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   1 /*
   2  * MPEG4 decoder.
   3  * Copyright (c) 2000,2001 Fabrice Bellard
   4  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "error_resilience.h"
  24 #include "internal.h"
  25 #include "mpegvideo.h"
  26 #include "mpeg4video.h"
  27 #include "h263.h"
  28 #include "thread.h"
  29
  30 // The defines below define the number of bits that are read at once for
  31 // reading vlc values. Changing these may improve speed and data cache needs
  32 // be aware though that decreasing them may need the number of stages that is
  33 // passed to get_vlc* to be increased.
  34 #define SPRITE_TRAJ_VLC_BITS 6
  35 #define DC_VLC_BITS 9
  36 #define MB_TYPE_B_VLC_BITS 4
  37
  38
  39 static VLC dc_lum, dc_chrom;
  40 static VLC sprite_trajectory;
  41 static VLC mb_type_b_vlc;
  42
  43 static const int mb_type_b_map[4]= {
  44     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  45     MB_TYPE_L0L1 | MB_TYPE_16x16,
  46     MB_TYPE_L1 | MB_TYPE_16x16,
  47     MB_TYPE_L0 | MB_TYPE_16x16,
  48 };
  49
  50 /**
  51  * Predict the ac.
  52  * @param n block index (0-3 are luma, 4-5 are chroma)
  53  * @param dir the ac prediction direction
  54  */
  55 void ff_mpeg4_pred_ac(MpegEncContext * s, int16_t *block, int n,
  56                       int dir)
  57 {
  58     int i;
  59     int16_t *ac_val, *ac_val1;
  60     int8_t * const qscale_table = s->current_picture.qscale_table;
  61
  62     /* find prediction */
  63     ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
  64     ac_val1 = ac_val;
  65     if (s->ac_pred) {
  66         if (dir == 0) {
  67             const int xy= s->mb_x-1 + s->mb_y*s->mb_stride;
  68             /* left prediction */
  69             ac_val -= 16;
  70
  71             if(s->mb_x==0 || s->qscale == qscale_table[xy] || n==1 || n==3){
  72                 /* same qscale */
  73                 for(i=1;i<8;i++) {
  74                     block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
  75                 }
  76             }else{
  77                 /* different qscale, we must rescale */
  78                 for(i=1;i<8;i++) {
  79                     block[s->dsp.idct_permutation[i<<3]] += ROUNDED_DIV(ac_val[i]*qscale_table[xy], s->qscale);
  80                 }
  81             }
  82         } else {
  83             const int xy= s->mb_x + s->mb_y*s->mb_stride - s->mb_stride;
  84             /* top prediction */
  85             ac_val -= 16 * s->block_wrap[n];
  86
  87             if(s->mb_y==0 || s->qscale == qscale_table[xy] || n==2 || n==3){
  88                 /* same qscale */
  89                 for(i=1;i<8;i++) {
  90                     block[s->dsp.idct_permutation[i]] += ac_val[i + 8];
  91                 }
  92             }else{
  93                 /* different qscale, we must rescale */
  94                 for(i=1;i<8;i++) {
  95                     block[s->dsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8]*qscale_table[xy], s->qscale);
  96                 }
  97             }
  98         }
  99     }
 100     /* left copy */
 101     for(i=1;i<8;i++)
 102         ac_val1[i    ] = block[s->dsp.idct_permutation[i<<3]];
 103
 104     /* top copy */
 105     for(i=1;i<8;i++)
 106         ac_val1[8 + i] = block[s->dsp.idct_permutation[i   ]];
 107
 108 }
 109
 110 /**
 111  * check if the next stuff is a resync marker or the end.
 112  * @return 0 if not
 113  */
 114 static inline int mpeg4_is_resync(MpegEncContext *s){
 115     int bits_count= get_bits_count(&s->gb);
 116     int v= show_bits(&s->gb, 16);
 117
 118     if(s->workaround_bugs&FF_BUG_NO_PADDING){
 119         return 0;
 120     }
 121
 122     while(v<=0xFF){
 123         if(s->pict_type==AV_PICTURE_TYPE_B || (v>>(8-s->pict_type)!=1) || s->partitioned_frame)
 124             break;
 125         skip_bits(&s->gb, 8+s->pict_type);
 126         bits_count+= 8+s->pict_type;
 127         v= show_bits(&s->gb, 16);
 128     }
 129
 130     if(bits_count + 8 >= s->gb.size_in_bits){
 131         v>>=8;
 132         v|= 0x7F >> (7-(bits_count&7));
 133
 134         if(v==0x7F)
 135             return 1;
 136     }else{
 137         if(v == ff_mpeg4_resync_prefix[bits_count&7]){
 138             int len;
 139             GetBitContext gb= s->gb;
 140
 141             skip_bits(&s->gb, 1);
 142             align_get_bits(&s->gb);
 143
 144             for(len=0; len<32; len++){
 145                 if(get_bits1(&s->gb)) break;
 146             }
 147
 148             s->gb= gb;
 149
 150             if(len>=ff_mpeg4_get_video_packet_prefix_length(s))
 151                 return 1;
 152         }
 153     }
 154     return 0;
 155 }
 156
 157 static void mpeg4_decode_sprite_trajectory(MpegEncContext * s, GetBitContext *gb)
 158 {
 159     int i;
 160     int a= 2<<s->sprite_warping_accuracy;
 161     int rho= 3-s->sprite_warping_accuracy;
 162     int r=16/a;
 163     const int vop_ref[4][2]= {{0,0}, {s->width,0}, {0, s->height}, {s->width, s->height}}; // only true for rectangle shapes
 164     int d[4][2]={{0,0}, {0,0}, {0,0}, {0,0}};
 165     int sprite_ref[4][2];
 166     int virtual_ref[2][2];
 167     int w2, h2, w3, h3;
 168     int alpha=0, beta=0;
 169     int w= s->width;
 170     int h= s->height;
 171     int min_ab;
 172
 173     for(i=0; i<s->num_sprite_warping_points; i++){
 174         int length;
 175         int x=0, y=0;
 176
 177         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 178         if(length){
 179             x= get_xbits(gb, length);
 180         }
 181         if(!(s->divx_version==500 && s->divx_build==413)) skip_bits1(gb); /* marker bit */
 182
 183         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 184         if(length){
 185             y=get_xbits(gb, length);
 186         }
 187         skip_bits1(gb); /* marker bit */
 188         s->sprite_traj[i][0]= d[i][0]= x;
 189         s->sprite_traj[i][1]= d[i][1]= y;
 190     }
 191     for(; i<4; i++)
 192         s->sprite_traj[i][0]= s->sprite_traj[i][1]= 0;
 193
 194     while((1<<alpha)<w) alpha++;
 195     while((1<<beta )<h) beta++; // there seems to be a typo in the mpeg4 std for the definition of w' and h'
 196     w2= 1<<alpha;
 197     h2= 1<<beta;
 198
 199 // Note, the 4th point isn't used for GMC
 200     if(s->divx_version==500 && s->divx_build==413){
 201         sprite_ref[0][0]= a*vop_ref[0][0] + d[0][0];
 202         sprite_ref[0][1]= a*vop_ref[0][1] + d[0][1];
 203         sprite_ref[1][0]= a*vop_ref[1][0] + d[0][0] + d[1][0];
 204         sprite_ref[1][1]= a*vop_ref[1][1] + d[0][1] + d[1][1];
 205         sprite_ref[2][0]= a*vop_ref[2][0] + d[0][0] + d[2][0];
 206         sprite_ref[2][1]= a*vop_ref[2][1] + d[0][1] + d[2][1];
 207     } else {
 208         sprite_ref[0][0]= (a>>1)*(2*vop_ref[0][0] + d[0][0]);
 209         sprite_ref[0][1]= (a>>1)*(2*vop_ref[0][1] + d[0][1]);
 210         sprite_ref[1][0]= (a>>1)*(2*vop_ref[1][0] + d[0][0] + d[1][0]);
 211         sprite_ref[1][1]= (a>>1)*(2*vop_ref[1][1] + d[0][1] + d[1][1]);
 212         sprite_ref[2][0]= (a>>1)*(2*vop_ref[2][0] + d[0][0] + d[2][0]);
 213         sprite_ref[2][1]= (a>>1)*(2*vop_ref[2][1] + d[0][1] + d[2][1]);
 214     }
 215 /*    sprite_ref[3][0]= (a>>1)*(2*vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
 216     sprite_ref[3][1]= (a>>1)*(2*vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
 217
 218 // this is mostly identical to the mpeg4 std (and is totally unreadable because of that ...)
 219 // perhaps it should be reordered to be more readable ...
