         if(!s->mcsel){
 657                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
 658                             if (mx >= 0xffff)
 659                                 return -1;
 660
 661                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
 662                             if (my >= 0xffff)
 663                                 return -1;
 664                             s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 665                         } else {
 666                             mx = get_amv(s, 0);
 667                             my = get_amv(s, 1);
 668                             s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 669                         }
 670
 671                         mot_val[0       ]= mot_val[2       ] =
 672                         mot_val[0+stride]= mot_val[2+stride]= mx;
 673                         mot_val[1       ]= mot_val[3       ]=
 674                         mot_val[1+stride]= mot_val[3+stride]= my;
 675                     } else {
 676                         int i;
 677                         s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 678                         for(i=0;i<4;i++) {
 679                             int16_t *mot_val= ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 680                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
 681                             if (mx >= 0xffff)
 682                                 return -1;
 683
 684                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
 685                             if (my >= 0xffff)
 686                                 return -1;
 687                             mot_val[0] = mx;
 688                             mot_val[1] = my;
 689                         }
 690                     }
 691                 }
 692             }
 693         }
 694         s->mb_x= 0;
 695     }
 696
 697     return mb_num;
 698 }
 699
 700 /**
 701  * decode second partition.
 702  * @return <0 if an error occurred
 703  */
 704 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count){
 705     int mb_num=0;
 706     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 707
 708     s->mb_x= s->resync_mb_x;
 709     s->first_slice_line=1;
 710     for(s->mb_y= s->resync_mb_y; mb_num < mb_count; s->mb_y++){
 711         ff_init_block_index(s);
 712         for(; mb_num < mb_count && s->mb_x<s->mb_width; s->mb_x++){
 713             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 714
 715             mb_num++;
 716             ff_update_block_index(s);
 717             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 718                 s->first_slice_line=0;
 719
 720             if(s->pict_type==AV_PICTURE_TYPE_I){
 721                 int ac_pred= get_bits1(&s->gb);
 722                 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 723                 if(cbpy<0){
 724                     av_log(s->avctx, AV_LOG_ERROR, "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 725                     return -1;
 726                 }
 727
 728                 s->cbp_table[xy]|= cbpy<<2;
 729                 s->current_picture.f.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 730             }else{ /* P || S_TYPE */
 731                 if (IS_INTRA(s->current_picture.f.mb_type[xy])) {
 732                     int dir=0,i;
 733                     int ac_pred = get_bits1(&s->gb);
 734                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 735
 736                     if(cbpy<0){
 737                         av_log(s->avctx, AV_LOG_ERROR, "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 738                         return -1;
 739                     }
 740
 741                     if(s->cbp_table[xy] & 8) {
 742                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 743                     }
 744                     s->current_picture.f.qscale_table[xy] = s->qscale;
 745
 746                     for(i=0; i<6; i++){
 747                         int dc_pred_dir;
 748                         int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 749                         if(dc < 0){
 750                             av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 751                             return -1;
 752                         }
 753                         dir<<=1;
 754                         if(dc_pred_dir) dir|=1;
 755                     }
 756                     s->cbp_table[xy]&= 3; //remove dquant
 757                     s->cbp_table[xy]|= cbpy<<2;
 758                     s->current_picture.f.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 759                     s->pred_dir_table[xy]= dir;
 760                 } else if (IS_SKIP(s->current_picture.f.mb_type[xy])) {
 761                     s->current_picture.f.qscale_table[xy] = s->qscale;
 762                     s->cbp_table[xy]= 0;
 763                 }else{
 764                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 765
 766                     if(cbpy<0){
 767                         av_log(s->avctx, AV_LOG_ERROR, "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 768                         return -1;
 769                     }
 770
 771                     if(s->cbp_table[xy] & 8) {
 772                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 773                     }
 774                     s->current_picture.f.qscale_table[xy] = s->qscale;
 775
 776                     s->cbp_table[xy]&= 3; //remove dquant
 777                     s->cbp_table[xy]|= (cbpy^0xf)<<2;
 778                 }
 779             }
 780         }
 781         if(mb_num >= mb_count) return 0;
 782         s->mb_x= 0;
 783     }
 784     return 0;
 785 }
 786
 787 /**
 788  * Decode the first and second partition.
 789  * @return <0 if error (and sets error type in the error_status_table)
 790  */
 791 int ff_mpeg4_decode_partitions(MpegEncContext *s)
 792 {
 793     int mb_num;
 794     const int part_a_error= s->pict_type==AV_PICTURE_TYPE_I ? (ER_DC_ERROR|ER_MV_ERROR) : ER_MV_ERROR;
 795     const int part_a_end  = s->pict_type==AV_PICTURE_TYPE_I ? (ER_DC_END  |ER_MV_END)   : ER_MV_END;
 796
 797     mb_num= mpeg4_decode_partition_a(s);
 798     if(mb_num<0){
 799         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 800         return -1;
 801     }
 802
 803     if(s->resync_mb_x + s->resync_mb_y*s->mb_width + mb_num > s->mb_num){
 804         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
 805         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 806         return -1;
 807     }
 808
 809     s->mb_num_left= mb_num;
 810
 811     if(s->pict_type==AV_PICTURE_TYPE_I){
 812         while(show_bits(&s->gb, 9) == 1)
 813             skip_bits(&s->gb, 9);
 814         if(get_bits_long(&s->gb, 19)!=DC_MARKER){
 815             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first I partition at %d %d\n", s->mb_x, s->mb_y);
 816             return -1;
 817         }
 818     }else{
 819         while(show_bits(&s->gb, 10) == 1)
 820             skip_bits(&s->gb, 10);
 821         if(get_bits(&s->gb, 17)!=MOTION_MARKER){
 822             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first P partition at %d %d\n", s->mb_x, s->mb_y);
 823             return -1;
 824         }
 825     }
 826     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, part_a_end);
 827
 828     if( mpeg4_decode_partition_b(s, mb_num) < 0){
 829         if(s->pict_type==AV_PICTURE_TYPE_P)
 830             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_DC_ERROR);
 831         return -1;
 832     }else{
 833         if(s->pict_type==AV_PICTURE_TYPE_P)
 834             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_DC_END);
 835     }
 836
 837     return 0;
 838 }
 839
 840 /**
 841  * Decode a block.
