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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 FFmpeg.
   7  *
   8  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #define UNCHECKED_BITSTREAM_READER 1
  24
  25 #include "libavutil/opt.h"
  26 #include "mpegvideo.h"
  27 #include "mpeg4video.h"
  28 #include "h263.h"
  29 #include "thread.h"
  30
  31 // The defines below define the number of bits that are read at once for
  32 // reading vlc values. Changing these may improve speed and data cache needs
  33 // be aware though that decreasing them may need the number of stages that is
  34 // passed to get_vlc* to be increased.
  35 #define SPRITE_TRAJ_VLC_BITS 6
  36 #define DC_VLC_BITS 9
  37 #define MB_TYPE_B_VLC_BITS 4
  38
  39
  40 static VLC dc_lum, dc_chrom;
  41 static VLC sprite_trajectory;
  42 static VLC mb_type_b_vlc;
  43
  44 static const int mb_type_b_map[4]= {
  45     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  46     MB_TYPE_L0L1 | MB_TYPE_16x16,
  47     MB_TYPE_L1 | MB_TYPE_16x16,
  48     MB_TYPE_L0 | MB_TYPE_16x16,
  49 };
  50
  51 /**
  52  * Predict the ac.
  53  * @param n block index (0-3 are luma, 4-5 are chroma)
  54  * @param dir the ac prediction direction
  55  */
  56 void mpeg4_pred_ac(MpegEncContext * s, DCTELEM *block, int n,
  57                    int dir)
  58 {
  59     int i;
  60     int16_t *ac_val, *ac_val1;
  61     int8_t * const qscale_table = s->current_picture.f.qscale_table;
  62
  63     /* find prediction */
  64     ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
  65     ac_val1 = ac_val;
  66     if (s->ac_pred) {
  67         if (dir == 0) {
  68             const int xy= s->mb_x-1 + s->mb_y*s->mb_stride;
  69             /* left prediction */
  70             ac_val -= 16;
  71
  72             if(s->mb_x==0 || s->qscale == qscale_table[xy] || n==1 || n==3){
  73                 /* same qscale */
  74                 for(i=1;i<8;i++) {
  75                     block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
  76                 }
  77             }else{
  78                 /* different qscale, we must rescale */
  79                 for(i=1;i<8;i++) {
  80                     block[s->dsp.idct_permutation[i<<3]] += ROUNDED_DIV(ac_val[i]*qscale_table[xy], s->qscale);
  81                 }
  82             }
  83         } else {
  84             const int xy= s->mb_x + s->mb_y*s->mb_stride - s->mb_stride;
  85             /* top prediction */
  86             ac_val -= 16 * s->block_wrap[n];
  87
  88             if(s->mb_y==0 || s->qscale == qscale_table[xy] || n==2 || n==3){
  89                 /* same qscale */
  90                 for(i=1;i<8;i++) {
  91                     block[s->dsp.idct_permutation[i]] += ac_val[i + 8];
  92                 }
  93             }else{
  94                 /* different qscale, we must rescale */
  95                 for(i=1;i<8;i++) {
  96                     block[s->dsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8]*qscale_table[xy], s->qscale);
  97                 }
  98             }
  99         }
 100     }
 101     /* left copy */
 102     for(i=1;i<8;i++)
 103         ac_val1[i    ] = block[s->dsp.idct_permutation[i<<3]];
 104
 105     /* top copy */
 106     for(i=1;i<8;i++)
 107         ac_val1[8 + i] = block[s->dsp.idct_permutation[i   ]];
 108
 109 }
 110
 111 /**
 112  * check if the next stuff is a resync marker or the end.
 113  * @return 0 if not
 114  */
 115 static inline int mpeg4_is_resync(MpegEncContext *s){
 116     int bits_count= get_bits_count(&s->gb);
 117     int v= show_bits(&s->gb, 16);
 118
 119     if(s->workaround_bugs&FF_BUG_NO_PADDING && !s->resync_marker){
 120         return 0;
 121     }
 122
 123     while(v<=0xFF){
 124         if(s->pict_type==AV_PICTURE_TYPE_B || (v>>(8-s->pict_type)!=1) || s->partitioned_frame)
 125             break;
 126         skip_bits(&s->gb, 8+s->pict_type);
 127         bits_count+= 8+s->pict_type;
 128         v= show_bits(&s->gb, 16);
 129     }
 130
 131     if(bits_count + 8 >= s->gb.size_in_bits){
 132         v>>=8;
 133         v|= 0x7F >> (7-(bits_count&7));
 134
 135         if(v==0x7F)
 136             return s->mb_num;
 137     }else{
 138         if(v == ff_mpeg4_resync_prefix[bits_count&7]){
 139             int len, mb_num;
 140             int mb_num_bits= av_log2(s->mb_num - 1) + 1;
 141             GetBitContext gb= s->gb;
 142
 143             skip_bits(&s->gb, 1);
 144             align_get_bits(&s->gb);
 145
 146             for(len=0; len<32; len++){
 147                 if(get_bits1(&s->gb)) break;
 148             }
 149
 150             mb_num= get_bits(&s->gb, mb_num_bits);
 151             if(!mb_num || mb_num > s->mb_num || get_bits_count(&s->gb)+6 > s->gb.size_in_bits)
 152                 mb_num= -1;
 153
 154             s->gb= gb;
 155
 156             if(len>=ff_mpeg4_get_video_packet_prefix_length(s))
 157                 return mb_num;
 158         }
 159     }
 160     return 0;
 161 }
 162
 163 static void mpeg4_decode_sprite_trajectory(MpegEncContext * s, GetBitContext *gb)
 164 {
 165     int i;
 166     int a= 2<<s->sprite_warping_accuracy;
 167     int rho= 3-s->sprite_warping_accuracy;
 168     int r=16/a;
 169     const int vop_ref[4][2]= {{0,0}, {s->width,0}, {0, s->height}, {s->width, s->height}}; // only true for rectangle shapes
 170     int d[4][2]={{0,0}, {0,0}, {0,0}, {0,0}};
 171     int sprite_ref[4][2];
 172     int virtual_ref[2][2];
 173     int w2, h2, w3, h3;
 174     int alpha=0, beta=0;
 175     int w= s->width;
 176     int h= s->height;
 177     int min_ab;
 178
 179     for(i=0; i<s->num_sprite_warping_points; i++){
 180         int length;
 181         int x=0, y=0;
 182
 183         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 184         if(length){
 185             x= get_xbits(gb, length);
 186         }
 187         if(!(s->divx_version==500 && s->divx_build==413)) skip_bits1(gb); /* marker bit */
 188
 189         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 190         if(length){
 191             y=get_xbits(gb, length);
 192         }
 193         skip_bits1(gb); /* marker bit */
 194         s->sprite_traj[i][0]= d[i][0]= x;
 195         s->sprite_traj[i][1]= d[i][1]= y;
 196     }
 197     for(; i<4; i++)
 198         s->sprite_traj[i][0]= s->sprite_traj[i][1]= 0;
 199
 200     while((1<<alpha)<w) alpha++;
 201     while((1<<beta )<h) beta++; // there seems to be a typo in the mpeg4 std for the definition of w' and h'
 202     w2= 1<<alpha;
 203     h2= 1<<beta;
 204
 205 // Note, the 4th point isn't used for GMC
 206     if(s->divx_version==500 && s->divx_build==413){
 207         sprite_ref[0][0]= a*vop_ref[0][0] + d[0][0];
 208         sprite_ref[0][1]= a*vop_ref[0][1] + d[0][1];
 209         sprite_ref[1][0]= a*vop_ref[1][0] + d[0][0] + d[1][0];
 210         sprite_ref[1][1]= a*vop_ref[1][1] + d[0][1] + d[1][1];
 211         sprite_ref[2][0]= a*vop_ref[2][0] + d[0][0] + d[2][0];
 212         sprite_ref[2][1]= a*vop_ref[2][1] + d[0][1] + d[2][1];
 213     } else {
 214         sprite_ref[0][0]= (a>>1)*(2*vop_ref[0][0] + d[0][0]);
 215         sprite_ref[0][1]= (a>>1)*(2*vop_ref[0][1] + d[0][1]);
 216         sprite_ref[1][0]= (a>>1)*(2*vop_ref[1][0] + d[0][0] + d[1][0]);
 217         sprite_ref[1][1]= (a>>1)*(2*vop_ref[1][1] + d[0][1] + d[1][1]);
 218         sprite_ref[2][0]= (a>>1)*(2*vop_ref[2][0] + d[0][0] + d[2][0]);
 219         sprite_ref[2][1]= (a>>1)*(2*vop_ref[2][1] + d[0][1] + d[2][1]);
 220     }
 221 /*    sprite_ref[3][0]= (a>>1)*(2*vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
 222     sprite_ref[3][1]= (a>>1)*(2*vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
 223
 224 // this is mostly identical to the mpeg4 std (and is totally unreadable because of that ...)
 225 // perhaps it should be reordered to be more readable ...