 220 // the idea behind this virtual_ref mess is to be able to use shifts later per pixel instead of divides
 221 // so the distance between points is converted from w&h based to w2&h2 based which are of the 2^x form
 222     virtual_ref[0][0]= 16*(vop_ref[0][0] + w2)
 223         + 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);
 224     virtual_ref[0][1]= 16*vop_ref[0][1]
 225         + 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);
 226     virtual_ref[1][0]= 16*vop_ref[0][0]
 227         + 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);
 228     virtual_ref[1][1]= 16*(vop_ref[0][1] + h2)
 229         + 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);
 230
 231     switch(s->num_sprite_warping_points)
 232     {
 233         case 0:
 234             s->sprite_offset[0][0]= 0;
 235             s->sprite_offset[0][1]= 0;
 236             s->sprite_offset[1][0]= 0;
 237             s->sprite_offset[1][1]= 0;
 238             s->sprite_delta[0][0]= a;
 239             s->sprite_delta[0][1]= 0;
 240             s->sprite_delta[1][0]= 0;
 241             s->sprite_delta[1][1]= a;
 242             s->sprite_shift[0]= 0;
 243             s->sprite_shift[1]= 0;
 244             break;
 245         case 1: //GMC only
 246             s->sprite_offset[0][0]= sprite_ref[0][0] - a*vop_ref[0][0];
 247             s->sprite_offset[0][1]= sprite_ref[0][1] - a*vop_ref[0][1];
 248             s->sprite_offset[1][0]= ((sprite_ref[0][0]>>1)|(sprite_ref[0][0]&1)) - a*(vop_ref[0][0]/2);
 249             s->sprite_offset[1][1]= ((sprite_ref[0][1]>>1)|(sprite_ref[0][1]&1)) - a*(vop_ref[0][1]/2);
 250             s->sprite_delta[0][0]= a;
 251             s->sprite_delta[0][1]= 0;
 252             s->sprite_delta[1][0]= 0;
 253             s->sprite_delta[1][1]= a;
 254             s->sprite_shift[0]= 0;
 255             s->sprite_shift[1]= 0;
 256             break;
 257         case 2:
 258             s->sprite_offset[0][0]= (sprite_ref[0][0]<<(alpha+rho))
 259                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][0])
 260                                                   + ( r*sprite_ref[0][1] - virtual_ref[0][1])*(-vop_ref[0][1])
 261                                                   + (1<<(alpha+rho-1));
 262             s->sprite_offset[0][1]= (sprite_ref[0][1]<<(alpha+rho))
 263                                                   + (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-vop_ref[0][0])
 264                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][1])
 265                                                   + (1<<(alpha+rho-1));
 266             s->sprite_offset[1][0]= ( (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][0] + 1)
 267                                      +( r*sprite_ref[0][1] - virtual_ref[0][1])*(-2*vop_ref[0][1] + 1)
 268                                      +2*w2*r*sprite_ref[0][0]
 269                                      - 16*w2
 270                                      + (1<<(alpha+rho+1)));
 271             s->sprite_offset[1][1]= ( (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-2*vop_ref[0][0] + 1)
 272                                      +(-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][1] + 1)
 273                                      +2*w2*r*sprite_ref[0][1]
 274                                      - 16*w2
 275                                      + (1<<(alpha+rho+1)));
 276             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 277             s->sprite_delta[0][1]=   (+r*sprite_ref[0][1] - virtual_ref[0][1]);
 278             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1]);
 279             s->sprite_delta[1][1]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 280
 281             s->sprite_shift[0]= alpha+rho;
 282             s->sprite_shift[1]= alpha+rho+2;
 283             break;
 284         case 3:
 285             min_ab= FFMIN(alpha, beta);
 286             w3= w2>>min_ab;
 287             h3= h2>>min_ab;
 288             s->sprite_offset[0][0]=  (sprite_ref[0][0]<<(alpha+beta+rho-min_ab))
 289                                    + (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-vop_ref[0][0])
 290                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-vop_ref[0][1])
 291                                    + (1<<(alpha+beta+rho-min_ab-1));
 292             s->sprite_offset[0][1]=  (sprite_ref[0][1]<<(alpha+beta+rho-min_ab))
 293                                    + (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-vop_ref[0][0])
 294                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-vop_ref[0][1])
 295                                    + (1<<(alpha+beta+rho-min_ab-1));
 296             s->sprite_offset[1][0]=  (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-2*vop_ref[0][0] + 1)
 297                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-2*vop_ref[0][1] + 1)
 298                                    + 2*w2*h3*r*sprite_ref[0][0]
 299                                    - 16*w2*h3
 300                                    + (1<<(alpha+beta+rho-min_ab+1));
 301             s->sprite_offset[1][1]=  (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-2*vop_ref[0][0] + 1)
 302                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-2*vop_ref[0][1] + 1)
 303                                    + 2*w2*h3*r*sprite_ref[0][1]
 304                                    - 16*w2*h3
 305                                    + (1<<(alpha+beta+rho-min_ab+1));
 306             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3;
 307             s->sprite_delta[0][1]=   (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3;
 308             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3;
 309             s->sprite_delta[1][1]=   (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3;
 310
 311             s->sprite_shift[0]= alpha + beta + rho - min_ab;
 312             s->sprite_shift[1]= alpha + beta + rho - min_ab + 2;
 313             break;
 314     }
 315     /* try to simplify the situation */
 316     if(   s->sprite_delta[0][0] == a<<s->sprite_shift[0]
 317        && s->sprite_delta[0][1] == 0
 318        && s->sprite_delta[1][0] == 0
 319        && s->sprite_delta[1][1] == a<<s->sprite_shift[0])
 320     {
 321         s->sprite_offset[0][0]>>=s->sprite_shift[0];
 322         s->sprite_offset[0][1]>>=s->sprite_shift[0];
 323         s->sprite_offset[1][0]>>=s->sprite_shift[1];
 324         s->sprite_offset[1][1]>>=s->sprite_shift[1];
 325         s->sprite_delta[0][0]= a;
 326         s->sprite_delta[0][1]= 0;
 327         s->sprite_delta[1][0]= 0;
 328         s->sprite_delta[1][1]= a;
 329         s->sprite_shift[0]= 0;
 330         s->sprite_shift[1]= 0;
 331         s->real_sprite_warping_points=1;
 332     }
 333     else{
 334         int shift_y= 16 - s->sprite_shift[0];
 335         int shift_c= 16 - s->sprite_shift[1];
 336         for(i=0; i<2; i++){
 337             s->sprite_offset[0][i]<<= shift_y;
 338             s->sprite_offset[1][i]<<= shift_c;
 339             s->sprite_delta[0][i]<<= shift_y;
 340             s->sprite_delta[1][i]<<= shift_y;
 341             s->sprite_shift[i]= 16;
 342         }
 343         s->real_sprite_warping_points= s->num_sprite_warping_points;
 344     }
 345 }
 346
 347 /**
 348  * Decode the next video packet.
 349  * @return <0 if something went wrong
 350  */
 351 int ff_mpeg4_decode_video_packet_header(MpegEncContext *s)
 352 {
 353     int mb_num_bits= av_log2(s->mb_num - 1) + 1;
 354     int header_extension=0, mb_num, len;
 355
 356     /* is there enough space left for a video packet + header */
 357     if( get_bits_count(&s->gb) > s->gb.size_in_bits-20) return -1;
 358
 359     for(len=0; len<32; len++){
 360         if(get_bits1(&s->gb)) break;
 361     }
 362
 363     if(len!=ff_mpeg4_get_video_packet_prefix_length(s)){
 364         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
 365         return -1;
 366     }
 367
 368     if(s->shape != RECT_SHAPE){
 369         header_extension= get_bits1(&s->gb);
 370         //FIXME more stuff here
 371     }
 372
 373     mb_num= get_bits(&s->gb, mb_num_bits);
 374     if(mb_num>=s->mb_num){
 375         av_log(s->avctx, AV_LOG_ERROR, "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
 376         return -1;
 377     }
 378     if(s->pict_type == AV_PICTURE_TYPE_B){
 379         int mb_x = 0, mb_y = 0;
 380
 381         while (s->next_picture.mbskip_table[s->mb_index2xy[mb_num]]) {
 382             if (!mb_x)
 383                 ff_thread_await_progress(&s->next_picture_ptr->tf, mb_y++, 0);
 384             mb_num++;
 385             if (++mb_x == s->mb_width) mb_x = 0;
 386         }
 387         if(mb_num >= s->mb_num) return -1; // slice contains just skipped MBs which where already decoded
 388     }
 389
 390     s->mb_x= mb_num % s->mb_width;
 391     s->mb_y= mb_num / s->mb_width;
 392
 393     if(s->shape != BIN_ONLY_SHAPE){
 394         int qscale= get_bits(&s->gb, s->quant_precision);
 395         if(qscale)
 396             s->chroma_qscale=s->qscale= qscale;
 397     }
 398
 399     if(s->shape == RECT_SHAPE){
 400         header_extension= get_bits1(&s->gb);
 401     }
 402     if(header_extension){
 403         int time_incr=0;
 404
 405         while (get_bits1(&s->gb) != 0)
 406             time_incr++;
 407
 408         check_marker(&s->gb, "before time_increment in video packed header");
 409         skip_bits(&s->gb, s->time_increment_bits); /* time_increment */
 410         check_marker(&s->gb, "before vop_coding_type in video packed header");
 411
 412         skip_bits(&s->gb, 2); /* vop coding type */
 413         //FIXME not rect stuff here
 414
 415         if(s->shape != BIN_ONLY_SHAPE){
 416             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
 417 //FIXME don't just ignore everything
 418             if(s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 419                 mpeg4_decode_sprite_trajectory(s, &s->gb);
 420                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
 421             }
 422
 423             //FIXME reduced res stuff here
 424
 425             if (s->pict_type != AV_PICTURE_TYPE_I) {
 426                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
 427                 if(f_code==0){
 428                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (f_code=0)\n");
 429                 }
 430             }
 431             if (s->pict_type == AV_PICTURE_TYPE_B) {
 432                 int b_code = get_bits(&s->gb, 3);
 433                 if(b_code==0){
 434                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (b_code=0)\n");
 435                 }
 436             }
 437         }
 438     }
 439     //FIXME new-pred stuff
 440
 441     return 0;
 442 }
 443
 444 /**
 445  * Get the average motion vector for a GMC MB.
 446  * @param n either 0 for the x component or 1 for y
 447  * @return the average MV for a GMC MB
 448  */
 449 static inline int get_amv(MpegEncContext *s, int n){
 450     int x, y, mb_v, sum, dx, dy, shift;
 451     int len = 1 << (s->f_code + 4);
 452     const int a= s->sprite_warping_accuracy;
 453
 454     if(s->workaround_bugs & FF_BUG_AMV)
 455         len >>= s->quarter_sample;
 456
 457     if(s->real_sprite_warping_points==1){
 458         if(s->divx_version==500 && s->divx_build==413)
 459             sum= s->sprite_offset[0][n] / (1<<(a - s->quarter_sample));
 460         else
 461             sum= RSHIFT(s->sprite_offset[0][n]<<s->quarter_sample, a);
 462     }else{
 463         dx= s->sprite_delta[n][0];
 464         dy= s->sprite_delta[n][1];
 465         shift= s->sprite_shift[0];
 466         if(n) dy -= 1<<(shift + a + 1);
 467         else  dx -= 1<<(shift + a + 1);
 468         mb_v= s->sprite_offset[0][n] + dx*s->mb_x*16 + dy*s->mb_y*16;
 469
 470         sum=0;
 471         for(y=0; y<16; y++){
 472             int v;
 473
 474             v= mb_v + dy*y;
 475             //XXX FIXME optimize
 476             for(x=0; x<16; x++){
 477                 sum+= v>>shift;
 478                 v+= dx;
 479             }
 480         }
 481         sum= RSHIFT(sum, a+8-s->quarter_sample);
 482     }
 483
 484     if      (sum < -len) sum= -len;
 485     else if (sum >= len) sum= len-1;
 486
 487     return sum;
 488 }
 489
 490 /**
 491  * Decode the dc value.
 492  * @param n block index (0-3 are luma, 4-5 are chroma)
 493  * @param dir_ptr the prediction direction will be stored here
 494  * @return the quantized dc
 495  */
 496 static inline int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
 497 {
 498     int level, code;
 499
 500     if (n < 4)
 501         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
 502     else
 503         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
 504     if (code < 0 || code > 9 /* && s->nbit<9 */){
 505         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
 506         return -1;
 507     }
 508     if (code == 0) {
 509         level = 0;
 510     } else {
 511         if(IS_3IV1){
 512             if(code==1)
 513                 level= 2*get_bits1(&s->gb)-1;
 514             else{
 515                 if(get_bits1(&s->gb))
 516                     level = get_bits(&s->gb, code-1) + (1<<(code-1));
 517                 else
 518                     level = -get_bits(&s->gb, code-1) - (1<<(code-1));
 519             }
 520         }else{
 521             level = get_xbits(&s->gb, code);
 522         }
 523
 524         if (code > 8){
 525             if(get_bits1(&s->gb)==0){ /* marker */
 526                 if(s->err_recognition&AV_EF_BITSTREAM){
 527                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
 528                     return -1;
 529                 }
 530             }
 531         }
 532     }
 533
 534     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
 535 }
 536
 537 /**
 538  * Decode first partition.
