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   1 /*
   2  * MPEG4 decoder.
   3  * Copyright (c) 2000,2001 Fabrice Bellard
   4  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #define UNCHECKED_BITSTREAM_READER 1
  24
  25 #include "libavutil/opt.h"
  26 #include "error_resilience.h"
  27 #include "internal.h"
  28 #include "mpegvideo.h"
  29 #include "mpeg4video.h"
  30 #include "h263.h"
  31 #include "thread.h"
  32
  33 // The defines below define the number of bits that are read at once for
  34 // reading vlc values. Changing these may improve speed and data cache needs
  35 // be aware though that decreasing them may need the number of stages that is
  36 // passed to get_vlc* to be increased.
  37 #define SPRITE_TRAJ_VLC_BITS 6
  38 #define DC_VLC_BITS 9
  39 #define MB_TYPE_B_VLC_BITS 4
  40
  41
  42 static VLC dc_lum, dc_chrom;
  43 static VLC sprite_trajectory;
  44 static VLC mb_type_b_vlc;
  45
  46 static const int mb_type_b_map[4]= {
  47     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  48     MB_TYPE_L0L1 | MB_TYPE_16x16,
  49     MB_TYPE_L1 | MB_TYPE_16x16,
  50     MB_TYPE_L0 | MB_TYPE_16x16,
  51 };
  52
  53 /**
  54  * Predict the ac.
  55  * @param n block index (0-3 are luma, 4-5 are chroma)
  56  * @param dir the ac prediction direction
  57  */
  58 void ff_mpeg4_pred_ac(MpegEncContext * s, int16_t *block, int n,
  59                       int dir)
  60 {
  61     int i;
  62     int16_t *ac_val, *ac_val1;
  63     int8_t * const qscale_table = s->current_picture.qscale_table;
  64
  65     /* find prediction */
  66     ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
  67     ac_val1 = ac_val;
  68     if (s->ac_pred) {
  69         if (dir == 0) {
  70             const int xy= s->mb_x-1 + s->mb_y*s->mb_stride;
  71             /* left prediction */
  72             ac_val -= 16;
  73
  74             if(s->mb_x==0 || s->qscale == qscale_table[xy] || n==1 || n==3){
  75                 /* same qscale */
  76                 for(i=1;i<8;i++) {
  77                     block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
  78                 }
  79             }else{
  80                 /* different qscale, we must rescale */
  81                 for(i=1;i<8;i++) {
  82                     block[s->dsp.idct_permutation[i<<3]] += ROUNDED_DIV(ac_val[i]*qscale_table[xy], s->qscale);
  83                 }
  84             }
  85         } else {
  86             const int xy= s->mb_x + s->mb_y*s->mb_stride - s->mb_stride;
  87             /* top prediction */
  88             ac_val -= 16 * s->block_wrap[n];
  89
  90             if(s->mb_y==0 || s->qscale == qscale_table[xy] || n==2 || n==3){
  91                 /* same qscale */
  92                 for(i=1;i<8;i++) {
  93                     block[s->dsp.idct_permutation[i]] += ac_val[i + 8];
  94                 }
  95             }else{
  96                 /* different qscale, we must rescale */
  97                 for(i=1;i<8;i++) {
  98                     block[s->dsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8]*qscale_table[xy], s->qscale);
  99                 }
 100             }
 101         }
 102     }
 103     /* left copy */
 104     for(i=1;i<8;i++)
 105         ac_val1[i    ] = block[s->dsp.idct_permutation[i<<3]];
 106
 107     /* top copy */
 108     for(i=1;i<8;i++)
 109         ac_val1[8 + i] = block[s->dsp.idct_permutation[i   ]];
 110
 111 }
 112
 113 /**
 114  * check if the next stuff is a resync marker or the end.