 226 // the idea behind this virtual_ref mess is to be able to use shifts later per pixel instead of divides
 227 // so the distance between points is converted from w&h based to w2&h2 based which are of the 2^x form
 228     virtual_ref[0][0]= 16*(vop_ref[0][0] + w2)
 229         + 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);
 230     virtual_ref[0][1]= 16*vop_ref[0][1]
 231         + 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);
 232     virtual_ref[1][0]= 16*vop_ref[0][0]
 233         + 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);
 234     virtual_ref[1][1]= 16*(vop_ref[0][1] + h2)
 235         + 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);
 236
 237     switch(s->num_sprite_warping_points)
 238     {
 239         case 0:
 240             s->sprite_offset[0][0]= 0;
 241             s->sprite_offset[0][1]= 0;
 242             s->sprite_offset[1][0]= 0;
 243             s->sprite_offset[1][1]= 0;
 244             s->sprite_delta[0][0]= a;
 245             s->sprite_delta[0][1]= 0;
 246             s->sprite_delta[1][0]= 0;
 247             s->sprite_delta[1][1]= a;
 248             s->sprite_shift[0]= 0;
 249             s->sprite_shift[1]= 0;
 250             break;
 251         case 1: //GMC only
 252             s->sprite_offset[0][0]= sprite_ref[0][0] - a*vop_ref[0][0];
 253             s->sprite_offset[0][1]= sprite_ref[0][1] - a*vop_ref[0][1];
 254             s->sprite_offset[1][0]= ((sprite_ref[0][0]>>1)|(sprite_ref[0][0]&1)) - a*(vop_ref[0][0]/2);
 255             s->sprite_offset[1][1]= ((sprite_ref[0][1]>>1)|(sprite_ref[0][1]&1)) - a*(vop_ref[0][1]/2);
 256             s->sprite_delta[0][0]= a;
 257             s->sprite_delta[0][1]= 0;
 258             s->sprite_delta[1][0]= 0;
 259             s->sprite_delta[1][1]= a;
 260             s->sprite_shift[0]= 0;
 261             s->sprite_shift[1]= 0;
 262             break;
 263         case 2:
 264             s->sprite_offset[0][0]= (sprite_ref[0][0]<<(alpha+rho))
 265                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][0])
 266                                                   + ( r*sprite_ref[0][1] - virtual_ref[0][1])*(-vop_ref[0][1])
 267                                                   + (1<<(alpha+rho-1));
 268             s->sprite_offset[0][1]= (sprite_ref[0][1]<<(alpha+rho))
 269                                                   + (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-vop_ref[0][0])
 270                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][1])
 271                                                   + (1<<(alpha+rho-1));
 272             s->sprite_offset[1][0]= ( (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][0] + 1)
 273                                      +( r*sprite_ref[0][1] - virtual_ref[0][1])*(-2*vop_ref[0][1] + 1)
 274                                      +2*w2*r*sprite_ref[0][0]
 275                                      - 16*w2
 276                                      + (1<<(alpha+rho+1)));
 277             s->sprite_offset[1][1]= ( (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-2*vop_ref[0][0] + 1)
 278                                      +(-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][1] + 1)
 279                                      +2*w2*r*sprite_ref[0][1]
 280                                      - 16*w2
 281                                      + (1<<(alpha+rho+1)));
 282             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 283             s->sprite_delta[0][1]=   (+r*sprite_ref[0][1] - virtual_ref[0][1]);
 284             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1]);
 285             s->sprite_delta[1][1]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 286
 287             s->sprite_shift[0]= alpha+rho;
 288             s->sprite_shift[1]= alpha+rho+2;
 289             break;
 290         case 3:
 291             min_ab= FFMIN(alpha, beta);
 292             w3= w2>>min_ab;
 293             h3= h2>>min_ab;
 294             s->sprite_offset[0][0]=  (sprite_ref[0][0]<<(alpha+beta+rho-min_ab))
 295                                    + (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-vop_ref[0][0])
 296                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-vop_ref[0][1])
 297                                    + (1<<(alpha+beta+rho-min_ab-1));
 298             s->sprite_offset[0][1]=  (sprite_ref[0][1]<<(alpha+beta+rho-min_ab))
 299                                    + (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-vop_ref[0][0])
 300                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-vop_ref[0][1])
 301                                    + (1<<(alpha+beta+rho-min_ab-1));
 302             s->sprite_offset[1][0]=  (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-2*vop_ref[0][0] + 1)
 303                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-2*vop_ref[0][1] + 1)
 304                                    + 2*w2*h3*r*sprite_ref[0][0]
 305                                    - 16*w2*h3
 306                                    + (1<<(alpha+beta+rho-min_ab+1));
 307             s->sprite_offset[1][1]=  (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-2*vop_ref[0][0] + 1)
 308                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-2*vop_ref[0][1] + 1)
 309                                    + 2*w2*h3*r*sprite_ref[0][1]
 310                                    - 16*w2*h3
 311                                    + (1<<(alpha+beta+rho-min_ab+1));
 312             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3;
 313             s->sprite_delta[0][1]=   (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3;
 314             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3;
 315             s->sprite_delta[1][1]=   (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3;
 316
 317             s->sprite_shift[0]= alpha + beta + rho - min_ab;
 318             s->sprite_shift[1]= alpha + beta + rho - min_ab + 2;
 319             break;
 320     }
 321     /* try to simplify the situation */
 322     if(   s->sprite_delta[0][0] == a<<s->sprite_shift[0]
 323        && s->sprite_delta[0][1] == 0
 324        && s->sprite_delta[1][0] == 0
 325        && s->sprite_delta[1][1] == a<<s->sprite_shift[0])
 326     {
 327         s->sprite_offset[0][0]>>=s->sprite_shift[0];
 328         s->sprite_offset[0][1]>>=s->sprite_shift[0];
 329         s->sprite_offset[1][0]>>=s->sprite_shift[1];
 330         s->sprite_offset[1][1]>>=s->sprite_shift[1];
 331         s->sprite_delta[0][0]= a;
 332         s->sprite_delta[0][1]= 0;
 333         s->sprite_delta[1][0]= 0;
 334         s->sprite_delta[1][1]= a;
 335         s->sprite_shift[0]= 0;
 336         s->sprite_shift[1]= 0;
 337         s->real_sprite_warping_points=1;
 338     }
 339     else{
 340         int shift_y= 16 - s->sprite_shift[0];
 341         int shift_c= 16 - s->sprite_shift[1];
 342         for(i=0; i<2; i++){
 343             s->sprite_offset[0][i]<<= shift_y;
 344             s->sprite_offset[1][i]<<= shift_c;
 345             s->sprite_delta[0][i]<<= shift_y;
 346             s->sprite_delta[1][i]<<= shift_y;
 347             s->sprite_shift[i]= 16;
 348         }
 349         s->real_sprite_warping_points= s->num_sprite_warping_points;
 350     }
 351 }
 352
 353 /**
 354  * Decode the next video packet.
 355  * @return <0 if something went wrong
 356  */
 357 int mpeg4_decode_video_packet_header(MpegEncContext *s)
 358 {
 359     int mb_num_bits= av_log2(s->mb_num - 1) + 1;
 360     int header_extension=0, mb_num, len;
 361
 362     /* is there enough space left for a video packet + header */
 363     if( get_bits_count(&s->gb) > s->gb.size_in_bits-20) return -1;
 364
 365     for(len=0; len<32; len++){
 366         if(get_bits1(&s->gb)) break;
 367     }
 368
 369     if(len!=ff_mpeg4_get_video_packet_prefix_length(s)){
 370         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
 371         return -1;
 372     }
 373
 374     if(s->shape != RECT_SHAPE){
 375         header_extension= get_bits1(&s->gb);
 376         //FIXME more stuff here
 377     }
 378
 379     mb_num= get_bits(&s->gb, mb_num_bits);
 380     if(mb_num>=s->mb_num){
 381         av_log(s->avctx, AV_LOG_ERROR, "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
 382         return -1;
 383     }
 384
 385     s->mb_x= mb_num % s->mb_width;
 386     s->mb_y= mb_num / s->mb_width;
 387
 388     if(s->shape != BIN_ONLY_SHAPE){
 389         int qscale= get_bits(&s->gb, s->quant_precision);
 390         if(qscale)
 391             s->chroma_qscale=s->qscale= qscale;
 392     }
 393
 394     if(s->shape == RECT_SHAPE){
 395         header_extension= get_bits1(&s->gb);
 396     }
 397     if(header_extension){
 398         int time_incr=0;
 399
 400         while (get_bits1(&s->gb) != 0)
 401             time_incr++;
 402
 403         check_marker(&s->gb, "before time_increment in video packed header");
 404         skip_bits(&s->gb, s->time_increment_bits); /* time_increment */
 405         check_marker(&s->gb, "before vop_coding_type in video packed header");
 406
 407         skip_bits(&s->gb, 2); /* vop coding type */
 408         //FIXME not rect stuff here
 409
 410         if(s->shape != BIN_ONLY_SHAPE){
 411             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
 412 //FIXME don't just ignore everything
 413             if(s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 414                 mpeg4_decode_sprite_trajectory(s, &s->gb);
 415                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
 416             }
 417
 418             //FIXME reduced res stuff here
 419
 420             if (s->pict_type != AV_PICTURE_TYPE_I) {
 421                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
 422                 if(f_code==0){
 423                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (f_code=0)\n");
 424                 }
 425             }
 426             if (s->pict_type == AV_PICTURE_TYPE_B) {
 427                 int b_code = get_bits(&s->gb, 3);
 428                 if(b_code==0){
 429                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (b_code=0)\n");
 430                 }
 431             }
 432         }
 433     }
 434     //FIXME new-pred stuff
 435
 436     return 0;
 437 }
 438
 439 /**
 440  * Get the average motion vector for a GMC MB.
 441  * @param n either 0 for the x component or 1 for y
 442  * @return the average MV for a GMC MB
 443  */
 444 static inline int get_amv(MpegEncContext *s, int n){
 445     int x, y, mb_v, sum, dx, dy, shift;
 446     int len = 1 << (s->f_code + 4);
 447     const int a= s->sprite_warping_accuracy;
 448
 449     if(s->workaround_bugs & FF_BUG_AMV)
 450         len >>= s->quarter_sample;
 451
 452     if(s->real_sprite_warping_points==1){
 453         if(s->divx_version==500 && s->divx_build==413)
 454             sum= s->sprite_offset[0][n] / (1<<(a - s->quarter_sample));
 455         else
 456             sum= RSHIFT(s->sprite_offset[0][n]<<s->quarter_sample, a);
 457     }else{
 458         dx= s->sprite_delta[n][0];
 459         dy= s->sprite_delta[n][1];
 460         shift= s->sprite_shift[0];
 461         if(n) dy -= 1<<(shift + a + 1);
 462         else  dx -= 1<<(shift + a + 1);
 463         mb_v= s->sprite_offset[0][n] + dx*s->mb_x*16 + dy*s->mb_y*16;
 464
 465         sum=0;
 466         for(y=0; y<16; y++){
 467             int v;
 468
 469             v= mb_v + dy*y;
 470             //XXX FIXME optimize
 471             for(x=0; x<16; x++){
 472                 sum+= v>>shift;
 473                 v+= dx;
 474             }
 475         }
 476         sum= RSHIFT(sum, a+8-s->quarter_sample);
 477     }
 478
 479     if      (sum < -len) sum= -len;
 480     else if (sum >= len) sum= len-1;
 481
 482     return sum;
 483 }
 484
 485 /**
 486  * Decode the dc value.
 487  * @param n block index (0-3 are luma, 4-5 are chroma)
 488  * @param dir_ptr the prediction direction will be stored here
 489  * @return the quantized dc
 490  */
 491 static inline int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
 492 {
 493     int level, code;
 494
 495     if (n < 4)
 496         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
 497     else
 498         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
 499     if (code < 0 || code > 9 /* && s->nbit<9 */){
 500         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
 501         return -1;
 502     }
 503     if (code == 0) {
 504         level = 0;
 505     } else {
 506         if(IS_3IV1){
 507             if(code==1)
 508                 level= 2*get_bits1(&s->gb)-1;
 509             else{
 510                 if(get_bits1(&s->gb))
 511                     level = get_bits(&s->gb, code-1) + (1<<(code-1));
 512                 else
 513                     level = -get_bits(&s->gb, code-1) - (1<<(code-1));
 514             }
 515         }else{
 516             level = get_xbits(&s->gb, code);
 517         }
 518
 519         if (code > 8){
 520             if(get_bits1(&s->gb)==0){ /* marker */
 521                 if(s->err_recognition&(AV_EF_BITSTREAM|AV_EF_COMPLIANT)){
 522                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
 523                     return -1;
 524                 }
 525             }
 526         }
 527     }
 528
 529     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
 530 }
 531
 532 /**
 533  * Decode first partition.
