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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 #include "mpegvideo.h"
  24 #include "mpeg4video.h"
  25 #include "h263.h"
  26 #include "thread.h"
  27
  28 // The defines below define the number of bits that are read at once for
  29 // reading vlc values. Changing these may improve speed and data cache needs
  30 // be aware though that decreasing them may need the number of stages that is
  31 // passed to get_vlc* to be increased.
  32 #define SPRITE_TRAJ_VLC_BITS 6
  33 #define DC_VLC_BITS 9
  34 #define MB_TYPE_B_VLC_BITS 4
  35
  36
  37 static VLC dc_lum, dc_chrom;
  38 static VLC sprite_trajectory;
  39 static VLC mb_type_b_vlc;
  40
  41 static const int mb_type_b_map[4]= {
  42     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  43     MB_TYPE_L0L1 | MB_TYPE_16x16,
  44     MB_TYPE_L1 | MB_TYPE_16x16,
  45     MB_TYPE_L0 | MB_TYPE_16x16,
  46 };
  47
  48 /**
  49  * predicts the ac.
  50  * @param n block index (0-3 are luma, 4-5 are chroma)
  51  * @param dir the ac prediction direction
  52  */
  53 void mpeg4_pred_ac(MpegEncContext * s, DCTELEM *block, int n,
  54                    int dir)
  55 {
  56     int i;
  57     int16_t *ac_val, *ac_val1;
  58     int8_t * const qscale_table = s->current_picture.f.qscale_table;
  59
  60     /* find prediction */
  61     ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
  62     ac_val1 = ac_val;
  63     if (s->ac_pred) {
  64         if (dir == 0) {
  65             const int xy= s->mb_x-1 + s->mb_y*s->mb_stride;
  66             /* left prediction */
  67             ac_val -= 16;
  68
  69             if(s->mb_x==0 || s->qscale == qscale_table[xy] || n==1 || n==3){
  70                 /* same qscale */
  71                 for(i=1;i<8;i++) {
  72                     block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
  73                 }
  74             }else{
  75                 /* different qscale, we must rescale */
  76                 for(i=1;i<8;i++) {
  77                     block[s->dsp.idct_permutation[i<<3]] += ROUNDED_DIV(ac_val[i]*qscale_table[xy], s->qscale);
  78                 }
  79             }
  80         } else {
  81             const int xy= s->mb_x + s->mb_y*s->mb_stride - s->mb_stride;
  82             /* top prediction */
  83             ac_val -= 16 * s->block_wrap[n];
  84
  85             if(s->mb_y==0 || s->qscale == qscale_table[xy] || n==2 || n==3){
  86                 /* same qscale */
  87                 for(i=1;i<8;i++) {
  88                     block[s->dsp.idct_permutation[i]] += ac_val[i + 8];
  89                 }
  90             }else{
  91                 /* different qscale, we must rescale */
  92                 for(i=1;i<8;i++) {
  93                     block[s->dsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8]*qscale_table[xy], s->qscale);
  94                 }
  95             }
  96         }
  97     }
  98     /* left copy */
  99     for(i=1;i<8;i++)
 100         ac_val1[i    ] = block[s->dsp.idct_permutation[i<<3]];
 101
 102     /* top copy */
 103     for(i=1;i<8;i++)
 104         ac_val1[8 + i] = block[s->dsp.idct_permutation[i   ]];
 105
 106 }
 107
 108 /**
 109  * check if the next stuff is a resync marker or the end.
 110  * @return 0 if not
 111  */
 112 static inline int mpeg4_is_resync(MpegEncContext *s){
 113     int bits_count= get_bits_count(&s->gb);
 114     int v= show_bits(&s->gb, 16);
 115
 116     if(s->workaround_bugs&FF_BUG_NO_PADDING && !s->resync_marker){
 117         return 0;
 118     }
 119
 120     while(v<=0xFF){
 121         if(s->pict_type==AV_PICTURE_TYPE_B || (v>>(8-s->pict_type)!=1) || s->partitioned_frame)
 122             break;
 123         skip_bits(&s->gb, 8+s->pict_type);
 124         bits_count+= 8+s->pict_type;
 125         v= show_bits(&s->gb, 16);
 126     }
 127
 128     if(bits_count + 8 >= s->gb.size_in_bits){
 129         v>>=8;
 130         v|= 0x7F >> (7-(bits_count&7));
 131
 132         if(v==0x7F)
 133             return s->mb_num;
 134     }else{
 135         if(v == ff_mpeg4_resync_prefix[bits_count&7]){
 136             int len, mb_num;
 137             int mb_num_bits= av_log2(s->mb_num - 1) + 1;
 138             GetBitContext gb= s->gb;
 139
 140             skip_bits(&s->gb, 1);
 141             align_get_bits(&s->gb);
 142
 143             for(len=0; len<32; len++){
 144                 if(get_bits1(&s->gb)) break;
 145             }
 146
 147             mb_num= get_bits(&s->gb, mb_num_bits);
 148             if(!mb_num || mb_num > s->mb_num || get_bits_count(&s->gb)+6 > s->gb.size_in_bits)
 149                 mb_num= -1;
 150
 151             s->gb= gb;
 152
 153             if(len>=ff_mpeg4_get_video_packet_prefix_length(s))
 154                 return mb_num;
 155         }
 156     }
 157     return 0;
 158 }
 159
 160 static void mpeg4_decode_sprite_trajectory(MpegEncContext * s, GetBitContext *gb)
 161 {
 162     int i;
 163     int a= 2<<s->sprite_warping_accuracy;
 164     int rho= 3-s->sprite_warping_accuracy;
 165     int r=16/a;
 166     const int vop_ref[4][2]= {{0,0}, {s->width,0}, {0, s->height}, {s->width, s->height}}; // only true for rectangle shapes
 167     int d[4][2]={{0,0}, {0,0}, {0,0}, {0,0}};
 168     int sprite_ref[4][2];
 169     int virtual_ref[2][2];
 170     int w2, h2, w3, h3;
 171     int alpha=0, beta=0;
 172     int w= s->width;
 173     int h= s->height;
 174     int min_ab;
 175
 176     for(i=0; i<s->num_sprite_warping_points; i++){
 177         int length;
 178         int x=0, y=0;
 179
 180         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 181         if(length){
 182             x= get_xbits(gb, length);
 183         }
 184         if(!(s->divx_version==500 && s->divx_build==413)) skip_bits1(gb); /* marker bit */
 185
 186         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 187         if(length){
 188             y=get_xbits(gb, length);
 189         }
 190         skip_bits1(gb); /* marker bit */
 191         s->sprite_traj[i][0]= d[i][0]= x;
 192         s->sprite_traj[i][1]= d[i][1]= y;
 193     }
 194     for(; i<4; i++)
 195         s->sprite_traj[i][0]= s->sprite_traj[i][1]= 0;
 196
 197     while((1<<alpha)<w) alpha++;
 198     while((1<<beta )<h) beta++; // there seems to be a typo in the mpeg4 std for the definition of w' and h'
 199     w2= 1<<alpha;
 200     h2= 1<<beta;
 201
 202 // Note, the 4th point isn't used for GMC
 203     if(s->divx_version==500 && s->divx_build==413){
 204         sprite_ref[0][0]= a*vop_ref[0][0] + d[0][0];
 205         sprite_ref[0][1]= a*vop_ref[0][1] + d[0][1];
 206         sprite_ref[1][0]= a*vop_ref[1][0] + d[0][0] + d[1][0];
 207         sprite_ref[1][1]= a*vop_ref[1][1] + d[0][1] + d[1][1];
 208         sprite_ref[2][0]= a*vop_ref[2][0] + d[0][0] + d[2][0];
 209         sprite_ref[2][1]= a*vop_ref[2][1] + d[0][1] + d[2][1];
 210     } else {
 211         sprite_ref[0][0]= (a>>1)*(2*vop_ref[0][0] + d[0][0]);
 212         sprite_ref[0][1]= (a>>1)*(2*vop_ref[0][1] + d[0][1]);
 213         sprite_ref[1][0]= (a>>1)*(2*vop_ref[1][0] + d[0][0] + d[1][0]);
 214         sprite_ref[1][1]= (a>>1)*(2*vop_ref[1][1] + d[0][1] + d[1][1]);
 215         sprite_ref[2][0]= (a>>1)*(2*vop_ref[2][0] + d[0][0] + d[2][0]);
 216         sprite_ref[2][1]= (a>>1)*(2*vop_ref[2][1] + d[0][1] + d[2][1]);
 217     }
 218 /*    sprite_ref[3][0]= (a>>1)*(2*vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
 219     sprite_ref[3][1]= (a>>1)*(2*vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
 220
 221 // this is mostly identical to the mpeg4 std (and is totally unreadable because of that ...)
 222 // perhaps it should be reordered to be more readable ...