 115  * @return 0 if not
 116  */
 117 static inline int mpeg4_is_resync(MpegEncContext *s){
 118     int bits_count= get_bits_count(&s->gb);
 119     int v= show_bits(&s->gb, 16);
 120
 121     if(s->workaround_bugs&FF_BUG_NO_PADDING && !s->resync_marker){
 122         return 0;
 123     }
 124
 125     while(v<=0xFF){
 126         if(s->pict_type==AV_PICTURE_TYPE_B || (v>>(8-s->pict_type)!=1) || s->partitioned_frame)
 127             break;
 128         skip_bits(&s->gb, 8+s->pict_type);
 129         bits_count+= 8+s->pict_type;
 130         v= show_bits(&s->gb, 16);
 131     }
 132
 133     if(bits_count + 8 >= s->gb.size_in_bits){
 134         v>>=8;
 135         v|= 0x7F >> (7-(bits_count&7));
 136
 137         if(v==0x7F)
 138             return s->mb_num;
 139     }else{
 140         if(v == ff_mpeg4_resync_prefix[bits_count&7]){
 141             int len, mb_num;
 142             int mb_num_bits= av_log2(s->mb_num - 1) + 1;
 143             GetBitContext gb= s->gb;
 144
 145             skip_bits(&s->gb, 1);
 146             align_get_bits(&s->gb);
 147
 148             for(len=0; len<32; len++){
 149                 if(get_bits1(&s->gb)) break;
 150             }
 151
 152             mb_num= get_bits(&s->gb, mb_num_bits);
 153             if(!mb_num || mb_num > s->mb_num || get_bits_count(&s->gb)+6 > s->gb.size_in_bits)
 154                 mb_num= -1;
 155
 156             s->gb= gb;
 157
 158             if(len>=ff_mpeg4_get_video_packet_prefix_length(s))
 159                 return mb_num;
 160         }
 161     }
 162     return 0;
 163 }
 164
 165 static int mpeg4_decode_sprite_trajectory(MpegEncContext *s, GetBitContext *gb)
 166 {
 167     int i;
 168     int a= 2<<s->sprite_warping_accuracy;
 169     int rho= 3-s->sprite_warping_accuracy;
 170     int r=16/a;
 171     const int vop_ref[4][2]= {{0,0}, {s->width,0}, {0, s->height}, {s->width, s->height}}; // only true for rectangle shapes
 172     int d[4][2]={{0,0}, {0,0}, {0,0}, {0,0}};
 173     int sprite_ref[4][2];
 174     int virtual_ref[2][2];
 175     int w2, h2, w3, h3;
 176     int alpha=0, beta=0;
 177     int w= s->width;
 178     int h= s->height;
 179     int min_ab;
 180
 181     if (w <= 0 || h <= 0)
 182         return AVERROR_INVALIDDATA;
 183
 184     for(i=0; i<s->num_sprite_warping_points; i++){
 185         int length;
 186         int x=0, y=0;
 187
 188         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 189         if(length){
 190             x= get_xbits(gb, length);
 191         }
 192         if(!(s->divx_version==500 && s->divx_build==413)) skip_bits1(gb); /* marker bit */
 193
 194         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 195         if(length){
 196             y=get_xbits(gb, length);
 197         }
 198         skip_bits1(gb); /* marker bit */
 199         s->sprite_traj[i][0]= d[i][0]= x;
 200         s->sprite_traj[i][1]= d[i][1]= y;
 201     }
 202     for(; i<4; i++)
 203         s->sprite_traj[i][0]= s->sprite_traj[i][1]= 0;
 204
 205     while((1<<alpha)<w) alpha++;
 206     while((1<<beta )<h) beta++; // there seems to be a typo in the mpeg4 std for the definition of w' and h'
 207     w2= 1<<alpha;
 208     h2= 1<<beta;
 209
 210 // Note, the 4th point isn't used for GMC
 211     if(s->divx_version==500 && s->divx_build==413){
 212         sprite_ref[0][0]= a*vop_ref[0][0] + d[0][0];
 213         sprite_ref[0][1]= a*vop_ref[0][1] + d[0][1];
 214         sprite_ref[1][0]= a*vop_ref[1][0] + d[0][0] + d[1][0];
 215         sprite_ref[1][1]= a*vop_ref[1][1] + d[0][1] + d[1][1];
 216         sprite_ref[2][0]= a*vop_ref[2][0] + d[0][0] + d[2][0];
 217         sprite_ref[2][1]= a*vop_ref[2][1] + d[0][1] + d[2][1];
 218     } else {
 219         sprite_ref[0][0]= (a>>1)*(2*vop_ref[0][0] + d[0][0]);
 220         sprite_ref[0][1]= (a>>1)*(2*vop_ref[0][1] + d[0][1]);
 221         sprite_ref[1][0]= (a>>1)*(2*vop_ref[1][0] + d[0][0] + d[1][0]);
 222         sprite_ref[1][1]= (a>>1)*(2*vop_ref[1][1] + d[0][1] + d[1][1]);
 223         sprite_ref[2][0]= (a>>1)*(2*vop_ref[2][0] + d[0][0] + d[2][0]);
 224         sprite_ref[2][1]= (a>>1)*(2*vop_ref[2][1] + d[0][1] + d[2][1]);
 225     }
 226 /*    sprite_ref[3][0]= (a>>1)*(2*vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
 227     sprite_ref[3][1]= (a>>1)*(2*vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
 228
 229 // this is mostly identical to the mpeg4 std (and is totally unreadable because of that ...)
 230 // perhaps it should be reordered to be more readable ...