 534  * @return number of MBs decoded or <0 if an error occurred
 535  */
 536 static int mpeg4_decode_partition_a(MpegEncContext *s){
 537     int mb_num;
 538     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 539
 540     /* decode first partition */
 541     mb_num=0;
 542     s->first_slice_line=1;
 543     for(; s->mb_y<s->mb_height; s->mb_y++){
 544         ff_init_block_index(s);
 545         for(; s->mb_x<s->mb_width; s->mb_x++){
 546             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 547             int cbpc;
 548             int dir=0;
 549
 550             mb_num++;
 551             ff_update_block_index(s);
 552             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 553                 s->first_slice_line=0;
 554
 555             if(s->pict_type==AV_PICTURE_TYPE_I){
 556                 int i;
 557
 558                 do{
 559                     if(show_bits_long(&s->gb, 19)==DC_MARKER){
 560                         return mb_num-1;
 561                     }
 562
 563                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 564                     if (cbpc < 0){
 565                         av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 566                         return -1;
 567                     }
 568                 }while(cbpc == 8);
 569
 570                 s->cbp_table[xy]= cbpc & 3;
 571                 s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
 572                 s->mb_intra = 1;
 573
 574                 if(cbpc & 4) {
 575                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 576                 }
 577                 s->current_picture.f.qscale_table[xy]= s->qscale;
 578
 579                 s->mbintra_table[xy]= 1;
 580                 for(i=0; i<6; i++){
 581                     int dc_pred_dir;
 582                     int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 583                     if(dc < 0){
 584                         av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 585                         return -1;
 586                     }
 587                     dir<<=1;
 588                     if(dc_pred_dir) dir|=1;
 589                 }
 590                 s->pred_dir_table[xy]= dir;
 591             }else{ /* P/S_TYPE */
 592                 int mx, my, pred_x, pred_y, bits;
 593                 int16_t * const mot_val = s->current_picture.f.motion_val[0][s->block_index[0]];
 594                 const int stride= s->b8_stride*2;
 595
 596 try_again:
 597                 bits= show_bits(&s->gb, 17);
 598                 if(bits==MOTION_MARKER){
 599                     return mb_num-1;
 600                 }
 601                 skip_bits1(&s->gb);
 602                 if(bits&0x10000){
 603                     /* skip mb */
 604                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 605                         s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 606                         mx= get_amv(s, 0);
 607                         my= get_amv(s, 1);
 608                     }else{
 609                         s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 610                         mx=my=0;
 611                     }
 612                     mot_val[0       ]= mot_val[2       ]=
 613                     mot_val[0+stride]= mot_val[2+stride]= mx;
 614                     mot_val[1       ]= mot_val[3       ]=
 615                     mot_val[1+stride]= mot_val[3+stride]= my;
 616
 617                     if(s->mbintra_table[xy])
 618                         ff_clean_intra_table_entries(s);
 619                     continue;
 620                 }
 621
 622                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 623                 if (cbpc < 0){
 624                     av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 625                     return -1;
 626                 }
 627                 if(cbpc == 20)
 628                     goto try_again;
 629
 630                 s->cbp_table[xy]= cbpc&(8+3); //8 is dquant
 631
 632                 s->mb_intra = ((cbpc & 4) != 0);
 633
 634                 if(s->mb_intra){
 635                     s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
 636                     s->mbintra_table[xy]= 1;
 637                     mot_val[0       ]= mot_val[2       ]=
 638                     mot_val[0+stride]= mot_val[2+stride]= 0;
 639                     mot_val[1       ]= mot_val[3       ]=
 640                     mot_val[1+stride]= mot_val[3+stride]= 0;
 641                 }else{
 642                     if(s->mbintra_table[xy])
 643                         ff_clean_intra_table_entries(s);
 644
 645                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
 646                         s->mcsel= get_bits1(&s->gb);
 647                     else s->mcsel= 0;
 648
 649                     if ((cbpc & 16) == 0) {
 650                         /* 16x16 motion prediction */
 651
 652                         h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 653                         if(!s->mcsel){
 654                             mx = h263_decode_motion(s, pred_x, s->f_code);
 655                             if (mx >= 0xffff)
 656                                 return -1;
 657
 658                             my = h263_decode_motion(s, pred_y, s->f_code);
 659                             if (my >= 0xffff)
 660                                 return -1;
 661                             s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 662                         } else {
 663                             mx = get_amv(s, 0);
 664                             my = get_amv(s, 1);
 665                             s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 666                         }
 667
 668                         mot_val[0       ]= mot_val[2       ] =
 669                         mot_val[0+stride]= mot_val[2+stride]= mx;
 670                         mot_val[1       ]= mot_val[3       ]=
 671                         mot_val[1+stride]= mot_val[3+stride]= my;
 672                     } else {
 673                         int i;
 674                         s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 675                         for(i=0;i<4;i++) {
 676                             int16_t *mot_val= h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 677                             mx = h263_decode_motion(s, pred_x, s->f_code);
 678                             if (mx >= 0xffff)
 679                                 return -1;
 680
 681                             my = h263_decode_motion(s, pred_y, s->f_code);
 682                             if (my >= 0xffff)
 683                                 return -1;
 684                             mot_val[0] = mx;
 685                             mot_val[1] = my;
 686                         }
 687                     }
 688                 }
 689             }
 690         }
 691         s->mb_x= 0;
 692     }
 693
 694     return mb_num;
 695 }
 696
 697 /**
 698  * decode second partition.
 699  * @return <0 if an error occurred
 700  */
 701 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count){
 702     int mb_num=0;
 703     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 704
 705     s->mb_x= s->resync_mb_x;
 706     s->first_slice_line=1;
 707     for(s->mb_y= s->resync_mb_y; mb_num < mb_count; s->mb_y++){
 708         ff_init_block_index(s);
 709         for(; mb_num < mb_count && s->mb_x<s->mb_width; s->mb_x++){
 710             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 711
 712             mb_num++;
 713             ff_update_block_index(s);
 714             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 715                 s->first_slice_line=0;
 716
 717             if(s->pict_type==AV_PICTURE_TYPE_I){
 718                 int ac_pred= get_bits1(&s->gb);
 719                 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 720                 if(cbpy<0){
 721                     av_log(s->avctx, AV_LOG_ERROR, "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 722                     return -1;
 723                 }
 724
 725                 s->cbp_table[xy]|= cbpy<<2;
 726                 s->current_picture.f.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 727             }else{ /* P || S_TYPE */
 728                 if (IS_INTRA(s->current_picture.f.mb_type[xy])) {
 729                     int dir=0,i;
 730                     int ac_pred = get_bits1(&s->gb);
 731                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 732
 733                     if(cbpy<0){
 734                         av_log(s->avctx, AV_LOG_ERROR, "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 735                         return -1;
 736                     }
 737
 738                     if(s->cbp_table[xy] & 8) {
 739                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 740                     }
 741                     s->current_picture.f.qscale_table[xy] = s->qscale;
 742
 743                     for(i=0; i<6; i++){
 744                         int dc_pred_dir;
 745                         int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 746                         if(dc < 0){
 747                             av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 748                             return -1;
 749                         }
 750                         dir<<=1;
 751                         if(dc_pred_dir) dir|=1;
 752                     }
 753                     s->cbp_table[xy]&= 3; //remove dquant
 754                     s->cbp_table[xy]|= cbpy<<2;
 755                     s->current_picture.f.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 756                     s->pred_dir_table[xy]= dir;
 757                 } else if (IS_SKIP(s->current_picture.f.mb_type[xy])) {
 758                     s->current_picture.f.qscale_table[xy] = s->qscale;
 759                     s->cbp_table[xy]= 0;
 760                 }else{
 761                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 762
 763                     if(cbpy<0){
 764                         av_log(s->avctx, AV_LOG_ERROR, "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 765                         return -1;
 766                     }
 767
 768                     if(s->cbp_table[xy] & 8) {
 769                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 770                     }
 771                     s->current_picture.f.qscale_table[xy] = s->qscale;
 772
 773                     s->cbp_table[xy]&= 3; //remove dquant
 774                     s->cbp_table[xy]|= (cbpy^0xf)<<2;
 775                 }
 776             }
 777         }
 778         if(mb_num >= mb_count) return 0;
 779         s->mb_x= 0;
 780     }
 781     return 0;
 782 }
 783
 784 /**
 785  * Decode the first and second partition.
 786  * @return <0 if error (and sets error type in the error_status_table)
 787  */
 788 int ff_mpeg4_decode_partitions(MpegEncContext *s)
 789 {
 790     int mb_num;
 791     const int part_a_error= s->pict_type==AV_PICTURE_TYPE_I ? (ER_DC_ERROR|ER_MV_ERROR) : ER_MV_ERROR;
 792     const int part_a_end  = s->pict_type==AV_PICTURE_TYPE_I ? (ER_DC_END  |ER_MV_END)   : ER_MV_END;
 793
 794     mb_num= mpeg4_decode_partition_a(s);
 795     if(mb_num<0){
 796         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 797         return -1;
 798     }
 799
 800     if(s->resync_mb_x + s->resync_mb_y*s->mb_width + mb_num > s->mb_num){
 801         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
 802         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 803         return -1;
 804     }
 805
 806     s->mb_num_left= mb_num;
 807
 808     if(s->pict_type==AV_PICTURE_TYPE_I){
 809         while(show_bits(&s->gb, 9) == 1)
 810             skip_bits(&s->gb, 9);
 811         if(get_bits_long(&s->gb, 19)!=DC_MARKER){
 812             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first I partition at %d %d\n", s->mb_x, s->mb_y);
 813             return -1;
 814         }
 815     }else{
 816         while(show_bits(&s->gb, 10) == 1)
 817             skip_bits(&s->gb, 10);
 818         if(get_bits(&s->gb, 17)!=MOTION_MARKER){
 819             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first P partition at %d %d\n", s->mb_x, s->mb_y);
 820             return -1;
 821         }
 822     }
 823     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, part_a_end);
 824
 825     if( mpeg4_decode_partition_b(s, mb_num) < 0){
 826         if(s->pict_type==AV_PICTURE_TYPE_P)
 827             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_DC_ERROR);
 828         return -1;
 829     }else{
 830         if(s->pict_type==AV_PICTURE_TYPE_P)
 831             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_DC_END);
 832     }
 833
 834     return 0;
 835 }
 836
 837 /**
 838  * Decode a block.