 842  * @return <0 if an error occurred
 843  */
 844 static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
 845                               int n, int coded, int intra, int rvlc)
 846 {
 847     int level, i, last, run;
 848     int dc_pred_dir;
 849     RLTable * rl;
 850     RL_VLC_ELEM * rl_vlc;
 851     const uint8_t * scan_table;
 852     int qmul, qadd;
 853
 854     //Note intra & rvlc should be optimized away if this is inlined
 855
 856     if(intra) {
 857       if(s->use_intra_dc_vlc){
 858         /* DC coef */
 859         if(s->partitioned_frame){
 860             level = s->dc_val[0][ s->block_index[n] ];
 861             if(n<4) level= FASTDIV((level + (s->y_dc_scale>>1)), s->y_dc_scale);
 862             else    level= FASTDIV((level + (s->c_dc_scale>>1)), s->c_dc_scale);
 863             dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_stride]<<n)&32;
 864         }else{
 865             level = mpeg4_decode_dc(s, n, &dc_pred_dir);
 866             if (level < 0)
 867                 return -1;
 868         }
 869         block[0] = level;
 870         i = 0;
 871       }else{
 872             i = -1;
 873             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
 874       }
 875       if (!coded)
 876           goto not_coded;
 877
 878       if(rvlc){
 879           rl = &ff_rvlc_rl_intra;
 880           rl_vlc = ff_rvlc_rl_intra.rl_vlc[0];
 881       }else{
 882           rl = &ff_mpeg4_rl_intra;
 883           rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
 884       }
 885       if (s->ac_pred) {
 886           if (dc_pred_dir == 0)
 887               scan_table = s->intra_v_scantable.permutated; /* left */
 888           else
 889               scan_table = s->intra_h_scantable.permutated; /* top */
 890       } else {
 891             scan_table = s->intra_scantable.permutated;
 892       }
 893       qmul=1;
 894       qadd=0;
 895     } else {
 896         i = -1;
 897         if (!coded) {
 898             s->block_last_index[n] = i;
 899             return 0;
 900         }
 901         if(rvlc) rl = &ff_rvlc_rl_inter;
 902         else     rl = &ff_h263_rl_inter;
 903
 904         scan_table = s->intra_scantable.permutated;
 905
 906         if(s->mpeg_quant){
 907             qmul=1;
 908             qadd=0;
 909             if(rvlc){
 910                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[0];
 911             }else{
 912                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
 913             }
 914         }else{
 915             qmul = s->qscale << 1;
 916             qadd = (s->qscale - 1) | 1;
 917             if(rvlc){
 918                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[s->qscale];
 919             }else{
 920                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
 921             }
 922         }
 923     }
 924   {
 925     OPEN_READER(re, &s->gb);
 926     for(;;) {
 927         UPDATE_CACHE(re, &s->gb);
 928         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
 929         if (level==0) {
 930           /* escape */
 931           if(rvlc){
 932                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 933                     av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in rvlc esc\n");
 934                     return -1;
 935                 }; SKIP_CACHE(re, &s->gb, 1);
 936
 937                 last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 938                 run=   SHOW_UBITS(re, &s->gb, 6);
 939                 SKIP_COUNTER(re, &s->gb, 1+1+6);
 940                 UPDATE_CACHE(re, &s->gb);
 941
 942                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 943                     av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in rvlc esc\n");
 944                     return -1;
 945                 }; SKIP_CACHE(re, &s->gb, 1);
 946
 947                 level= SHOW_UBITS(re, &s->gb, 11); SKIP_CACHE(re, &s->gb, 11);
 948
 949                 if(SHOW_UBITS(re, &s->gb, 5)!=0x10){
 950                     av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
 951                     return -1;
 952                 }; SKIP_CACHE(re, &s->gb, 5);
 953
 954                 level=  level * qmul + qadd;
 955                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 956                 SKIP_COUNTER(re, &s->gb, 1+11+5+1);
 957
 958                 i+= run + 1;
 959                 if(last) i+=192;
 960           }else{
 961             int cache;
 962             cache= GET_CACHE(re, &s->gb);
 963
 964             if(IS_3IV1)
 965                 cache ^= 0xC0000000;
 966
 967             if (cache&0x80000000) {
 968                 if (cache&0x40000000) {
 969                     /* third escape */
 970                     SKIP_CACHE(re, &s->gb, 2);
 971                     last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 972                     run=   SHOW_UBITS(re, &s->gb, 6);
 973                     SKIP_COUNTER(re, &s->gb, 2+1+6);
 974                     UPDATE_CACHE(re, &s->gb);
 975
 976                     if(IS_3IV1){
 977                         level= SHOW_SBITS(re, &s->gb, 12); LAST_SKIP_BITS(re, &s->gb, 12);
 978                     }else{
 979                         if(SHOW_UBITS(re, &s->gb, 1)==0){
 980                             av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in 3. esc\n");
 981                             return -1;
 982                         }; SKIP_CACHE(re, &s->gb, 1);
 983
 984                         level= SHOW_SBITS(re, &s->gb, 12); SKIP_CACHE(re, &s->gb, 12);
 985
 986                         if(SHOW_UBITS(re, &s->gb, 1)==0){
 987                             av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in 3. esc\n");
 988                             return -1;
 989                         }
 990
 991                         SKIP_COUNTER(re, &s->gb, 1+12+1);
 992                     }
 993
 994                     if (level>0) level= level * qmul + qadd;
 995                     else         level= level * qmul - qadd;
 996
 997                     if((unsigned)(level + 2048) > 4095){
 998                         if(s->err_recognition & AV_EF_BITSTREAM){
 999                             if(level > 2560 || level<-2560){
1000                                 av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
1001                                 return -1;
1002                             }
1003                         }
1004                         level= level<0 ? -2048 : 2047;
1005                     }
1006
1007                     i+= run + 1;
1008                     if(last) i+=192;
1009                 } else {
1010                     /* second escape */
1011                     SKIP_BITS(re, &s->gb, 2);
1012                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1013                     i+= run + rl->max_run[run>>7][level/qmul] +1; //FIXME opt indexing
1014                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1015                     LAST_SKIP_BITS(re, &s->gb, 1);
1016                 }
1017             } else {
1018                 /* first escape */
1019                 SKIP_BITS(re, &s->gb, 1);
1020                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1021                 i+= run;
1022                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
1023                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1024                 LAST_SKIP_BITS(re, &s->gb, 1);
1025             }
1026           }
1027         } else {
1028             i+= run;
1029             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1030             LAST_SKIP_BITS(re, &s->gb, 1);
1031         }
1032         if (i > 62){
1033             i-= 192;
1034             if(i&(~63)){
1035                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1036                 return -1;
1037             }
1038
1039             block[scan_table[i]] = level;
1040             break;
1041         }
1042
1043         block[scan_table[i]] = level;
1044     }
1045     CLOSE_READER(re, &s->gb);
1046   }
1047  not_coded:
1048     if (intra) {
1049         if(!s->use_intra_dc_vlc){
1050             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1051
1052             i -= i>>31; //if(i == -1) i=0;
1053         }
1054
1055         ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
1056         if (s->ac_pred) {
1057             i = 63; /* XXX: not optimal */
1058         }
1059     }
1060     s->block_last_index[n] = i;
1061     return 0;
1062 }
1063
1064 /**
1065  * decode partition C of one MB.