 231 // the idea behind this virtual_ref mess is to be able to use shifts later per pixel instead of divides
 232 // so the distance between points is converted from w&h based to w2&h2 based which are of the 2^x form
 233     virtual_ref[0][0]= 16*(vop_ref[0][0] + w2)
 234         + 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);
 235     virtual_ref[0][1]= 16*vop_ref[0][1]
 236         + 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);
 237     virtual_ref[1][0]= 16*vop_ref[0][0]
 238         + 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);
 239     virtual_ref[1][1]= 16*(vop_ref[0][1] + h2)
 240         + 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);
 241
 242     switch(s->num_sprite_warping_points)
 243     {
 244         case 0:
 245             s->sprite_offset[0][0]= 0;
 246             s->sprite_offset[0][1]= 0;
 247             s->sprite_offset[1][0]= 0;
 248             s->sprite_offset[1][1]= 0;
 249             s->sprite_delta[0][0]= a;
 250             s->sprite_delta[0][1]= 0;
 251             s->sprite_delta[1][0]= 0;
 252             s->sprite_delta[1][1]= a;
 253             s->sprite_shift[0]= 0;
 254             s->sprite_shift[1]= 0;
 255             break;
 256         case 1: //GMC only
 257             s->sprite_offset[0][0]= sprite_ref[0][0] - a*vop_ref[0][0];
 258             s->sprite_offset[0][1]= sprite_ref[0][1] - a*vop_ref[0][1];
 259             s->sprite_offset[1][0]= ((sprite_ref[0][0]>>1)|(sprite_ref[0][0]&1)) - a*(vop_ref[0][0]/2);
 260             s->sprite_offset[1][1]= ((sprite_ref[0][1]>>1)|(sprite_ref[0][1]&1)) - a*(vop_ref[0][1]/2);
 261             s->sprite_delta[0][0]= a;
 262             s->sprite_delta[0][1]= 0;
 263             s->sprite_delta[1][0]= 0;
 264             s->sprite_delta[1][1]= a;
 265             s->sprite_shift[0]= 0;
 266             s->sprite_shift[1]= 0;
 267             break;
 268         case 2:
 269             s->sprite_offset[0][0]= (sprite_ref[0][0]<<(alpha+rho))
 270                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][0])
 271                                                   + ( r*sprite_ref[0][1] - virtual_ref[0][1])*(-vop_ref[0][1])
 272                                                   + (1<<(alpha+rho-1));
 273             s->sprite_offset[0][1]= (sprite_ref[0][1]<<(alpha+rho))
 274                                                   + (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-vop_ref[0][0])
 275                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][1])
 276                                                   + (1<<(alpha+rho-1));
 277             s->sprite_offset[1][0]= ( (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][0] + 1)
 278                                      +( r*sprite_ref[0][1] - virtual_ref[0][1])*(-2*vop_ref[0][1] + 1)
 279                                      +2*w2*r*sprite_ref[0][0]
 280                                      - 16*w2
 281                                      + (1<<(alpha+rho+1)));
 282             s->sprite_offset[1][1]= ( (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-2*vop_ref[0][0] + 1)
 283                                      +(-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][1] + 1)
 284                                      +2*w2*r*sprite_ref[0][1]
 285                                      - 16*w2
 286                                      + (1<<(alpha+rho+1)));
 287             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 288             s->sprite_delta[0][1]=   (+r*sprite_ref[0][1] - virtual_ref[0][1]);
 289             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1]);
 290             s->sprite_delta[1][1]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
 291
 292             s->sprite_shift[0]= alpha+rho;
 293             s->sprite_shift[1]= alpha+rho+2;
 294             break;
 295         case 3:
 296             min_ab= FFMIN(alpha, beta);
 297             w3= w2>>min_ab;
 298             h3= h2>>min_ab;
 299             s->sprite_offset[0][0]=  (sprite_ref[0][0]<<(alpha+beta+rho-min_ab))
 300                                    + (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-vop_ref[0][0])
 301                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-vop_ref[0][1])
 302                                    + (1<<(alpha+beta+rho-min_ab-1));
 303             s->sprite_offset[0][1]=  (sprite_ref[0][1]<<(alpha+beta+rho-min_ab))
 304                                    + (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-vop_ref[0][0])
 305                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-vop_ref[0][1])
 306                                    + (1<<(alpha+beta+rho-min_ab-1));
 307             s->sprite_offset[1][0]=  (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-2*vop_ref[0][0] + 1)
 308                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-2*vop_ref[0][1] + 1)
 309                                    + 2*w2*h3*r*sprite_ref[0][0]
 310                                    - 16*w2*h3
 311                                    + (1<<(alpha+beta+rho-min_ab+1));
 312             s->sprite_offset[1][1]=  (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-2*vop_ref[0][0] + 1)
 313                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-2*vop_ref[0][1] + 1)
 314                                    + 2*w2*h3*r*sprite_ref[0][1]