 839  * @return <0 if an error occurred
 840  */
 841 static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
 842                               int n, int coded, int intra, int rvlc)
 843 {
 844     int level, i, last, run;
 845     int dc_pred_dir;
 846     RLTable * rl;
 847     RL_VLC_ELEM * rl_vlc;
 848     const uint8_t * scan_table;
 849     int qmul, qadd;
 850
 851     //Note intra & rvlc should be optimized away if this is inlined
 852
 853     if(intra) {
 854       if(s->use_intra_dc_vlc){
 855         /* DC coef */
 856         if(s->partitioned_frame){
 857             level = s->dc_val[0][ s->block_index[n] ];
 858             if(n<4) level= FASTDIV((level + (s->y_dc_scale>>1)), s->y_dc_scale);
 859             else    level= FASTDIV((level + (s->c_dc_scale>>1)), s->c_dc_scale);
 860             dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_stride]<<n)&32;
 861         }else{
 862             level = mpeg4_decode_dc(s, n, &dc_pred_dir);
 863             if (level < 0)
 864                 return -1;
 865         }
 866         block[0] = level;
 867         i = 0;
 868       }else{
 869             i = -1;
 870             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
 871       }
 872       if (!coded)
 873           goto not_coded;
 874
 875       if(rvlc){
 876           rl = &rvlc_rl_intra;
 877           rl_vlc = rvlc_rl_intra.rl_vlc[0];
 878       }else{
 879           rl = &ff_mpeg4_rl_intra;
 880           rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
 881       }
 882       if (s->ac_pred) {
 883           if (dc_pred_dir == 0)
 884               scan_table = s->intra_v_scantable.permutated; /* left */
 885           else
 886               scan_table = s->intra_h_scantable.permutated; /* top */
 887       } else {
 888             scan_table = s->intra_scantable.permutated;
 889       }
 890       qmul=1;
 891       qadd=0;
 892     } else {
 893         i = -1;
 894         if (!coded) {
 895             s->block_last_index[n] = i;
 896             return 0;
 897         }
 898         if(rvlc) rl = &rvlc_rl_inter;
 899         else     rl = &ff_h263_rl_inter;
 900
 901         scan_table = s->intra_scantable.permutated;
 902
 903         if(s->mpeg_quant){
 904             qmul=1;
 905             qadd=0;
 906             if(rvlc){
 907                 rl_vlc = rvlc_rl_inter.rl_vlc[0];
 908             }else{
 909                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
 910             }
 911         }else{
 912             qmul = s->qscale << 1;
 913             qadd = (s->qscale - 1) | 1;
 914             if(rvlc){
 915                 rl_vlc = rvlc_rl_inter.rl_vlc[s->qscale];
 916             }else{
 917                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
 918             }
 919         }
 920     }
 921   {
 922     OPEN_READER(re, &s->gb);
 923     for(;;) {
 924         UPDATE_CACHE(re, &s->gb);
 925         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
 926         if (level==0) {
 927           /* escape */
 928           if(rvlc){
 929                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 930                     av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in rvlc esc\n");
 931                     return -1;
 932                 }; SKIP_CACHE(re, &s->gb, 1);
 933
 934                 last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 935                 run=   SHOW_UBITS(re, &s->gb, 6);
 936                 SKIP_COUNTER(re, &s->gb, 1+1+6);
 937                 UPDATE_CACHE(re, &s->gb);
 938
 939                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 940                     av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in rvlc esc\n");
 941                     return -1;
 942                 }; SKIP_CACHE(re, &s->gb, 1);
 943
 944                 level= SHOW_UBITS(re, &s->gb, 11); SKIP_CACHE(re, &s->gb, 11);
 945
 946                 if(SHOW_UBITS(re, &s->gb, 5)!=0x10){
 947                     av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
 948                     return -1;
 949                 }; SKIP_CACHE(re, &s->gb, 5);
 950
 951                 level=  level * qmul + qadd;
 952                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 953                 SKIP_COUNTER(re, &s->gb, 1+11+5+1);
 954
 955                 i+= run + 1;
 956                 if(last) i+=192;
 957           }else{
 958             int cache;
 959             cache= GET_CACHE(re, &s->gb);
 960
 961             if(IS_3IV1)
 962                 cache ^= 0xC0000000;
 963
 964             if (cache&0x80000000) {
 965                 if (cache&0x40000000) {
 966                     /* third escape */
 967                     SKIP_CACHE(re, &s->gb, 2);
 968                     last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 969                     run=   SHOW_UBITS(re, &s->gb, 6);
 970                     SKIP_COUNTER(re, &s->gb, 2+1+6);
 971                     UPDATE_CACHE(re, &s->gb);
 972
 973                     if(IS_3IV1){
 974                         level= SHOW_SBITS(re, &s->gb, 12); LAST_SKIP_BITS(re, &s->gb, 12);
 975                     }else{
 976                         if(SHOW_UBITS(re, &s->gb, 1)==0){
 977                             av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in 3. esc\n");
 978                             return -1;
 979                         }; SKIP_CACHE(re, &s->gb, 1);
 980
 981                         level= SHOW_SBITS(re, &s->gb, 12); SKIP_CACHE(re, &s->gb, 12);
 982
 983                         if(SHOW_UBITS(re, &s->gb, 1)==0){
 984                             av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in 3. esc\n");
 985                             return -1;
 986                         }
 987
 988                         SKIP_COUNTER(re, &s->gb, 1+12+1);
 989                     }
 990
 991 #if 0
 992                     if(s->error_recognition >= FF_ER_COMPLIANT){
 993                         const int abs_level= FFABS(level);
 994                         if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
 995                             const int run1= run - rl->max_run[last][abs_level] - 1;
 996                             if(abs_level <= rl->max_level[last][run]){
 997                                 av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
 998                                 return -1;
 999                             }
1000                             if(s->error_recognition > FF_ER_COMPLIANT){
1001                                 if(abs_level <= rl->max_level[last][run]*2){
1002                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
1003                                     return -1;
1004                                 }
1005                                 if(run1 >= 0 && abs_level <= rl->max_level[last][run1]){
1006                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
1007                                     return -1;
1008                                 }
1009                             }
1010                         }
1011                     }
1012 #endif
1013                     if (level>0) level= level * qmul + qadd;
1014                     else         level= level * qmul - qadd;
1015
1016                     if((unsigned)(level + 2048) > 4095){
1017                         if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_AGGRESSIVE)){
1018                             if(level > 2560 || level<-2560){
1019                                 av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
1020                                 return -1;
1021                             }
1022                         }
1023                         level= level<0 ? -2048 : 2047;
1024                     }
1025
1026                     i+= run + 1;
1027                     if(last) i+=192;
1028                 } else {
1029                     /* second escape */
1030                     SKIP_BITS(re, &s->gb, 2);
1031                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1032                     i+= run + rl->max_run[run>>7][level/qmul] +1; //FIXME opt indexing
1033                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1034                     LAST_SKIP_BITS(re, &s->gb, 1);
1035                 }
1036             } else {
1037                 /* first escape */
1038                 SKIP_BITS(re, &s->gb, 1);
1039                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1040                 i+= run;
1041                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
1042                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1043                 LAST_SKIP_BITS(re, &s->gb, 1);
1044             }
1045           }
1046         } else {
1047             i+= run;
1048             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1049             LAST_SKIP_BITS(re, &s->gb, 1);
1050         }
1051         if (i > 62){
1052             i-= 192;
1053             if(i&(~63)){
1054                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1055                 return -1;
1056             }
1057
1058             block[scan_table[i]] = level;
1059             break;
1060         }
1061
1062         block[scan_table[i]] = level;
1063     }
1064     CLOSE_READER(re, &s->gb);
1065   }
1066  not_coded:
1067     if (intra) {
1068         if(!s->use_intra_dc_vlc){
1069             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1070
1071             i -= i>>31; //if(i == -1) i=0;
1072         }
1073
1074         mpeg4_pred_ac(s, block, n, dc_pred_dir);
1075         if (s->ac_pred) {
1076             i = 63; /* XXX: not optimal */
1077         }
1078     }
1079     s->block_last_index[n] = i;
1080     return 0;
1081 }
1082
1083 /**
1084  * decode partition C of one MB.
1085  * @return <0 if an error occurred
1086  */
1087 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, DCTELEM block[6][64])
1088 {
1089     int cbp, mb_type;
1090     const int xy= s->mb_x + s->mb_y*s->mb_stride;
1091
1092     mb_type = s->current_picture.f.mb_type[xy];
1093     cbp = s->cbp_table[xy];
1094
1095     s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1096
1097     if (s->current_picture.f.qscale_table[xy] != s->qscale) {
1098         ff_set_qscale(s, s->current_picture.f.qscale_table[xy]);
1099     }
1100
1101     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1102         int i;
1103         for(i=0; i<4; i++){
1104             s->mv[0][i][0] = s->current_picture.f.motion_val[0][s->block_index[i]][0];
1105             s->mv[0][i][1] = s->current_picture.f.motion_val[0][s->block_index[i]][1];
1106         }
1107         s->mb_intra = IS_INTRA(mb_type);
1108
1109         if (IS_SKIP(mb_type)) {
1110             /* skip mb */
1111             for(i=0;i<6;i++)
1112                 s->block_last_index[i] = -1;
1113             s->mv_dir = MV_DIR_FORWARD;
1114             s->mv_type = MV_TYPE_16X16;
1115             if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1116                 s->mcsel=1;
1117                 s->mb_skipped = 0;
1118             }else{
1119                 s->mcsel=0;
1120                 s->mb_skipped = 1;
1121             }
1122         }else if(s->mb_intra){
1123             s->ac_pred = IS_ACPRED(s->current_picture.f.mb_type[xy]);
1124         }else if(!s->mb_intra){
1125 //            s->mcsel= 0; //FIXME do we need to init that
1126
1127             s->mv_dir = MV_DIR_FORWARD;
1128             if (IS_8X8(mb_type)) {
1129                 s->mv_type = MV_TYPE_8X8;
1130             } else {
1131                 s->mv_type = MV_TYPE_16X16;
1132             }
1133         }
1134     } else { /* I-Frame */
1135         s->mb_intra = 1;
1136         s->ac_pred = IS_ACPRED(s->current_picture.f.mb_type[xy]);
1137     }
1138
1139     if (!IS_SKIP(mb_type)) {
1140         int i;
1141         s->dsp.clear_blocks(s->block[0]);
1142         /* decode each block */
1143         for (i = 0; i < 6; i++) {
1144             if(mpeg4_decode_block(s, block[i], i, cbp&32, s->mb_intra, s->rvlc) < 0){
1145                 av_log(s->avctx, AV_LOG_ERROR, "texture corrupted at %d %d %d\n", s->mb_x, s->mb_y, s->mb_intra);
1146                 return -1;
1147             }
1148             cbp+=cbp;
1149         }
1150     }
1151
1152     /* per-MB end of slice check */
1153
1154     if(--s->mb_num_left <= 0){
1155         if(mpeg4_is_resync(s))
1156             return SLICE_END;
1157         else
1158             return SLICE_NOEND;
1159     }else{
1160         if(mpeg4_is_resync(s)){
1161             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1162             if(s->cbp_table[xy+delta])
1163                 return SLICE_END;
1164         }
1165         return SLICE_OK;
1166     }
1167 }
1168
1169 static int mpeg4_decode_mb(MpegEncContext *s,
1170                       DCTELEM block[6][64])
1171 {
1172     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1173     int16_t *mot_val;
1174     static int8_t quant_tab[4] = { -1, -2, 1, 2 };
1175     const int xy= s->mb_x + s->mb_y * s->mb_stride;
1176
1177     assert(s->h263_pred);
1178
1179     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1180         do{
1181             if (get_bits1(&s->gb)) {
1182                 /* skip mb */
1183                 s->mb_intra = 0;
1184                 for(i=0;i<6;i++)
1185                     s->block_last_index[i] = -1;
1186                 s->mv_dir = MV_DIR_FORWARD;
1187                 s->mv_type = MV_TYPE_16X16;