 223 // the idea behind this virtual_ref mess is to be able to use shifts later per pixel instead of divides
 224 // so the distance between points is converted from w&h based to w2&h2 based which are of the 2^x form
 225     virtual_ref[0][0]= 16*(vop_ref[0][0] + w2)
 226         + 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);
 227     virtual_ref[0][1]= 16*vop_ref[0][1]
 228         + 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);
 229     virtual_ref[1][0]= 16*vop_ref[0][0]
 230         + 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);
 231     virtual_ref[1][1]= 16*(vop_ref[0][1] + h2)
 232         + 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);
 233
 234     switch(s->num_sprite_warping_points)
 235     {
 236         case 0:
 237             s->sprite_offset[0][0]= 0;
 238             s->sprite_offset[0][1]= 0;
 239             s->sprite_offset[1][0]= 0;
 240             s->sprite_offset[1][1]= 0;
 241             s->sprite_delta[0][0]= a;
 242             s->sprite_delta[0][1]= 0;
 243             s->sprite_delta[1][0]= 0;
 244             s->sprite_delta[1][1]= a;
 245             s->sprite_shift[0]= 0;
 246             s->sprite_shift[1]= 0;
 247             break;
 248         case 1: //GMC only
 249             s->sprite_offset[0][0]= sprite_ref[0][0] - a*vop_ref[0][0];
 250             s->sprite_offset[0][1]= sprite_ref[0][1] - a*vop_ref[0][1];
 251             s->sprite_offset[1][0]= ((sprite_ref[0][0]>>1)|(sprite_ref[0][0]&1)) - a*(vop_ref[0][0]/2);
 252             s->sprite_offset[1][1]= ((sprite_ref[0][1]>>1)|(sprite_ref[0][1]&1)) - a*(vop_ref[0][1]/2);
 253             s->sprite_delta[0][0]= a;
 254             s->sprite_delta[0][1]= 0;
 255             s->sprite_delta[1][0]= 0;
 256             s->sprite_delta[1][1]= a;
 257             s->sprite_shift[0]= 0;
 258             s->sprite_shift[1]= 0;
 259             break;
 260         case 2:
 261             s->sprite_offset[0][0]= (sprite_ref[0][0]<<(alpha+rho))
 262                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][0])
 263                                                   + ( r*sprite_ref[0][1] - virtual_ref[0][1])*(-vop_ref[0][1])
 264                                                   + (1<<(alpha+rho-1));
 265             s->sprite_offset[0][1]= (sprite_ref[0][1]<<(alpha+rho))
 266                                                   + (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-vop_ref[0][0])
 267                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][1])
 268                                                   + (1<<(alpha+rho-1));
 269             s->sprite_offset[1][0]= ( (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][0] + 1)
 270                                      +( r*sprite_ref[0][1] - virtual_ref[0][1])*(-2*vop_ref[0][1] + 1)
 271                                      +2*w2*r*sprite_ref[0][0]
 272                                      - 16*w2
 273                                      + (1<<(alpha+rho+1)));
 274             s->sprite_offset[1][1]= ( (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-2*vop_ref[0][0] + 1)
 275                                      +(-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][1] + 1)
 276                                      +2*w2*r*sprite_ref[0][1]
 277                                      - 16*w2
 278                                      + (1<<(alpha+rho+1)));
 279             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 280             s->sprite_delta[0][1]=   (+r*sprite_ref[0][1] - virtual_ref[0][1]);
 281             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1]);
 282             s->sprite_delta[1][1]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 283
 284             s->sprite_shift[0]= alpha+rho;
 285             s->sprite_shift[1]= alpha+rho+2;
 286             break;
 287         case 3:
 288             min_ab= FFMIN(alpha, beta);
 289             w3= w2>>min_ab;
 290             h3= h2>>min_ab;
 291             s->sprite_offset[0][0]=  (sprite_ref[0][0]<<(alpha+beta+rho-min_ab))
 292                                    + (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-vop_ref[0][0])
 293                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-vop_ref[0][1])
 294                                    + (1<<(alpha+beta+rho-min_ab-1));
 295             s->sprite_offset[0][1]=  (sprite_ref[0][1]<<(alpha+beta+rho-min_ab))
 296                                    + (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-vop_ref[0][0])
 297                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-vop_ref[0][1])
 298                                    + (1<<(alpha+beta+rho-min_ab-1));
 299             s->sprite_offset[1][0]=  (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-2*vop_ref[0][0] + 1)
 300                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-2*vop_ref[0][1] + 1)
 301                                    + 2*w2*h3*r*sprite_ref[0][0]
 302                                    - 16*w2*h3
 303                                    + (1<<(alpha+beta+rho-min_ab+1));
 304             s->sprite_offset[1][1]=  (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-2*vop_ref[0][0] + 1)
 305                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-2*vop_ref[0][1] + 1)
 306                                    + 2*w2*h3*r*sprite_ref[0][1]
 307                                    - 16*w2*h3
 308                                    + (1<<(alpha+beta+rho-min_ab+1));
 309             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3;
 310             s->sprite_delta[0][1]=   (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3;
 311             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3;
 312             s->sprite_delta[1][1]=   (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3;
 313
 314             s->sprite_shift[0]= alpha + beta + rho - min_ab;
 315             s->sprite_shift[1]= alpha + beta + rho - min_ab + 2;
 316             break;
 317     }
 318     /* try to simplify the situation */
 319     if(   s->sprite_delta[0][0] == a<<s->sprite_shift[0]
 320        && s->sprite_delta[0][1] == 0
 321        && s->sprite_delta[1][0] == 0
 322        && s->sprite_delta[1][1] == a<<s->sprite_shift[0])
 323     {
 324         s->sprite_offset[0][0]>>=s->sprite_shift[0];
 325         s->sprite_offset[0][1]>>=s->sprite_shift[0];
 326         s->sprite_offset[1][0]>>=s->sprite_shift[1];
 327         s->sprite_offset[1][1]>>=s->sprite_shift[1];
 328         s->sprite_delta[0][0]= a;
 329         s->sprite_delta[0][1]= 0;
 330         s->sprite_delta[1][0]= 0;
 331         s->sprite_delta[1][1]= a;
 332         s->sprite_shift[0]= 0;
 333         s->sprite_shift[1]= 0;
 334         s->real_sprite_warping_points=1;
 335     }
 336     else{
 337         int shift_y= 16 - s->sprite_shift[0];
 338         int shift_c= 16 - s->sprite_shift[1];
 339         for(i=0; i<2; i++){
 340             s->sprite_offset[0][i]<<= shift_y;
 341             s->sprite_offset[1][i]<<= shift_c;
 342             s->sprite_delta[0][i]<<= shift_y;
 343             s->sprite_delta[1][i]<<= shift_y;
 344             s->sprite_shift[i]= 16;
 345         }
 346         s->real_sprite_warping_points= s->num_sprite_warping_points;
 347     }
 348 }
 349
 350 /**
 351  * decodes the next video packet.
 352  * @return <0 if something went wrong
 353  */
 354 int mpeg4_decode_video_packet_header(MpegEncContext *s)
 355 {
 356     int mb_num_bits= av_log2(s->mb_num - 1) + 1;
 357     int header_extension=0, mb_num, len;
 358
 359     /* is there enough space left for a video packet + header */
 360     if( get_bits_count(&s->gb) > s->gb.size_in_bits-20) return -1;
 361
 362     for(len=0; len<32; len++){
 363         if(get_bits1(&s->gb)) break;
 364     }
 365
 366     if(len!=ff_mpeg4_get_video_packet_prefix_length(s)){
 367         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
 368         return -1;
 369     }
 370
 371     if(s->shape != RECT_SHAPE){
 372         header_extension= get_bits1(&s->gb);
 373         //FIXME more stuff here
 374     }
 375
 376     mb_num= get_bits(&s->gb, mb_num_bits);
 377     if(mb_num>=s->mb_num){
 378         av_log(s->avctx, AV_LOG_ERROR, "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
 379         return -1;
 380     }
 381
 382     s->mb_x= mb_num % s->mb_width;
 383     s->mb_y= mb_num / s->mb_width;
 384
 385     if(s->shape != BIN_ONLY_SHAPE){
 386         int qscale= get_bits(&s->gb, s->quant_precision);
 387         if(qscale)
 388             s->chroma_qscale=s->qscale= qscale;
 389     }
 390
 391     if(s->shape == RECT_SHAPE){
 392         header_extension= get_bits1(&s->gb);
 393     }
 394     if(header_extension){
 395         int time_incr=0;
 396
 397         while (get_bits1(&s->gb) != 0)
 398             time_incr++;
 399
 400         check_marker(&s->gb, "before time_increment in video packed header");
 401         skip_bits(&s->gb, s->time_increment_bits); /* time_increment */
 402         check_marker(&s->gb, "before vop_coding_type in video packed header");
 403
 404         skip_bits(&s->gb, 2); /* vop coding type */
 405         //FIXME not rect stuff here
 406
 407         if(s->shape != BIN_ONLY_SHAPE){
 408             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
 409 //FIXME don't just ignore everything
 410             if(s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 411                 mpeg4_decode_sprite_trajectory(s, &s->gb);
 412                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
 413             }
 414
 415             //FIXME reduced res stuff here
 416
 417             if (s->pict_type != AV_PICTURE_TYPE_I) {
 418                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
 419                 if(f_code==0){
 420                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (f_code=0)\n");
 421                 }
 422             }
 423             if (s->pict_type == AV_PICTURE_TYPE_B) {
 424                 int b_code = get_bits(&s->gb, 3);
 425                 if(b_code==0){
 426                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (b_code=0)\n");
 427                 }
 428             }
 429         }
 430     }
 431     //FIXME new-pred stuff
 432
 433     return 0;
 434 }
 435
 436 /**
 437  * gets the average motion vector for a GMC MB.
 438  * @param n either 0 for the x component or 1 for y
 439  * @return the average MV for a GMC MB
 440  */
 441 static inline int get_amv(MpegEncContext *s, int n){
 442     int x, y, mb_v, sum, dx, dy, shift;
 443     int len = 1 << (s->f_code + 4);
 444     const int a= s->sprite_warping_accuracy;
 445
 446     if(s->workaround_bugs & FF_BUG_AMV)
 447         len >>= s->quarter_sample;
 448
 449     if(s->real_sprite_warping_points==1){
 450         if(s->divx_version==500 && s->divx_build==413)
 451             sum= s->sprite_offset[0][n] / (1<<(a - s->quarter_sample));
 452         else
 453             sum= RSHIFT(s->sprite_offset[0][n]<<s->quarter_sample, a);
 454     }else{
 455         dx= s->sprite_delta[n][0];
 456         dy= s->sprite_delta[n][1];
 457         shift= s->sprite_shift[0];
 458         if(n) dy -= 1<<(shift + a + 1);
 459         else  dx -= 1<<(shift + a + 1);
 460         mb_v= s->sprite_offset[0][n] + dx*s->mb_x*16 + dy*s->mb_y*16;
 461
 462         sum=0;
 463         for(y=0; y<16; y++){
 464             int v;
 465
 466             v= mb_v + dy*y;
 467             //XXX FIXME optimize
 468             for(x=0; x<16; x++){
 469                 sum+= v>>shift;
 470                 v+= dx;
 471             }
 472         }
 473         sum= RSHIFT(sum, a+8-s->quarter_sample);
 474     }
 475
 476     if      (sum < -len) sum= -len;
 477     else if (sum >= len) sum= len-1;
 478
 479     return sum;
 480 }
 481
 482 /**
 483  * decodes the dc value.
 484  * @param n block index (0-3 are luma, 4-5 are chroma)
 485  * @param dir_ptr the prediction direction will be stored here
 486  * @return the quantized dc
 487  */
 488 static inline int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
 489 {
 490     int level, code;
 491
 492     if (n < 4)
 493         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
 494     else
 495         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
 496     if (code < 0 || code > 9 /* && s->nbit<9 */){
 497         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
 498         return -1;
 499     }
 500     if (code == 0) {
 501         level = 0;
 502     } else {
 503         if(IS_3IV1){
 504             if(code==1)
 505                 level= 2*get_bits1(&s->gb)-1;
 506             else{
 507                 if(get_bits1(&s->gb))
 508                     level = get_bits(&s->gb, code-1) + (1<<(code-1));
 509                 else
 510                     level = -get_bits(&s->gb, code-1) - (1<<(code-1));
 511             }
 512         }else{
 513             level = get_xbits(&s->gb, code);
 514         }
 515
 516         if (code > 8){
 517             if(get_bits1(&s->gb)==0){ /* marker */
 518                 if(s->error_recognition>=2){
 519                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
 520                     return -1;
 521                 }
 522             }
 523         }
 524     }
 525
 526     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
 527 }
 528
 529 /**
 530  * decodes first partition.