 315                                    - 16*w2*h3
 316                                    + (1<<(alpha+beta+rho-min_ab+1));
 317             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3;
 318             s->sprite_delta[0][1]=   (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3;
 319             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3;
 320             s->sprite_delta[1][1]=   (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3;
 321
 322             s->sprite_shift[0]= alpha + beta + rho - min_ab;
 323             s->sprite_shift[1]= alpha + beta + rho - min_ab + 2;
 324             break;
 325     }
 326     /* try to simplify the situation */
 327     if(   s->sprite_delta[0][0] == a<<s->sprite_shift[0]
 328        && s->sprite_delta[0][1] == 0
 329        && s->sprite_delta[1][0] == 0
 330        && s->sprite_delta[1][1] == a<<s->sprite_shift[0])
 331     {
 332         s->sprite_offset[0][0]>>=s->sprite_shift[0];
 333         s->sprite_offset[0][1]>>=s->sprite_shift[0];
 334         s->sprite_offset[1][0]>>=s->sprite_shift[1];
 335         s->sprite_offset[1][1]>>=s->sprite_shift[1];
 336         s->sprite_delta[0][0]= a;
 337         s->sprite_delta[0][1]= 0;
 338         s->sprite_delta[1][0]= 0;
 339         s->sprite_delta[1][1]= a;
 340         s->sprite_shift[0]= 0;
 341         s->sprite_shift[1]= 0;
 342         s->real_sprite_warping_points=1;
 343     }
 344     else{
 345         int shift_y= 16 - s->sprite_shift[0];
 346         int shift_c= 16 - s->sprite_shift[1];
 347         for(i=0; i<2; i++){
 348             s->sprite_offset[0][i]<<= shift_y;
 349             s->sprite_offset[1][i]<<= shift_c;
 350             s->sprite_delta[0][i]<<= shift_y;
 351             s->sprite_delta[1][i]<<= shift_y;
 352             s->sprite_shift[i]= 16;
 353         }
 354         s->real_sprite_warping_points= s->num_sprite_warping_points;
 355     }
 356     return 0;
 357 }
 358
 359 static int decode_new_pred(MpegEncContext *s, GetBitContext *gb){
 360     int len = FFMIN(s->time_increment_bits + 3, 15);
 361
 362     get_bits(gb, len);
 363     if (get_bits1(gb))
 364         get_bits(gb, len);
 365     check_marker(gb, "after new_pred");
 366
 367     return 0;
 368 }
 369
 370 /**
 371  * Decode the next video packet.
 372  * @return <0 if something went wrong
 373  */
 374 int ff_mpeg4_decode_video_packet_header(MpegEncContext *s)
 375 {
 376     int mb_num_bits= av_log2(s->mb_num - 1) + 1;
 377     int header_extension=0, mb_num, len;
 378
 379     /* is there enough space left for a video packet + header */
 380     if( get_bits_count(&s->gb) > s->gb.size_in_bits-20) return -1;
 381
 382     for(len=0; len<32; len++){
 383         if(get_bits1(&s->gb)) break;
 384     }
 385
 386     if(len!=ff_mpeg4_get_video_packet_prefix_length(s)){
 387         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
 388         return -1;
 389     }
 390
 391     if(s->shape != RECT_SHAPE){
 392         header_extension= get_bits1(&s->gb);
 393         //FIXME more stuff here
 394     }
 395
 396     mb_num= get_bits(&s->gb, mb_num_bits);
 397     if(mb_num>=s->mb_num){
 398         av_log(s->avctx, AV_LOG_ERROR, "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
 399         return -1;
 400     }
 401
 402     s->mb_x= mb_num % s->mb_width;
 403     s->mb_y= mb_num / s->mb_width;
 404
 405     if(s->shape != BIN_ONLY_SHAPE){
 406         int qscale= get_bits(&s->gb, s->quant_precision);
 407         if(qscale)
 408             s->chroma_qscale=s->qscale= qscale;
 409     }
 410
 411     if(s->shape == RECT_SHAPE){
 412         header_extension= get_bits1(&s->gb);
 413     }
 414     if(header_extension){
 415         int time_incr=0;
 416
 417         while (get_bits1(&s->gb) != 0)
 418             time_incr++;
 419
 420         check_marker(&s->gb, "before time_increment in video packed header");
 421         skip_bits(&s->gb, s->time_increment_bits); /* time_increment */
 422         check_marker(&s->gb, "before vop_coding_type in video packed header");
 423
 424         skip_bits(&s->gb, 2); /* vop coding type */
 425         //FIXME not rect stuff here
 426
 427         if(s->shape != BIN_ONLY_SHAPE){
 428             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
 429 //FIXME don't just ignore everything
 430             if(s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 431                 if (mpeg4_decode_sprite_trajectory(s, &s->gb) < 0)
 432                     return AVERROR_INVALIDDATA;
 433                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
 434             }
 435
 436             //FIXME reduced res stuff here
 437
 438             if (s->pict_type != AV_PICTURE_TYPE_I) {
 439                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
 440                 if(f_code==0){
 441                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (f_code=0)\n");
 442                 }
 443             }
 444             if (s->pict_type == AV_PICTURE_TYPE_B) {
 445                 int b_code = get_bits(&s->gb, 3);
 446                 if(b_code==0){
 447                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (b_code=0)\n");
 448                 }
 449             }
 450         }
 451     }
 452     if (s->new_pred)
 453         decode_new_pred(s, &s->gb);
 454
 455     return 0;
 456 }
 457
 458 /**
 459  * Get the average motion vector for a GMC MB.