1188                 if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1189                     s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1190                     s->mcsel=1;
1191                     s->mv[0][0][0]= get_amv(s, 0);
1192                     s->mv[0][0][1]= get_amv(s, 1);
1193
1194                     s->mb_skipped = 0;
1195                 }else{
1196                     s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1197                     s->mcsel=0;
1198                     s->mv[0][0][0] = 0;
1199                     s->mv[0][0][1] = 0;
1200                     s->mb_skipped = 1;
1201                 }
1202                 goto end;
1203             }
1204             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1205             if (cbpc < 0){
1206                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1207                 return -1;
1208             }
1209         }while(cbpc == 20);
1210
1211         s->dsp.clear_blocks(s->block[0]);
1212         dquant = cbpc & 8;
1213         s->mb_intra = ((cbpc & 4) != 0);
1214         if (s->mb_intra) goto intra;
1215
1216         if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
1217             s->mcsel= get_bits1(&s->gb);
1218         else s->mcsel= 0;
1219         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1220
1221         cbp = (cbpc & 3) | (cbpy << 2);
1222         if (dquant) {
1223             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1224         }
1225         if((!s->progressive_sequence) && (cbp || (s->workaround_bugs&FF_BUG_XVID_ILACE)))
1226             s->interlaced_dct= get_bits1(&s->gb);
1227
1228         s->mv_dir = MV_DIR_FORWARD;
1229         if ((cbpc & 16) == 0) {
1230             if(s->mcsel){
1231                 s->current_picture.f.mb_type[xy] = MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1232                 /* 16x16 global motion prediction */
1233                 s->mv_type = MV_TYPE_16X16;
1234                 mx= get_amv(s, 0);
1235                 my= get_amv(s, 1);
1236                 s->mv[0][0][0] = mx;
1237                 s->mv[0][0][1] = my;
1238             }else if((!s->progressive_sequence) && get_bits1(&s->gb)){
1239                 s->current_picture.f.mb_type[xy] = MB_TYPE_16x8 | MB_TYPE_L0 | MB_TYPE_INTERLACED;
1240                 /* 16x8 field motion prediction */
1241                 s->mv_type= MV_TYPE_FIELD;
1242
1243                 s->field_select[0][0]= get_bits1(&s->gb);
1244                 s->field_select[0][1]= get_bits1(&s->gb);
1245
1246                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1247
1248                 for(i=0; i<2; i++){
1249                     mx = h263_decode_motion(s, pred_x, s->f_code);
1250                     if (mx >= 0xffff)
1251                         return -1;
1252
1253                     my = h263_decode_motion(s, pred_y/2, s->f_code);
1254                     if (my >= 0xffff)
1255                         return -1;
1256
1257                     s->mv[0][i][0] = mx;
1258                     s->mv[0][i][1] = my;
1259                 }
1260             }else{
1261                 s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1262                 /* 16x16 motion prediction */
1263                 s->mv_type = MV_TYPE_16X16;
1264                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1265                 mx = h263_decode_motion(s, pred_x, s->f_code);
1266
1267                 if (mx >= 0xffff)
1268                     return -1;
1269
1270                 my = h263_decode_motion(s, pred_y, s->f_code);
1271
1272                 if (my >= 0xffff)
1273                     return -1;
1274                 s->mv[0][0][0] = mx;
1275                 s->mv[0][0][1] = my;
1276             }
1277         } else {
1278             s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1279             s->mv_type = MV_TYPE_8X8;
1280             for(i=0;i<4;i++) {
1281                 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1282                 mx = h263_decode_motion(s, pred_x, s->f_code);
1283                 if (mx >= 0xffff)
1284                     return -1;
1285
1286                 my = h263_decode_motion(s, pred_y, s->f_code);
1287                 if (my >= 0xffff)
1288                     return -1;
1289                 s->mv[0][i][0] = mx;
1290                 s->mv[0][i][1] = my;
1291                 mot_val[0] = mx;
1292                 mot_val[1] = my;
1293             }
1294         }
1295     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
1296         int modb1; // first bit of modb
1297         int modb2; // second bit of modb
1298         int mb_type;
1299
1300         s->mb_intra = 0; //B-frames never contain intra blocks
1301         s->mcsel=0;      //     ...               true gmc blocks
1302
1303         if(s->mb_x==0){
1304             for(i=0; i<2; i++){
1305                 s->last_mv[i][0][0]=
1306                 s->last_mv[i][0][1]=
1307                 s->last_mv[i][1][0]=
1308                 s->last_mv[i][1][1]= 0;
1309             }
1310
1311             ff_thread_await_progress((AVFrame*)s->next_picture_ptr, s->mb_y, 0);
1312         }
1313
1314         /* if we skipped it in the future P Frame than skip it now too */
1315         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
1316
1317         if(s->mb_skipped){
1318                 /* skip mb */
1319             for(i=0;i<6;i++)
1320                 s->block_last_index[i] = -1;
1321
1322             s->mv_dir = MV_DIR_FORWARD;
1323             s->mv_type = MV_TYPE_16X16;
1324             s->mv[0][0][0] = 0;
1325             s->mv[0][0][1] = 0;
1326             s->mv[1][0][0] = 0;
1327             s->mv[1][0][1] = 0;
1328             s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1329             goto end;
1330         }
1331
1332         modb1= get_bits1(&s->gb);
1333         if(modb1){
1334             mb_type= MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1; //like MB_TYPE_B_DIRECT but no vectors coded
1335             cbp=0;
1336         }else{
1337             modb2= get_bits1(&s->gb);
1338             mb_type= get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1339             if(mb_type<0){
1340                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1341                 return -1;
1342             }
1343             mb_type= mb_type_b_map[ mb_type ];
1344             if(modb2) cbp= 0;
1345             else{
1346                 s->dsp.clear_blocks(s->block[0]);
1347                 cbp= get_bits(&s->gb, 6);
1348             }
1349
1350             if ((!IS_DIRECT(mb_type)) && cbp) {
1351                 if(get_bits1(&s->gb)){
1352                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb)*4 - 2);
1353                 }
1354             }
1355
1356             if(!s->progressive_sequence){
1357                 if(cbp)
1358                     s->interlaced_dct= get_bits1(&s->gb);
1359
1360                 if(!IS_DIRECT(mb_type) && get_bits1(&s->gb)){
1361                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1362                     mb_type &= ~MB_TYPE_16x16;
1363
1364                     if(USES_LIST(mb_type, 0)){
1365                         s->field_select[0][0]= get_bits1(&s->gb);
1366                         s->field_select[0][1]= get_bits1(&s->gb);
1367                     }
1368                     if(USES_LIST(mb_type, 1)){
1369                         s->field_select[1][0]= get_bits1(&s->gb);
1370                         s->field_select[1][1]= get_bits1(&s->gb);
1371                     }
1372                 }
1373             }
1374
1375             s->mv_dir = 0;
1376             if((mb_type & (MB_TYPE_DIRECT2|MB_TYPE_INTERLACED)) == 0){
1377                 s->mv_type= MV_TYPE_16X16;
1378
1379                 if(USES_LIST(mb_type, 0)){
1380                     s->mv_dir = MV_DIR_FORWARD;
1381
1382                     mx = h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1383                     my = h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1384                     s->last_mv[0][1][0]= s->last_mv[0][0][0]= s->mv[0][0][0] = mx;
1385                     s->last_mv[0][1][1]= s->last_mv[0][0][1]= s->mv[0][0][1] = my;
1386                 }
1387
1388                 if(USES_LIST(mb_type, 1)){
1389                     s->mv_dir |= MV_DIR_BACKWARD;
1390
1391                     mx = h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1392                     my = h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1393                     s->last_mv[1][1][0]= s->last_mv[1][0][0]= s->mv[1][0][0] = mx;
1394                     s->last_mv[1][1][1]= s->last_mv[1][0][1]= s->mv[1][0][1] = my;
1395                 }
1396             }else if(!IS_DIRECT(mb_type)){
1397                 s->mv_type= MV_TYPE_FIELD;
1398
1399                 if(USES_LIST(mb_type, 0)){
1400                     s->mv_dir = MV_DIR_FORWARD;
1401
1402                     for(i=0; i<2; i++){
1403                         mx = h263_decode_motion(s, s->last_mv[0][i][0]  , s->f_code);
1404                         my = h263_decode_motion(s, s->last_mv[0][i][1]/2, s->f_code);
1405                         s->last_mv[0][i][0]=  s->mv[0][i][0] = mx;
1406                         s->last_mv[0][i][1]= (s->mv[0][i][1] = my)*2;
1407                     }
1408                 }
1409
1410                 if(USES_LIST(mb_type, 1)){
1411                     s->mv_dir |= MV_DIR_BACKWARD;
1412
1413                     for(i=0; i<2; i++){
1414                         mx = h263_decode_motion(s, s->last_mv[1][i][0]  , s->b_code);
1415                         my = h263_decode_motion(s, s->last_mv[1][i][1]/2, s->b_code);
1416                         s->last_mv[1][i][0]=  s->mv[1][i][0] = mx;
1417                         s->last_mv[1][i][1]= (s->mv[1][i][1] = my)*2;
1418                     }
1419                 }
1420             }
1421         }
1422
1423         if(IS_DIRECT(mb_type)){
1424             if(IS_SKIP(mb_type))
1425                 mx=my=0;
1426             else{
1427                 mx = h263_decode_motion(s, 0, 1);
1428                 my = h263_decode_motion(s, 0, 1);
1429             }
1430
1431             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1432             mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
1433         }
1434         s->current_picture.f.mb_type[xy] = mb_type;
1435     } else { /* I-Frame */
1436         do{
1437             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1438             if (cbpc < 0){
1439                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1440                 return -1;
1441             }
1442         }while(cbpc == 8);
1443
1444         dquant = cbpc & 4;
1445         s->mb_intra = 1;
1446 intra:
1447         s->ac_pred = get_bits1(&s->gb);
1448         if(s->ac_pred)
1449             s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1450         else
1451             s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
1452
1453         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1454         if(cbpy<0){
1455             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1456             return -1;
1457         }
1458         cbp = (cbpc & 3) | (cbpy << 2);
1459
1460         s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1461
1462         if (dquant) {
1463             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1464         }
1465
1466         if(!s->progressive_sequence)
1467             s->interlaced_dct= get_bits1(&s->gb);
1468
1469         s->dsp.clear_blocks(s->block[0]);
1470         /* decode each block */
1471         for (i = 0; i < 6; i++) {
1472             if (mpeg4_decode_block(s, block[i], i, cbp&32, 1, 0) < 0)
1473                 return -1;
1474             cbp+=cbp;
1475         }
1476         goto end;
1477     }
1478
1479     /* decode each block */
1480     for (i = 0; i < 6; i++) {
1481         if (mpeg4_decode_block(s, block[i], i, cbp&32, 0, 0) < 0)
1482             return -1;
1483         cbp+=cbp;
1484     }
1485 end:
1486
1487         /* per-MB end of slice check */
1488     if(s->codec_id==CODEC_ID_MPEG4){
1489         int next= mpeg4_is_resync(s);
1490         if(next) {
1491             if        (s->mb_x + s->mb_y*s->mb_width + 1 >  next && s->avctx->error_recognition >= FF_ER_AGGRESSIVE) {
1492                 return -1;
1493             } else if (s->mb_x + s->mb_y*s->mb_width + 1 >= next)
1494                 return SLICE_END;
1495
1496             if(s->pict_type==AV_PICTURE_TYPE_B){
1497                 const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1498                 ff_thread_await_progress((AVFrame*)s->next_picture_ptr,
1499                                         (s->mb_x + delta >= s->mb_width) ? FFMIN(s->mb_y+1, s->mb_height-1) : s->mb_y, 0);
1500                 if (s->next_picture.f.mbskip_table[xy + delta])
1501                     return SLICE_OK;
1502             }
1503
1504             return SLICE_END;
1505         }
1506     }
1507
1508     return SLICE_OK;
1509 }
1510
1511
1512 static int mpeg4_decode_gop_header(MpegEncContext * s, GetBitContext *gb){
1513     int hours, minutes, seconds;
1514
1515     if(!show_bits(gb, 23)){
1516         av_log(s->avctx, AV_LOG_WARNING, "GOP header invalid\n");
1517         return -1;
1518     }
1519
1520     hours= get_bits(gb, 5);
1521     minutes= get_bits(gb, 6);
1522     skip_bits1(gb);
1523     seconds= get_bits(gb, 6);
1524
1525     s->time_base= seconds + 60*(minutes + 60*hours);
1526
1527     skip_bits1(gb);
1528     skip_bits1(gb);
1529
1530     return 0;
1531 }
1532