 539  * @return number of MBs decoded or <0 if an error occurred
 540  */
 541 static int mpeg4_decode_partition_a(MpegEncContext *s){
 542     int mb_num;
 543     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 544
 545     /* decode first partition */
 546     mb_num=0;
 547     s->first_slice_line=1;
 548     for(; s->mb_y<s->mb_height; s->mb_y++){
 549         ff_init_block_index(s);
 550         for(; s->mb_x<s->mb_width; s->mb_x++){
 551             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 552             int cbpc;
 553             int dir=0;
 554
 555             mb_num++;
 556             ff_update_block_index(s);
 557             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 558                 s->first_slice_line=0;
 559
 560             if(s->pict_type==AV_PICTURE_TYPE_I){
 561                 int i;
 562
 563                 do{
 564                     if(show_bits_long(&s->gb, 19)==DC_MARKER){
 565                         return mb_num-1;
 566                     }
 567
 568                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 569                     if (cbpc < 0){
 570                         av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 571                         return -1;
 572                     }
 573                 }while(cbpc == 8);
 574
 575                 s->cbp_table[xy]= cbpc & 3;
 576                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 577                 s->mb_intra = 1;
 578
 579                 if(cbpc & 4) {
 580                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 581                 }
 582                 s->current_picture.qscale_table[xy]= s->qscale;
 583
 584                 s->mbintra_table[xy]= 1;
 585                 for(i=0; i<6; i++){
 586                     int dc_pred_dir;
 587                     int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 588                     if(dc < 0){
 589                         av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 590                         return -1;
 591                     }
 592                     dir<<=1;
 593                     if(dc_pred_dir) dir|=1;
 594                 }
 595                 s->pred_dir_table[xy]= dir;
 596             }else{ /* P/S_TYPE */
 597                 int mx, my, pred_x, pred_y, bits;
 598                 int16_t * const mot_val = s->current_picture.motion_val[0][s->block_index[0]];
 599                 const int stride= s->b8_stride*2;
 600
 601 try_again:
 602                 bits= show_bits(&s->gb, 17);
 603                 if(bits==MOTION_MARKER){
 604                     return mb_num-1;
 605                 }
 606                 skip_bits1(&s->gb);
 607                 if(bits&0x10000){
 608                     /* skip mb */
 609                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 610                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 611                         mx= get_amv(s, 0);
 612                         my= get_amv(s, 1);
 613                     }else{
 614                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 615                         mx=my=0;
 616                     }
 617                     mot_val[0       ]= mot_val[2       ]=
 618                     mot_val[0+stride]= mot_val[2+stride]= mx;
 619                     mot_val[1       ]= mot_val[3       ]=
 620                     mot_val[1+stride]= mot_val[3+stride]= my;
 621
 622                     if(s->mbintra_table[xy])
 623                         ff_clean_intra_table_entries(s);
 624                     continue;
 625                 }
 626
 627                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 628                 if (cbpc < 0){
 629                     av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 630                     return -1;
 631                 }
 632                 if(cbpc == 20)
 633                     goto try_again;
 634
 635                 s->cbp_table[xy]= cbpc&(8+3); //8 is dquant
 636
 637                 s->mb_intra = ((cbpc & 4) != 0);
 638
 639                 if(s->mb_intra){
 640                     s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 641                     s->mbintra_table[xy]= 1;
 642                     mot_val[0       ]= mot_val[2       ]=
 643                     mot_val[0+stride]= mot_val[2+stride]= 0;
 644                     mot_val[1       ]= mot_val[3       ]=
 645                     mot_val[1+stride]= mot_val[3+stride]= 0;
 646                 }else{
 647                     if(s->mbintra_table[xy])
 648                         ff_clean_intra_table_entries(s);
 649
 650                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
 651                         s->mcsel= get_bits1(&s->gb);
 652                     else s->mcsel= 0;
 653
 654                     if ((cbpc & 16) == 0) {
 655                         /* 16x16 motion prediction */
 656
 657                         ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 658                         if(!s->mcsel){
 659                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
 660                             if (mx >= 0xffff)
 661                                 return -1;
 662
 663                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
 664                             if (my >= 0xffff)
 665                                 return -1;
 666                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 667                         } else {
 668                             mx = get_amv(s, 0);
 669                             my = get_amv(s, 1);
 670                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 671                         }
 672
 673                         mot_val[0       ]= mot_val[2       ] =
 674                         mot_val[0+stride]= mot_val[2+stride]= mx;
 675                         mot_val[1       ]= mot_val[3       ]=
 676                         mot_val[1+stride]= mot_val[3+stride]= my;
 677                     } else {
 678                         int i;
 679                         s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 680                         for(i=0;i<4;i++) {
 681                             int16_t *mot_val= ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 682                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
 683                             if (mx >= 0xffff)
 684                                 return -1;
 685
 686                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
 687                             if (my >= 0xffff)
 688                                 return -1;
 689                             mot_val[0] = mx;
 690                             mot_val[1] = my;
 691                         }
 692                     }
 693                 }
 694             }
 695         }
 696         s->mb_x= 0;
 697     }
 698
 699     return mb_num;
 700 }
 701
 702 /**
 703  * decode second partition.
 704  * @return <0 if an error occurred
 705  */
 706 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count){
 707     int mb_num=0;
 708     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 709
 710     s->mb_x= s->resync_mb_x;
 711     s->first_slice_line=1;
 712     for(s->mb_y= s->resync_mb_y; mb_num < mb_count; s->mb_y++){
 713         ff_init_block_index(s);
 714         for(; mb_num < mb_count && s->mb_x<s->mb_width; s->mb_x++){
 715             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 716
 717             mb_num++;
 718             ff_update_block_index(s);
 719             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 720                 s->first_slice_line=0;
 721
 722             if(s->pict_type==AV_PICTURE_TYPE_I){
 723                 int ac_pred= get_bits1(&s->gb);
 724                 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 725                 if(cbpy<0){
 726                     av_log(s->avctx, AV_LOG_ERROR, "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 727                     return -1;
 728                 }
 729
 730                 s->cbp_table[xy]|= cbpy<<2;
 731                 s->current_picture.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 732             }else{ /* P || S_TYPE */
 733                 if (IS_INTRA(s->current_picture.mb_type[xy])) {
 734                     int dir=0,i;
 735                     int ac_pred = get_bits1(&s->gb);
 736                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 737
 738                     if(cbpy<0){
 739                         av_log(s->avctx, AV_LOG_ERROR, "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 740                         return -1;
 741                     }
 742
 743                     if(s->cbp_table[xy] & 8) {
 744                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 745                     }
 746                     s->current_picture.qscale_table[xy] = s->qscale;
 747
 748                     for(i=0; i<6; i++){
 749                         int dc_pred_dir;
 750                         int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 751                         if(dc < 0){
 752                             av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 753                             return -1;
 754                         }
 755                         dir<<=1;
 756                         if(dc_pred_dir) dir|=1;
 757                     }
 758                     s->cbp_table[xy]&= 3; //remove dquant
 759                     s->cbp_table[xy]|= cbpy<<2;
 760                     s->current_picture.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 761                     s->pred_dir_table[xy]= dir;
 762                 } else if (IS_SKIP(s->current_picture.mb_type[xy])) {
 763                     s->current_picture.qscale_table[xy] = s->qscale;
 764                     s->cbp_table[xy]= 0;
 765                 }else{
 766                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 767
 768                     if(cbpy<0){
 769                         av_log(s->avctx, AV_LOG_ERROR, "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 770                         return -1;
 771                     }
 772
 773                     if(s->cbp_table[xy] & 8) {
 774                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 775                     }
 776                     s->current_picture.qscale_table[xy] = s->qscale;
 777
 778                     s->cbp_table[xy]&= 3; //remove dquant
 779                     s->cbp_table[xy]|= (cbpy^0xf)<<2;
 780                 }
 781             }
 782         }
 783         if(mb_num >= mb_count) return 0;
 784         s->mb_x= 0;
 785     }
 786     return 0;
 787 }
 788
 789 /**
 790  * Decode the first and second partition.
 791  * @return <0 if error (and sets error type in the error_status_table)
 792  */
 793 int ff_mpeg4_decode_partitions(MpegEncContext *s)
 794 {
 795     int mb_num;
 796     const int part_a_error= s->pict_type==AV_PICTURE_TYPE_I ? (ER_DC_ERROR|ER_MV_ERROR) : ER_MV_ERROR;
 797     const int part_a_end  = s->pict_type==AV_PICTURE_TYPE_I ? (ER_DC_END  |ER_MV_END)   : ER_MV_END;
 798
 799     mb_num= mpeg4_decode_partition_a(s);
 800     if(mb_num<0){
 801         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 802         return -1;
 803     }
 804
 805     if(s->resync_mb_x + s->resync_mb_y*s->mb_width + mb_num > s->mb_num){
 806         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
 807         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 808         return -1;
 809     }
 810
 811     s->mb_num_left= mb_num;
 812
 813     if(s->pict_type==AV_PICTURE_TYPE_I){
 814         while(show_bits(&s->gb, 9) == 1)
 815             skip_bits(&s->gb, 9);
 816         if(get_bits_long(&s->gb, 19)!=DC_MARKER){
 817             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first I partition at %d %d\n", s->mb_x, s->mb_y);
 818             return -1;
 819         }
 820     }else{
 821         while(show_bits(&s->gb, 10) == 1)
 822             skip_bits(&s->gb, 10);
 823         if(get_bits(&s->gb, 17)!=MOTION_MARKER){
 824             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first P partition at %d %d\n", s->mb_x, s->mb_y);
 825             return -1;
 826         }
 827     }
 828     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, part_a_end);
 829
 830     if( mpeg4_decode_partition_b(s, mb_num) < 0){
 831         if(s->pict_type==AV_PICTURE_TYPE_P)
 832             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_DC_ERROR);
 833         return -1;
 834     }else{
 835         if(s->pict_type==AV_PICTURE_TYPE_P)
 836             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_DC_END);
 837     }
 838
 839     return 0;
 840 }
 841
 842 /**
 843  * Decode a block.