 460  * @param n either 0 for the x component or 1 for y
 461  * @return the average MV for a GMC MB
 462  */
 463 static inline int get_amv(MpegEncContext *s, int n){
 464     int x, y, mb_v, sum, dx, dy, shift;
 465     int len = 1 << (s->f_code + 4);
 466     const int a= s->sprite_warping_accuracy;
 467
 468     if(s->workaround_bugs & FF_BUG_AMV)
 469         len >>= s->quarter_sample;
 470
 471     if(s->real_sprite_warping_points==1){
 472         if(s->divx_version==500 && s->divx_build==413)
 473             sum= s->sprite_offset[0][n] / (1<<(a - s->quarter_sample));
 474         else
 475             sum= RSHIFT(s->sprite_offset[0][n]<<s->quarter_sample, a);
 476     }else{
 477         dx= s->sprite_delta[n][0];
 478         dy= s->sprite_delta[n][1];
 479         shift= s->sprite_shift[0];
 480         if(n) dy -= 1<<(shift + a + 1);
 481         else  dx -= 1<<(shift + a + 1);
 482         mb_v= s->sprite_offset[0][n] + dx*s->mb_x*16 + dy*s->mb_y*16;
 483
 484         sum=0;
 485         for(y=0; y<16; y++){
 486             int v;
 487
 488             v= mb_v + dy*y;
 489             //XXX FIXME optimize
 490             for(x=0; x<16; x++){
 491                 sum+= v>>shift;
 492                 v+= dx;
 493             }
 494         }
 495         sum= RSHIFT(sum, a+8-s->quarter_sample);
 496     }
 497
 498     if      (sum < -len) sum= -len;
 499     else if (sum >= len) sum= len-1;
 500
 501     return sum;
 502 }
 503
 504 /**
 505  * Decode the dc value.
 506  * @param n block index (0-3 are luma, 4-5 are chroma)
 507  * @param dir_ptr the prediction direction will be stored here
 508  * @return the quantized dc
 509  */
 510 static inline int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
 511 {
 512     int level, code;
 513
 514     if (n < 4)
 515         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
 516     else
 517         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
 518     if (code < 0 || code > 9 /* && s->nbit<9 */){
 519         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
 520         return -1;
 521     }
 522     if (code == 0) {
 523         level = 0;
 524     } else {
 525         if(IS_3IV1){
 526             if(code==1)
 527                 level= 2*get_bits1(&s->gb)-1;
 528             else{
 529                 if(get_bits1(&s->gb))
 530                     level = get_bits(&s->gb, code-1) + (1<<(code-1));
 531                 else
 532                     level = -get_bits(&s->gb, code-1) - (1<<(code-1));
 533             }
 534         }else{
 535             level = get_xbits(&s->gb, code);
 536         }
 537
 538         if (code > 8){
 539             if(get_bits1(&s->gb)==0){ /* marker */
 540                 if(s->err_recognition&(AV_EF_BITSTREAM|AV_EF_COMPLIANT)){
 541                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
 542                     return -1;
 543                 }
 544             }
 545         }
 546     }
 547
 548     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
 549 }
 550
 551 /**
 552  * Decode first partition.