1066  * @return <0 if an error occurred
1067  */
1068 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, DCTELEM block[6][64])
1069 {
1070     int cbp, mb_type;
1071     const int xy= s->mb_x + s->mb_y*s->mb_stride;
1072
1073     mb_type = s->current_picture.f.mb_type[xy];
1074     cbp = s->cbp_table[xy];
1075
1076     s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1077
1078     if (s->current_picture.f.qscale_table[xy] != s->qscale) {
1079         ff_set_qscale(s, s->current_picture.f.qscale_table[xy]);
1080     }
1081
1082     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1083         int i;
1084         for(i=0; i<4; i++){
1085             s->mv[0][i][0] = s->current_picture.f.motion_val[0][s->block_index[i]][0];
1086             s->mv[0][i][1] = s->current_picture.f.motion_val[0][s->block_index[i]][1];
1087         }
1088         s->mb_intra = IS_INTRA(mb_type);
1089
1090         if (IS_SKIP(mb_type)) {
1091             /* skip mb */
1092             for(i=0;i<6;i++)
1093                 s->block_last_index[i] = -1;
1094             s->mv_dir = MV_DIR_FORWARD;
1095             s->mv_type = MV_TYPE_16X16;
1096             if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1097                 s->mcsel=1;
1098                 s->mb_skipped = 0;
1099             }else{
1100                 s->mcsel=0;
1101                 s->mb_skipped = 1;
1102             }
1103         }else if(s->mb_intra){
1104             s->ac_pred = IS_ACPRED(s->current_picture.f.mb_type[xy]);
1105         }else if(!s->mb_intra){
1106 //            s->mcsel= 0; //FIXME do we need to init that
1107
1108             s->mv_dir = MV_DIR_FORWARD;
1109             if (IS_8X8(mb_type)) {
1110                 s->mv_type = MV_TYPE_8X8;
1111             } else {
1112                 s->mv_type = MV_TYPE_16X16;
1113             }
1114         }
1115     } else { /* I-Frame */
1116         s->mb_intra = 1;
1117         s->ac_pred = IS_ACPRED(s->current_picture.f.mb_type[xy]);
1118     }
1119
1120     if (!IS_SKIP(mb_type)) {
1121         int i;
1122         s->dsp.clear_blocks(s->block[0]);
1123         /* decode each block */
1124         for (i = 0; i < 6; i++) {
1125             if(mpeg4_decode_block(s, block[i], i, cbp&32, s->mb_intra, s->rvlc) < 0){
1126                 av_log(s->avctx, AV_LOG_ERROR, "texture corrupted at %d %d %d\n", s->mb_x, s->mb_y, s->mb_intra);
1127                 return -1;
1128             }
1129             cbp+=cbp;
1130         }
1131     }
1132
1133     /* per-MB end of slice check */
1134
1135     if(--s->mb_num_left <= 0){
1136         if(mpeg4_is_resync(s))
1137             return SLICE_END;
1138         else
1139             return SLICE_NOEND;
1140     }else{
1141         if(mpeg4_is_resync(s)){
1142             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1143             if(s->cbp_table[xy+delta])
1144                 return SLICE_END;
1145         }
1146         return SLICE_OK;
1147     }
1148 }
1149
1150 static int mpeg4_decode_mb(MpegEncContext *s,
1151                       DCTELEM block[6][64])
1152 {
1153     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1154     int16_t *mot_val;
1155     static int8_t quant_tab[4] = { -1, -2, 1, 2 };
1156     const int xy= s->mb_x + s->mb_y * s->mb_stride;
1157
1158     assert(s->h263_pred);
1159
1160     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1161         do{
1162             if (get_bits1(&s->gb)) {
1163                 /* skip mb */
1164                 s->mb_intra = 0;
1165                 for(i=0;i<6;i++)
1166                     s->block_last_index[i] = -1;
1167                 s->mv_dir = MV_DIR_FORWARD;
1168                 s->mv_type = MV_TYPE_16X16;
1169                 if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1170                     s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1171                     s->mcsel=1;
1172                     s->mv[0][0][0]= get_amv(s, 0);
1173                     s->mv[0][0][1]= get_amv(s, 1);
1174
1175                     s->mb_skipped = 0;
1176                 }else{
1177                     s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1178                     s->mcsel=0;
1179                     s->mv[0][0][0] = 0;
1180                     s->mv[0][0][1] = 0;
1181                     s->mb_skipped = 1;
1182                 }
1183                 goto end;
1184             }
1185             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1186             if (cbpc < 0){
1187                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1188                 return -1;
1189             }
1190         }while(cbpc == 20);
1191
1192         s->dsp.clear_blocks(s->block[0]);
1193         dquant = cbpc & 8;
1194         s->mb_intra = ((cbpc & 4) != 0);
1195         if (s->mb_intra) goto intra;
1196
1197         if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
1198             s->mcsel= get_bits1(&s->gb);
1199         else s->mcsel= 0;
1200         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1201
1202         cbp = (cbpc & 3) | (cbpy << 2);
1203         if (dquant) {
1204             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1205         }
1206         if((!s->progressive_sequence) && (cbp || (s->workaround_bugs&FF_BUG_XVID_ILACE)))
1207             s->interlaced_dct= get_bits1(&s->gb);
1208
1209         s->mv_dir = MV_DIR_FORWARD;
1210         if ((cbpc & 16) == 0) {
1211             if(s->mcsel){
1212                 s->current_picture.f.mb_type[xy] = MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1213                 /* 16x16 global motion prediction */
1214                 s->mv_type = MV_TYPE_16X16;
1215                 mx= get_amv(s, 0);
1216                 my= get_amv(s, 1);
1217                 s->mv[0][0][0] = mx;
1218                 s->mv[0][0][1] = my;
1219             }else if((!s->progressive_sequence) && get_bits1(&s->gb)){
1220                 s->current_picture.f.mb_type[xy] = MB_TYPE_16x8 | MB_TYPE_L0 | MB_TYPE_INTERLACED;
1221                 /* 16x8 field motion prediction */
1222                 s->mv_type= MV_TYPE_FIELD;
1223
1224                 s->field_select[0][0]= get_bits1(&s->gb);
1225                 s->field_select[0][1]= get_bits1(&s->gb);
1226
1227                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1228
1229                 for(i=0; i<2; i++){
1230                     mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1231                     if (mx >= 0xffff)
1232                         return -1;
1233
1234                     my = ff_h263_decode_motion(s, pred_y/2, s->f_code);
1235                     if (my >= 0xffff)
1236                         return -1;
1237
1238                     s->mv[0][i][0] = mx;
1239                     s->mv[0][i][1] = my;
1240                 }
1241             }else{
1242                 s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1243                 /* 16x16 motion prediction */
1244                 s->mv_type = MV_TYPE_16X16;
1245                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1246                 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1247
1248                 if (mx >= 0xffff)
1249                     return -1;
1250
1251                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1252
1253                 if (my >= 0xffff)
1254                     return -1;
1255                 s->mv[0][0][0] = mx;
1256                 s->mv[0][0][1] = my;
1257             }
1258         } else {
1259             s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1260             s->mv_type = MV_TYPE_8X8;
1261             for(i=0;i<4;i++) {
1262                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1263                 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1264                 if (mx >= 0xffff)
1265                     return -1;
1266
1267                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1268                 if (my >= 0xffff)
1269                     return -1;
1270                 s->mv[0][i][0] = mx;
1271                 s->mv[0][i][1] = my;
1272                 mot_val[0] = mx;
1273                 mot_val[1] = my;
1274             }
1275         }
1276     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
1277         int modb1; // first bit of modb
1278         int modb2; // second bit of modb
1279         int mb_type;
1280
1281         s->mb_intra = 0; //B-frames never contain intra blocks
1282         s->mcsel=0;      //     ...               true gmc blocks
1283
1284         if(s->mb_x==0){
1285             for(i=0; i<2; i++){
1286                 s->last_mv[i][0][0]=
1287                 s->last_mv[i][0][1]=
1288                 s->last_mv[i][1][0]=