1533 static int mpeg4_decode_profile_level(MpegEncContext * s, GetBitContext *gb){
1534
1535     s->avctx->profile = get_bits(gb, 4);
1536     s->avctx->level   = get_bits(gb, 4);
1537
1538     // for Simple profile, level 0
1539     if (s->avctx->profile == 0 && s->avctx->level == 8) {
1540         s->avctx->level = 0;
1541     }
1542
1543     return 0;
1544 }
1545
1546 static int decode_vol_header(MpegEncContext *s, GetBitContext *gb){
1547     int width, height, vo_ver_id;
1548
1549     /* vol header */
1550     skip_bits(gb, 1); /* random access */
1551     s->vo_type= get_bits(gb, 8);
1552     if (get_bits1(gb) != 0) { /* is_ol_id */
1553         vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
1554         skip_bits(gb, 3); /* vo_priority */
1555     } else {
1556         vo_ver_id = 1;
1557     }
1558     s->aspect_ratio_info= get_bits(gb, 4);
1559     if(s->aspect_ratio_info == FF_ASPECT_EXTENDED){
1560         s->avctx->sample_aspect_ratio.num= get_bits(gb, 8); // par_width
1561         s->avctx->sample_aspect_ratio.den= get_bits(gb, 8); // par_height
1562     }else{
1563         s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1564     }
1565
1566     if ((s->vol_control_parameters=get_bits1(gb))) { /* vol control parameter */
1567         int chroma_format= get_bits(gb, 2);
1568         if(chroma_format!=CHROMA_420){
1569             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1570         }
1571         s->low_delay= get_bits1(gb);
1572         if(get_bits1(gb)){ /* vbv parameters */
1573             get_bits(gb, 15);   /* first_half_bitrate */
1574             skip_bits1(gb);     /* marker */
1575             get_bits(gb, 15);   /* latter_half_bitrate */
1576             skip_bits1(gb);     /* marker */
1577             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
1578             skip_bits1(gb);     /* marker */
1579             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
1580             get_bits(gb, 11);   /* first_half_vbv_occupancy */
1581             skip_bits1(gb);     /* marker */
1582             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
1583             skip_bits1(gb);     /* marker */
1584         }
1585     }else{
1586         // set low delay flag only once the smartest? low delay detection won't be overriden
1587         if(s->picture_number==0)
1588             s->low_delay=0;
1589     }
1590
1591     s->shape = get_bits(gb, 2); /* vol shape */
1592     if(s->shape != RECT_SHAPE) av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1593     if(s->shape == GRAY_SHAPE && vo_ver_id != 1){
1594         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1595         skip_bits(gb, 4);  //video_object_layer_shape_extension
1596     }
1597
1598     check_marker(gb, "before time_increment_resolution");
1599
1600     s->avctx->time_base.den = get_bits(gb, 16);
1601     if(!s->avctx->time_base.den){
1602         av_log(s->avctx, AV_LOG_ERROR, "time_base.den==0\n");
1603         s->avctx->time_base.num = 0;
1604         return -1;
1605     }
1606
1607     s->time_increment_bits = av_log2(s->avctx->time_base.den - 1) + 1;
1608     if (s->time_increment_bits < 1)
1609         s->time_increment_bits = 1;
1610
1611     check_marker(gb, "before fixed_vop_rate");
1612
1613     if (get_bits1(gb) != 0) {   /* fixed_vop_rate  */
1614         s->avctx->time_base.num = get_bits(gb, s->time_increment_bits);
1615     }else
1616         s->avctx->time_base.num = 1;
1617
1618     s->t_frame=0;
1619
1620     if (s->shape != BIN_ONLY_SHAPE) {
1621         if (s->shape == RECT_SHAPE) {
1622             skip_bits1(gb);   /* marker */
1623             width = get_bits(gb, 13);
1624             skip_bits1(gb);   /* marker */
1625             height = get_bits(gb, 13);
1626             skip_bits1(gb);   /* marker */
1627             if(width && height && !(s->width && s->codec_tag == AV_RL32("MP4S"))){ /* they should be non zero but who knows ... */
1628                 s->width = width;
1629                 s->height = height;
1630             }
1631         }
1632
1633         s->progressive_sequence=
1634         s->progressive_frame= get_bits1(gb)^1;
1635         s->interlaced_dct=0;
1636         if(!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1637             av_log(s->avctx, AV_LOG_INFO, "MPEG4 OBMC not supported (very likely buggy encoder)\n");   /* OBMC Disable */
1638         if (vo_ver_id == 1) {
1639             s->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
1640         } else {
1641             s->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
1642         }
1643         if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1644         if(s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE){
1645             if(s->vol_sprite_usage==STATIC_SPRITE){
1646                 s->sprite_width = get_bits(gb, 13);
1647                 skip_bits1(gb); /* marker */
1648                 s->sprite_height= get_bits(gb, 13);
1649                 skip_bits1(gb); /* marker */
1650                 s->sprite_left  = get_bits(gb, 13);
1651                 skip_bits1(gb); /* marker */
1652                 s->sprite_top   = get_bits(gb, 13);
1653                 skip_bits1(gb); /* marker */
1654             }
1655             s->num_sprite_warping_points= get_bits(gb, 6);
1656             if(s->num_sprite_warping_points > 3){
1657                 av_log(s->avctx, AV_LOG_ERROR, "%d sprite_warping_points\n", s->num_sprite_warping_points);
1658                 s->num_sprite_warping_points= 0;
1659                 return -1;
1660             }
1661             s->sprite_warping_accuracy = get_bits(gb, 2);
1662             s->sprite_brightness_change= get_bits1(gb);
1663             if(s->vol_sprite_usage==STATIC_SPRITE)
1664                 s->low_latency_sprite= get_bits1(gb);
1665         }
1666         // FIXME sadct disable bit if verid!=1 && shape not rect
1667
1668         if (get_bits1(gb) == 1) {   /* not_8_bit */
1669             s->quant_precision = get_bits(gb, 4); /* quant_precision */
1670             if(get_bits(gb, 4)!=8) av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n"); /* bits_per_pixel */
1671             if(s->quant_precision!=5) av_log(s->avctx, AV_LOG_ERROR, "quant precision %d\n", s->quant_precision);
1672         } else {
1673             s->quant_precision = 5;
1674         }
1675
1676         // FIXME a bunch of grayscale shape things
1677
1678         if((s->mpeg_quant=get_bits1(gb))){ /* vol_quant_type */
1679             int i, v;
1680
1681             /* load default matrixes */
1682             for(i=0; i<64; i++){
1683                 int j= s->dsp.idct_permutation[i];
1684                 v= ff_mpeg4_default_intra_matrix[i];
1685                 s->intra_matrix[j]= v;
1686                 s->chroma_intra_matrix[j]= v;
1687
1688                 v= ff_mpeg4_default_non_intra_matrix[i];
1689                 s->inter_matrix[j]= v;
1690                 s->chroma_inter_matrix[j]= v;
1691             }
1692
1693             /* load custom 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->intra_matrix[j]= v;
1704                     s->chroma_intra_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->intra_matrix[j]= last;
1711                     s->chroma_intra_matrix[j]= last;
1712                 }
1713             }
1714
1715             /* load custom non intra matrix */
1716             if(get_bits1(gb)){
1717                 int last=0;
1718                 for(i=0; i<64; i++){
1719                     int j;
1720                     v= get_bits(gb, 8);
1721                     if(v==0) break;
1722
1723                     last= v;
1724                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1725                     s->inter_matrix[j]= v;
1726                     s->chroma_inter_matrix[j]= v;
1727                 }
1728
1729                 /* replicate last value */
1730                 for(; i<64; i++){
1731                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1732                     s->inter_matrix[j]= last;
1733                     s->chroma_inter_matrix[j]= last;
1734                 }
1735             }
1736
1737             // FIXME a bunch of grayscale shape things
1738         }
1739
1740         if(vo_ver_id != 1)
1741              s->quarter_sample= get_bits1(gb);
1742         else s->quarter_sample=0;
1743
1744         if(!get_bits1(gb)){
1745             int pos= get_bits_count(gb);
1746             int estimation_method= get_bits(gb, 2);
1747             if(estimation_method<2){
1748                 if(!get_bits1(gb)){
1749                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //opaque
1750                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //transparent
1751                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_cae
1752                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //inter_cae
1753                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //no_update
1754                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //upampling
1755                 }
1756                 if(!get_bits1(gb)){
1757                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_blocks
1758                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter_blocks
1759                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter4v_blocks
1760                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //not coded blocks
1761                 }
1762                 if(!check_marker(gb, "in complexity estimation part 1")){
1763                     skip_bits_long(gb, pos - get_bits_count(gb));
1764                     goto no_cplx_est;
1765                 }
1766                 if(!get_bits1(gb)){
1767                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_coeffs
1768                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_lines
1769                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //vlc_syms
1770                     s->cplx_estimation_trash_i += 4*get_bits1(gb); //vlc_bits
1771                 }
1772                 if(!get_bits1(gb)){
1773                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //apm
1774                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //npm
1775                     s->cplx_estimation_trash_b += 8*get_bits1(gb); //interpolate_mc_q
1776                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //forwback_mc_q
1777                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel2
1778                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel4
1779                 }
1780                 if(!check_marker(gb, "in complexity estimation part 2")){
1781                     skip_bits_long(gb, pos - get_bits_count(gb));
1782                     goto no_cplx_est;
1783                 }
1784                 if(estimation_method==1){
1785                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //sadct
1786                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //qpel
1787                 }
1788             }else
1789                 av_log(s->avctx, AV_LOG_ERROR, "Invalid Complexity estimation method %d\n", estimation_method);
1790         }else{
1791 no_cplx_est:
1792             s->cplx_estimation_trash_i=
1793             s->cplx_estimation_trash_p=
1794             s->cplx_estimation_trash_b= 0;
1795         }
1796
1797         s->resync_marker= !get_bits1(gb); /* resync_marker_disabled */
1798
1799         s->data_partitioning= get_bits1(gb);
1800         if(s->data_partitioning){
1801             s->rvlc= get_bits1(gb);
1802         }
1803
1804         if(vo_ver_id != 1) {
1805             s->new_pred= get_bits1(gb);
1806             if(s->new_pred){
1807                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
1808                 skip_bits(gb, 2); /* requested upstream message type */
1809                 skip_bits1(gb); /* newpred segment type */
1810             }
1811             s->reduced_res_vop= get_bits1(gb);
1812             if(s->reduced_res_vop) av_log(s->avctx, AV_LOG_ERROR, "reduced resolution VOP not supported\n");
1813         }
1814         else{
1815             s->new_pred=0;
1816             s->reduced_res_vop= 0;
1817         }
1818
1819         s->scalability= get_bits1(gb);
1820
1821         if (s->scalability) {
1822             GetBitContext bak= *gb;
1823             int h_sampling_factor_n;
1824             int h_sampling_factor_m;
1825             int v_sampling_factor_n;
1826             int v_sampling_factor_m;
1827
1828             s->hierachy_type= get_bits1(gb);
1829             skip_bits(gb, 4);  /* ref_layer_id */
1830             skip_bits1(gb);    /* ref_layer_sampling_dir */
1831             h_sampling_factor_n= get_bits(gb, 5);
1832             h_sampling_factor_m= get_bits(gb, 5);
1833             v_sampling_factor_n= get_bits(gb, 5);
1834             v_sampling_factor_m= get_bits(gb, 5);
1835             s->enhancement_type= get_bits1(gb);
1836
1837             if(   h_sampling_factor_n==0 || h_sampling_factor_m==0
1838                || v_sampling_factor_n==0 || v_sampling_factor_m==0){
1839                 /* illegal scalability header (VERY broken encoder),
1840                  * trying to workaround */
1841                 s->scalability=0;
1842                 *gb= bak;
1843             }else
1844                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
1845
1846             // bin shape stuff FIXME
1847         }
1848     }
1849     return 0;
1850 }
1851
1852 /**
1853  * Decode the user data stuff in the header.