 531  * @return number of MBs decoded or <0 if an error occurred
 532  */
 533 static int mpeg4_decode_partition_a(MpegEncContext *s){
 534     int mb_num;
 535     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 536
 537     /* decode first partition */
 538     mb_num=0;
 539     s->first_slice_line=1;
 540     for(; s->mb_y<s->mb_height; s->mb_y++){
 541         ff_init_block_index(s);
 542         for(; s->mb_x<s->mb_width; s->mb_x++){
 543             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 544             int cbpc;
 545             int dir=0;
 546
 547             mb_num++;
 548             ff_update_block_index(s);
 549             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 550                 s->first_slice_line=0;
 551
 552             if(s->pict_type==AV_PICTURE_TYPE_I){
 553                 int i;
 554
 555                 do{
 556                     if(show_bits_long(&s->gb, 19)==DC_MARKER){
 557                         return mb_num-1;
 558                     }
 559
 560                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 561                     if (cbpc < 0){
 562                         av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 563                         return -1;
 564                     }
 565                 }while(cbpc == 8);
 566
 567                 s->cbp_table[xy]= cbpc & 3;
 568                 s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
 569                 s->mb_intra = 1;
 570
 571                 if(cbpc & 4) {
 572                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 573                 }
 574                 s->current_picture.f.qscale_table[xy]= s->qscale;
 575
 576                 s->mbintra_table[xy]= 1;
 577                 for(i=0; i<6; i++){
 578                     int dc_pred_dir;
 579                     int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 580                     if(dc < 0){
 581                         av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 582                         return -1;
 583                     }
 584                     dir<<=1;
 585                     if(dc_pred_dir) dir|=1;
 586                 }
 587                 s->pred_dir_table[xy]= dir;
 588             }else{ /* P/S_TYPE */
 589                 int mx, my, pred_x, pred_y, bits;
 590                 int16_t * const mot_val = s->current_picture.f.motion_val[0][s->block_index[0]];
 591                 const int stride= s->b8_stride*2;
 592
 593 try_again:
 594                 bits= show_bits(&s->gb, 17);
 595                 if(bits==MOTION_MARKER){
 596                     return mb_num-1;
 597                 }
 598                 skip_bits1(&s->gb);
 599                 if(bits&0x10000){
 600                     /* skip mb */
 601                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 602                         s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 603                         mx= get_amv(s, 0);
 604                         my= get_amv(s, 1);
 605                     }else{
 606                         s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 607                         mx=my=0;
 608                     }
 609                     mot_val[0       ]= mot_val[2       ]=
 610                     mot_val[0+stride]= mot_val[2+stride]= mx;
 611                     mot_val[1       ]= mot_val[3       ]=
 612                     mot_val[1+stride]= mot_val[3+stride]= my;
 613
 614                     if(s->mbintra_table[xy])
 615                         ff_clean_intra_table_entries(s);
 616                     continue;
 617                 }
 618
 619                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 620                 if (cbpc < 0){
 621                     av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 622                     return -1;
 623                 }
 624                 if(cbpc == 20)
 625                     goto try_again;
 626
 627                 s->cbp_table[xy]= cbpc&(8+3); //8 is dquant
 628
 629                 s->mb_intra = ((cbpc & 4) != 0);
 630
 631                 if(s->mb_intra){
 632                     s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
 633                     s->mbintra_table[xy]= 1;
 634                     mot_val[0       ]= mot_val[2       ]=
 635                     mot_val[0+stride]= mot_val[2+stride]= 0;
 636                     mot_val[1       ]= mot_val[3       ]=
 637                     mot_val[1+stride]= mot_val[3+stride]= 0;
 638                 }else{
 639                     if(s->mbintra_table[xy])
 640                         ff_clean_intra_table_entries(s);
 641
 642                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
 643                         s->mcsel= get_bits1(&s->gb);
 644                     else s->mcsel= 0;
 645
 646                     if ((cbpc & 16) == 0) {
 647                         /* 16x16 motion prediction */
 648
 649                         h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 650                         if(!s->mcsel){
 651                             mx = h263_decode_motion(s, pred_x, s->f_code);
 652                             if (mx >= 0xffff)
 653                                 return -1;
 654
 655                             my = h263_decode_motion(s, pred_y, s->f_code);
 656                             if (my >= 0xffff)
 657                                 return -1;
 658                             s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 659                         } else {
 660                             mx = get_amv(s, 0);
 661                             my = get_amv(s, 1);
 662                             s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 663                         }
 664
 665                         mot_val[0       ]= mot_val[2       ] =
 666                         mot_val[0+stride]= mot_val[2+stride]= mx;
 667                         mot_val[1       ]= mot_val[3       ]=
 668                         mot_val[1+stride]= mot_val[3+stride]= my;
 669                     } else {
 670                         int i;
 671                         s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 672                         for(i=0;i<4;i++) {
 673                             int16_t *mot_val= h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 674                             mx = h263_decode_motion(s, pred_x, s->f_code);
 675                             if (mx >= 0xffff)
 676                                 return -1;
 677
 678                             my = h263_decode_motion(s, pred_y, s->f_code);
 679                             if (my >= 0xffff)
 680                                 return -1;
 681                             mot_val[0] = mx;
 682                             mot_val[1] = my;
 683                         }
 684                     }
 685                 }
 686             }
 687         }
 688         s->mb_x= 0;
 689     }
 690
 691     return mb_num;
 692 }
 693
 694 /**
 695  * decode second partition.
 696  * @return <0 if an error occurred
 697  */
 698 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count){
 699     int mb_num=0;
 700     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 701
 702     s->mb_x= s->resync_mb_x;
 703     s->first_slice_line=1;
 704     for(s->mb_y= s->resync_mb_y; mb_num < mb_count; s->mb_y++){
 705         ff_init_block_index(s);
 706         for(; mb_num < mb_count && s->mb_x<s->mb_width; s->mb_x++){
 707             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 708
 709             mb_num++;
 710             ff_update_block_index(s);
 711             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 712                 s->first_slice_line=0;
 713
 714             if(s->pict_type==AV_PICTURE_TYPE_I){
 715                 int ac_pred= get_bits1(&s->gb);
 716                 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 717                 if(cbpy<0){
 718                     av_log(s->avctx, AV_LOG_ERROR, "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 719                     return -1;
 720                 }
 721
 722                 s->cbp_table[xy]|= cbpy<<2;
 723                 s->current_picture.f.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 724             }else{ /* P || S_TYPE */
 725                 if (IS_INTRA(s->current_picture.f.mb_type[xy])) {
 726                     int dir=0,i;
 727                     int ac_pred = get_bits1(&s->gb);
 728                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 729
 730                     if(cbpy<0){
 731                         av_log(s->avctx, AV_LOG_ERROR, "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 732                         return -1;
 733                     }
 734
 735                     if(s->cbp_table[xy] & 8) {
 736                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 737                     }
 738                     s->current_picture.f.qscale_table[xy] = s->qscale;
 739
 740                     for(i=0; i<6; i++){
 741                         int dc_pred_dir;
 742                         int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 743                         if(dc < 0){
 744                             av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 745                             return -1;
 746                         }
 747                         dir<<=1;
 748                         if(dc_pred_dir) dir|=1;
 749                     }
 750                     s->cbp_table[xy]&= 3; //remove dquant
 751                     s->cbp_table[xy]|= cbpy<<2;
 752                     s->current_picture.f.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 753                     s->pred_dir_table[xy]= dir;
 754                 } else if (IS_SKIP(s->current_picture.f.mb_type[xy])) {
 755                     s->current_picture.f.qscale_table[xy] = s->qscale;
 756                     s->cbp_table[xy]= 0;
 757                 }else{
 758                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 759
 760                     if(cbpy<0){
 761                         av_log(s->avctx, AV_LOG_ERROR, "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 762                         return -1;
 763                     }
 764
 765                     if(s->cbp_table[xy] & 8) {
 766                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 767                     }
 768                     s->current_picture.f.qscale_table[xy] = s->qscale;
 769
 770                     s->cbp_table[xy]&= 3; //remove dquant
 771                     s->cbp_table[xy]|= (cbpy^0xf)<<2;
 772                 }
 773             }
 774         }
 775         if(mb_num >= mb_count) return 0;
 776         s->mb_x= 0;
 777     }
 778     return 0;
 779 }
 780
 781 /**
 782  * decodes the first & second partition
 783  * @return <0 if error (and sets error type in the error_status_table)
 784  */
 785 int ff_mpeg4_decode_partitions(MpegEncContext *s)
 786 {
 787     int mb_num;
 788     const int part_a_error= s->pict_type==AV_PICTURE_TYPE_I ? (DC_ERROR|MV_ERROR) : MV_ERROR;
 789     const int part_a_end  = s->pict_type==AV_PICTURE_TYPE_I ? (DC_END  |MV_END)   : MV_END;
 790
 791     mb_num= mpeg4_decode_partition_a(s);
 792     if(mb_num<0){
 793         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 794         return -1;
 795     }
 796
 797     if(s->resync_mb_x + s->resync_mb_y*s->mb_width + mb_num > s->mb_num){
 798         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
 799         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 800         return -1;
 801     }
 802
 803     s->mb_num_left= mb_num;
 804
 805     if(s->pict_type==AV_PICTURE_TYPE_I){
 806         while(show_bits(&s->gb, 9) == 1)
 807             skip_bits(&s->gb, 9);
 808         if(get_bits_long(&s->gb, 19)!=DC_MARKER){
 809             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first I partition at %d %d\n", s->mb_x, s->mb_y);
 810             return -1;
 811         }
 812     }else{
 813         while(show_bits(&s->gb, 10) == 1)
 814             skip_bits(&s->gb, 10);
 815         if(get_bits(&s->gb, 17)!=MOTION_MARKER){
 816             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first P partition at %d %d\n", s->mb_x, s->mb_y);
 817             return -1;
 818         }
 819     }
 820     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, part_a_end);
 821
 822     if( mpeg4_decode_partition_b(s, mb_num) < 0){
 823         if(s->pict_type==AV_PICTURE_TYPE_P)
 824             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, DC_ERROR);
 825         return -1;
 826     }else{
 827         if(s->pict_type==AV_PICTURE_TYPE_P)
 828             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, DC_END);
 829     }
 830
 831     return 0;
 832 }
 833
 834 /**
 835  * decodes a block.