 553  * @return number of MBs decoded or <0 if an error occurred
 554  */
 555 static int mpeg4_decode_partition_a(MpegEncContext *s){
 556     int mb_num;
 557     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 558
 559     /* decode first partition */
 560     mb_num=0;
 561     s->first_slice_line=1;
 562     for(; s->mb_y<s->mb_height; s->mb_y++){
 563         ff_init_block_index(s);
 564         for(; s->mb_x<s->mb_width; s->mb_x++){
 565             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 566             int cbpc;
 567             int dir=0;
 568
 569             mb_num++;
 570             ff_update_block_index(s);
 571             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 572                 s->first_slice_line=0;
 573
 574             if(s->pict_type==AV_PICTURE_TYPE_I){
 575                 int i;
 576
 577                 do{
 578                     if(show_bits_long(&s->gb, 19)==DC_MARKER){
 579                         return mb_num-1;
 580                     }
 581
 582                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 583                     if (cbpc < 0){
 584                         av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 585                         return -1;
 586                     }
 587                 }while(cbpc == 8);
 588
 589                 s->cbp_table[xy]= cbpc & 3;
 590                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 591                 s->mb_intra = 1;
 592
 593                 if(cbpc & 4) {
 594                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 595                 }
 596                 s->current_picture.qscale_table[xy]= s->qscale;
 597
 598                 s->mbintra_table[xy]= 1;
 599                 for(i=0; i<6; i++){
 600                     int dc_pred_dir;
 601                     int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 602                     if(dc < 0){
 603                         av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 604                         return -1;
 605                     }
 606                     dir<<=1;
 607                     if(dc_pred_dir) dir|=1;
 608                 }
 609                 s->pred_dir_table[xy]= dir;
 610             }else{ /* P/S_TYPE */
 611                 int mx, my, pred_x, pred_y, bits;
 612                 int16_t * const mot_val = s->current_picture.motion_val[0][s->block_index[0]];
 613                 const int stride= s->b8_stride*2;
 614
 615 try_again:
 616                 bits= show_bits(&s->gb, 17);
 617                 if(bits==MOTION_MARKER){
 618                     return mb_num-1;
 619                 }
 620                 skip_bits1(&s->gb);
 621                 if(bits&0x10000){
 622                     /* skip mb */
 623                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
 624                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 625                         mx= get_amv(s, 0);
 626                         my= get_amv(s, 1);
 627                     }else{
 628                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
 629                         mx=my=0;
 630                     }
 631                     mot_val[0       ]= mot_val[2       ]=
 632                     mot_val[0+stride]= mot_val[2+stride]= mx;
 633                     mot_val[1       ]= mot_val[3       ]=
 634                     mot_val[1+stride]= mot_val[3+stride]= my;
 635
 636                     if(s->mbintra_table[xy])
 637                         ff_clean_intra_table_entries(s);
 638                     continue;
 639                 }
 640
 641                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 642                 if (cbpc < 0){
 643                     av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 644                     return -1;
 645                 }
 646                 if(cbpc == 20)
 647                     goto try_again;
 648
 649                 s->cbp_table[xy]= cbpc&(8+3); //8 is dquant
 650
 651                 s->mb_intra = ((cbpc & 4) != 0);
 652
 653                 if(s->mb_intra){
 654                     s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 655                     s->mbintra_table[xy]= 1;
 656                     mot_val[0       ]= mot_val[2       ]=
 657                     mot_val[0+stride]= mot_val[2+stride]= 0;
 658                     mot_val[1       ]= mot_val[3       ]=
 659                     mot_val[1+stride]= mot_val[3+stride]= 0;
 660                 }else{
 661                     if(s->mbintra_table[xy])
 662                         ff_clean_intra_table_entries(s);
 663
 664                     if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
 665                         s->mcsel= get_bits1(&s->gb);
 666                     else s->mcsel= 0;
 667
 668                     if ((cbpc & 16) == 0) {
 669                         /* 16x16 motion prediction */
 670
 671                         ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 672                         if(!s->mcsel){
 673                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
 674                             if (mx >= 0xffff)
 675                                 return -1;
 676
 677                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
 678                             if (my >= 0xffff)
 679                                 return -1;
 680                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
 681                         } else {
 682                             mx = get_amv(s, 0);
 683                             my = get_amv(s, 1);
 684                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
 685                         }
 686
 687                         mot_val[0       ]= mot_val[2       ] =
 688                         mot_val[0+stride]= mot_val[2+stride]= mx;
 689                         mot_val[1       ]= mot_val[3       ]=
 690                         mot_val[1+stride]= mot_val[3+stride]= my;
 691                     } else {
 692                         int i;
 693                         s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
 694                         for(i=0;i<4;i++) {
 695                             int16_t *mot_val= ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 696                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
 697                             if (mx >= 0xffff)
 698                                 return -1;
 699
 700                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
 701                             if (my >= 0xffff)
 702                                 return -1;
 703                             mot_val[0] = mx;
 704                             mot_val[1] = my;
 705                         }
 706                     }
 707                 }
 708             }
 709         }
 710         s->mb_x= 0;
 711     }
 712
 713     return mb_num;
 714 }
 715
 716 /**
 717  * decode second partition.