 844  * @return <0 if an error occurred
 845  */
 846 static inline int mpeg4_decode_block(MpegEncContext * s, int16_t * block,
 847                               int n, int coded, int intra, int rvlc)
 848 {
 849     int level, i, last, run;
 850     int dc_pred_dir;
 851     RLTable * rl;
 852     RL_VLC_ELEM * rl_vlc;
 853     const uint8_t * scan_table;
 854     int qmul, qadd;
 855
 856     //Note intra & rvlc should be optimized away if this is inlined
 857
 858     if(intra) {
 859       if(s->use_intra_dc_vlc){
 860         /* DC coef */
 861         if(s->partitioned_frame){
 862             level = s->dc_val[0][ s->block_index[n] ];
 863             if(n<4) level= FASTDIV((level + (s->y_dc_scale>>1)), s->y_dc_scale);
 864             else    level= FASTDIV((level + (s->c_dc_scale>>1)), s->c_dc_scale);
 865             dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_stride]<<n)&32;
 866         }else{
 867             level = mpeg4_decode_dc(s, n, &dc_pred_dir);
 868             if (level < 0)
 869                 return -1;
 870         }
 871         block[0] = level;
 872         i = 0;
 873       }else{
 874             i = -1;
 875             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
 876       }
 877       if (!coded)
 878           goto not_coded;
 879
 880       if(rvlc){
 881           rl = &ff_rvlc_rl_intra;
 882           rl_vlc = ff_rvlc_rl_intra.rl_vlc[0];
 883       }else{
 884           rl = &ff_mpeg4_rl_intra;
 885           rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
 886       }
 887       if (s->ac_pred) {
 888           if (dc_pred_dir == 0)
 889               scan_table = s->intra_v_scantable.permutated; /* left */
 890           else
 891               scan_table = s->intra_h_scantable.permutated; /* top */
 892       } else {
 893             scan_table = s->intra_scantable.permutated;
 894       }
 895       qmul=1;
 896       qadd=0;
 897     } else {
 898         i = -1;
 899         if (!coded) {
 900             s->block_last_index[n] = i;
 901             return 0;
 902         }
 903         if(rvlc) rl = &ff_rvlc_rl_inter;
 904         else     rl = &ff_h263_rl_inter;
 905
 906         scan_table = s->intra_scantable.permutated;
 907
 908         if(s->mpeg_quant){
 909             qmul=1;
 910             qadd=0;
 911             if(rvlc){
 912                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[0];
 913             }else{
 914                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
 915             }
 916         }else{
 917             qmul = s->qscale << 1;
 918             qadd = (s->qscale - 1) | 1;
 919             if(rvlc){
 920                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[s->qscale];
 921             }else{
 922                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
 923             }
 924         }
 925     }
 926   {
 927     OPEN_READER(re, &s->gb);
 928     for(;;) {
 929         UPDATE_CACHE(re, &s->gb);
 930         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
 931         if (level==0) {
 932           /* escape */
 933           if(rvlc){
 934                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 935                     av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in rvlc esc\n");
 936                     return -1;
 937                 }; SKIP_CACHE(re, &s->gb, 1);
 938
 939                 last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 940                 run=   SHOW_UBITS(re, &s->gb, 6);
 941                 SKIP_COUNTER(re, &s->gb, 1+1+6);
 942                 UPDATE_CACHE(re, &s->gb);
 943
 944                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 945                     av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in rvlc esc\n");
 946                     return -1;
 947                 }; SKIP_CACHE(re, &s->gb, 1);
 948
 949                 level= SHOW_UBITS(re, &s->gb, 11); SKIP_CACHE(re, &s->gb, 11);
 950
 951                 if(SHOW_UBITS(re, &s->gb, 5)!=0x10){
 952                     av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
 953                     return -1;
 954                 }; SKIP_CACHE(re, &s->gb, 5);
 955
 956                 level=  level * qmul + qadd;
 957                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 958                 SKIP_COUNTER(re, &s->gb, 1+11+5+1);
 959
 960                 i+= run + 1;
 961                 if(last) i+=192;
 962           }else{
 963             int cache;
 964             cache= GET_CACHE(re, &s->gb);
 965
 966             if(IS_3IV1)
 967                 cache ^= 0xC0000000;
 968
 969             if (cache&0x80000000) {
 970                 if (cache&0x40000000) {
 971                     /* third escape */
 972                     SKIP_CACHE(re, &s->gb, 2);
 973                     last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 974                     run=   SHOW_UBITS(re, &s->gb, 6);
 975                     SKIP_COUNTER(re, &s->gb, 2+1+6);
 976                     UPDATE_CACHE(re, &s->gb);
 977
 978                     if(IS_3IV1){
 979                         level= SHOW_SBITS(re, &s->gb, 12); LAST_SKIP_BITS(re, &s->gb, 12);
 980                     }else{
 981                         if(SHOW_UBITS(re, &s->gb, 1)==0){
 982                             av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in 3. esc\n");
 983                             return -1;
 984                         }; SKIP_CACHE(re, &s->gb, 1);
 985
 986                         level= SHOW_SBITS(re, &s->gb, 12); SKIP_CACHE(re, &s->gb, 12);
 987
 988                         if(SHOW_UBITS(re, &s->gb, 1)==0){
 989                             av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in 3. esc\n");
 990                             return -1;
 991                         }
 992
 993                         SKIP_COUNTER(re, &s->gb, 1+12+1);
 994                     }
 995
 996                     if (level>0) level= level * qmul + qadd;
 997                     else         level= level * qmul - qadd;
 998
 999                     if((unsigned)(level + 2048) > 4095){
1000                         if(s->err_recognition & AV_EF_BITSTREAM){
1001                             if(level > 2560 || level<-2560){
1002                                 av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
1003                                 return -1;
1004                             }
1005                         }
1006                         level= level<0 ? -2048 : 2047;
1007                     }
1008
1009                     i+= run + 1;
1010                     if(last) i+=192;
1011                 } else {
1012                     /* second escape */
1013                     SKIP_BITS(re, &s->gb, 2);
1014                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1015                     i+= run + rl->max_run[run>>7][level/qmul] +1; //FIXME opt indexing
1016                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1017                     LAST_SKIP_BITS(re, &s->gb, 1);
1018                 }
1019             } else {
1020                 /* first escape */
1021                 SKIP_BITS(re, &s->gb, 1);
1022                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1023                 i+= run;
1024                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
1025                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1026                 LAST_SKIP_BITS(re, &s->gb, 1);
1027             }
1028           }
1029         } else {
1030             i+= run;
1031             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1032             LAST_SKIP_BITS(re, &s->gb, 1);
1033         }
1034         if (i > 62){
1035             i-= 192;
1036             if(i&(~63)){
1037                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1038                 return -1;
1039             }
1040
1041             block[scan_table[i]] = level;
1042             break;
1043         }
1044
1045         block[scan_table[i]] = level;
1046     }
1047     CLOSE_READER(re, &s->gb);
1048   }
1049  not_coded:
1050     if (intra) {
1051         if(!s->use_intra_dc_vlc){
1052             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1053
1054             i -= i>>31; //if(i == -1) i=0;
1055         }
1056
1057         ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
1058         if (s->ac_pred) {
1059             i = 63; /* XXX: not optimal */
1060         }
1061     }
1062     s->block_last_index[n] = i;
1063     return 0;
1064 }
1065
1066 /**
1067  * decode partition C of one MB.
1068  * @return <0 if an error occurred
1069  */
1070 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, int16_t block[6][64])
1071 {
1072     int cbp, mb_type;
1073     const int xy= s->mb_x + s->mb_y*s->mb_stride;
1074
1075     mb_type = s->current_picture.mb_type[xy];
1076     cbp = s->cbp_table[xy];
1077
1078     s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1079
1080     if (s->current_picture.qscale_table[xy] != s->qscale) {
1081         ff_set_qscale(s, s->current_picture.qscale_table[xy]);
1082     }
1083
1084     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1085         int i;
1086         for(i=0; i<4; i++){
1087             s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0];
1088             s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1];
1089         }
1090         s->mb_intra = IS_INTRA(mb_type);
1091
1092         if (IS_SKIP(mb_type)) {
1093             /* skip mb */
1094             for(i=0;i<6;i++)
1095                 s->block_last_index[i] = -1;
1096             s->mv_dir = MV_DIR_FORWARD;
1097             s->mv_type = MV_TYPE_16X16;
1098             if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1099                 s->mcsel=1;
1100                 s->mb_skipped = 0;
1101             }else{
1102                 s->mcsel=0;
1103                 s->mb_skipped = 1;
1104             }
1105         }else if(s->mb_intra){
1106             s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1107         }else if(!s->mb_intra){
1108 //            s->mcsel= 0; //FIXME do we need to init that
1109
1110             s->mv_dir = MV_DIR_FORWARD;
1111             if (IS_8X8(mb_type)) {
1112                 s->mv_type = MV_TYPE_8X8;
1113             } else {
1114                 s->mv_type = MV_TYPE_16X16;
1115             }
1116         }
1117     } else { /* I-Frame */
1118         s->mb_intra = 1;
1119         s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1120     }
1121
1122     if (!IS_SKIP(mb_type)) {
1123         int i;
1124         s->dsp.clear_blocks(s->block[0]);
1125         /* decode each block */
1126         for (i = 0; i < 6; i++) {
1127             if(mpeg4_decode_block(s, block[i], i, cbp&32, s->mb_intra, s->rvlc) < 0){
1128                 av_log(s->avctx, AV_LOG_ERROR, "texture corrupted at %d %d %d\n", s->mb_x, s->mb_y, s->mb_intra);
1129                 return -1;
1130             }
1131             cbp+=cbp;
1132         }
1133     }
1134
1135     /* per-MB end of slice check */
1136
1137     if(--s->mb_num_left <= 0){
1138         if(mpeg4_is_resync(s))
1139             return SLICE_END;
1140         else
1141             return SLICE_NOEND;
1142     }else{
1143         if(mpeg4_is_resync(s)){
1144             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1145             if(s->cbp_table[xy+delta])
1146                 return SLICE_END;
1147         }
1148         return SLICE_OK;
1149     }
1150 }
1151
1152 static int mpeg4_decode_mb(MpegEncContext *s,
1153                       int16_t block[6][64])
1154 {
1155     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1156     int16_t *mot_val;
1157     static int8_t quant_tab[4] = { -1, -2, 1, 2 };
1158     const int xy= s->mb_x + s->mb_y * s->mb_stride;
1159
1160     assert(s->h263_pred);
1161
1162     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1163         do{
1164             if (get_bits1(&s->gb)) {
1165                 /* skip mb */
1166                 s->mb_intra = 0;
1167                 for(i=0;i<6;i++)
1168                     s->block_last_index[i] = -1;
1169                 s->mv_dir = MV_DIR_FORWARD;
1170                 s->mv_type = MV_TYPE_16X16;
1171                 if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1172                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1173                     s->mcsel=1;
1174                     s->mv[0][0][0]= get_amv(s, 0);
1175                     s->mv[0][0][1]= get_amv(s, 1);
1176
1177                     s->mb_skipped = 0;
1178                 }else{
1179                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1180                     s->mcsel=0;
1181                     s->mv[0][0][0] = 0;
1182                     s->mv[0][0][1] = 0;
1183                     s->mb_skipped = 1;
1184                 }
1185                 goto end;
1186             }
1187             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1188             if (cbpc < 0){
1189                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1190                 return -1;
1191             }
1192         }while(cbpc == 20);
1193
1194         s->dsp.clear_blocks(s->block[0]);
1195         dquant = cbpc & 8;
1196         s->mb_intra = ((cbpc & 4) != 0);
1197         if (s->mb_intra) goto intra;
1198
1199         if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