 836  * @return <0 if an error occurred
 837  */
 838 static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
 839                               int n, int coded, int intra, int rvlc)
 840 {
 841     int level, i, last, run;
 842     int dc_pred_dir;
 843     RLTable * rl;
 844     RL_VLC_ELEM * rl_vlc;
 845     const uint8_t * scan_table;
 846     int qmul, qadd;
 847
 848     //Note intra & rvlc should be optimized away if this is inlined
 849
 850     if(intra) {
 851       if(s->use_intra_dc_vlc){
 852         /* DC coef */
 853         if(s->partitioned_frame){
 854             level = s->dc_val[0][ s->block_index[n] ];
 855             if(n<4) level= FASTDIV((level + (s->y_dc_scale>>1)), s->y_dc_scale);
 856             else    level= FASTDIV((level + (s->c_dc_scale>>1)), s->c_dc_scale);
 857             dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_stride]<<n)&32;
 858         }else{
 859             level = mpeg4_decode_dc(s, n, &dc_pred_dir);
 860             if (level < 0)
 861                 return -1;
 862         }
 863         block[0] = level;
 864         i = 0;
 865       }else{
 866             i = -1;
 867             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
 868       }
 869       if (!coded)
 870           goto not_coded;
 871
 872       if(rvlc){
 873           rl = &rvlc_rl_intra;
 874           rl_vlc = rvlc_rl_intra.rl_vlc[0];
 875       }else{
 876           rl = &ff_mpeg4_rl_intra;
 877           rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
 878       }
 879       if (s->ac_pred) {
 880           if (dc_pred_dir == 0)
 881               scan_table = s->intra_v_scantable.permutated; /* left */
 882           else
 883               scan_table = s->intra_h_scantable.permutated; /* top */
 884       } else {
 885             scan_table = s->intra_scantable.permutated;
 886       }
 887       qmul=1;
 888       qadd=0;
 889     } else {
 890         i = -1;
 891         if (!coded) {
 892             s->block_last_index[n] = i;
 893             return 0;
 894         }
 895         if(rvlc) rl = &rvlc_rl_inter;
 896         else     rl = &ff_h263_rl_inter;
 897
 898         scan_table = s->intra_scantable.permutated;
 899
 900         if(s->mpeg_quant){
 901             qmul=1;
 902             qadd=0;
 903             if(rvlc){
 904                 rl_vlc = rvlc_rl_inter.rl_vlc[0];
 905             }else{
 906                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
 907             }
 908         }else{
 909             qmul = s->qscale << 1;
 910             qadd = (s->qscale - 1) | 1;
 911             if(rvlc){
 912                 rl_vlc = rvlc_rl_inter.rl_vlc[s->qscale];
 913             }else{
 914                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
 915             }
 916         }
 917     }
 918   {
 919     OPEN_READER(re, &s->gb);
 920     for(;;) {
 921         UPDATE_CACHE(re, &s->gb);
 922         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
 923         if (level==0) {
 924           /* escape */
 925           if(rvlc){
 926                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 927                     av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in rvlc esc\n");
 928                     return -1;
 929                 }; SKIP_CACHE(re, &s->gb, 1);
 930
 931                 last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 932                 run=   SHOW_UBITS(re, &s->gb, 6); LAST_SKIP_CACHE(re, &s->gb, 6);
 933                 SKIP_COUNTER(re, &s->gb, 1+1+6);
 934                 UPDATE_CACHE(re, &s->gb);
 935
 936                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 937                     av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in rvlc esc\n");
 938                     return -1;
 939                 }; SKIP_CACHE(re, &s->gb, 1);
 940
 941                 level= SHOW_UBITS(re, &s->gb, 11); SKIP_CACHE(re, &s->gb, 11);
 942
 943                 if(SHOW_UBITS(re, &s->gb, 5)!=0x10){
 944                     av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
 945                     return -1;
 946                 }; SKIP_CACHE(re, &s->gb, 5);
 947
 948                 level=  level * qmul + qadd;
 949                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); LAST_SKIP_CACHE(re, &s->gb, 1);
 950                 SKIP_COUNTER(re, &s->gb, 1+11+5+1);
 951
 952                 i+= run + 1;
 953                 if(last) i+=192;
 954           }else{
 955             int cache;
 956             cache= GET_CACHE(re, &s->gb);
 957
 958             if(IS_3IV1)
 959                 cache ^= 0xC0000000;
 960
 961             if (cache&0x80000000) {
 962                 if (cache&0x40000000) {
 963                     /* third escape */
 964                     SKIP_CACHE(re, &s->gb, 2);
 965                     last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 966                     run=   SHOW_UBITS(re, &s->gb, 6); LAST_SKIP_CACHE(re, &s->gb, 6);
 967                     SKIP_COUNTER(re, &s->gb, 2+1+6);
 968                     UPDATE_CACHE(re, &s->gb);
 969
 970                     if(IS_3IV1){
 971                         level= SHOW_SBITS(re, &s->gb, 12); LAST_SKIP_BITS(re, &s->gb, 12);
 972                     }else{
 973                         if(SHOW_UBITS(re, &s->gb, 1)==0){
 974                             av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in 3. esc\n");
 975                             return -1;
 976                         }; SKIP_CACHE(re, &s->gb, 1);
 977
 978                         level= SHOW_SBITS(re, &s->gb, 12); SKIP_CACHE(re, &s->gb, 12);
 979
 980                         if(SHOW_UBITS(re, &s->gb, 1)==0){
 981                             av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in 3. esc\n");
 982                             return -1;
 983                         }; LAST_SKIP_CACHE(re, &s->gb, 1);
 984
 985                         SKIP_COUNTER(re, &s->gb, 1+12+1);
 986                     }
 987
 988 #if 0
 989                     if(s->error_recognition >= FF_ER_COMPLIANT){
 990                         const int abs_level= FFABS(level);
 991                         if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
 992                             const int run1= run - rl->max_run[last][abs_level] - 1;
 993                             if(abs_level <= rl->max_level[last][run]){
 994                                 av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
 995                                 return -1;
 996                             }
 997                             if(s->error_recognition > FF_ER_COMPLIANT){
 998                                 if(abs_level <= rl->max_level[last][run]*2){
 999                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
1000                                     return -1;
1001                                 }
1002                                 if(run1 >= 0 && abs_level <= rl->max_level[last][run1]){
1003                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
1004                                     return -1;
1005                                 }
1006                             }
1007                         }
1008                     }
1009 #endif
1010                     if (level>0) level= level * qmul + qadd;
1011                     else         level= level * qmul - qadd;
1012
1013                     if((unsigned)(level + 2048) > 4095){
1014                         if(s->error_recognition > FF_ER_COMPLIANT){
1015                             if(level > 2560 || level<-2560){
1016                                 av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
1017                                 return -1;
1018                             }
1019                         }
1020                         level= level<0 ? -2048 : 2047;
1021                     }
1022
1023                     i+= run + 1;
1024                     if(last) i+=192;
1025                 } else {
1026                     /* second escape */
1027                     SKIP_BITS(re, &s->gb, 2);
1028                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1029                     i+= run + rl->max_run[run>>7][level/qmul] +1; //FIXME opt indexing
1030                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1031                     LAST_SKIP_BITS(re, &s->gb, 1);
1032                 }
1033             } else {
1034                 /* first escape */
1035                 SKIP_BITS(re, &s->gb, 1);
1036                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1037                 i+= run;
1038                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
1039                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1040                 LAST_SKIP_BITS(re, &s->gb, 1);
1041             }
1042           }
1043         } else {
1044             i+= run;
1045             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1046             LAST_SKIP_BITS(re, &s->gb, 1);
1047         }
1048         if (i > 62){
1049             i-= 192;
1050             if(i&(~63)){
1051                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1052                 return -1;
1053             }
1054
1055             block[scan_table[i]] = level;
1056             break;
1057         }
1058
1059         block[scan_table[i]] = level;
1060     }
1061     CLOSE_READER(re, &s->gb);
1062   }
1063  not_coded:
1064     if (intra) {
1065         if(!s->use_intra_dc_vlc){
1066             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1067
1068             i -= i>>31; //if(i == -1) i=0;
1069         }
1070
1071         mpeg4_pred_ac(s, block, n, dc_pred_dir);
1072         if (s->ac_pred) {
1073             i = 63; /* XXX: not optimal */
1074         }
1075     }
1076     s->block_last_index[n] = i;
1077     return 0;
1078 }
1079
1080 /**
1081  * decode partition C of one MB.
1082  * @return <0 if an error occurred
1083  */
1084 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, DCTELEM block[6][64])
1085 {
1086     int cbp, mb_type;
1087     const int xy= s->mb_x + s->mb_y*s->mb_stride;
1088
1089     mb_type = s->current_picture.f.mb_type[xy];
1090     cbp = s->cbp_table[xy];
1091
1092     s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1093
1094     if (s->current_picture.f.qscale_table[xy] != s->qscale) {
1095         ff_set_qscale(s, s->current_picture.f.qscale_table[xy]);
1096     }
1097
1098     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1099         int i;
1100         for(i=0; i<4; i++){
1101             s->mv[0][i][0] = s->current_picture.f.motion_val[0][s->block_index[i]][0];
1102             s->mv[0][i][1] = s->current_picture.f.motion_val[0][s->block_index[i]][1];
1103         }
1104         s->mb_intra = IS_INTRA(mb_type);
1105
1106         if (IS_SKIP(mb_type)) {
1107             /* skip mb */
1108             for(i=0;i<6;i++)
1109                 s->block_last_index[i] = -1;
1110             s->mv_dir = MV_DIR_FORWARD;
1111             s->mv_type = MV_TYPE_16X16;
1112             if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1113                 s->mcsel=1;
1114                 s->mb_skipped = 0;
1115             }else{
1116                 s->mcsel=0;
1117                 s->mb_skipped = 1;
1118             }
1119         }else if(s->mb_intra){
1120             s->ac_pred = IS_ACPRED(s->current_picture.f.mb_type[xy]);
1121         }else if(!s->mb_intra){
1122 //            s->mcsel= 0; //FIXME do we need to init that
1123
1124             s->mv_dir = MV_DIR_FORWARD;
1125             if (IS_8X8(mb_type)) {
1126                 s->mv_type = MV_TYPE_8X8;
1127             } else {
1128                 s->mv_type = MV_TYPE_16X16;
1129             }
1130         }
1131     } else { /* I-Frame */
1132         s->mb_intra = 1;
1133         s->ac_pred = IS_ACPRED(s->current_picture.f.mb_type[xy]);
1134     }
1135
1136     if (!IS_SKIP(mb_type)) {
1137         int i;
1138         s->dsp.clear_blocks(s->block[0]);
1139         /* decode each block */
1140         for (i = 0; i < 6; i++) {
1141             if(mpeg4_decode_block(s, block[i], i, cbp&32, s->mb_intra, s->rvlc) < 0){
1142                 av_log(s->avctx, AV_LOG_ERROR, "texture corrupted at %d %d %d\n", s->mb_x, s->mb_y, s->mb_intra);
1143                 return -1;
1144             }
1145             cbp+=cbp;
1146         }
1147     }
1148
1149     /* per-MB end of slice check */
1150
1151     if(--s->mb_num_left <= 0){
1152         if(mpeg4_is_resync(s))
1153             return SLICE_END;
1154         else
1155             return SLICE_NOEND;
1156     }else{
1157         if(mpeg4_is_resync(s)){
1158             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1159             if(s->cbp_table[xy+delta])
1160                 return SLICE_END;
1161         }
1162         return SLICE_OK;
1163     }
1164 }
1165
1166 static int mpeg4_decode_mb(MpegEncContext *s,
1167                       DCTELEM block[6][64])
1168 {
1169     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1170     int16_t *mot_val;
1171     static int8_t quant_tab[4] = { -1, -2, 1, 2 };
1172     const int xy= s->mb_x + s->mb_y * s->mb_stride;
1173
1174     assert(s->h263_pred);
1175
1176     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1177         do{
1178             if (get_bits1(&s->gb)) {
1179                 /* skip mb */
1180                 s->mb_intra = 0;
1181                 for(i=0;i<6;i++)
1182                     s->block_last_index[i] = -1;
1183                 s->mv_dir = MV_DIR_FORWARD;
1184                 s->mv_type = MV_TYPE_16X16;
1185                 if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1186                     s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1187                     s->mcsel=1;