 718  * @return <0 if an error occurred
 719  */
 720 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count){
 721     int mb_num=0;
 722     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 723
 724     s->mb_x= s->resync_mb_x;
 725     s->first_slice_line=1;
 726     for(s->mb_y= s->resync_mb_y; mb_num < mb_count; s->mb_y++){
 727         ff_init_block_index(s);
 728         for(; mb_num < mb_count && s->mb_x<s->mb_width; s->mb_x++){
 729             const int xy= s->mb_x + s->mb_y*s->mb_stride;
 730
 731             mb_num++;
 732             ff_update_block_index(s);
 733             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
 734                 s->first_slice_line=0;
 735
 736             if(s->pict_type==AV_PICTURE_TYPE_I){
 737                 int ac_pred= get_bits1(&s->gb);
 738                 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 739                 if(cbpy<0){
 740                     av_log(s->avctx, AV_LOG_ERROR, "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 741                     return -1;
 742                 }
 743
 744                 s->cbp_table[xy]|= cbpy<<2;
 745                 s->current_picture.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 746             }else{ /* P || S_TYPE */
 747                 if (IS_INTRA(s->current_picture.mb_type[xy])) {
 748                     int dir=0,i;
 749                     int ac_pred = get_bits1(&s->gb);
 750                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 751
 752                     if(cbpy<0){
 753                         av_log(s->avctx, AV_LOG_ERROR, "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 754                         return -1;
 755                     }
 756
 757                     if(s->cbp_table[xy] & 8) {
 758                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 759                     }
 760                     s->current_picture.qscale_table[xy] = s->qscale;
 761
 762                     for(i=0; i<6; i++){
 763                         int dc_pred_dir;
 764                         int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
 765                         if(dc < 0){
 766                             av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 767                             return -1;
 768                         }
 769                         dir<<=1;
 770                         if(dc_pred_dir) dir|=1;
 771                     }
 772                     s->cbp_table[xy]&= 3; //remove dquant
 773                     s->cbp_table[xy]|= cbpy<<2;
 774                     s->current_picture.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
 775                     s->pred_dir_table[xy]= dir;
 776                 } else if (IS_SKIP(s->current_picture.mb_type[xy])) {
 777                     s->current_picture.qscale_table[xy] = s->qscale;
 778                     s->cbp_table[xy]= 0;
 779                 }else{
 780                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 781
 782                     if(cbpy<0){
 783                         av_log(s->avctx, AV_LOG_ERROR, "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 784                         return -1;
 785                     }
 786
 787                     if(s->cbp_table[xy] & 8) {
 788                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 789                     }
 790                     s->current_picture.qscale_table[xy] = s->qscale;
 791
 792                     s->cbp_table[xy]&= 3; //remove dquant
 793                     s->cbp_table[xy]|= (cbpy^0xf)<<2;
 794                 }
 795             }
 796         }
 797         if(mb_num >= mb_count) return 0;
 798         s->mb_x= 0;
 799     }
 800     return 0;
 801 }
 802
 803 /**
 804  * Decode the first and second partition.
 805  * @return <0 if error (and sets error type in the error_status_table)
 806  */
 807 int ff_mpeg4_decode_partitions(MpegEncContext *s)
 808 {
 809     int mb_num;
 810     const int part_a_error= s->pict_type==AV_PICTURE_TYPE_I ? (ER_DC_ERROR|ER_MV_ERROR) : ER_MV_ERROR;
 811     const int part_a_end  = s->pict_type==AV_PICTURE_TYPE_I ? (ER_DC_END  |ER_MV_END)   : ER_MV_END;
 812
 813     mb_num= mpeg4_decode_partition_a(s);
 814     if(mb_num<0){
 815         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 816         return -1;
 817     }
 818
 819     if(s->resync_mb_x + s->resync_mb_y*s->mb_width + mb_num > s->mb_num){
 820         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
 821         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
 822         return -1;
 823     }
 824
 825     s->mb_num_left= mb_num;
 826
 827     if(s->pict_type==AV_PICTURE_TYPE_I){
 828         while(show_bits(&s->gb, 9) == 1)
 829             skip_bits(&s->gb, 9);
 830         if(get_bits_long(&s->gb, 19)!=DC_MARKER){
 831             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first I partition at %d %d\n", s->mb_x, s->mb_y);
 832             return -1;
 833         }
 834     }else{
 835         while(show_bits(&s->gb, 10) == 1)
 836             skip_bits(&s->gb, 10);
 837         if(get_bits(&s->gb, 17)!=MOTION_MARKER){
 838             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first P partition at %d %d\n", s->mb_x, s->mb_y);
 839             return -1;
 840         }
 841     }
 842     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, part_a_end);
 843
 844     if( mpeg4_decode_partition_b(s, mb_num) < 0){
 845         if(s->pict_type==AV_PICTURE_TYPE_P)
 846             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_DC_ERROR);
 847         return -1;
 848     }else{
 849         if(s->pict_type==AV_PICTURE_TYPE_P)
 850             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_DC_END);
 851     }
 852
 853     return 0;
 854 }
 855
 856 /**
 857  * Decode a block.