1289                 s->last_mv[i][1][1]= 0;
1290             }
1291
1292             ff_thread_await_progress(&s->next_picture_ptr->f, s->mb_y, 0);
1293         }
1294
1295         /* if we skipped it in the future P Frame than skip it now too */
1296         s->mb_skipped = s->next_picture.f.mbskip_table[s->mb_y * s->mb_stride + s->mb_x]; // Note, skiptab=0 if last was GMC
1297
1298         if(s->mb_skipped){
1299                 /* skip mb */
1300             for(i=0;i<6;i++)
1301                 s->block_last_index[i] = -1;
1302
1303             s->mv_dir = MV_DIR_FORWARD;
1304             s->mv_type = MV_TYPE_16X16;
1305             s->mv[0][0][0] = 0;
1306             s->mv[0][0][1] = 0;
1307             s->mv[1][0][0] = 0;
1308             s->mv[1][0][1] = 0;
1309             s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1310             goto end;
1311         }
1312
1313         modb1= get_bits1(&s->gb);
1314         if(modb1){
1315             mb_type= MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1; //like MB_TYPE_B_DIRECT but no vectors coded
1316             cbp=0;
1317         }else{
1318             modb2= get_bits1(&s->gb);
1319             mb_type= get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1320             if(mb_type<0){
1321                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1322                 return -1;
1323             }
1324             mb_type= mb_type_b_map[ mb_type ];
1325             if(modb2) cbp= 0;
1326             else{
1327                 s->dsp.clear_blocks(s->block[0]);
1328                 cbp= get_bits(&s->gb, 6);
1329             }
1330
1331             if ((!IS_DIRECT(mb_type)) && cbp) {
1332                 if(get_bits1(&s->gb)){
1333                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb)*4 - 2);
1334                 }
1335             }
1336
1337             if(!s->progressive_sequence){
1338                 if(cbp)
1339                     s->interlaced_dct= get_bits1(&s->gb);
1340
1341                 if(!IS_DIRECT(mb_type) && get_bits1(&s->gb)){
1342                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1343                     mb_type &= ~MB_TYPE_16x16;
1344
1345                     if(USES_LIST(mb_type, 0)){
1346                         s->field_select[0][0]= get_bits1(&s->gb);
1347                         s->field_select[0][1]= get_bits1(&s->gb);
1348                     }
1349                     if(USES_LIST(mb_type, 1)){
1350                         s->field_select[1][0]= get_bits1(&s->gb);
1351                         s->field_select[1][1]= get_bits1(&s->gb);
1352                     }
1353                 }
1354             }
1355
1356             s->mv_dir = 0;
1357             if((mb_type & (MB_TYPE_DIRECT2|MB_TYPE_INTERLACED)) == 0){
1358                 s->mv_type= MV_TYPE_16X16;
1359
1360                 if(USES_LIST(mb_type, 0)){
1361                     s->mv_dir = MV_DIR_FORWARD;
1362
1363                     mx = ff_h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1364                     my = ff_h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1365                     s->last_mv[0][1][0]= s->last_mv[0][0][0]= s->mv[0][0][0] = mx;
1366                     s->last_mv[0][1][1]= s->last_mv[0][0][1]= s->mv[0][0][1] = my;
1367                 }
1368
1369                 if(USES_LIST(mb_type, 1)){
1370                     s->mv_dir |= MV_DIR_BACKWARD;
1371
1372                     mx = ff_h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1373                     my = ff_h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1374                     s->last_mv[1][1][0]= s->last_mv[1][0][0]= s->mv[1][0][0] = mx;
1375                     s->last_mv[1][1][1]= s->last_mv[1][0][1]= s->mv[1][0][1] = my;
1376                 }
1377             }else if(!IS_DIRECT(mb_type)){
1378                 s->mv_type= MV_TYPE_FIELD;
1379
1380                 if(USES_LIST(mb_type, 0)){
1381                     s->mv_dir = MV_DIR_FORWARD;
1382
1383                     for(i=0; i<2; i++){
1384                         mx = ff_h263_decode_motion(s, s->last_mv[0][i][0]  , s->f_code);
1385                         my = ff_h263_decode_motion(s, s->last_mv[0][i][1]/2, s->f_code);
1386                         s->last_mv[0][i][0]=  s->mv[0][i][0] = mx;
1387                         s->last_mv[0][i][1]= (s->mv[0][i][1] = my)*2;
1388                     }
1389                 }
1390
1391                 if(USES_LIST(mb_type, 1)){
1392                     s->mv_dir |= MV_DIR_BACKWARD;
1393
1394                     for(i=0; i<2; i++){
1395                         mx = ff_h263_decode_motion(s, s->last_mv[1][i][0]  , s->b_code);
1396                         my = ff_h263_decode_motion(s, s->last_mv[1][i][1]/2, s->b_code);
1397                         s->last_mv[1][i][0]=  s->mv[1][i][0] = mx;
1398                         s->last_mv[1][i][1]= (s->mv[1][i][1] = my)*2;
1399                     }
1400                 }
1401             }
1402         }
1403
1404         if(IS_DIRECT(mb_type)){
1405             if(IS_SKIP(mb_type))
1406                 mx=my=0;
1407             else{
1408                 mx = ff_h263_decode_motion(s, 0, 1);
1409                 my = ff_h263_decode_motion(s, 0, 1);
1410             }
1411
1412             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1413             mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
1414         }
1415         s->current_picture.f.mb_type[xy] = mb_type;
1416     } else { /* I-Frame */
1417         do{
1418             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1419             if (cbpc < 0){
1420                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1421                 return -1;
1422             }
1423         }while(cbpc == 8);
1424
1425         dquant = cbpc & 4;
1426         s->mb_intra = 1;
1427 intra:
1428         s->ac_pred = get_bits1(&s->gb);
1429         if(s->ac_pred)
1430             s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1431         else
1432             s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
1433
1434         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1435         if(cbpy<0){
1436             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1437             return -1;
1438         }
1439         cbp = (cbpc & 3) | (cbpy << 2);
1440
1441         s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1442
1443         if (dquant) {
1444             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1445         }
1446
1447         if(!s->progressive_sequence)
1448             s->interlaced_dct= get_bits1(&s->gb);
1449
1450         s->dsp.clear_blocks(s->block[0]);
1451         /* decode each block */
1452         for (i = 0; i < 6; i++) {
1453             if (mpeg4_decode_block(s, block[i], i, cbp&32, 1, 0) < 0)
1454                 return -1;
1455             cbp+=cbp;
1456         }
1457         goto end;
1458     }
1459
1460     /* decode each block */
1461     for (i = 0; i < 6; i++) {
1462         if (mpeg4_decode_block(s, block[i], i, cbp&32, 0, 0) < 0)
1463             return -1;
1464         cbp+=cbp;
1465     }
1466 end:
1467
1468         /* per-MB end of slice check */
1469     if(s->codec_id==AV_CODEC_ID_MPEG4){
1470         if(mpeg4_is_resync(s)){
1471             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1472
1473             if (s->pict_type == AV_PICTURE_TYPE_B && s->next_picture.f.mbskip_table[xy + delta]) {
1474                 ff_thread_await_progress(&s->next_picture_ptr->f,
1475                                         (s->mb_x + delta >= s->mb_width) ? FFMIN(s->mb_y+1, s->mb_height-1) : s->mb_y, 0);
1476             }
1477
1478             if (s->pict_type == AV_PICTURE_TYPE_B && s->next_picture.f.mbskip_table[xy + delta])
1479                 return SLICE_OK;
1480             return SLICE_END;
1481         }
1482     }
1483
1484     return SLICE_OK;
1485 }
1486
1487
1488 static int mpeg4_decode_gop_header(MpegEncContext * s, GetBitContext *gb){
1489     int hours, minutes, seconds;
1490     unsigned time_code = show_bits(gb, 18);
1491
1492     if (time_code & 0x40) {     /* marker_bit */
1493         hours   = time_code >> 13;
1494         minutes = time_code >>  7 & 0x3f;
1495         seconds = time_code       & 0x3f;
1496         s->time_base = seconds + 60*(minutes + 60*hours);
1497         skip_bits(gb, 20);      /* time_code, closed_gov, broken_link */
1498     } else {
1499         av_log(s->avctx, AV_LOG_WARNING, "GOP header missing marker_bit\n");
1500     }
1501
1502     return 0;
1503 }
1504
1505 static int mpeg4_decode_profile_level(MpegEncContext * s, GetBitContext *gb){
1506   int profile_and_level_indication;
1507