1188                     s->mv[0][0][0]= get_amv(s, 0);
1189                     s->mv[0][0][1]= get_amv(s, 1);
1190
1191                     s->mb_skipped = 0;
1192                 }else{
1193                     s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1194                     s->mcsel=0;
1195                     s->mv[0][0][0] = 0;
1196                     s->mv[0][0][1] = 0;
1197                     s->mb_skipped = 1;
1198                 }
1199                 goto end;
1200             }
1201             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1202             if (cbpc < 0){
1203                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1204                 return -1;
1205             }
1206         }while(cbpc == 20);
1207
1208         s->dsp.clear_blocks(s->block[0]);
1209         dquant = cbpc & 8;
1210         s->mb_intra = ((cbpc & 4) != 0);
1211         if (s->mb_intra) goto intra;
1212
1213         if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
1214             s->mcsel= get_bits1(&s->gb);
1215         else s->mcsel= 0;
1216         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1217
1218         cbp = (cbpc & 3) | (cbpy << 2);
1219         if (dquant) {
1220             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1221         }
1222         if((!s->progressive_sequence) && (cbp || (s->workaround_bugs&FF_BUG_XVID_ILACE)))
1223             s->interlaced_dct= get_bits1(&s->gb);
1224
1225         s->mv_dir = MV_DIR_FORWARD;
1226         if ((cbpc & 16) == 0) {
1227             if(s->mcsel){
1228                 s->current_picture.f.mb_type[xy] = MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1229                 /* 16x16 global motion prediction */
1230                 s->mv_type = MV_TYPE_16X16;
1231                 mx= get_amv(s, 0);
1232                 my= get_amv(s, 1);
1233                 s->mv[0][0][0] = mx;
1234                 s->mv[0][0][1] = my;
1235             }else if((!s->progressive_sequence) && get_bits1(&s->gb)){
1236                 s->current_picture.f.mb_type[xy] = MB_TYPE_16x8 | MB_TYPE_L0 | MB_TYPE_INTERLACED;
1237                 /* 16x8 field motion prediction */
1238                 s->mv_type= MV_TYPE_FIELD;
1239
1240                 s->field_select[0][0]= get_bits1(&s->gb);
1241                 s->field_select[0][1]= get_bits1(&s->gb);
1242
1243                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1244
1245                 for(i=0; i<2; i++){
1246                     mx = h263_decode_motion(s, pred_x, s->f_code);
1247                     if (mx >= 0xffff)
1248                         return -1;
1249
1250                     my = h263_decode_motion(s, pred_y/2, s->f_code);
1251                     if (my >= 0xffff)
1252                         return -1;
1253
1254                     s->mv[0][i][0] = mx;
1255                     s->mv[0][i][1] = my;
1256                 }
1257             }else{
1258                 s->current_picture.f.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1259                 /* 16x16 motion prediction */
1260                 s->mv_type = MV_TYPE_16X16;
1261                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1262                 mx = h263_decode_motion(s, pred_x, s->f_code);
1263
1264                 if (mx >= 0xffff)
1265                     return -1;
1266
1267                 my = h263_decode_motion(s, pred_y, s->f_code);
1268
1269                 if (my >= 0xffff)
1270                     return -1;
1271                 s->mv[0][0][0] = mx;
1272                 s->mv[0][0][1] = my;
1273             }
1274         } else {
1275             s->current_picture.f.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1276             s->mv_type = MV_TYPE_8X8;
1277             for(i=0;i<4;i++) {
1278                 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1279                 mx = h263_decode_motion(s, pred_x, s->f_code);
1280                 if (mx >= 0xffff)
1281                     return -1;
1282
1283                 my = h263_decode_motion(s, pred_y, s->f_code);
1284                 if (my >= 0xffff)
1285                     return -1;
1286                 s->mv[0][i][0] = mx;
1287                 s->mv[0][i][1] = my;
1288                 mot_val[0] = mx;
1289                 mot_val[1] = my;
1290             }
1291         }
1292     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
1293         int modb1; // first bit of modb
1294         int modb2; // second bit of modb
1295         int mb_type;
1296
1297         s->mb_intra = 0; //B-frames never contain intra blocks
1298         s->mcsel=0;      //     ...               true gmc blocks
1299
1300         if(s->mb_x==0){
1301             for(i=0; i<2; i++){
1302                 s->last_mv[i][0][0]=
1303                 s->last_mv[i][0][1]=
1304                 s->last_mv[i][1][0]=
1305                 s->last_mv[i][1][1]= 0;
1306             }
1307
1308             ff_thread_await_progress((AVFrame*)s->next_picture_ptr, s->mb_y, 0);
1309         }
1310
1311         /* if we skipped it in the future P Frame than skip it now too */
1312         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
1313
1314         if(s->mb_skipped){
1315                 /* skip mb */
1316             for(i=0;i<6;i++)
1317                 s->block_last_index[i] = -1;
1318
1319             s->mv_dir = MV_DIR_FORWARD;
1320             s->mv_type = MV_TYPE_16X16;
1321             s->mv[0][0][0] = 0;
1322             s->mv[0][0][1] = 0;
1323             s->mv[1][0][0] = 0;
1324             s->mv[1][0][1] = 0;
1325             s->current_picture.f.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1326             goto end;
1327         }
1328
1329         modb1= get_bits1(&s->gb);
1330         if(modb1){
1331             mb_type= MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1; //like MB_TYPE_B_DIRECT but no vectors coded
1332             cbp=0;
1333         }else{
1334             modb2= get_bits1(&s->gb);
1335             mb_type= get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1336             if(mb_type<0){
1337                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1338                 return -1;
1339             }
1340             mb_type= mb_type_b_map[ mb_type ];
1341             if(modb2) cbp= 0;
1342             else{
1343                 s->dsp.clear_blocks(s->block[0]);
1344                 cbp= get_bits(&s->gb, 6);
1345             }
1346
1347             if ((!IS_DIRECT(mb_type)) && cbp) {
1348                 if(get_bits1(&s->gb)){
1349                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb)*4 - 2);
1350                 }
1351             }
1352
1353             if(!s->progressive_sequence){
1354                 if(cbp)
1355                     s->interlaced_dct= get_bits1(&s->gb);
1356
1357                 if(!IS_DIRECT(mb_type) && get_bits1(&s->gb)){
1358                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1359                     mb_type &= ~MB_TYPE_16x16;
1360
1361                     if(USES_LIST(mb_type, 0)){
1362                         s->field_select[0][0]= get_bits1(&s->gb);
1363                         s->field_select[0][1]= get_bits1(&s->gb);
1364                     }
1365                     if(USES_LIST(mb_type, 1)){
1366                         s->field_select[1][0]= get_bits1(&s->gb);
1367                         s->field_select[1][1]= get_bits1(&s->gb);
1368                     }
1369                 }
1370             }
1371
1372             s->mv_dir = 0;
1373             if((mb_type & (MB_TYPE_DIRECT2|MB_TYPE_INTERLACED)) == 0){
1374                 s->mv_type= MV_TYPE_16X16;
1375
1376                 if(USES_LIST(mb_type, 0)){
1377                     s->mv_dir = MV_DIR_FORWARD;
1378
1379                     mx = h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1380                     my = h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1381                     s->last_mv[0][1][0]= s->last_mv[0][0][0]= s->mv[0][0][0] = mx;
1382                     s->last_mv[0][1][1]= s->last_mv[0][0][1]= s->mv[0][0][1] = my;
1383                 }
1384
1385                 if(USES_LIST(mb_type, 1)){
1386                     s->mv_dir |= MV_DIR_BACKWARD;
1387
1388                     mx = h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1389                     my = h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1390                     s->last_mv[1][1][0]= s->last_mv[1][0][0]= s->mv[1][0][0] = mx;
1391                     s->last_mv[1][1][1]= s->last_mv[1][0][1]= s->mv[1][0][1] = my;
1392                 }
1393             }else if(!IS_DIRECT(mb_type)){
1394                 s->mv_type= MV_TYPE_FIELD;
1395
1396                 if(USES_LIST(mb_type, 0)){
1397                     s->mv_dir = MV_DIR_FORWARD;
1398
1399                     for(i=0; i<2; i++){
1400                         mx = h263_decode_motion(s, s->last_mv[0][i][0]  , s->f_code);
1401                         my = h263_decode_motion(s, s->last_mv[0][i][1]/2, s->f_code);
1402                         s->last_mv[0][i][0]=  s->mv[0][i][0] = mx;
1403                         s->last_mv[0][i][1]= (s->mv[0][i][1] = my)*2;
1404                     }
1405                 }
1406
1407                 if(USES_LIST(mb_type, 1)){
1408                     s->mv_dir |= MV_DIR_BACKWARD;
1409
1410                     for(i=0; i<2; i++){
1411                         mx = h263_decode_motion(s, s->last_mv[1][i][0]  , s->b_code);
1412                         my = h263_decode_motion(s, s->last_mv[1][i][1]/2, s->b_code);
1413                         s->last_mv[1][i][0]=  s->mv[1][i][0] = mx;
1414                         s->last_mv[1][i][1]= (s->mv[1][i][1] = my)*2;
1415                     }
1416                 }
1417             }
1418         }
1419
1420         if(IS_DIRECT(mb_type)){
1421             if(IS_SKIP(mb_type))
1422                 mx=my=0;
1423             else{
1424                 mx = h263_decode_motion(s, 0, 1);
1425                 my = h263_decode_motion(s, 0, 1);
1426             }
1427
1428             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1429             mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
1430         }
1431         s->current_picture.f.mb_type[xy] = mb_type;
1432     } else { /* I-Frame */
1433         do{
1434             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1435             if (cbpc < 0){
1436                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1437                 return -1;
1438             }
1439         }while(cbpc == 8);
1440
1441         dquant = cbpc & 4;
1442         s->mb_intra = 1;
1443 intra:
1444         s->ac_pred = get_bits1(&s->gb);
1445         if(s->ac_pred)
1446             s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1447         else
1448             s->current_picture.f.mb_type[xy] = MB_TYPE_INTRA;
1449
1450         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1451         if(cbpy<0){
1452             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1453             return -1;
1454         }
1455         cbp = (cbpc & 3) | (cbpy << 2);
1456
1457         s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1458
1459         if (dquant) {
1460             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1461         }
1462
1463         if(!s->progressive_sequence)
1464             s->interlaced_dct= get_bits1(&s->gb);
1465
1466         s->dsp.clear_blocks(s->block[0]);
1467         /* decode each block */
1468         for (i = 0; i < 6; i++) {
1469             if (mpeg4_decode_block(s, block[i], i, cbp&32, 1, 0) < 0)
1470                 return -1;
1471             cbp+=cbp;
1472         }
1473         goto end;
1474     }
1475
1476     /* decode each block */
1477     for (i = 0; i < 6; i++) {
1478         if (mpeg4_decode_block(s, block[i], i, cbp&32, 0, 0) < 0)
1479             return -1;
1480         cbp+=cbp;
1481     }
1482 end:
1483
1484         /* per-MB end of slice check */
1485     if(s->codec_id==CODEC_ID_MPEG4){
1486         int next= mpeg4_is_resync(s);
1487         if(next) {
1488             if        (s->mb_x + s->mb_y*s->mb_width + 1 >  next && s->avctx->error_recognition >= FF_ER_AGGRESSIVE) {
1489                 return -1;
1490             } else if (s->mb_x + s->mb_y*s->mb_width + 1 >= next)
1491                 return SLICE_END;
1492
1493             if(s->pict_type==AV_PICTURE_TYPE_B){
1494                 const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1495                 ff_thread_await_progress((AVFrame*)s->next_picture_ptr,
1496                                         (s->mb_x + delta >= s->mb_width) ? FFMIN(s->mb_y+1, s->mb_height-1) : s->mb_y, 0);
1497                 if (s->next_picture.f.mbskip_table[xy + delta])
1498                     return SLICE_OK;
1499             }
1500
1501             return SLICE_END;
1502         }
1503     }
1504
1505     return SLICE_OK;
1506 }
1507
1508
1509 static int mpeg4_decode_gop_header(MpegEncContext * s, GetBitContext *gb){
1510     int hours, minutes, seconds;
1511
1512     if(!show_bits(gb, 23)){
1513         av_log(s->avctx, AV_LOG_WARNING, "GOP header invalid\n");
1514         return -1;
1515     }
1516
1517     hours= get_bits(gb, 5);
1518     minutes= get_bits(gb, 6);
1519     skip_bits1(gb);
1520     seconds= get_bits(gb, 6);
1521
1522     s->time_base= seconds + 60*(minutes + 60*hours);
1523
1524     skip_bits1(gb);
1525     skip_bits1(gb);
1526
1527     return 0;
1528 }
1529
1530 static int mpeg4_decode_profile_level(MpegEncContext * s, GetBitContext *gb){
1531
1532     s->avctx->profile = get_bits(gb, 4);
1533     s->avctx->level   = get_bits(gb, 4);
1534
1535     // for Simple profile, level 0
1536     if (s->avctx->profile == 0 && s->avctx->level == 8) {
1537         s->avctx->level = 0;