1200             s->mcsel= get_bits1(&s->gb);
1201         else s->mcsel= 0;
1202         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1203
1204         cbp = (cbpc & 3) | (cbpy << 2);
1205         if (dquant) {
1206             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1207         }
1208         if((!s->progressive_sequence) && (cbp || (s->workaround_bugs&FF_BUG_XVID_ILACE)))
1209             s->interlaced_dct= get_bits1(&s->gb);
1210
1211         s->mv_dir = MV_DIR_FORWARD;
1212         if ((cbpc & 16) == 0) {
1213             if(s->mcsel){
1214                 s->current_picture.mb_type[xy] = MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1215                 /* 16x16 global motion prediction */
1216                 s->mv_type = MV_TYPE_16X16;
1217                 mx= get_amv(s, 0);
1218                 my= get_amv(s, 1);
1219                 s->mv[0][0][0] = mx;
1220                 s->mv[0][0][1] = my;
1221             }else if((!s->progressive_sequence) && get_bits1(&s->gb)){
1222                 s->current_picture.mb_type[xy] = MB_TYPE_16x8 | MB_TYPE_L0 | MB_TYPE_INTERLACED;
1223                 /* 16x8 field motion prediction */
1224                 s->mv_type= MV_TYPE_FIELD;
1225
1226                 s->field_select[0][0]= get_bits1(&s->gb);
1227                 s->field_select[0][1]= get_bits1(&s->gb);
1228
1229                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1230
1231                 for(i=0; i<2; i++){
1232                     mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1233                     if (mx >= 0xffff)
1234                         return -1;
1235
1236                     my = ff_h263_decode_motion(s, pred_y/2, s->f_code);
1237                     if (my >= 0xffff)
1238                         return -1;
1239
1240                     s->mv[0][i][0] = mx;
1241                     s->mv[0][i][1] = my;
1242                 }
1243             }else{
1244                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1245                 /* 16x16 motion prediction */
1246                 s->mv_type = MV_TYPE_16X16;
1247                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1248                 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1249
1250                 if (mx >= 0xffff)
1251                     return -1;
1252
1253                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1254
1255                 if (my >= 0xffff)
1256                     return -1;
1257                 s->mv[0][0][0] = mx;
1258                 s->mv[0][0][1] = my;
1259             }
1260         } else {
1261             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1262             s->mv_type = MV_TYPE_8X8;
1263             for(i=0;i<4;i++) {
1264                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1265                 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1266                 if (mx >= 0xffff)
1267                     return -1;
1268
1269                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1270                 if (my >= 0xffff)
1271                     return -1;
1272                 s->mv[0][i][0] = mx;
1273                 s->mv[0][i][1] = my;
1274                 mot_val[0] = mx;
1275                 mot_val[1] = my;
1276             }
1277         }
1278     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
1279         int modb1; // first bit of modb
1280         int modb2; // second bit of modb
1281         int mb_type;
1282
1283         s->mb_intra = 0; //B-frames never contain intra blocks
1284         s->mcsel=0;      //     ...               true gmc blocks
1285
1286         if(s->mb_x==0){
1287             for(i=0; i<2; i++){
1288                 s->last_mv[i][0][0]=
1289                 s->last_mv[i][0][1]=
1290                 s->last_mv[i][1][0]=
1291                 s->last_mv[i][1][1]= 0;
1292             }
1293
1294             ff_thread_await_progress(&s->next_picture_ptr->tf, s->mb_y, 0);
1295         }
1296
1297         /* if we skipped it in the future P Frame than skip it now too */
1298         s->mb_skipped = s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x]; // Note, skiptab=0 if last was GMC
1299
1300         if(s->mb_skipped){
1301                 /* skip mb */
1302             for(i=0;i<6;i++)
1303                 s->block_last_index[i] = -1;
1304
1305             s->mv_dir = MV_DIR_FORWARD;
1306             s->mv_type = MV_TYPE_16X16;
1307             s->mv[0][0][0] = 0;
1308             s->mv[0][0][1] = 0;
1309             s->mv[1][0][0] = 0;
1310             s->mv[1][0][1] = 0;
1311             s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1312             goto end;
1313         }
1314
1315         modb1= get_bits1(&s->gb);
1316         if(modb1){
1317             mb_type= MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1; //like MB_TYPE_B_DIRECT but no vectors coded
1318             cbp=0;
1319         }else{
1320             modb2= get_bits1(&s->gb);
1321             mb_type= get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1322             if(mb_type<0){
1323                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1324                 return -1;
1325             }
1326             mb_type= mb_type_b_map[ mb_type ];
1327             if(modb2) cbp= 0;
1328             else{
1329                 s->dsp.clear_blocks(s->block[0]);
1330                 cbp= get_bits(&s->gb, 6);
1331             }
1332
1333             if ((!IS_DIRECT(mb_type)) && cbp) {
1334                 if(get_bits1(&s->gb)){
1335                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb)*4 - 2);
1336                 }
1337             }
1338
1339             if(!s->progressive_sequence){
1340                 if(cbp)
1341                     s->interlaced_dct= get_bits1(&s->gb);
1342
1343                 if(!IS_DIRECT(mb_type) && get_bits1(&s->gb)){
1344                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1345                     mb_type &= ~MB_TYPE_16x16;
1346
1347                     if(USES_LIST(mb_type, 0)){
1348                         s->field_select[0][0]= get_bits1(&s->gb);
1349                         s->field_select[0][1]= get_bits1(&s->gb);
1350                     }
1351                     if(USES_LIST(mb_type, 1)){
1352                         s->field_select[1][0]= get_bits1(&s->gb);
1353                         s->field_select[1][1]= get_bits1(&s->gb);
1354                     }
1355                 }
1356             }
1357
1358             s->mv_dir = 0;
1359             if((mb_type & (MB_TYPE_DIRECT2|MB_TYPE_INTERLACED)) == 0){
1360                 s->mv_type= MV_TYPE_16X16;
1361
1362                 if(USES_LIST(mb_type, 0)){
1363                     s->mv_dir = MV_DIR_FORWARD;
1364
1365                     mx = ff_h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1366                     my = ff_h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1367                     s->last_mv[0][1][0]= s->last_mv[0][0][0]= s->mv[0][0][0] = mx;
1368                     s->last_mv[0][1][1]= s->last_mv[0][0][1]= s->mv[0][0][1] = my;
1369                 }
1370
1371                 if(USES_LIST(mb_type, 1)){
1372                     s->mv_dir |= MV_DIR_BACKWARD;
1373
1374                     mx = ff_h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1375                     my = ff_h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1376                     s->last_mv[1][1][0]= s->last_mv[1][0][0]= s->mv[1][0][0] = mx;
1377                     s->last_mv[1][1][1]= s->last_mv[1][0][1]= s->mv[1][0][1] = my;
1378                 }
1379             }else if(!IS_DIRECT(mb_type)){
1380                 s->mv_type= MV_TYPE_FIELD;
1381
1382                 if(USES_LIST(mb_type, 0)){
1383                     s->mv_dir = MV_DIR_FORWARD;
1384
1385                     for(i=0; i<2; i++){
1386                         mx = ff_h263_decode_motion(s, s->last_mv[0][i][0]  , s->f_code);
1387                         my = ff_h263_decode_motion(s, s->last_mv[0][i][1]/2, s->f_code);
1388                         s->last_mv[0][i][0]=  s->mv[0][i][0] = mx;
1389                         s->last_mv[0][i][1]= (s->mv[0][i][1] = my)*2;
1390                     }
1391                 }
1392
1393                 if(USES_LIST(mb_type, 1)){
1394                     s->mv_dir |= MV_DIR_BACKWARD;
1395
1396                     for(i=0; i<2; i++){
1397                         mx = ff_h263_decode_motion(s, s->last_mv[1][i][0]  , s->b_code);
1398                         my = ff_h263_decode_motion(s, s->last_mv[1][i][1]/2, s->b_code);
1399                         s->last_mv[1][i][0]=  s->mv[1][i][0] = mx;
1400                         s->last_mv[1][i][1]= (s->mv[1][i][1] = my)*2;
1401                     }
1402                 }
1403             }
1404         }
1405
1406         if(IS_DIRECT(mb_type)){
1407             if(IS_SKIP(mb_type))
1408                 mx=my=0;
1409             else{
1410                 mx = ff_h263_decode_motion(s, 0, 1);
1411                 my = ff_h263_decode_motion(s, 0, 1);
1412             }
1413
1414             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1415             mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
1416         }
1417         s->current_picture.mb_type[xy] = mb_type;
1418     } else { /* I-Frame */
1419         do{
1420             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1421             if (cbpc < 0){
1422                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1423                 return -1;
1424             }
1425         }while(cbpc == 8);
1426
1427         dquant = cbpc & 4;
1428         s->mb_intra = 1;
1429 intra:
1430         s->ac_pred = get_bits1(&s->gb);
1431         if(s->ac_pred)
1432             s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1433         else
1434             s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
1435
1436         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1437         if(cbpy<0){
1438             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1439             return -1;
1440         }
1441         cbp = (cbpc & 3) | (cbpy << 2);
1442
1443         s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1444
1445         if (dquant) {
1446             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1447         }
1448
1449         if(!s->progressive_sequence)
1450             s->interlaced_dct= get_bits1(&s->gb);
1451
1452         s->dsp.clear_blocks(s->block[0]);
1453         /* decode each block */
1454         for (i = 0; i < 6; i++) {
1455             if (mpeg4_decode_block(s, block[i], i, cbp&32, 1, 0) < 0)
1456                 return -1;
1457             cbp+=cbp;
1458         }
1459         goto end;
1460     }
1461
1462     /* decode each block */
1463     for (i = 0; i < 6; i++) {
1464         if (mpeg4_decode_block(s, block[i], i, cbp&32, 0, 0) < 0)
1465             return -1;
1466         cbp+=cbp;
1467     }
1468 end:
1469
1470         /* per-MB end of slice check */
1471     if(s->codec_id==AV_CODEC_ID_MPEG4){
1472         if(mpeg4_is_resync(s)){
1473             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1474
1475             if (s->pict_type == AV_PICTURE_TYPE_B && s->next_picture.mbskip_table[xy + delta]) {
1476                 ff_thread_await_progress(&s->next_picture_ptr->tf,
1477                                         (s->mb_x + delta >= s->mb_width) ? FFMIN(s->mb_y+1, s->mb_height-1) : s->mb_y, 0);
1478             }
1479
1480             if (s->pict_type == AV_PICTURE_TYPE_B && s->next_picture.mbskip_table[xy + delta])
1481                 return SLICE_OK;
1482             return SLICE_END;
1483         }
1484     }
1485
1486     return SLICE_OK;
1487 }
1488
1489
1490 static int mpeg4_decode_gop_header(MpegEncContext * s, GetBitContext *gb){
1491     int hours, minutes, seconds;
1492     unsigned time_code = show_bits(gb, 18);
1493
1494     if (time_code & 0x40) {     /* marker_bit */
1495         hours   = time_code >> 13;
1496         minutes = time_code >>  7 & 0x3f;
1497         seconds = time_code       & 0x3f;
1498         s->time_base = seconds + 60*(minutes + 60*hours);
1499         skip_bits(gb, 20);      /* time_code, closed_gov, broken_link */
1500     } else {
1501         av_log(s->avctx, AV_LOG_WARNING, "GOP header missing marker_bit\n");
1502     }
1503
1504     return 0;
1505 }
1506
1507 static int mpeg4_decode_profile_level(MpegEncContext * s, GetBitContext *gb){
1508   int profile_and_level_indication;
1509
1510   profile_and_level_indication = get_bits(gb, 8);
1511
1512   s->avctx->profile = (profile_and_level_indication & 0xf0) >> 4;
1513   s->avctx->level   = (profile_and_level_indication & 0x0f);
1514
1515   // for Simple profile, level 0
1516   if (s->avctx->profile == 0 && s->avctx->level == 8) {
1517       s->avctx->level = 0;
1518   }
1519
1520   return 0;
1521 }
1522
1523 static int decode_vol_header(MpegEncContext *s, GetBitContext *gb){
1524     int width, height, vo_ver_id;
1525
1526     /* vol header */
1527     skip_bits(gb, 1); /* random access */
1528     s->vo_type= get_bits(gb, 8);
1529     if (get_bits1(gb) != 0) { /* is_ol_id */
1530         vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
1531         skip_bits(gb, 3); /* vo_priority */
1532     } else {
1533         vo_ver_id = 1;
1534     }
1535     s->aspect_ratio_info= get_bits(gb, 4);