1508   profile_and_level_indication = get_bits(gb, 8);
1509
1510   s->avctx->profile = (profile_and_level_indication & 0xf0) >> 4;
1511   s->avctx->level   = (profile_and_level_indication & 0x0f);
1512
1513   // for Simple profile, level 0
1514   if (s->avctx->profile == 0 && s->avctx->level == 8) {
1515       s->avctx->level = 0;
1516   }
1517
1518   return 0;
1519 }
1520
1521 static int decode_vol_header(MpegEncContext *s, GetBitContext *gb){
1522     int width, height, vo_ver_id;
1523
1524     /* vol header */
1525     skip_bits(gb, 1); /* random access */
1526     s->vo_type= get_bits(gb, 8);
1527     if (get_bits1(gb) != 0) { /* is_ol_id */
1528         vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
1529         skip_bits(gb, 3); /* vo_priority */
1530     } else {
1531         vo_ver_id = 1;
1532     }
1533     s->aspect_ratio_info= get_bits(gb, 4);
1534     if(s->aspect_ratio_info == FF_ASPECT_EXTENDED){
1535         s->avctx->sample_aspect_ratio.num= get_bits(gb, 8); // par_width
1536         s->avctx->sample_aspect_ratio.den= get_bits(gb, 8); // par_height
1537     }else{
1538         s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1539     }
1540
1541     if ((s->vol_control_parameters=get_bits1(gb))) { /* vol control parameter */
1542         int chroma_format= get_bits(gb, 2);
1543         if(chroma_format!=CHROMA_420){
1544             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1545         }
1546         s->low_delay= get_bits1(gb);
1547         if(get_bits1(gb)){ /* vbv parameters */
1548             get_bits(gb, 15);   /* first_half_bitrate */
1549             skip_bits1(gb);     /* marker */
1550             get_bits(gb, 15);   /* latter_half_bitrate */
1551             skip_bits1(gb);     /* marker */
1552             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
1553             skip_bits1(gb);     /* marker */
1554             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
1555             get_bits(gb, 11);   /* first_half_vbv_occupancy */
1556             skip_bits1(gb);     /* marker */
1557             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
1558             skip_bits1(gb);     /* marker */
1559         }
1560     }else{
1561         // set low delay flag only once the smartest? low delay detection won't be overriden
1562         if(s->picture_number==0)
1563             s->low_delay=0;
1564     }
1565
1566     s->shape = get_bits(gb, 2); /* vol shape */
1567     if(s->shape != RECT_SHAPE) av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1568     if(s->shape == GRAY_SHAPE && vo_ver_id != 1){
1569         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1570         skip_bits(gb, 4);  //video_object_layer_shape_extension
1571     }
1572
1573     check_marker(gb, "before time_increment_resolution");
1574
1575     s->avctx->time_base.den = get_bits(gb, 16);
1576     if(!s->avctx->time_base.den){
1577         av_log(s->avctx, AV_LOG_ERROR, "time_base.den==0\n");
1578         s->avctx->time_base.num = 0;
1579         return -1;
1580     }
1581
1582     s->time_increment_bits = av_log2(s->avctx->time_base.den - 1) + 1;
1583     if (s->time_increment_bits < 1)
1584         s->time_increment_bits = 1;
1585
1586     check_marker(gb, "before fixed_vop_rate");
1587
1588     if (get_bits1(gb) != 0) {   /* fixed_vop_rate  */
1589         s->avctx->time_base.num = get_bits(gb, s->time_increment_bits);
1590     }else
1591         s->avctx->time_base.num = 1;
1592
1593     s->t_frame=0;
1594
1595     if (s->shape != BIN_ONLY_SHAPE) {
1596         if (s->shape == RECT_SHAPE) {
1597             skip_bits1(gb);   /* marker */
1598             width = get_bits(gb, 13);
1599             skip_bits1(gb);   /* marker */
1600             height = get_bits(gb, 13);
1601             skip_bits1(gb);   /* marker */
1602             if(width && height && !(s->width && s->codec_tag == AV_RL32("MP4S"))){ /* they should be non zero but who knows ... */
1603                 if (s->width && s->height &&
1604                     (s->width != width || s->height != height))
1605                     s->context_reinit = 1;
1606                 s->width = width;
1607                 s->height = height;
1608             }
1609         }
1610
1611         s->progressive_sequence=
1612         s->progressive_frame= get_bits1(gb)^1;
1613         s->interlaced_dct=0;
1614         if(!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1615             av_log(s->avctx, AV_LOG_INFO, "MPEG4 OBMC not supported (very likely buggy encoder)\n");   /* OBMC Disable */
1616         if (vo_ver_id == 1) {
1617             s->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
1618         } else {
1619             s->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
1620         }
1621         if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1622         if(s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE){
1623             if(s->vol_sprite_usage==STATIC_SPRITE){
1624                 s->sprite_width = get_bits(gb, 13);
1625                 skip_bits1(gb); /* marker */
1626                 s->sprite_height= get_bits(gb, 13);
1627                 skip_bits1(gb); /* marker */
1628                 s->sprite_left  = get_bits(gb, 13);
1629                 skip_bits1(gb); /* marker */
1630                 s->sprite_top   = get_bits(gb, 13);
1631                 skip_bits1(gb); /* marker */
1632             }
1633             s->num_sprite_warping_points= get_bits(gb, 6);
1634             if(s->num_sprite_warping_points > 3){
1635                 av_log(s->avctx, AV_LOG_ERROR, "%d sprite_warping_points\n", s->num_sprite_warping_points);
1636                 s->num_sprite_warping_points= 0;
1637                 return -1;
1638             }
1639             s->sprite_warping_accuracy = get_bits(gb, 2);
1640             s->sprite_brightness_change= get_bits1(gb);
1641             if(s->vol_sprite_usage==STATIC_SPRITE)
1642                 s->low_latency_sprite= get_bits1(gb);
1643         }
1644         // FIXME sadct disable bit if verid!=1 && shape not rect
1645
1646         if (get_bits1(gb) == 1) {   /* not_8_bit */
1647             s->quant_precision = get_bits(gb, 4); /* quant_precision */
1648             if(get_bits(gb, 4)!=8) av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n"); /* bits_per_pixel */
1649             if(s->quant_precision!=5) av_log(s->avctx, AV_LOG_ERROR, "quant precision %d\n", s->quant_precision);
1650         } else {
1651             s->quant_precision = 5;
1652         }
1653
1654         // FIXME a bunch of grayscale shape things
1655
1656         if((s->mpeg_quant=get_bits1(gb))){ /* vol_quant_type */
1657             int i, v;
1658
1659             /* load default matrixes */
1660             for(i=0; i<64; i++){
1661                 int j= s->dsp.idct_permutation[i];
1662                 v= ff_mpeg4_default_intra_matrix[i];
1663                 s->intra_matrix[j]= v;
1664                 s->chroma_intra_matrix[j]= v;
1665
1666                 v= ff_mpeg4_default_non_intra_matrix[i];
1667                 s->inter_matrix[j]= v;
1668                 s->chroma_inter_matrix[j]= v;
1669             }
1670
1671             /* load custom intra matrix */
1672             if(get_bits1(gb)){
1673                 int last=0;
1674                 for(i=0; i<64; i++){
1675                     int j;
1676                     v= get_bits(gb, 8);
1677                     if(v==0) break;
1678
1679                     last= v;
1680                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1681                     s->intra_matrix[j]= v;
1682                     s->chroma_intra_matrix[j]= v;
1683                 }
1684
1685                 /* replicate last value */
1686                 for(; i<64; i++){
1687                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1688                     s->intra_matrix[j]= last;
1689                     s->chroma_intra_matrix[j]= last;
1690                 }
1691             }
1692
1693             /* load custom non intra matrix */
1694             if(get_bits1(gb)){
1695                 int last=0;
1696                 for(i=0; i<64; i++){
1697                     int j;
1698                     v= get_bits(gb, 8);
1699                     if(v==0) break;
1700
1701                     last= v;
1702                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1703                     s->inter_matrix[j]= v;
1704                     s->chroma_inter_matrix[j]= v;
1705                 }
1706
1707                 /* replicate last value */
1708                 for(; i<64; i++){
1709                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1710                     s->inter_matrix[j]= last;
