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