1854  * Also initializes divx/xvid/lavc_version/build.
1855  */
1856 static int decode_user_data(MpegEncContext *s, GetBitContext *gb){
1857     char buf[256];
1858     int i;
1859     int e;
1860     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
1861     char last;
1862
1863     for(i=0; i<255 && get_bits_count(gb) < gb->size_in_bits; i++){
1864         if(show_bits(gb, 23) == 0) break;
1865         buf[i]= get_bits(gb, 8);
1866     }
1867     buf[i]=0;
1868
1869     /* divx detection */
1870     e=sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
1871     if(e<2)
1872         e=sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
1873     if(e>=2){
1874         s->divx_version= ver;
1875         s->divx_build= build;
1876         s->divx_packed= e==3 && last=='p';
1877         if(s->divx_packed && !s->showed_packed_warning) {
1878             av_log(s->avctx, AV_LOG_WARNING, "Invalid and inefficient vfw-avi packed B frames detected\n");
1879             s->showed_packed_warning=1;
1880         }
1881     }
1882
1883     /* libavcodec detection */
1884     e=sscanf(buf, "FFmpe%*[^b]b%d", &build)+3;
1885     if(e!=4)
1886         e=sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
1887     if(e!=4){
1888         e=sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3)+1;
1889         if (e>1)
1890             build= (ver<<16) + (ver2<<8) + ver3;
1891     }
1892     if(e!=4){
1893         if(strcmp(buf, "ffmpeg")==0){
1894             s->lavc_build= 4600;
1895         }
1896     }
1897     if(e==4){
1898         s->lavc_build= build;
1899     }
1900
1901     /* Xvid detection */
1902     e=sscanf(buf, "XviD%d", &build);
1903     if(e==1){
1904         s->xvid_build= build;
1905     }
1906
1907     return 0;
1908 }
1909
1910 static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
1911     int time_incr, time_increment;
1912
1913     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I;        /* pict type: I = 0 , P = 1 */
1914     if(s->pict_type==AV_PICTURE_TYPE_B && s->low_delay && s->vol_control_parameters==0 && !(s->flags & CODEC_FLAG_LOW_DELAY)){
1915         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag incorrectly, clearing it\n");
1916         s->low_delay=0;
1917     }
1918
1919     s->partitioned_frame= s->data_partitioning && s->pict_type!=AV_PICTURE_TYPE_B;
1920     if(s->partitioned_frame)
1921         s->decode_mb= mpeg4_decode_partitioned_mb;
1922     else
1923         s->decode_mb= mpeg4_decode_mb;
1924
1925     time_incr=0;
1926     while (get_bits1(gb) != 0)
1927         time_incr++;
1928
1929     check_marker(gb, "before time_increment");
1930
1931     if(s->time_increment_bits==0 || !(show_bits(gb, s->time_increment_bits+1)&1)){
1932         av_log(s->avctx, AV_LOG_ERROR, "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
1933
1934         for(s->time_increment_bits=1 ;s->time_increment_bits<16; s->time_increment_bits++){
1935             if (    s->pict_type == AV_PICTURE_TYPE_P
1936                 || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE)) {
1937                 if((show_bits(gb, s->time_increment_bits+6)&0x37) == 0x30) break;
1938             }else
1939                 if((show_bits(gb, s->time_increment_bits+5)&0x1F) == 0x18) break;
1940         }
1941
1942         av_log(s->avctx, AV_LOG_ERROR, "my guess is %d bits ;)\n",s->time_increment_bits);
1943     }
1944
1945     if(IS_3IV1) time_increment= get_bits1(gb); //FIXME investigate further
1946     else time_increment= get_bits(gb, s->time_increment_bits);
1947
1948     if(s->pict_type!=AV_PICTURE_TYPE_B){
1949         s->last_time_base= s->time_base;
1950         s->time_base+= time_incr;
1951         s->time= s->time_base*s->avctx->time_base.den + time_increment;
1952         if(s->workaround_bugs&FF_BUG_UMP4){
1953             if(s->time < s->last_non_b_time){
1954                 /* header is not mpeg-4-compatible, broken encoder,
1955                  * trying to workaround */
1956                 s->time_base++;
1957                 s->time+= s->avctx->time_base.den;
1958             }
1959         }
1960         s->pp_time= s->time - s->last_non_b_time;
1961         s->last_non_b_time= s->time;
1962     }else{
1963         s->time= (s->last_time_base + time_incr)*s->avctx->time_base.den + time_increment;
1964         s->pb_time= s->pp_time - (s->last_non_b_time - s->time);
1965         if(s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0){
1966             /* messed up order, maybe after seeking? skipping current b-frame */
1967             return FRAME_SKIPPED;
1968         }
1969         ff_mpeg4_init_direct_mv(s);
1970
1971         if(s->t_frame==0) s->t_frame= s->pb_time;
1972         if(s->t_frame==0) s->t_frame=1; // 1/0 protection
1973         s->pp_field_time= (  ROUNDED_DIV(s->last_non_b_time, s->t_frame)
1974                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1975         s->pb_field_time= (  ROUNDED_DIV(s->time, s->t_frame)
1976                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1977         if(!s->progressive_sequence){
1978             if(s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
1979                 return FRAME_SKIPPED;
1980         }
1981     }
1982
1983     if(s->avctx->time_base.num)
1984         s->current_picture_ptr->f.pts = (s->time + s->avctx->time_base.num / 2) / s->avctx->time_base.num;
1985     else
1986         s->current_picture_ptr->f.pts = AV_NOPTS_VALUE;
1987     if(s->avctx->debug&FF_DEBUG_PTS)
1988         av_log(s->avctx, AV_LOG_DEBUG, "MPEG4 PTS: %"PRId64"\n",
1989                s->current_picture_ptr->f.pts);
1990
1991     check_marker(gb, "before vop_coded");
1992
1993     /* vop coded */
1994     if (get_bits1(gb) != 1){
1995         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
1996             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
1997         return FRAME_SKIPPED;
1998     }
1999     if (s->shape != BIN_ONLY_SHAPE && ( s->pict_type == AV_PICTURE_TYPE_P
2000                           || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE))) {
2001         /* rounding type for motion estimation */
2002         s->no_rounding = get_bits1(gb);
2003     } else {
2004         s->no_rounding = 0;
2005     }
2006 //FIXME reduced res stuff
2007
2008      if (s->shape != RECT_SHAPE) {
2009          if (s->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
2010              skip_bits(gb, 13); /* width */
2011              skip_bits1(gb);   /* marker */
2012              skip_bits(gb, 13); /* height */
2013              skip_bits1(gb);   /* marker */
2014              skip_bits(gb, 13); /* hor_spat_ref */
2015              skip_bits1(gb);   /* marker */
2016              skip_bits(gb, 13); /* ver_spat_ref */
2017          }
2018          skip_bits1(gb); /* change_CR_disable */
2019
2020          if (get_bits1(gb) != 0) {
2021              skip_bits(gb, 8); /* constant_alpha_value */
2022          }
2023      }
2024 //FIXME complexity estimation stuff
2025
2026      if (s->shape != BIN_ONLY_SHAPE) {
2027          skip_bits_long(gb, s->cplx_estimation_trash_i);
2028          if(s->pict_type != AV_PICTURE_TYPE_I)
2029             skip_bits_long(gb, s->cplx_estimation_trash_p);
2030          if(s->pict_type == AV_PICTURE_TYPE_B)
2031             skip_bits_long(gb, s->cplx_estimation_trash_b);
2032
2033          s->intra_dc_threshold= mpeg4_dc_threshold[ get_bits(gb, 3) ];
2034          if(!s->progressive_sequence){
2035              s->top_field_first= get_bits1(gb);
2036              s->alternate_scan= get_bits1(gb);
2037          }else
2038              s->alternate_scan= 0;
2039      }
2040
2041      if(s->alternate_scan){
2042          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
2043          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
2044          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2045          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2046      } else{
2047          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
2048          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
2049          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2050          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2051      }
2052
2053      if(s->pict_type == AV_PICTURE_TYPE_S && (s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE)){
2054          mpeg4_decode_sprite_trajectory(s, gb);
2055          if(s->sprite_brightness_change) av_log(s->avctx, AV_LOG_ERROR, "sprite_brightness_change not supported\n");
2056          if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2057      }
2058
2059      if (s->shape != BIN_ONLY_SHAPE) {
2060          s->chroma_qscale= s->qscale = get_bits(gb, s->quant_precision);
2061          if(s->qscale==0){
2062              av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (qscale=0)\n");
2063              return -1; // makes no sense to continue, as there is nothing left from the image then
2064          }
2065
2066          if (s->pict_type != AV_PICTURE_TYPE_I) {
2067              s->f_code = get_bits(gb, 3);       /* fcode_for */
2068              if(s->f_code==0){
2069                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (f_code=0)\n");
2070                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
2071              }
2072          }else
2073              s->f_code=1;
2074
2075          if (s->pict_type == AV_PICTURE_TYPE_B) {
2076              s->b_code = get_bits(gb, 3);
2077          }else
2078              s->b_code=1;
2079
2080          if(s->avctx->debug&FF_DEBUG_PICT_INFO){
2081              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",
2082                  s->qscale, s->f_code, s->b_code,
2083                  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")),
2084                  gb->size_in_bits,s->progressive_sequence, s->alternate_scan, s->top_field_first,
2085                  s->quarter_sample ? "q" : "h", s->data_partitioning, s->resync_marker, s->num_sprite_warping_points,
2086                  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);
2087          }
2088
2089          if(!s->scalability){
2090              if (s->shape!=RECT_SHAPE && s->pict_type!=AV_PICTURE_TYPE_I) {
2091                  skip_bits1(gb); // vop shape coding type
2092              }
2093          }else{
2094              if(s->enhancement_type){
2095                  int load_backward_shape= get_bits1(gb);
2096                  if(load_backward_shape){
2097                      av_log(s->avctx, AV_LOG_ERROR, "load backward shape isn't supported\n");
2098                  }
2099              }
2100              skip_bits(gb, 2); //ref_select_code
2101          }
2102      }
2103      /* detect buggy encoders which don't set the low_delay flag (divx4/xvid/opendivx)*/
2104      // note we cannot detect divx5 without b-frames easily (although it's buggy too)
2105      if(s->vo_type==0 && s->vol_control_parameters==0 && s->divx_version==-1 && s->picture_number==0){
2106          av_log(s->avctx, AV_LOG_WARNING, "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2107          s->low_delay=1;
2108      }
2109
2110      s->picture_number++; // better than pic number==0 always ;)
2111
2112      s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table; //FIXME add short header support
2113      s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
2114
2115      if(s->workaround_bugs&FF_BUG_EDGE){
2116          s->h_edge_pos= s->width;
2117          s->v_edge_pos= s->height;
2118      }
2119      return 0;
2120 }
2121
2122 /**
2123  * Decode mpeg4 headers.