1711                     s->chroma_inter_matrix[j]= last;
1712                 }
1713             }
1714
1715             // FIXME a bunch of grayscale shape things
1716         }
1717
1718         if(vo_ver_id != 1)
1719              s->quarter_sample= get_bits1(gb);
1720         else s->quarter_sample=0;
1721
1722         if(!get_bits1(gb)){
1723             int pos= get_bits_count(gb);
1724             int estimation_method= get_bits(gb, 2);
1725             if(estimation_method<2){
1726                 if(!get_bits1(gb)){
1727                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //opaque
1728                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //transparent
1729                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_cae
1730                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //inter_cae
1731                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //no_update
1732                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //upampling
1733                 }
1734                 if(!get_bits1(gb)){
1735                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_blocks
1736                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter_blocks
1737                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter4v_blocks
1738                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //not coded blocks
1739                 }
1740                 if(!check_marker(gb, "in complexity estimation part 1")){
1741                     skip_bits_long(gb, pos - get_bits_count(gb));
1742                     goto no_cplx_est;
1743                 }
1744                 if(!get_bits1(gb)){
1745                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_coeffs
1746                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_lines
1747                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //vlc_syms
1748                     s->cplx_estimation_trash_i += 4*get_bits1(gb); //vlc_bits
1749                 }
1750                 if(!get_bits1(gb)){
1751                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //apm
1752                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //npm
1753                     s->cplx_estimation_trash_b += 8*get_bits1(gb); //interpolate_mc_q
1754                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //forwback_mc_q
1755                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel2
1756                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel4
1757                 }
1758                 if(!check_marker(gb, "in complexity estimation part 2")){
1759                     skip_bits_long(gb, pos - get_bits_count(gb));
1760                     goto no_cplx_est;
1761                 }
1762                 if(estimation_method==1){
1763                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //sadct
1764                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //qpel
1765                 }
1766             }else
1767                 av_log(s->avctx, AV_LOG_ERROR, "Invalid Complexity estimation method %d\n", estimation_method);
1768         }else{
1769 no_cplx_est:
1770             s->cplx_estimation_trash_i=
1771             s->cplx_estimation_trash_p=
1772             s->cplx_estimation_trash_b= 0;
1773         }
1774
1775         s->resync_marker= !get_bits1(gb); /* resync_marker_disabled */
1776
1777         s->data_partitioning= get_bits1(gb);
1778         if(s->data_partitioning){
1779             s->rvlc= get_bits1(gb);
1780         }
1781
1782         if(vo_ver_id != 1) {
1783             s->new_pred= get_bits1(gb);
1784             if(s->new_pred){
1785                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
1786                 skip_bits(gb, 2); /* requested upstream message type */
1787                 skip_bits1(gb); /* newpred segment type */
1788             }
1789             s->reduced_res_vop= get_bits1(gb);
1790             if(s->reduced_res_vop) av_log(s->avctx, AV_LOG_ERROR, "reduced resolution VOP not supported\n");
1791         }
1792         else{
1793             s->new_pred=0;
1794             s->reduced_res_vop= 0;
1795         }
1796
1797         s->scalability= get_bits1(gb);
1798
1799         if (s->scalability) {
1800             GetBitContext bak= *gb;
1801             int h_sampling_factor_n;
1802             int h_sampling_factor_m;
1803             int v_sampling_factor_n;
1804             int v_sampling_factor_m;
1805
1806             s->hierachy_type= get_bits1(gb);
1807             skip_bits(gb, 4);  /* ref_layer_id */
1808             skip_bits1(gb);    /* ref_layer_sampling_dir */
1809             h_sampling_factor_n= get_bits(gb, 5);
1810             h_sampling_factor_m= get_bits(gb, 5);
1811             v_sampling_factor_n= get_bits(gb, 5);
1812             v_sampling_factor_m= get_bits(gb, 5);
1813             s->enhancement_type= get_bits1(gb);
1814
1815             if(   h_sampling_factor_n==0 || h_sampling_factor_m==0
1816                || v_sampling_factor_n==0 || v_sampling_factor_m==0){
1817                 /* illegal scalability header (VERY broken encoder),
1818                  * trying to workaround */
1819                 s->scalability=0;
1820                 *gb= bak;
1821             }else
1822                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
1823
1824             // bin shape stuff FIXME
1825         }
1826     }
1827     return 0;
1828 }
1829
1830 /**
1831  * Decode the user data stuff in the header.
1832  * Also initializes divx/xvid/lavc_version/build.
1833  */
1834 static int decode_user_data(MpegEncContext *s, GetBitContext *gb){
1835     char buf[256];
1836     int i;
1837     int e;
1838     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
1839     char last;
1840
1841     for(i=0; i<255 && get_bits_count(gb) < gb->size_in_bits; i++){
1842         if(show_bits(gb, 23) == 0) break;
1843         buf[i]= get_bits(gb, 8);
1844     }
1845     buf[i]=0;
1846
1847     /* divx detection */
1848     e=sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
1849     if(e<2)
1850         e=sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
1851     if(e>=2){
1852         s->divx_version= ver;
1853         s->divx_build= build;
1854         s->divx_packed= e==3 && last=='p';
1855         if(s->divx_packed && !s->showed_packed_warning) {
1856             av_log(s->avctx, AV_LOG_WARNING, "Invalid and inefficient vfw-avi packed B frames detected\n");
1857             s->showed_packed_warning=1;
1858         }
1859     }
1860
1861     /* libavcodec detection */
1862     e=sscanf(buf, "FFmpe%*[^b]b%d", &build)+3;
1863     if(e!=4)
1864         e=sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
1865     if(e!=4){
1866         e=sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3)+1;
1867         if (e>1)
1868             build= (ver<<16) + (ver2<<8) + ver3;
1869     }
1870     if(e!=4){
1871         if(strcmp(buf, "ffmpeg")==0){
1872             s->lavc_build= 4600;
1873         }
1874     }
1875     if(e==4){
1876         s->lavc_build= build;
1877     }
1878
1879     /* Xvid detection */
1880     e=sscanf(buf, "XviD%d", &build);
1881     if(e==1){
1882         s->xvid_build= build;
1883     }
1884
1885     return 0;
1886 }
1887
1888 static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
1889     int time_incr, time_increment;
1890
1891     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I;        /* pict type: I = 0 , P = 1 */
1892     if(s->pict_type==AV_PICTURE_TYPE_B && s->low_delay && s->vol_control_parameters==0 && !(s->flags & CODEC_FLAG_LOW_DELAY)){
1893         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag incorrectly, clearing it\n");
1894         s->low_delay=0;
1895     }
1896
1897     s->partitioned_frame= s->data_partitioning && s->pict_type!=AV_PICTURE_TYPE_B;
1898     if(s->partitioned_frame)
1899         s->decode_mb= mpeg4_decode_partitioned_mb;
1900     else
1901         s->decode_mb= mpeg4_decode_mb;
1902
1903     time_incr=0;
1904     while (get_bits1(gb) != 0)
1905         time_incr++;
1906
1907     check_marker(gb, "before time_increment");
1908
1909     if(s->time_increment_bits==0 || !(show_bits(gb, s->time_increment_bits+1)&1)){
1910         av_log(s->avctx, AV_LOG_ERROR, "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
1911
1912         for(s->time_increment_bits=1 ;s->time_increment_bits<16; s->time_increment_bits++){
1913             if (    s->pict_type == AV_PICTURE_TYPE_P
1914                 || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE)) {
1915                 if((show_bits(gb, s->time_increment_bits+6)&0x37) == 0x30) break;
1916             }else