1538     }
1539
1540     return 0;
1541 }
1542
1543 static int decode_vol_header(MpegEncContext *s, GetBitContext *gb){
1544     int width, height, vo_ver_id;
1545
1546     /* vol header */
1547     skip_bits(gb, 1); /* random access */
1548     s->vo_type= get_bits(gb, 8);
1549     if (get_bits1(gb) != 0) { /* is_ol_id */
1550         vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
1551         skip_bits(gb, 3); /* vo_priority */
1552     } else {
1553         vo_ver_id = 1;
1554     }
1555     s->aspect_ratio_info= get_bits(gb, 4);
1556     if(s->aspect_ratio_info == FF_ASPECT_EXTENDED){
1557         s->avctx->sample_aspect_ratio.num= get_bits(gb, 8); // par_width
1558         s->avctx->sample_aspect_ratio.den= get_bits(gb, 8); // par_height
1559     }else{
1560         s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1561     }
1562
1563     if ((s->vol_control_parameters=get_bits1(gb))) { /* vol control parameter */
1564         int chroma_format= get_bits(gb, 2);
1565         if(chroma_format!=CHROMA_420){
1566             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1567         }
1568         s->low_delay= get_bits1(gb);
1569         if(get_bits1(gb)){ /* vbv parameters */
1570             get_bits(gb, 15);   /* first_half_bitrate */
1571             skip_bits1(gb);     /* marker */
1572             get_bits(gb, 15);   /* latter_half_bitrate */
1573             skip_bits1(gb);     /* marker */
1574             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
1575             skip_bits1(gb);     /* marker */
1576             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
1577             get_bits(gb, 11);   /* first_half_vbv_occupancy */
1578             skip_bits1(gb);     /* marker */
1579             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
1580             skip_bits1(gb);     /* marker */
1581         }
1582     }else{
1583         // set low delay flag only once the smartest? low delay detection won't be overriden
1584         if(s->picture_number==0)
1585             s->low_delay=0;
1586     }
1587
1588     s->shape = get_bits(gb, 2); /* vol shape */
1589     if(s->shape != RECT_SHAPE) av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1590     if(s->shape == GRAY_SHAPE && vo_ver_id != 1){
1591         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1592         skip_bits(gb, 4);  //video_object_layer_shape_extension
1593     }
1594
1595     check_marker(gb, "before time_increment_resolution");
1596
1597     s->avctx->time_base.den = get_bits(gb, 16);
1598     if(!s->avctx->time_base.den){
1599         av_log(s->avctx, AV_LOG_ERROR, "time_base.den==0\n");
1600         s->avctx->time_base.num = 0;
1601         return -1;
1602     }
1603
1604     s->time_increment_bits = av_log2(s->avctx->time_base.den - 1) + 1;
1605     if (s->time_increment_bits < 1)
1606         s->time_increment_bits = 1;
1607
1608     check_marker(gb, "before fixed_vop_rate");
1609
1610     if (get_bits1(gb) != 0) {   /* fixed_vop_rate  */
1611         s->avctx->time_base.num = get_bits(gb, s->time_increment_bits);
1612     }else
1613         s->avctx->time_base.num = 1;
1614
1615     s->t_frame=0;
1616
1617     if (s->shape != BIN_ONLY_SHAPE) {
1618         if (s->shape == RECT_SHAPE) {
1619             skip_bits1(gb);   /* marker */
1620             width = get_bits(gb, 13);
1621             skip_bits1(gb);   /* marker */
1622             height = get_bits(gb, 13);
1623             skip_bits1(gb);   /* marker */
1624             if(width && height && !(s->width && s->codec_tag == AV_RL32("MP4S"))){ /* they should be non zero but who knows ... */
1625                 s->width = width;
1626                 s->height = height;
1627             }
1628         }
1629
1630         s->progressive_sequence=
1631         s->progressive_frame= get_bits1(gb)^1;
1632         s->interlaced_dct=0;
1633         if(!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1634             av_log(s->avctx, AV_LOG_INFO, "MPEG4 OBMC not supported (very likely buggy encoder)\n");   /* OBMC Disable */
1635         if (vo_ver_id == 1) {
1636             s->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
1637         } else {
1638             s->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
1639         }
1640         if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1641         if(s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE){
1642             if(s->vol_sprite_usage==STATIC_SPRITE){
1643                 s->sprite_width = get_bits(gb, 13);
1644                 skip_bits1(gb); /* marker */
1645                 s->sprite_height= get_bits(gb, 13);
1646                 skip_bits1(gb); /* marker */
1647                 s->sprite_left  = get_bits(gb, 13);
1648                 skip_bits1(gb); /* marker */
1649                 s->sprite_top   = get_bits(gb, 13);
1650                 skip_bits1(gb); /* marker */
1651             }
1652             s->num_sprite_warping_points= get_bits(gb, 6);
1653             if(s->num_sprite_warping_points > 3){
1654                 av_log(s->avctx, AV_LOG_ERROR, "%d sprite_warping_points\n", s->num_sprite_warping_points);
1655                 s->num_sprite_warping_points= 0;
1656                 return -1;
1657             }
1658             s->sprite_warping_accuracy = get_bits(gb, 2);
1659             s->sprite_brightness_change= get_bits1(gb);
1660             if(s->vol_sprite_usage==STATIC_SPRITE)
1661                 s->low_latency_sprite= get_bits1(gb);
1662         }
1663         // FIXME sadct disable bit if verid!=1 && shape not rect
1664
1665         if (get_bits1(gb) == 1) {   /* not_8_bit */
1666             s->quant_precision = get_bits(gb, 4); /* quant_precision */
1667             if(get_bits(gb, 4)!=8) av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n"); /* bits_per_pixel */
1668             if(s->quant_precision!=5) av_log(s->avctx, AV_LOG_ERROR, "quant precision %d\n", s->quant_precision);
1669         } else {
1670             s->quant_precision = 5;
1671         }
1672
1673         // FIXME a bunch of grayscale shape things
1674
1675         if((s->mpeg_quant=get_bits1(gb))){ /* vol_quant_type */
1676             int i, v;
1677
1678             /* load default matrixes */
1679             for(i=0; i<64; i++){
1680                 int j= s->dsp.idct_permutation[i];
1681                 v= ff_mpeg4_default_intra_matrix[i];
1682                 s->intra_matrix[j]= v;
1683                 s->chroma_intra_matrix[j]= v;
1684
1685                 v= ff_mpeg4_default_non_intra_matrix[i];
1686                 s->inter_matrix[j]= v;
1687                 s->chroma_inter_matrix[j]= v;
1688             }
1689
1690             /* load custom intra matrix */
1691             if(get_bits1(gb)){
1692                 int last=0;
1693                 for(i=0; i<64; i++){
1694                     int j;
1695                     v= get_bits(gb, 8);
1696                     if(v==0) break;
1697
1698                     last= v;
1699                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1700                     s->intra_matrix[j]= v;
1701                     s->chroma_intra_matrix[j]= v;
1702                 }
1703
1704                 /* replicate last value */
1705                 for(; i<64; i++){
1706                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1707                     s->intra_matrix[j]= last;
1708                     s->chroma_intra_matrix[j]= last;
1709                 }
1710             }
1711
1712             /* load custom non intra matrix */
1713             if(get_bits1(gb)){
1714                 int last=0;
1715                 for(i=0; i<64; i++){
1716                     int j;
1717                     v= get_bits(gb, 8);
1718                     if(v==0) break;
1719
1720                     last= v;
1721                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1722                     s->inter_matrix[j]= v;
1723                     s->chroma_inter_matrix[j]= v;
1724                 }
1725
1726                 /* replicate last value */
1727                 for(; i<64; i++){
1728                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1729                     s->inter_matrix[j]= last;
1730                     s->chroma_inter_matrix[j]= last;
1731                 }
1732             }
1733
1734             // FIXME a bunch of grayscale shape things
1735         }
1736
1737         if(vo_ver_id != 1)
1738              s->quarter_sample= get_bits1(gb);
1739         else s->quarter_sample=0;
1740
1741         if(!get_bits1(gb)){
1742             int pos= get_bits_count(gb);
1743             int estimation_method= get_bits(gb, 2);
1744             if(estimation_method<2){
1745                 if(!get_bits1(gb)){
1746                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //opaque
1747                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //transparent
1748                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_cae
1749                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //inter_cae
1750                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //no_update
1751                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //upampling
1752                 }
1753                 if(!get_bits1(gb)){
1754                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_blocks
1755                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter_blocks
1756                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter4v_blocks
1757                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //not coded blocks
1758                 }
1759                 if(!check_marker(gb, "in complexity estimation part 1")){
1760                     skip_bits_long(gb, pos - get_bits_count(gb));
1761                     goto no_cplx_est;
1762                 }
1763                 if(!get_bits1(gb)){
1764                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_coeffs
1765                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_lines
1766                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //vlc_syms
1767                     s->cplx_estimation_trash_i += 4*get_bits1(gb); //vlc_bits
1768                 }
1769                 if(!get_bits1(gb)){
1770                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //apm
1771                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //npm
1772                     s->cplx_estimation_trash_b += 8*get_bits1(gb); //interpolate_mc_q
1773                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //forwback_mc_q
1774                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel2
1775                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel4
1776                 }
1777                 if(!check_marker(gb, "in complexity estimation part 2")){
1778                     skip_bits_long(gb, pos - get_bits_count(gb));
1779                     goto no_cplx_est;
1780                 }
1781                 if(estimation_method==1){
1782                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //sadct
1783                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //qpel
1784                 }
1785             }else
1786                 av_log(s->avctx, AV_LOG_ERROR, "Invalid Complexity estimation method %d\n", estimation_method);
1787         }else{
1788 no_cplx_est:
1789             s->cplx_estimation_trash_i=
1790             s->cplx_estimation_trash_p=
1791             s->cplx_estimation_trash_b= 0;
1792         }
1793
1794         s->resync_marker= !get_bits1(gb); /* resync_marker_disabled */
1795
1796         s->data_partitioning= get_bits1(gb);
1797         if(s->data_partitioning){
1798             s->rvlc= get_bits1(gb);
1799         }
1800
1801         if(vo_ver_id != 1) {
1802             s->new_pred= get_bits1(gb);
1803             if(s->new_pred){
1804                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
1805                 skip_bits(gb, 2); /* requested upstream message type */
1806                 skip_bits1(gb); /* newpred segment type */
1807             }
1808             s->reduced_res_vop= get_bits1(gb);
1809             if(s->reduced_res_vop) av_log(s->avctx, AV_LOG_ERROR, "reduced resolution VOP not supported\n");
1810         }
1811         else{
1812             s->new_pred=0;
1813             s->reduced_res_vop= 0;
1814         }
1815
1816         s->scalability= get_bits1(gb);
1817
1818         if (s->scalability) {
1819             GetBitContext bak= *gb;
1820             int h_sampling_factor_n;
1821             int h_sampling_factor_m;
1822             int v_sampling_factor_n;
1823             int v_sampling_factor_m;
1824
1825             s->hierachy_type= get_bits1(gb);
1826             skip_bits(gb, 4);  /* ref_layer_id */
1827             skip_bits1(gb);    /* ref_layer_sampling_dir */
1828             h_sampling_factor_n= get_bits(gb, 5);
1829             h_sampling_factor_m= get_bits(gb, 5);
1830             v_sampling_factor_n= get_bits(gb, 5);
1831             v_sampling_factor_m= get_bits(gb, 5);
1832             s->enhancement_type= get_bits1(gb);
1833
1834             if(   h_sampling_factor_n==0 || h_sampling_factor_m==0
1835                || v_sampling_factor_n==0 || v_sampling_factor_m==0){
1836                 /* illegal scalability header (VERY broken encoder),
1837                  * trying to workaround */
1838                 s->scalability=0;
1839                 *gb= bak;
1840             }else
1841                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
1842
1843             // bin shape stuff FIXME
1844         }
1845     }
1846     return 0;
1847 }
1848
1849 /**
1850  * decodes the user data stuff in the header.