1536     if(s->aspect_ratio_info == FF_ASPECT_EXTENDED){
1537         s->avctx->sample_aspect_ratio.num= get_bits(gb, 8); // par_width
1538         s->avctx->sample_aspect_ratio.den= get_bits(gb, 8); // par_height
1539     }else{
1540         s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1541     }
1542
1543     if ((s->vol_control_parameters=get_bits1(gb))) { /* vol control parameter */
1544         int chroma_format= get_bits(gb, 2);
1545         if(chroma_format!=CHROMA_420){
1546             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1547         }
1548         s->low_delay= get_bits1(gb);
1549         if(get_bits1(gb)){ /* vbv parameters */
1550             get_bits(gb, 15);   /* first_half_bitrate */
1551             skip_bits1(gb);     /* marker */
1552             get_bits(gb, 15);   /* latter_half_bitrate */
1553             skip_bits1(gb);     /* marker */
1554             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
1555             skip_bits1(gb);     /* marker */
1556             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
1557             get_bits(gb, 11);   /* first_half_vbv_occupancy */
1558             skip_bits1(gb);     /* marker */
1559             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
1560             skip_bits1(gb);     /* marker */
1561         }
1562     }else{
1563         // set low delay flag only once the smartest? low delay detection won't be overriden
1564         if(s->picture_number==0)
1565             s->low_delay=0;
1566     }
1567
1568     s->shape = get_bits(gb, 2); /* vol shape */
1569     if(s->shape != RECT_SHAPE) av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1570     if(s->shape == GRAY_SHAPE && vo_ver_id != 1){
1571         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1572         skip_bits(gb, 4);  //video_object_layer_shape_extension
1573     }
1574
1575     check_marker(gb, "before time_increment_resolution");
1576
1577     s->avctx->time_base.den = get_bits(gb, 16);
1578     if(!s->avctx->time_base.den){
1579         av_log(s->avctx, AV_LOG_ERROR, "time_base.den==0\n");
1580         s->avctx->time_base.num = 0;
1581         return -1;
1582     }
1583
1584     s->time_increment_bits = av_log2(s->avctx->time_base.den - 1) + 1;
1585     if (s->time_increment_bits < 1)
1586         s->time_increment_bits = 1;
1587
1588     check_marker(gb, "before fixed_vop_rate");
1589
1590     if (get_bits1(gb) != 0) {   /* fixed_vop_rate  */
1591         s->avctx->time_base.num = get_bits(gb, s->time_increment_bits);
1592     }else
1593         s->avctx->time_base.num = 1;
1594
1595     s->t_frame=0;
1596
1597     if (s->shape != BIN_ONLY_SHAPE) {
1598         if (s->shape == RECT_SHAPE) {
1599             skip_bits1(gb);   /* marker */
1600             width = get_bits(gb, 13);
1601             skip_bits1(gb);   /* marker */
1602             height = get_bits(gb, 13);
1603             skip_bits1(gb);   /* marker */
1604             if(width && height && !(s->width && s->codec_tag == AV_RL32("MP4S"))){ /* they should be non zero but who knows ... */
1605                 if (s->width && s->height &&
1606                     (s->width != width || s->height != height))
1607                     s->context_reinit = 1;
1608                 s->width = width;
1609                 s->height = height;
1610             }
1611         }
1612
1613         s->progressive_sequence=
1614         s->progressive_frame= get_bits1(gb)^1;
1615         s->interlaced_dct=0;
1616         if(!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1617             av_log(s->avctx, AV_LOG_INFO, "MPEG4 OBMC not supported (very likely buggy encoder)\n");   /* OBMC Disable */
1618         if (vo_ver_id == 1) {
1619             s->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
1620         } else {
1621             s->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
1622         }
1623         if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1624         if(s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE){
1625             if(s->vol_sprite_usage==STATIC_SPRITE){
1626                 s->sprite_width = get_bits(gb, 13);
1627                 skip_bits1(gb); /* marker */
1628                 s->sprite_height= get_bits(gb, 13);
1629                 skip_bits1(gb); /* marker */
1630                 s->sprite_left  = get_bits(gb, 13);
1631                 skip_bits1(gb); /* marker */
1632                 s->sprite_top   = get_bits(gb, 13);
1633                 skip_bits1(gb); /* marker */
1634             }
1635             s->num_sprite_warping_points= get_bits(gb, 6);
1636             if(s->num_sprite_warping_points > 3){
1637                 av_log(s->avctx, AV_LOG_ERROR, "%d sprite_warping_points\n", s->num_sprite_warping_points);
1638                 s->num_sprite_warping_points= 0;
1639                 return -1;
1640             }
1641             s->sprite_warping_accuracy = get_bits(gb, 2);
1642             s->sprite_brightness_change= get_bits1(gb);
1643             if(s->vol_sprite_usage==STATIC_SPRITE)
1644                 s->low_latency_sprite= get_bits1(gb);
1645         }
1646         // FIXME sadct disable bit if verid!=1 && shape not rect
1647
1648         if (get_bits1(gb) == 1) {   /* not_8_bit */
1649             s->quant_precision = get_bits(gb, 4); /* quant_precision */
1650             if(get_bits(gb, 4)!=8) av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n"); /* bits_per_pixel */
1651             if(s->quant_precision!=5) av_log(s->avctx, AV_LOG_ERROR, "quant precision %d\n", s->quant_precision);
1652         } else {
1653             s->quant_precision = 5;
1654         }
1655
1656         // FIXME a bunch of grayscale shape things
1657
1658         if((s->mpeg_quant=get_bits1(gb))){ /* vol_quant_type */
1659             int i, v;
1660
1661             /* load default matrixes */
1662             for(i=0; i<64; i++){
1663                 int j= s->dsp.idct_permutation[i];
1664                 v= ff_mpeg4_default_intra_matrix[i];
1665                 s->intra_matrix[j]= v;
1666                 s->chroma_intra_matrix[j]= v;
1667
1668                 v= ff_mpeg4_default_non_intra_matrix[i];
1669                 s->inter_matrix[j]= v;
1670                 s->chroma_inter_matrix[j]= v;
1671             }
1672
1673             /* load custom intra matrix */
1674             if(get_bits1(gb)){
1675                 int last=0;
1676                 for(i=0; i<64; i++){
1677                     int j;
1678                     v= get_bits(gb, 8);
1679                     if(v==0) break;
1680
1681                     last= v;
1682                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1683                     s->intra_matrix[j]= v;
1684                     s->chroma_intra_matrix[j]= v;
1685                 }
1686
1687                 /* replicate last value */
1688                 for(; i<64; i++){
1689                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1690                     s->intra_matrix[j]= last;
1691                     s->chroma_intra_matrix[j]= last;
1692                 }
1693             }
1694
1695             /* load custom non intra matrix */
1696             if(get_bits1(gb)){
1697                 int last=0;
1698                 for(i=0; i<64; i++){
1699                     int j;
1700                     v= get_bits(gb, 8);
1701                     if(v==0) break;
1702
1703                     last= v;
1704                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1705                     s->inter_matrix[j]= v;
1706                     s->chroma_inter_matrix[j]= v;
1707                 }
1708
1709                 /* replicate last value */
1710                 for(; i<64; i++){
1711                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1712                     s->inter_matrix[j]= last;
1713                     s->chroma_inter_matrix[j]= last;
1714                 }
1715             }
1716
1717             // FIXME a bunch of grayscale shape things
1718         }
1719
1720         if(vo_ver_id != 1)
1721              s->quarter_sample= get_bits1(gb);
1722         else s->quarter_sample=0;
1723
1724         if(!get_bits1(gb)){
1725             int pos= get_bits_count(gb);
1726             int estimation_method= get_bits(gb, 2);
1727             if(estimation_method<2){
1728                 if(!get_bits1(gb)){
1729                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //opaque
1730                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //transparent
1731                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_cae
1732                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //inter_cae
1733                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //no_update
1734                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //upampling
1735                 }
1736                 if(!get_bits1(gb)){
1737                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_blocks
1738                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter_blocks
1739                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter4v_blocks
1740                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //not coded blocks
1741                 }
1742                 if(!check_marker(gb, "in complexity estimation part 1")){
1743                     skip_bits_long(gb, pos - get_bits_count(gb));
1744                     goto no_cplx_est;
1745                 }
1746                 if(!get_bits1(gb)){
1747                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_coeffs
1748                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_lines
1749                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //vlc_syms
1750                     s->cplx_estimation_trash_i += 4*get_bits1(gb); //vlc_bits
1751                 }
1752                 if(!get_bits1(gb)){
1753                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //apm
1754                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //npm
1755                     s->cplx_estimation_trash_b += 8*get_bits1(gb); //interpolate_mc_q
1756                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //forwback_mc_q
1757                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel2
1758                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel4
1759                 }
1760                 if(!check_marker(gb, "in complexity estimation part 2")){
1761                     skip_bits_long(gb, pos - get_bits_count(gb));
1762                     goto no_cplx_est;
1763                 }
1764                 if(estimation_method==1){
1765                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //sadct
1766                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //qpel
1767                 }
1768             }else
1769                 av_log(s->avctx, AV_LOG_ERROR, "Invalid Complexity estimation method %d\n", estimation_method);
1770         }else{
1771 no_cplx_est:
1772             s->cplx_estimation_trash_i=
1773             s->cplx_estimation_trash_p=
1774             s->cplx_estimation_trash_b= 0;
1775         }
1776
1777         s->resync_marker= !get_bits1(gb); /* resync_marker_disabled */
1778
1779         s->data_partitioning= get_bits1(gb);
1780         if(s->data_partitioning){
1781             s->rvlc= get_bits1(gb);
1782         }
1783
1784         if(vo_ver_id != 1) {
1785             s->new_pred= get_bits1(gb);
1786             if(s->new_pred){
1787                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
1788                 skip_bits(gb, 2); /* requested upstream message type */
1789                 skip_bits1(gb); /* newpred segment type */
1790             }
1791             s->reduced_res_vop= get_bits1(gb);
1792             if(s->reduced_res_vop) av_log(s->avctx, AV_LOG_ERROR, "reduced resolution VOP not supported\n");
1793         }
1794         else{
1795             s->new_pred=0;
1796             s->reduced_res_vop= 0;
1797         }
1798
1799         s->scalability= get_bits1(gb);
1800
1801         if (s->scalability) {
1802             GetBitContext bak= *gb;
1803             int h_sampling_factor_n;
1804             int h_sampling_factor_m;
1805             int v_sampling_factor_n;
1806             int v_sampling_factor_m;
1807
1808             s->hierachy_type= get_bits1(gb);
1809             skip_bits(gb, 4);  /* ref_layer_id */
1810             skip_bits1(gb);    /* ref_layer_sampling_dir */
1811             h_sampling_factor_n= get_bits(gb, 5);
1812             h_sampling_factor_m= get_bits(gb, 5);
1813             v_sampling_factor_n= get_bits(gb, 5);
1814             v_sampling_factor_m= get_bits(gb, 5);
1815             s->enhancement_type= get_bits1(gb);
1816
1817             if(   h_sampling_factor_n==0 || h_sampling_factor_m==0
1818                || v_sampling_factor_n==0 || v_sampling_factor_m==0){
1819                 /* illegal scalability header (VERY broken encoder),
1820                  * trying to workaround */
1821                 s->scalability=0;
1822                 *gb= bak;
1823             }else
1824                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
1825
1826             // bin shape stuff FIXME
1827         }
1828     }
1829     return 0;
1830 }
1831
1832 /**
1833  * Decode the user data stuff in the header.