1917                 if((show_bits(gb, s->time_increment_bits+5)&0x1F) == 0x18) break;
1918         }
1919
1920         av_log(s->avctx, AV_LOG_ERROR, "my guess is %d bits ;)\n",s->time_increment_bits);
1921     }
1922
1923     if(IS_3IV1) time_increment= get_bits1(gb); //FIXME investigate further
1924     else time_increment= get_bits(gb, s->time_increment_bits);
1925
1926     if(s->pict_type!=AV_PICTURE_TYPE_B){
1927         s->last_time_base= s->time_base;
1928         s->time_base+= time_incr;
1929         s->time= s->time_base*s->avctx->time_base.den + time_increment;
1930         if(s->workaround_bugs&FF_BUG_UMP4){
1931             if(s->time < s->last_non_b_time){
1932                 /* header is not mpeg-4-compatible, broken encoder,
1933                  * trying to workaround */
1934                 s->time_base++;
1935                 s->time+= s->avctx->time_base.den;
1936             }
1937         }
1938         s->pp_time= s->time - s->last_non_b_time;
1939         s->last_non_b_time= s->time;
1940     }else{
1941         s->time= (s->last_time_base + time_incr)*s->avctx->time_base.den + time_increment;
1942         s->pb_time= s->pp_time - (s->last_non_b_time - s->time);
1943         if(s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0){
1944             /* messed up order, maybe after seeking? skipping current b-frame */
1945             return FRAME_SKIPPED;
1946         }
1947         ff_mpeg4_init_direct_mv(s);
1948
1949         if(s->t_frame==0) s->t_frame= s->pb_time;
1950         if(s->t_frame==0) s->t_frame=1; // 1/0 protection
1951         s->pp_field_time= (  ROUNDED_DIV(s->last_non_b_time, s->t_frame)
1952                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1953         s->pb_field_time= (  ROUNDED_DIV(s->time, s->t_frame)
1954                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1955         if(!s->progressive_sequence){
1956             if(s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
1957                 return FRAME_SKIPPED;
1958         }
1959     }
1960
1961     if(s->avctx->time_base.num)
1962         s->current_picture_ptr->f.pts = (s->time + s->avctx->time_base.num / 2) / s->avctx->time_base.num;
1963     else
1964         s->current_picture_ptr->f.pts = AV_NOPTS_VALUE;
1965     if(s->avctx->debug&FF_DEBUG_PTS)
1966         av_log(s->avctx, AV_LOG_DEBUG, "MPEG4 PTS: %"PRId64"\n",
1967                s->current_picture_ptr->f.pts);
1968
1969     check_marker(gb, "before vop_coded");
1970
1971     /* vop coded */
1972     if (get_bits1(gb) != 1){
1973         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
1974             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
1975         return FRAME_SKIPPED;
1976     }
1977     if (s->shape != BIN_ONLY_SHAPE && ( s->pict_type == AV_PICTURE_TYPE_P
1978                           || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE))) {
1979         /* rounding type for motion estimation */
1980         s->no_rounding = get_bits1(gb);
1981     } else {
1982         s->no_rounding = 0;
1983     }
1984 //FIXME reduced res stuff
1985
1986      if (s->shape != RECT_SHAPE) {
1987          if (s->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
1988              skip_bits(gb, 13); /* width */
1989              skip_bits1(gb);   /* marker */
1990              skip_bits(gb, 13); /* height */
1991              skip_bits1(gb);   /* marker */
1992              skip_bits(gb, 13); /* hor_spat_ref */
1993              skip_bits1(gb);   /* marker */
1994              skip_bits(gb, 13); /* ver_spat_ref */
1995          }
1996          skip_bits1(gb); /* change_CR_disable */
1997
1998          if (get_bits1(gb) != 0) {
1999              skip_bits(gb, 8); /* constant_alpha_value */
2000          }
2001      }
2002 //FIXME complexity estimation stuff
2003
2004      if (s->shape != BIN_ONLY_SHAPE) {
2005          skip_bits_long(gb, s->cplx_estimation_trash_i);
2006          if(s->pict_type != AV_PICTURE_TYPE_I)
2007             skip_bits_long(gb, s->cplx_estimation_trash_p);
2008          if(s->pict_type == AV_PICTURE_TYPE_B)
2009             skip_bits_long(gb, s->cplx_estimation_trash_b);
2010
2011          s->intra_dc_threshold= ff_mpeg4_dc_threshold[ get_bits(gb, 3) ];
2012          if(!s->progressive_sequence){
2013              s->top_field_first= get_bits1(gb);
2014              s->alternate_scan= get_bits1(gb);
2015          }else
2016              s->alternate_scan= 0;
2017      }
2018
2019      if(s->alternate_scan){
2020          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
2021          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
2022          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2023          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2024      } else{
2025          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
2026          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
2027          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2028          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2029      }
2030
2031      if(s->pict_type == AV_PICTURE_TYPE_S && (s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE)){
2032          mpeg4_decode_sprite_trajectory(s, gb);
2033          if(s->sprite_brightness_change) av_log(s->avctx, AV_LOG_ERROR, "sprite_brightness_change not supported\n");
2034          if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2035      }
2036
2037      if (s->shape != BIN_ONLY_SHAPE) {
2038          s->chroma_qscale= s->qscale = get_bits(gb, s->quant_precision);
2039          if(s->qscale==0){
2040              av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (qscale=0)\n");
2041              return -1; // makes no sense to continue, as there is nothing left from the image then
2042          }
2043
2044          if (s->pict_type != AV_PICTURE_TYPE_I) {
2045              s->f_code = get_bits(gb, 3);       /* fcode_for */
2046              if(s->f_code==0){
2047                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (f_code=0)\n");
2048                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
2049              }
2050          }else
2051              s->f_code=1;
2052
2053          if (s->pict_type == AV_PICTURE_TYPE_B) {
2054              s->b_code = get_bits(gb, 3);
2055          }else
2056              s->b_code=1;
2057
2058          if(s->avctx->debug&FF_DEBUG_PICT_INFO){
2059              av_log(s->avctx, AV_LOG_DEBUG, "qp:%d fc:%d,%d %s size:%d pro:%d alt:%d top:%d %spel part:%d resync:%d w:%d a:%d rnd:%d vot:%d%s dc:%d ce:%d/%d/%d\n",
2060                  s->qscale, s->f_code, s->b_code,
2061                  s->pict_type == AV_PICTURE_TYPE_I ? "I" : (s->pict_type == AV_PICTURE_TYPE_P ? "P" : (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
2062                  gb->size_in_bits,s->progressive_sequence, s->alternate_scan, s->top_field_first,
2063                  s->quarter_sample ? "q" : "h", s->data_partitioning, s->resync_marker, s->num_sprite_warping_points,
2064                  s->sprite_warping_accuracy, 1-s->no_rounding, s->vo_type, s->vol_control_parameters ? " VOLC" : " ", s->intra_dc_threshold, s->cplx_estimation_trash_i, s->cplx_estimation_trash_p, s->cplx_estimation_trash_b);
2065          }
2066
2067          if(!s->scalability){
2068              if (s->shape!=RECT_SHAPE && s->pict_type!=AV_PICTURE_TYPE_I) {
2069                  skip_bits1(gb); // vop shape coding type
2070              }
2071          }else{
2072              if(s->enhancement_type){
2073                  int load_backward_shape= get_bits1(gb);
2074                  if(load_backward_shape){
2075                      av_log(s->avctx, AV_LOG_ERROR, "load backward shape isn't supported\n");
2076                  }
2077              }
2078              skip_bits(gb, 2); //ref_select_code
2079          }
2080      }
2081      /* detect buggy encoders which don't set the low_delay flag (divx4/xvid/opendivx)*/
2082      // note we cannot detect divx5 without b-frames easily (although it's buggy too)
2083      if(s->vo_type==0 && s->vol_control_parameters==0 && s->divx_version==-1 && s->picture_number==0){
2084          av_log(s->avctx, AV_LOG_WARNING, "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2085          s->low_delay=1;
2086      }
2087
2088      s->picture_number++; // better than pic number==0 always ;)
2089
2090      s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table; //FIXME add short header support
2091      s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
2092
2093      if(s->workaround_bugs&FF_BUG_EDGE){
2094          s->h_edge_pos= s->width;
2095          s->v_edge_pos= s->height;
2096      }
2097      return 0;
2098 }
2099
2100 /**
2101  * Decode mpeg4 headers.