2124  * @return <0 if no VOP found (or a damaged one)
2125  *         FRAME_SKIPPED if a not coded VOP is found
2126  *         0 if a VOP is found
2127  */
2128 int ff_mpeg4_decode_picture_header(MpegEncContext * s, GetBitContext *gb)
2129 {
2130     unsigned startcode, v;
2131
2132     /* search next start code */
2133     align_get_bits(gb);
2134
2135     if(s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630){
2136         skip_bits(gb, 24);
2137         if(get_bits(gb, 8) == 0xF0)
2138             goto end;
2139     }
2140
2141     startcode = 0xff;
2142     for(;;) {
2143         if(get_bits_count(gb) >= gb->size_in_bits){
2144             if(gb->size_in_bits==8 && (s->divx_version>=0 || s->xvid_build>=0) || s->codec_tag == AV_RL32("QMP4")){
2145                 av_log(s->avctx, AV_LOG_VERBOSE, "frame skip %d\n", gb->size_in_bits);
2146                 return FRAME_SKIPPED; //divx bug
2147             }else
2148                 return -1; //end of stream
2149         }
2150
2151         /* use the bits after the test */
2152         v = get_bits(gb, 8);
2153         startcode = ((startcode << 8) | v) & 0xffffffff;
2154
2155         if((startcode&0xFFFFFF00) != 0x100)
2156             continue; //no startcode
2157
2158         if(s->avctx->debug&FF_DEBUG_STARTCODE){
2159             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2160             if     (startcode<=0x11F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2161             else if(startcode<=0x12F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2162             else if(startcode<=0x13F) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2163             else if(startcode<=0x15F) av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2164             else if(startcode<=0x1AF) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2165             else if(startcode==0x1B0) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2166             else if(startcode==0x1B1) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2167             else if(startcode==0x1B2) av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2168             else if(startcode==0x1B3) av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2169             else if(startcode==0x1B4) av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2170             else if(startcode==0x1B5) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2171             else if(startcode==0x1B6) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2172             else if(startcode==0x1B7) av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2173             else if(startcode==0x1B8) av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2174             else if(startcode==0x1B9) av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2175             else if(startcode==0x1BA) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2176             else if(startcode==0x1BB) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2177             else if(startcode==0x1BC) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2178             else if(startcode==0x1BD) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2179             else if(startcode==0x1BE) av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2180             else if(startcode==0x1BF) av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2181             else if(startcode==0x1C0) av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2182             else if(startcode==0x1C1) av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2183             else if(startcode==0x1C2) av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2184             else if(startcode==0x1C3) av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2185             else if(startcode<=0x1C5) av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2186             else if(startcode<=0x1FF) av_log(s->avctx, AV_LOG_DEBUG, "System start");
2187             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2188         }
2189
2190         if(startcode >= 0x120 && startcode <= 0x12F){
2191             if(decode_vol_header(s, gb) < 0)
2192                 return -1;
2193         }
2194         else if(startcode == USER_DATA_STARTCODE){
2195             decode_user_data(s, gb);
2196         }
2197         else if(startcode == GOP_STARTCODE){
2198             mpeg4_decode_gop_header(s, gb);
2199         }
2200         else if(startcode == VOS_STARTCODE){
2201             mpeg4_decode_profile_level(s, gb);
2202         }
2203         else if(startcode == VOP_STARTCODE){
2204             break;
2205         }
2206
2207         align_get_bits(gb);
2208         startcode = 0xff;
2209     }
2210 end:
2211     if(s->flags& CODEC_FLAG_LOW_DELAY)
2212         s->low_delay=1;
2213     s->avctx->has_b_frames= !s->low_delay;
2214     return decode_vop_header(s, gb);
2215 }
2216
2217 static av_cold int decode_init(AVCodecContext *avctx)
2218 {
2219     MpegEncContext *s = avctx->priv_data;
2220     int ret;
2221     static int done = 0;
2222
2223     s->divx_version=
2224     s->divx_build=
2225     s->xvid_build=
2226     s->lavc_build= -1;
2227
2228     if((ret=ff_h263_decode_init(avctx)) < 0)
2229         return ret;
2230
2231     if (!done) {
2232         done = 1;
2233
2234         init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2235         init_rl(&rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2236         init_rl(&rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2237         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2238         INIT_VLC_RL(rvlc_rl_inter, 1072);
2239         INIT_VLC_RL(rvlc_rl_intra, 1072);
2240         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2241                  &ff_mpeg4_DCtab_lum[0][1], 2, 1,
2242                  &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2243         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2244                  &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2245                  &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2246         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2247                  &sprite_trajectory_tab[0][1], 4, 2,
2248                  &sprite_trajectory_tab[0][0], 4, 2, 128);
2249         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2250                  &mb_type_b_tab[0][1], 2, 1,
2251                  &mb_type_b_tab[0][0], 2, 1, 16);
2252     }
2253
2254     s->h263_pred = 1;
2255     s->low_delay = 0; //default, might be overriden in the vol header during header parsing
2256     s->decode_mb= mpeg4_decode_mb;
2257     s->time_increment_bits = 4; /* default value for broken headers */
2258     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2259
2260     return 0;
2261 }
2262
2263 static const AVProfile mpeg4_video_profiles[] = {
2264     { FF_PROFILE_MPEG4_SIMPLE,                    "Simple Profile" },
2265     { FF_PROFILE_MPEG4_SIMPLE_SCALABLE,           "Simple Scalable Profile" },
2266     { FF_PROFILE_MPEG4_CORE,                      "Core Profile" },
2267     { FF_PROFILE_MPEG4_MAIN,                      "Main Profile" },
2268     { FF_PROFILE_MPEG4_N_BIT,                     "N-bit Profile" },
2269     { FF_PROFILE_MPEG4_SCALABLE_TEXTURE,          "Scalable Texture Profile" },
2270     { FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION,     "Simple Face Animation Profile" },
2271     { FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE,    "Basic Animated Texture Profile" },
2272     { FF_PROFILE_MPEG4_HYBRID,                    "Hybrid Profile" },
2273     { FF_PROFILE_MPEG4_ADVANCED_REAL_TIME,        "Advanced Real Time Simple Profile" },
2274     { FF_PROFILE_MPEG4_CORE_SCALABLE,             "Code Scalable Profile" },
2275     { FF_PROFILE_MPEG4_ADVANCED_CODING,           "Advanced Coding Profile" },
2276     { FF_PROFILE_MPEG4_ADVANCED_CORE,             "Advanced Core Profile" },
2277     { FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE, "Advanced Scalable Texture Profile" },
2278     { FF_PROFILE_MPEG4_SIMPLE_STUDIO,             "Simple Studio Profile" },
2279     { FF_PROFILE_MPEG4_ADVANCED_SIMPLE,           "Advanced Simple Profile" },
2280 };
2281
2282 static const AVOption mpeg4_options[] = {
2283     {"quarter_sample", "1/4 subpel MC", offsetof(MpegEncContext, quarter_sample), FF_OPT_TYPE_INT, {.dbl = 0}, 0, 1, 0},
2284     {"divx_packed", "divx style packed b frames", offsetof(MpegEncContext, divx_packed), FF_OPT_TYPE_INT, {.dbl = 0}, 0, 1, 0},
2285     {NULL}
2286 };
2287
2288 static const AVClass mpeg4_class = {
2289     "MPEG4 Video Decoder",
2290     av_default_item_name,
2291     mpeg4_options,
2292     LIBAVUTIL_VERSION_INT,
2293 };
2294
2295 static const AVClass mpeg4_vdpau_class = {
2296     "MPEG4 Video VDPAU Decoder",
2297     av_default_item_name,
2298     mpeg4_options,
2299     LIBAVUTIL_VERSION_INT,
2300 };
2301
2302 AVCodec ff_mpeg4_decoder = {
2303     .name           = "mpeg4",
2304     .type           = AVMEDIA_TYPE_VIDEO,
2305     .id             = CODEC_ID_MPEG4,
2306     .priv_data_size = sizeof(MpegEncContext),
2307     .init           = decode_init,
2308     .close          = ff_h263_decode_end,
2309     .decode         = ff_h263_decode_frame,
2310     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_FRAME_THREADS,
2311     .flush= ff_mpeg_flush,
2312     .max_lowres= 3,
2313     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2314     .pix_fmts= ff_hwaccel_pixfmt_list_420,
2315     .profiles = NULL_IF_CONFIG_SMALL(mpeg4_video_profiles),
2316     .update_thread_context= ONLY_IF_THREADS_ENABLED(ff_mpeg_update_thread_context),
2317     .priv_class = &mpeg4_class,
2318 };
2319
2320
2321 #if CONFIG_MPEG4_VDPAU_DECODER
2322 AVCodec ff_mpeg4_vdpau_decoder = {
2323     .name           = "mpeg4_vdpau",
2324     .type           = AVMEDIA_TYPE_VIDEO,
2325     .id             = CODEC_ID_MPEG4,
2326     .priv_data_size = sizeof(MpegEncContext),
2327     .init           = decode_init,
2328     .close          = ff_h263_decode_end,
2329     .decode         = ff_h263_decode_frame,
2330     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_HWACCEL_VDPAU,
2331     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
2332     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_VDPAU_MPEG4, PIX_FMT_NONE},
2333     .priv_class = &mpeg4_vdpau_class,
2334 };
2335 #endif