1834  * Also initializes divx/xvid/lavc_version/build.
1835  */
1836 static int decode_user_data(MpegEncContext *s, GetBitContext *gb){
1837     char buf[256];
1838     int i;
1839     int e;
1840     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
1841     char last;
1842
1843     for(i=0; i<255 && get_bits_count(gb) < gb->size_in_bits; i++){
1844         if(show_bits(gb, 23) == 0) break;
1845         buf[i]= get_bits(gb, 8);
1846     }
1847     buf[i]=0;
1848
1849     /* divx detection */
1850     e=sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
1851     if(e<2)
1852         e=sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
1853     if(e>=2){
1854         s->divx_version= ver;
1855         s->divx_build= build;
1856         s->divx_packed= e==3 && last=='p';
1857         if(s->divx_packed && !s->showed_packed_warning) {
1858             av_log(s->avctx, AV_LOG_WARNING, "Invalid and inefficient vfw-avi packed B frames detected\n");
1859             s->showed_packed_warning=1;
1860         }
1861     }
1862
1863     /* libavcodec detection */
1864     e=sscanf(buf, "FFmpe%*[^b]b%d", &build)+3;
1865     if(e!=4)
1866         e=sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
1867     if(e!=4){
1868         e=sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3)+1;
1869         if (e>1)
1870             build= (ver<<16) + (ver2<<8) + ver3;
1871     }
1872     if(e!=4){
1873         if(strcmp(buf, "ffmpeg")==0){
1874             s->lavc_build= 4600;
1875         }
1876     }
1877     if(e==4){
1878         s->lavc_build= build;
1879     }
1880
1881     /* Xvid detection */
1882     e=sscanf(buf, "XviD%d", &build);
1883     if(e==1){
1884         s->xvid_build= build;
1885     }
1886
1887     return 0;
1888 }
1889
1890 static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
1891     int time_incr, time_increment;
1892
1893     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I;        /* pict type: I = 0 , P = 1 */
1894     if(s->pict_type==AV_PICTURE_TYPE_B && s->low_delay && s->vol_control_parameters==0 && !(s->flags & CODEC_FLAG_LOW_DELAY)){
1895         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag incorrectly, clearing it\n");
1896         s->low_delay=0;
1897     }
1898
1899     s->partitioned_frame= s->data_partitioning && s->pict_type!=AV_PICTURE_TYPE_B;
1900     if(s->partitioned_frame)
1901         s->decode_mb= mpeg4_decode_partitioned_mb;
1902     else
1903         s->decode_mb= mpeg4_decode_mb;
1904
1905     time_incr=0;
1906     while (get_bits1(gb) != 0)
1907         time_incr++;
1908
1909     check_marker(gb, "before time_increment");
1910
1911     if(s->time_increment_bits==0 || !(show_bits(gb, s->time_increment_bits+1)&1)){
1912         av_log(s->avctx, AV_LOG_ERROR, "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
1913
1914         for(s->time_increment_bits=1 ;s->time_increment_bits<16; s->time_increment_bits++){
1915             if (    s->pict_type == AV_PICTURE_TYPE_P
1916                 || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE)) {
1917                 if((show_bits(gb, s->time_increment_bits+6)&0x37) == 0x30) break;
1918             }else
1919                 if((show_bits(gb, s->time_increment_bits+5)&0x1F) == 0x18) break;
1920         }
1921
1922         av_log(s->avctx, AV_LOG_ERROR, "my guess is %d bits ;)\n",s->time_increment_bits);
1923     }
1924
1925     if(IS_3IV1) time_increment= get_bits1(gb); //FIXME investigate further
1926     else time_increment= get_bits(gb, s->time_increment_bits);
1927
1928     if(s->pict_type!=AV_PICTURE_TYPE_B){
1929         s->last_time_base= s->time_base;
1930         s->time_base+= time_incr;
1931         s->time= s->time_base*s->avctx->time_base.den + time_increment;
1932         if(s->workaround_bugs&FF_BUG_UMP4){
1933             if(s->time < s->last_non_b_time){
1934                 /* header is not mpeg-4-compatible, broken encoder,
1935                  * trying to workaround */
1936                 s->time_base++;
1937                 s->time+= s->avctx->time_base.den;
1938             }
1939         }
1940         s->pp_time= s->time - s->last_non_b_time;
1941         s->last_non_b_time= s->time;
1942     }else{
1943         s->time= (s->last_time_base + time_incr)*s->avctx->time_base.den + time_increment;
1944         s->pb_time= s->pp_time - (s->last_non_b_time - s->time);
1945         if(s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0){
1946             /* messed up order, maybe after seeking? skipping current b-frame */
1947             return FRAME_SKIPPED;
1948         }
1949         ff_mpeg4_init_direct_mv(s);
1950
1951         if(s->t_frame==0) s->t_frame= s->pb_time;
1952         if(s->t_frame==0) s->t_frame=1; // 1/0 protection
1953         s->pp_field_time= (  ROUNDED_DIV(s->last_non_b_time, s->t_frame)
1954                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1955         s->pb_field_time= (  ROUNDED_DIV(s->time, s->t_frame)
1956                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
1957         if(!s->progressive_sequence){
1958             if(s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
1959                 return FRAME_SKIPPED;
1960         }
1961     }
1962
1963     if(s->avctx->time_base.num)
1964         s->current_picture_ptr->f.pts = (s->time + s->avctx->time_base.num / 2) / s->avctx->time_base.num;
1965     else
1966         s->current_picture_ptr->f.pts = AV_NOPTS_VALUE;
1967     if(s->avctx->debug&FF_DEBUG_PTS)
1968         av_log(s->avctx, AV_LOG_DEBUG, "MPEG4 PTS: %"PRId64"\n",
1969                s->current_picture_ptr->f.pts);
1970
1971     check_marker(gb, "before vop_coded");
1972
1973     /* vop coded */
1974     if (get_bits1(gb) != 1){
1975         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
1976             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
1977         return FRAME_SKIPPED;
1978     }
1979     if (s->shape != BIN_ONLY_SHAPE && ( s->pict_type == AV_PICTURE_TYPE_P
1980                           || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE))) {
1981         /* rounding type for motion estimation */
1982         s->no_rounding = get_bits1(gb);
1983     } else {
1984         s->no_rounding = 0;
1985     }
1986 //FIXME reduced res stuff
1987
1988      if (s->shape != RECT_SHAPE) {
1989          if (s->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
1990              skip_bits(gb, 13); /* width */
1991              skip_bits1(gb);   /* marker */
1992              skip_bits(gb, 13); /* height */
1993              skip_bits1(gb);   /* marker */
1994              skip_bits(gb, 13); /* hor_spat_ref */
1995              skip_bits1(gb);   /* marker */
1996              skip_bits(gb, 13); /* ver_spat_ref */
1997          }
1998          skip_bits1(gb); /* change_CR_disable */
1999
2000          if (get_bits1(gb) != 0) {
2001              skip_bits(gb, 8); /* constant_alpha_value */
2002          }
2003      }
2004 //FIXME complexity estimation stuff
2005
2006      if (s->shape != BIN_ONLY_SHAPE) {
2007          skip_bits_long(gb, s->cplx_estimation_trash_i);
2008          if(s->pict_type != AV_PICTURE_TYPE_I)
2009             skip_bits_long(gb, s->cplx_estimation_trash_p);
2010          if(s->pict_type == AV_PICTURE_TYPE_B)
2011             skip_bits_long(gb, s->cplx_estimation_trash_b);
2012
2013          s->intra_dc_threshold= ff_mpeg4_dc_threshold[ get_bits(gb, 3) ];
2014          if(!s->progressive_sequence){
2015              s->top_field_first= get_bits1(gb);
2016              s->alternate_scan= get_bits1(gb);
2017          }else
2018              s->alternate_scan= 0;
2019      }
2020
2021      if(s->alternate_scan){
2022          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
2023          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
2024          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2025          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2026      } else{
2027          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
2028          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
2029          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2030          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2031      }
2032
2033      if(s->pict_type == AV_PICTURE_TYPE_S && (s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE)){
2034          mpeg4_decode_sprite_trajectory(s, gb);
2035          if(s->sprite_brightness_change) av_log(s->avctx, AV_LOG_ERROR, "sprite_brightness_change not supported\n");
2036          if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2037      }
2038
2039      if (s->shape != BIN_ONLY_SHAPE) {
2040          s->chroma_qscale= s->qscale = get_bits(gb, s->quant_precision);
2041          if(s->qscale==0){
2042              av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (qscale=0)\n");
2043              return -1; // makes no sense to continue, as there is nothing left from the image then
2044          }
2045
2046          if (s->pict_type != AV_PICTURE_TYPE_I) {
2047              s->f_code = get_bits(gb, 3);       /* fcode_for */
2048              if(s->f_code==0){
2049                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (f_code=0)\n");
2050                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
2051              }
2052          }else
2053              s->f_code=1;
2054
2055          if (s->pict_type == AV_PICTURE_TYPE_B) {
2056              s->b_code = get_bits(gb, 3);
2057          }else
2058              s->b_code=1;
2059
2060          if(s->avctx->debug&FF_DEBUG_PICT_INFO){
2061              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",
2062                  s->qscale, s->f_code, s->b_code,
2063                  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")),
2064                  gb->size_in_bits,s->progressive_sequence, s->alternate_scan, s->top_field_first,
2065                  s->quarter_sample ? "q" : "h", s->data_partitioning, s->resync_marker, s->num_sprite_warping_points,
2066                  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);
2067          }
2068
2069          if(!s->scalability){
2070              if (s->shape!=RECT_SHAPE && s->pict_type!=AV_PICTURE_TYPE_I) {
2071                  skip_bits1(gb); // vop shape coding type
2072              }
2073          }else{
2074              if(s->enhancement_type){
2075                  int load_backward_shape= get_bits1(gb);
2076                  if(load_backward_shape){
2077                      av_log(s->avctx, AV_LOG_ERROR, "load backward shape isn't supported\n");
2078                  }
2079              }
2080              skip_bits(gb, 2); //ref_select_code
2081          }
2082      }
2083      /* detect buggy encoders which don't set the low_delay flag (divx4/xvid/opendivx)*/
2084      // note we cannot detect divx5 without b-frames easily (although it's buggy too)
2085      if(s->vo_type==0 && s->vol_control_parameters==0 && s->divx_version==-1 && s->picture_number==0){
2086          av_log(s->avctx, AV_LOG_WARNING, "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2087          s->low_delay=1;
2088      }
2089
2090      s->picture_number++; // better than pic number==0 always ;)
2091
2092      s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table; //FIXME add short header support
2093      s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
2094
2095      if(s->workaround_bugs&FF_BUG_EDGE){
2096          s->h_edge_pos= s->width;
2097          s->v_edge_pos= s->height;
2098      }
2099      return 0;
2100 }
2101
2102 /**
2103  * Decode mpeg4 headers.