1851  * Also initializes divx/xvid/lavc_version/build.
1852  */
1853 static int decode_user_data(MpegEncContext *s, GetBitContext *gb){
1854     char buf[256];
1855     int i;
1856     int e;
1857     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
1858     char last;
1859
1860     for(i=0; i<255 && get_bits_count(gb) < gb->size_in_bits; i++){
1861         if(show_bits(gb, 23) == 0) break;
1862         buf[i]= get_bits(gb, 8);
1863     }
1864     buf[i]=0;
1865
1866     /* divx detection */
1867     e=sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
1868     if(e<2)
1869         e=sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
1870     if(e>=2){
1871         s->divx_version= ver;
1872         s->divx_build= build;
1873         s->divx_packed= e==3 && last=='p';
1874         if(s->divx_packed && !s->showed_packed_warning) {
1875             av_log(s->avctx, AV_LOG_WARNING, "Invalid and inefficient vfw-avi packed B frames detected\n");
1876             s->showed_packed_warning=1;
1877         }
1878     }
1879
1880     /* ffmpeg detection */
1881     e=sscanf(buf, "FFmpe%*[^b]b%d", &build)+3;
1882     if(e!=4)
1883         e=sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
1884     if(e!=4){
1885         e=sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3)+1;
1886         if (e>1)
1887             build= (ver<<16) + (ver2<<8) + ver3;
1888     }
1889     if(e!=4){
1890         if(strcmp(buf, "ffmpeg")==0){
1891             s->lavc_build= 4600;
1892         }
1893     }
1894     if(e==4){
1895         s->lavc_build= build;
1896     }
1897
1898     /* Xvid detection */
1899     e=sscanf(buf, "XviD%d", &build);
1900     if(e==1){
1901         s->xvid_build= build;
1902     }
1903
1904     return 0;
1905 }
1906
1907 static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
1908     int time_incr, time_increment;
1909
1910     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I;        /* pict type: I = 0 , P = 1 */
1911     if(s->pict_type==AV_PICTURE_TYPE_B && s->low_delay && s->vol_control_parameters==0 && !(s->flags & CODEC_FLAG_LOW_DELAY)){
1912         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag incorrectly, clearing it\n");
1913         s->low_delay=0;
1914     }
1915
1916     s->partitioned_frame= s->data_partitioning && s->pict_type!=AV_PICTURE_TYPE_B;
1917     if(s->partitioned_frame)
1918         s->decode_mb= mpeg4_decode_partitioned_mb;
1919     else
1920         s->decode_mb= mpeg4_decode_mb;
1921
1922     time_incr=0;
1923     while (get_bits1(gb) != 0)
1924         time_incr++;
1925
1926     check_marker(gb, "before time_increment");
1927
1928     if(s->time_increment_bits==0 || !(show_bits(gb, s->time_increment_bits+1)&1)){
1929         av_log(s->avctx, AV_LOG_ERROR, "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
1930
1931         for(s->time_increment_bits=1 ;s->time_increment_bits<16; s->time_increment_bits++){
1932             if (    s->pict_type == AV_PICTURE_TYPE_P
1933                 || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE)) {
1934                 if((show_bits(gb, s->time_increment_bits+6)&0x37) == 0x30) break;
1935             }else
1936                 if((show_bits(gb, s->time_increment_bits+5)&0x1F) == 0x18) break;
1937         }
1938
1939         av_log(s->avctx, AV_LOG_ERROR, "my guess is %d bits ;)\n",s->time_increment_bits);
1940     }
1941
1942     if(IS_3IV1) time_increment= get_bits1(gb); //FIXME investigate further
1943     else time_increment= get_bits(gb, s->time_increment_bits);
1944
1945     if(s->pict_type!=AV_PICTURE_TYPE_B){
1946         s->last_time_base= s->time_base;
1947         s->time_base+= time_incr;
1948         s->time= s->time_base*s->avctx->time_base.den + time_increment;
1949         if(s->workaround_bugs&FF_BUG_UMP4){
1950             if(s->time < s->last_non_b_time){
1951                 /* header is not mpeg-4-compatible, broken encoder,
1952                  * trying to workaround */
1953                 s->time_base++;
1954                 s->time+= s->avctx->time_base.den;
1955             }
1956         }
1957         s->pp_time= s->time - s->last_non_b_time;
1958         s->last_non_b_time= s->time;
1959     }else{
1960         s->time= (s->last_time_base + time_incr)*s->avctx->time_base.den + time_increment;
1961         s->pb_time= s->pp_time - (s->last_non_b_time - s->time);
1962         if(s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0){
1963             /* messed up order, maybe after seeking? skipping current b-frame */
1964             return FRAME_SKIPPED;
1965         }
1966         ff_mpeg4_init_direct_mv(s);
1967
1968         if(s->t_frame==0) s->t_frame= s->pb_time;
1969         if(s->t_frame==0) s->t_frame=1; // 1/0 protection
1970         s->pp_field_time= (  ROUNDED_DIV(s->last_non_b_time, s->t_frame)
1971                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1972         s->pb_field_time= (  ROUNDED_DIV(s->time, s->t_frame)
1973                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1974         if(!s->progressive_sequence){
1975             if(s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
1976                 return FRAME_SKIPPED;
1977         }
1978     }
1979
1980     if(s->avctx->time_base.num)
1981         s->current_picture_ptr->f.pts = (s->time + s->avctx->time_base.num / 2) / s->avctx->time_base.num;
1982     else
1983         s->current_picture_ptr->f.pts = AV_NOPTS_VALUE;
1984     if(s->avctx->debug&FF_DEBUG_PTS)
1985         av_log(s->avctx, AV_LOG_DEBUG, "MPEG4 PTS: %"PRId64"\n",
1986                s->current_picture_ptr->f.pts);
1987
1988     check_marker(gb, "before vop_coded");
1989
1990     /* vop coded */
1991     if (get_bits1(gb) != 1){
1992         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
1993             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
1994         return FRAME_SKIPPED;
1995     }
1996     if (s->shape != BIN_ONLY_SHAPE && ( s->pict_type == AV_PICTURE_TYPE_P
1997                           || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE))) {
1998         /* rounding type for motion estimation */
1999         s->no_rounding = get_bits1(gb);
2000     } else {
2001         s->no_rounding = 0;
2002     }
2003 //FIXME reduced res stuff
2004
2005      if (s->shape != RECT_SHAPE) {
2006          if (s->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
2007              skip_bits(gb, 13); /* width */
2008              skip_bits1(gb);   /* marker */
2009              skip_bits(gb, 13); /* height */
2010              skip_bits1(gb);   /* marker */
2011              skip_bits(gb, 13); /* hor_spat_ref */
2012              skip_bits1(gb);   /* marker */
2013              skip_bits(gb, 13); /* ver_spat_ref */
2014          }
2015          skip_bits1(gb); /* change_CR_disable */
2016
2017          if (get_bits1(gb) != 0) {
2018              skip_bits(gb, 8); /* constant_alpha_value */
2019          }
2020      }
2021 //FIXME complexity estimation stuff
2022
2023      if (s->shape != BIN_ONLY_SHAPE) {
2024          skip_bits_long(gb, s->cplx_estimation_trash_i);
2025          if(s->pict_type != AV_PICTURE_TYPE_I)
2026             skip_bits_long(gb, s->cplx_estimation_trash_p);
2027          if(s->pict_type == AV_PICTURE_TYPE_B)
2028             skip_bits_long(gb, s->cplx_estimation_trash_b);
2029
2030          s->intra_dc_threshold= mpeg4_dc_threshold[ get_bits(gb, 3) ];
2031          if(!s->progressive_sequence){
2032              s->top_field_first= get_bits1(gb);
2033              s->alternate_scan= get_bits1(gb);
2034          }else
2035              s->alternate_scan= 0;
2036      }
2037
2038      if(s->alternate_scan){
2039          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
2040          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
2041          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2042          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2043      } else{
2044          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
2045          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
2046          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2047          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2048      }
2049
2050      if(s->pict_type == AV_PICTURE_TYPE_S && (s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE)){
2051          mpeg4_decode_sprite_trajectory(s, gb);
2052          if(s->sprite_brightness_change) av_log(s->avctx, AV_LOG_ERROR, "sprite_brightness_change not supported\n");
2053          if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2054      }
2055
2056      if (s->shape != BIN_ONLY_SHAPE) {
2057          s->chroma_qscale= s->qscale = get_bits(gb, s->quant_precision);
2058          if(s->qscale==0){
2059              av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (qscale=0)\n");
2060              return -1; // makes no sense to continue, as there is nothing left from the image then
2061          }
2062
2063          if (s->pict_type != AV_PICTURE_TYPE_I) {
2064              s->f_code = get_bits(gb, 3);       /* fcode_for */
2065              if(s->f_code==0){
2066                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (f_code=0)\n");
2067                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
2068              }
2069          }else
2070              s->f_code=1;
2071
2072          if (s->pict_type == AV_PICTURE_TYPE_B) {
2073              s->b_code = get_bits(gb, 3);
2074          }else
2075              s->b_code=1;
2076
2077          if(s->avctx->debug&FF_DEBUG_PICT_INFO){
2078              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",
2079                  s->qscale, s->f_code, s->b_code,
2080                  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")),
2081                  gb->size_in_bits,s->progressive_sequence, s->alternate_scan, s->top_field_first,
2082                  s->quarter_sample ? "q" : "h", s->data_partitioning, s->resync_marker, s->num_sprite_warping_points,
2083                  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);
2084          }
2085
2086          if(!s->scalability){
2087              if (s->shape!=RECT_SHAPE && s->pict_type!=AV_PICTURE_TYPE_I) {
2088                  skip_bits1(gb); // vop shape coding type
2089              }
2090          }else{
2091              if(s->enhancement_type){
2092                  int load_backward_shape= get_bits1(gb);
2093                  if(load_backward_shape){
2094                      av_log(s->avctx, AV_LOG_ERROR, "load backward shape isn't supported\n");