2102  * @return <0 if no VOP found (or a damaged one)
2103  *         FRAME_SKIPPED if a not coded VOP is found
2104  *         0 if a VOP is found
2105  */
2106 int ff_mpeg4_decode_picture_header(MpegEncContext * s, GetBitContext *gb)
2107 {
2108     unsigned startcode, v;
2109
2110     /* search next start code */
2111     align_get_bits(gb);
2112
2113     if(s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630){
2114         skip_bits(gb, 24);
2115         if(get_bits(gb, 8) == 0xF0)
2116             goto end;
2117     }
2118
2119     startcode = 0xff;
2120     for(;;) {
2121         if(get_bits_count(gb) >= gb->size_in_bits){
2122             if(gb->size_in_bits==8 && (s->divx_version>=0 || s->xvid_build>=0)){
2123                 av_log(s->avctx, AV_LOG_WARNING, "frame skip %d\n", gb->size_in_bits);
2124                 return FRAME_SKIPPED; //divx bug
2125             }else
2126                 return -1; //end of stream
2127         }
2128
2129         /* use the bits after the test */
2130         v = get_bits(gb, 8);
2131         startcode = ((startcode << 8) | v) & 0xffffffff;
2132
2133         if((startcode&0xFFFFFF00) != 0x100)
2134             continue; //no startcode
2135
2136         if(s->avctx->debug&FF_DEBUG_STARTCODE){
2137             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2138             if     (startcode<=0x11F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2139             else if(startcode<=0x12F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2140             else if(startcode<=0x13F) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2141             else if(startcode<=0x15F) av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2142             else if(startcode<=0x1AF) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2143             else if(startcode==0x1B0) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2144             else if(startcode==0x1B1) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2145             else if(startcode==0x1B2) av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2146             else if(startcode==0x1B3) av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2147             else if(startcode==0x1B4) av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2148             else if(startcode==0x1B5) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2149             else if(startcode==0x1B6) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2150             else if(startcode==0x1B7) av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2151             else if(startcode==0x1B8) av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2152             else if(startcode==0x1B9) av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2153             else if(startcode==0x1BA) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2154             else if(startcode==0x1BB) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2155             else if(startcode==0x1BC) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2156             else if(startcode==0x1BD) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2157             else if(startcode==0x1BE) av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2158             else if(startcode==0x1BF) av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2159             else if(startcode==0x1C0) av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2160             else if(startcode==0x1C1) av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2161             else if(startcode==0x1C2) av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2162             else if(startcode==0x1C3) av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2163             else if(startcode<=0x1C5) av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2164             else if(startcode<=0x1FF) av_log(s->avctx, AV_LOG_DEBUG, "System start");
2165             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2166         }
2167
2168         if(startcode >= 0x120 && startcode <= 0x12F){
2169             if(decode_vol_header(s, gb) < 0)
2170                 return -1;
2171         }
2172         else if(startcode == USER_DATA_STARTCODE){
2173             decode_user_data(s, gb);
2174         }
2175         else if(startcode == GOP_STARTCODE){
2176             mpeg4_decode_gop_header(s, gb);
2177         }
2178         else if(startcode == VOS_STARTCODE){
2179             mpeg4_decode_profile_level(s, gb);
2180         }
2181         else if(startcode == VOP_STARTCODE){
2182             break;
2183         }
2184
2185         align_get_bits(gb);
2186         startcode = 0xff;
2187     }
2188 end:
2189     if(s->flags& CODEC_FLAG_LOW_DELAY)
2190         s->low_delay=1;
2191     s->avctx->has_b_frames= !s->low_delay;
2192     return decode_vop_header(s, gb);
2193 }
2194
2195 static av_cold int decode_init(AVCodecContext *avctx)
2196 {
2197     MpegEncContext *s = avctx->priv_data;
2198     int ret;
2199     static int done = 0;
2200
2201     s->divx_version=
2202     s->divx_build=
2203     s->xvid_build=
2204     s->lavc_build= -1;
2205
2206     if((ret=ff_h263_decode_init(avctx)) < 0)
2207         return ret;
2208
2209     if (!done) {
2210         done = 1;
2211
2212         ff_init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2213         ff_init_rl(&ff_rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2214         ff_init_rl(&ff_rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2215         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2216         INIT_VLC_RL(ff_rvlc_rl_inter, 1072);
2217         INIT_VLC_RL(ff_rvlc_rl_intra, 1072);
2218         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2219                  &ff_mpeg4_DCtab_lum[0][1], 2, 1,
2220                  &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2221         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2222                  &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2223                  &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2224         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2225                  &ff_sprite_trajectory_tab[0][1], 4, 2,
2226                  &ff_sprite_trajectory_tab[0][0], 4, 2, 128);
2227         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2228                  &ff_mb_type_b_tab[0][1], 2, 1,
2229                  &ff_mb_type_b_tab[0][0], 2, 1, 16);
2230     }
2231
2232     s->h263_pred = 1;
2233     s->low_delay = 0; //default, might be overriden in the vol header during header parsing
2234     s->decode_mb= mpeg4_decode_mb;
2235     s->time_increment_bits = 4; /* default value for broken headers */
2236     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2237
2238     return 0;
2239 }
2240
2241 static const AVProfile mpeg4_video_profiles[] = {
2242     { FF_PROFILE_MPEG4_SIMPLE,                    "Simple Profile" },
2243     { FF_PROFILE_MPEG4_SIMPLE_SCALABLE,           "Simple Scalable Profile" },
2244     { FF_PROFILE_MPEG4_CORE,                      "Core Profile" },
2245     { FF_PROFILE_MPEG4_MAIN,                      "Main Profile" },
2246     { FF_PROFILE_MPEG4_N_BIT,                     "N-bit Profile" },
2247     { FF_PROFILE_MPEG4_SCALABLE_TEXTURE,          "Scalable Texture Profile" },
2248     { FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION,     "Simple Face Animation Profile" },
2249     { FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE,    "Basic Animated Texture Profile" },
2250     { FF_PROFILE_MPEG4_HYBRID,                    "Hybrid Profile" },
2251     { FF_PROFILE_MPEG4_ADVANCED_REAL_TIME,        "Advanced Real Time Simple Profile" },
2252     { FF_PROFILE_MPEG4_CORE_SCALABLE,             "Code Scalable Profile" },
2253     { FF_PROFILE_MPEG4_ADVANCED_CODING,           "Advanced Coding Profile" },
2254     { FF_PROFILE_MPEG4_ADVANCED_CORE,             "Advanced Core Profile" },
2255     { FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE, "Advanced Scalable Texture Profile" },
2256     { FF_PROFILE_MPEG4_SIMPLE_STUDIO,             "Simple Studio Profile" },
2257     { FF_PROFILE_MPEG4_ADVANCED_SIMPLE,           "Advanced Simple Profile" },
2258 };
2259
2260 AVCodec ff_mpeg4_decoder = {
2261     .name                  = "mpeg4",
2262     .type                  = AVMEDIA_TYPE_VIDEO,
2263     .id                    = AV_CODEC_ID_MPEG4,
2264     .priv_data_size        = sizeof(MpegEncContext),
2265     .init                  = decode_init,
2266     .close                 = ff_h263_decode_end,
2267     .decode                = ff_h263_decode_frame,
2268     .capabilities          = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
2269                              CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2270                              CODEC_CAP_FRAME_THREADS,
2271     .flush                 = ff_mpeg_flush,
2272     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2273     .pix_fmts              = ff_hwaccel_pixfmt_list_420,
2274     .profiles              = NULL_IF_CONFIG_SMALL(mpeg4_video_profiles),
2275     .update_thread_context = ONLY_IF_THREADS_ENABLED(ff_mpeg_update_thread_context),
2276 };
2277
2278
2279 #if CONFIG_MPEG4_VDPAU_DECODER
2280 AVCodec ff_mpeg4_vdpau_decoder = {
2281     .name           = "mpeg4_vdpau",
2282     .type           = AVMEDIA_TYPE_VIDEO,
2283     .id             = AV_CODEC_ID_MPEG4,
2284     .priv_data_size = sizeof(MpegEncContext),
2285     .init           = decode_init,
2286     .close          = ff_h263_decode_end,
2287     .decode         = ff_h263_decode_frame,
2288     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2289                       CODEC_CAP_HWACCEL_VDPAU,
2290     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
2291     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_VDPAU_MPEG4,
2292                                                   AV_PIX_FMT_NONE },
2293 };
2294 #endif