2104  * @return <0 if no VOP found (or a damaged one)
2105  *         FRAME_SKIPPED if a not coded VOP is found
2106  *         0 if a VOP is found
2107  */
2108 int ff_mpeg4_decode_picture_header(MpegEncContext * s, GetBitContext *gb)
2109 {
2110     unsigned startcode, v;
2111
2112     /* search next start code */
2113     align_get_bits(gb);
2114
2115     if(s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630){
2116         skip_bits(gb, 24);
2117         if(get_bits(gb, 8) == 0xF0)
2118             goto end;
2119     }
2120
2121     startcode = 0xff;
2122     for(;;) {
2123         if(get_bits_count(gb) >= gb->size_in_bits){
2124             if(gb->size_in_bits==8 && (s->divx_version>=0 || s->xvid_build>=0)){
2125                 av_log(s->avctx, AV_LOG_WARNING, "frame skip %d\n", gb->size_in_bits);
2126                 return FRAME_SKIPPED; //divx bug
2127             }else
2128                 return -1; //end of stream
2129         }
2130
2131         /* use the bits after the test */
2132         v = get_bits(gb, 8);
2133         startcode = ((startcode << 8) | v) & 0xffffffff;
2134
2135         if((startcode&0xFFFFFF00) != 0x100)
2136             continue; //no startcode
2137
2138         if(s->avctx->debug&FF_DEBUG_STARTCODE){
2139             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2140             if     (startcode<=0x11F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2141             else if(startcode<=0x12F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2142             else if(startcode<=0x13F) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2143             else if(startcode<=0x15F) av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2144             else if(startcode<=0x1AF) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2145             else if(startcode==0x1B0) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2146             else if(startcode==0x1B1) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2147             else if(startcode==0x1B2) av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2148             else if(startcode==0x1B3) av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2149             else if(startcode==0x1B4) av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2150             else if(startcode==0x1B5) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2151             else if(startcode==0x1B6) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2152             else if(startcode==0x1B7) av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2153             else if(startcode==0x1B8) av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2154             else if(startcode==0x1B9) av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2155             else if(startcode==0x1BA) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2156             else if(startcode==0x1BB) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2157             else if(startcode==0x1BC) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2158             else if(startcode==0x1BD) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2159             else if(startcode==0x1BE) av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2160             else if(startcode==0x1BF) av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2161             else if(startcode==0x1C0) av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2162             else if(startcode==0x1C1) av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2163             else if(startcode==0x1C2) av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2164             else if(startcode==0x1C3) av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2165             else if(startcode<=0x1C5) av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2166             else if(startcode<=0x1FF) av_log(s->avctx, AV_LOG_DEBUG, "System start");
2167             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2168         }
2169
2170         if(startcode >= 0x120 && startcode <= 0x12F){
2171             if(decode_vol_header(s, gb) < 0)
2172                 return -1;
2173         }
2174         else if(startcode == USER_DATA_STARTCODE){
2175             decode_user_data(s, gb);
2176         }
2177         else if(startcode == GOP_STARTCODE){
2178             mpeg4_decode_gop_header(s, gb);
2179         }
2180         else if(startcode == VOS_STARTCODE){
2181             mpeg4_decode_profile_level(s, gb);
2182         }
2183         else if(startcode == VOP_STARTCODE){
2184             break;
2185         }
2186
2187         align_get_bits(gb);
2188         startcode = 0xff;
2189     }
2190 end:
2191     if(s->flags& CODEC_FLAG_LOW_DELAY)
2192         s->low_delay=1;
2193     s->avctx->has_b_frames= !s->low_delay;
2194     return decode_vop_header(s, gb);
2195 }
2196
2197 static av_cold int decode_init(AVCodecContext *avctx)
2198 {
2199     MpegEncContext *s = avctx->priv_data;
2200     int ret;
2201     static int done = 0;
2202
2203     s->divx_version=
2204     s->divx_build=
2205     s->xvid_build=
2206     s->lavc_build= -1;
2207
2208     if((ret=ff_h263_decode_init(avctx)) < 0)
2209         return ret;
2210
2211     if (!done) {
2212         done = 1;
2213
2214         ff_init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2215         ff_init_rl(&ff_rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2216         ff_init_rl(&ff_rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2217         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2218         INIT_VLC_RL(ff_rvlc_rl_inter, 1072);
2219         INIT_VLC_RL(ff_rvlc_rl_intra, 1072);
2220         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2221                  &ff_mpeg4_DCtab_lum[0][1], 2, 1,
2222                  &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2223         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2224                  &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2225                  &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2226         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2227                  &ff_sprite_trajectory_tab[0][1], 4, 2,
2228                  &ff_sprite_trajectory_tab[0][0], 4, 2, 128);
2229         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2230                  &ff_mb_type_b_tab[0][1], 2, 1,
2231                  &ff_mb_type_b_tab[0][0], 2, 1, 16);
2232     }
2233
2234     s->h263_pred = 1;
2235     s->low_delay = 0; //default, might be overriden in the vol header during header parsing
2236     s->decode_mb= mpeg4_decode_mb;
2237     s->time_increment_bits = 4; /* default value for broken headers */
2238     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2239
2240     avctx->internal->allocate_progress = 1;
2241
2242     return 0;
2243 }
2244
2245 static const AVProfile mpeg4_video_profiles[] = {
2246     { FF_PROFILE_MPEG4_SIMPLE,                    "Simple Profile" },
2247     { FF_PROFILE_MPEG4_SIMPLE_SCALABLE,           "Simple Scalable Profile" },
2248     { FF_PROFILE_MPEG4_CORE,                      "Core Profile" },
2249     { FF_PROFILE_MPEG4_MAIN,                      "Main Profile" },
2250     { FF_PROFILE_MPEG4_N_BIT,                     "N-bit Profile" },
2251     { FF_PROFILE_MPEG4_SCALABLE_TEXTURE,          "Scalable Texture Profile" },
2252     { FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION,     "Simple Face Animation Profile" },
2253     { FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE,    "Basic Animated Texture Profile" },
2254     { FF_PROFILE_MPEG4_HYBRID,                    "Hybrid Profile" },
2255     { FF_PROFILE_MPEG4_ADVANCED_REAL_TIME,        "Advanced Real Time Simple Profile" },
2256     { FF_PROFILE_MPEG4_CORE_SCALABLE,             "Code Scalable Profile" },
2257     { FF_PROFILE_MPEG4_ADVANCED_CODING,           "Advanced Coding Profile" },
2258     { FF_PROFILE_MPEG4_ADVANCED_CORE,             "Advanced Core Profile" },
2259     { FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE, "Advanced Scalable Texture Profile" },
2260     { FF_PROFILE_MPEG4_SIMPLE_STUDIO,             "Simple Studio Profile" },
2261     { FF_PROFILE_MPEG4_ADVANCED_SIMPLE,           "Advanced Simple Profile" },
2262 };
2263
2264 AVCodec ff_mpeg4_decoder = {
2265     .name                  = "mpeg4",
2266     .type                  = AVMEDIA_TYPE_VIDEO,
2267     .id                    = AV_CODEC_ID_MPEG4,
2268     .priv_data_size        = sizeof(MpegEncContext),
2269     .init                  = decode_init,
2270     .close                 = ff_h263_decode_end,
2271     .decode                = ff_h263_decode_frame,
2272     .capabilities          = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
2273                              CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2274                              CODEC_CAP_FRAME_THREADS,
2275     .flush                 = ff_mpeg_flush,
2276     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2277     .pix_fmts              = ff_h263_hwaccel_pixfmt_list_420,
2278     .profiles              = NULL_IF_CONFIG_SMALL(mpeg4_video_profiles),
2279     .update_thread_context = ONLY_IF_THREADS_ENABLED(ff_mpeg_update_thread_context),
2280 };
2281
2282
2283 #if CONFIG_MPEG4_VDPAU_DECODER
2284 AVCodec ff_mpeg4_vdpau_decoder = {
2285     .name           = "mpeg4_vdpau",
2286     .type           = AVMEDIA_TYPE_VIDEO,
2287     .id             = AV_CODEC_ID_MPEG4,
2288     .priv_data_size = sizeof(MpegEncContext),
2289     .init           = decode_init,
2290     .close          = ff_h263_decode_end,
2291     .decode         = ff_h263_decode_frame,
2292     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2293                       CODEC_CAP_HWACCEL_VDPAU,
2294     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
2295     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_VDPAU_MPEG4,
2296                                                   AV_PIX_FMT_NONE },
2297 };
2298 #endif