2095                  }
2096              }
2097              skip_bits(gb, 2); //ref_select_code
2098          }
2099      }
2100      /* detect buggy encoders which don't set the low_delay flag (divx4/xvid/opendivx)*/
2101      // note we cannot detect divx5 without b-frames easily (although it's buggy too)
2102      if(s->vo_type==0 && s->vol_control_parameters==0 && s->divx_version==-1 && s->picture_number==0){
2103          av_log(s->avctx, AV_LOG_WARNING, "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2104          s->low_delay=1;
2105      }
2106
2107      s->picture_number++; // better than pic number==0 always ;)
2108
2109      s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table; //FIXME add short header support
2110      s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
2111
2112      if(s->workaround_bugs&FF_BUG_EDGE){
2113          s->h_edge_pos= s->width;
2114          s->v_edge_pos= s->height;
2115      }
2116      return 0;
2117 }
2118
2119 /**
2120  * decode mpeg4 headers
2121  * @return <0 if no VOP found (or a damaged one)
2122  *         FRAME_SKIPPED if a not coded VOP is found
2123  *         0 if a VOP is found
2124  */
2125 int ff_mpeg4_decode_picture_header(MpegEncContext * s, GetBitContext *gb)
2126 {
2127     int startcode, v;
2128
2129     /* search next start code */
2130     align_get_bits(gb);
2131
2132     if(s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630){
2133         skip_bits(gb, 24);
2134         if(get_bits(gb, 8) == 0xF0)
2135             goto end;
2136     }
2137
2138     startcode = 0xff;
2139     for(;;) {
2140         if(get_bits_count(gb) >= gb->size_in_bits){
2141             if(gb->size_in_bits==8 && (s->divx_version>=0 || s->xvid_build>=0)){
2142                 av_log(s->avctx, AV_LOG_WARNING, "frame skip %d\n", gb->size_in_bits);
2143                 return FRAME_SKIPPED; //divx bug
2144             }else
2145                 return -1; //end of stream
2146         }
2147
2148         /* use the bits after the test */
2149         v = get_bits(gb, 8);
2150         startcode = ((startcode << 8) | v) & 0xffffffff;
2151
2152         if((startcode&0xFFFFFF00) != 0x100)
2153             continue; //no startcode
2154
2155         if(s->avctx->debug&FF_DEBUG_STARTCODE){
2156             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2157             if     (startcode<=0x11F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2158             else if(startcode<=0x12F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2159             else if(startcode<=0x13F) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2160             else if(startcode<=0x15F) av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2161             else if(startcode<=0x1AF) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2162             else if(startcode==0x1B0) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2163             else if(startcode==0x1B1) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2164             else if(startcode==0x1B2) av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2165             else if(startcode==0x1B3) av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2166             else if(startcode==0x1B4) av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2167             else if(startcode==0x1B5) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2168             else if(startcode==0x1B6) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2169             else if(startcode==0x1B7) av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2170             else if(startcode==0x1B8) av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2171             else if(startcode==0x1B9) av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2172             else if(startcode==0x1BA) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2173             else if(startcode==0x1BB) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2174             else if(startcode==0x1BC) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2175             else if(startcode==0x1BD) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2176             else if(startcode==0x1BE) av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2177             else if(startcode==0x1BF) av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2178             else if(startcode==0x1C0) av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2179             else if(startcode==0x1C1) av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2180             else if(startcode==0x1C2) av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2181             else if(startcode==0x1C3) av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2182             else if(startcode<=0x1C5) av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2183             else if(startcode<=0x1FF) av_log(s->avctx, AV_LOG_DEBUG, "System start");
2184             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2185         }
2186
2187         if(startcode >= 0x120 && startcode <= 0x12F){
2188             if(decode_vol_header(s, gb) < 0)
2189                 return -1;
2190         }
2191         else if(startcode == USER_DATA_STARTCODE){
2192             decode_user_data(s, gb);
2193         }
2194         else if(startcode == GOP_STARTCODE){
2195             mpeg4_decode_gop_header(s, gb);
2196         }
2197         else if(startcode == VOS_STARTCODE){
2198             mpeg4_decode_profile_level(s, gb);
2199         }
2200         else if(startcode == VOP_STARTCODE){
2201             break;
2202         }
2203
2204         align_get_bits(gb);
2205         startcode = 0xff;
2206     }
2207 end:
2208     if(s->flags& CODEC_FLAG_LOW_DELAY)
2209         s->low_delay=1;
2210     s->avctx->has_b_frames= !s->low_delay;
2211     return decode_vop_header(s, gb);
2212 }
2213
2214 static av_cold int decode_init(AVCodecContext *avctx)
2215 {
2216     MpegEncContext *s = avctx->priv_data;
2217     int ret;
2218     static int done = 0;
2219
2220     s->divx_version=
2221     s->divx_build=
2222     s->xvid_build=
2223     s->lavc_build= -1;
2224
2225     if((ret=ff_h263_decode_init(avctx)) < 0)
2226         return ret;
2227
2228     if (!done) {
2229         done = 1;
2230
2231         init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2232         init_rl(&rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2233         init_rl(&rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2234         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2235         INIT_VLC_RL(rvlc_rl_inter, 1072);
2236         INIT_VLC_RL(rvlc_rl_intra, 1072);
2237         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2238                  &ff_mpeg4_DCtab_lum[0][1], 2, 1,
2239                  &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2240         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2241                  &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2242                  &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2243         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2244                  &sprite_trajectory_tab[0][1], 4, 2,
2245                  &sprite_trajectory_tab[0][0], 4, 2, 128);
2246         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2247                  &mb_type_b_tab[0][1], 2, 1,
2248                  &mb_type_b_tab[0][0], 2, 1, 16);
2249     }
2250
2251     s->h263_pred = 1;
2252     s->low_delay = 0; //default, might be overriden in the vol header during header parsing
2253     s->decode_mb= mpeg4_decode_mb;
2254     s->time_increment_bits = 4; /* default value for broken headers */
2255     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2256
2257     return 0;
2258 }
2259
2260 static const AVProfile mpeg4_video_profiles[] = {
2261     { FF_PROFILE_MPEG4_SIMPLE,                    "Simple Profile" },
2262     { FF_PROFILE_MPEG4_SIMPLE_SCALABLE,           "Simple Scalable Profile" },
2263     { FF_PROFILE_MPEG4_CORE,                      "Core Profile" },
2264     { FF_PROFILE_MPEG4_MAIN,                      "Main Profile" },
2265     { FF_PROFILE_MPEG4_N_BIT,                     "N-bit Profile" },
2266     { FF_PROFILE_MPEG4_SCALABLE_TEXTURE,          "Scalable Texture Profile" },
2267     { FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION,     "Simple Face Animation Profile" },
2268     { FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE,    "Basic Animated Texture Profile" },
2269     { FF_PROFILE_MPEG4_HYBRID,                    "Hybrid Profile" },
2270     { FF_PROFILE_MPEG4_ADVANCED_REAL_TIME,        "Advanced Real Time Simple Profile" },
2271     { FF_PROFILE_MPEG4_CORE_SCALABLE,             "Code Scalable Profile" },
2272     { FF_PROFILE_MPEG4_ADVANCED_CODING,           "Advanced Coding Profile" },
2273     { FF_PROFILE_MPEG4_ADVANCED_CORE,             "Advanced Core Profile" },
2274     { FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE, "Advanced Scalable Texture Profile" },
2275     { FF_PROFILE_MPEG4_SIMPLE_STUDIO,             "Simple Studio Profile" },
2276     { FF_PROFILE_MPEG4_ADVANCED_SIMPLE,           "Advanced Simple Profile" },
2277 };
2278
2279 AVCodec ff_mpeg4_decoder = {
2280     .name           = "mpeg4",
2281     .type           = AVMEDIA_TYPE_VIDEO,
2282     .id             = CODEC_ID_MPEG4,
2283     .priv_data_size = sizeof(MpegEncContext),
2284     .init           = decode_init,
2285     .close          = ff_h263_decode_end,
2286     .decode         = ff_h263_decode_frame,
2287     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_FRAME_THREADS,
2288     .flush= ff_mpeg_flush,
2289     .max_lowres= 3,
2290     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2291     .pix_fmts= ff_hwaccel_pixfmt_list_420,
2292     .profiles = NULL_IF_CONFIG_SMALL(mpeg4_video_profiles),
2293     .update_thread_context= ONLY_IF_THREADS_ENABLED(ff_mpeg_update_thread_context)
2294 };
2295
2296
2297 #if CONFIG_MPEG4_VDPAU_DECODER
2298 AVCodec ff_mpeg4_vdpau_decoder = {
2299     .name           = "mpeg4_vdpau",
2300     .type           = AVMEDIA_TYPE_VIDEO,
2301     .id             = CODEC_ID_MPEG4,
2302     .priv_data_size = sizeof(MpegEncContext),
2303     .init           = decode_init,
2304     .close          = ff_h263_decode_end,
2305     .decode         = ff_h263_decode_frame,
2306     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_HWACCEL_VDPAU,
2307     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
2308     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_VDPAU_MPEG4, PIX_FMT_NONE},
2309 };
2310 #endif