 858  * @return <0 if an error occurred
 859  */
 860 static inline int mpeg4_decode_block(MpegEncContext * s, int16_t * block,
 861                               int n, int coded, int intra, int rvlc)
 862 {
 863     int level, i, last, run;
 864     int av_uninit(dc_pred_dir);
 865     RLTable * rl;
 866     RL_VLC_ELEM * rl_vlc;
 867     const uint8_t * scan_table;
 868     int qmul, qadd;
 869
 870     //Note intra & rvlc should be optimized away if this is inlined
 871
 872     if(intra) {
 873       if(s->use_intra_dc_vlc){
 874         /* DC coef */
 875         if(s->partitioned_frame){
 876             level = s->dc_val[0][ s->block_index[n] ];
 877             if(n<4) level= FASTDIV((level + (s->y_dc_scale>>1)), s->y_dc_scale);
 878             else    level= FASTDIV((level + (s->c_dc_scale>>1)), s->c_dc_scale);
 879             dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_stride]<<n)&32;
 880         }else{
 881             level = mpeg4_decode_dc(s, n, &dc_pred_dir);
 882             if (level < 0)
 883                 return -1;
 884         }
 885         block[0] = level;
 886         i = 0;
 887       }else{
 888             i = -1;
 889             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
 890       }
 891       if (!coded)
 892           goto not_coded;
 893
 894       if(rvlc){
 895           rl = &ff_rvlc_rl_intra;
 896           rl_vlc = ff_rvlc_rl_intra.rl_vlc[0];
 897       }else{
 898           rl = &ff_mpeg4_rl_intra;
 899           rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
 900       }
 901       if (s->ac_pred) {
 902           if (dc_pred_dir == 0)
 903               scan_table = s->intra_v_scantable.permutated; /* left */
 904           else
 905               scan_table = s->intra_h_scantable.permutated; /* top */
 906       } else {
 907             scan_table = s->intra_scantable.permutated;
 908       }
 909       qmul=1;
 910       qadd=0;
 911     } else {
 912         i = -1;
 913         if (!coded) {
 914             s->block_last_index[n] = i;
 915             return 0;
 916         }
 917         if(rvlc) rl = &ff_rvlc_rl_inter;
 918         else     rl = &ff_h263_rl_inter;
 919
 920         scan_table = s->intra_scantable.permutated;
 921
 922         if(s->mpeg_quant){
 923             qmul=1;
 924             qadd=0;
 925             if(rvlc){
 926                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[0];
 927             }else{
 928                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
 929             }
 930         }else{
 931             qmul = s->qscale << 1;
 932             qadd = (s->qscale - 1) | 1;
 933             if(rvlc){
 934                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[s->qscale];
 935             }else{
 936                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
 937             }
 938         }
 939     }
 940   {
 941     OPEN_READER(re, &s->gb);
 942     for(;;) {
 943         UPDATE_CACHE(re, &s->gb);
 944         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
 945         if (level==0) {
 946           /* escape */
 947           if(rvlc){
 948                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 949                     av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in rvlc esc\n");
 950                     return -1;
 951                 }; SKIP_CACHE(re, &s->gb, 1);
 952
 953                 last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 954                 run=   SHOW_UBITS(re, &s->gb, 6);
 955                 SKIP_COUNTER(re, &s->gb, 1+1+6);
 956                 UPDATE_CACHE(re, &s->gb);
 957
 958                 if(SHOW_UBITS(re, &s->gb, 1)==0){
 959                     av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in rvlc esc\n");
 960                     return -1;
 961                 }; SKIP_CACHE(re, &s->gb, 1);
 962
 963                 level= SHOW_UBITS(re, &s->gb, 11); SKIP_CACHE(re, &s->gb, 11);
 964
 965                 if(SHOW_UBITS(re, &s->gb, 5)!=0x10){
 966                     av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
 967                     return -1;
 968                 }; SKIP_CACHE(re, &s->gb, 5);
 969
 970                 level=  level * qmul + qadd;
 971                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 972                 SKIP_COUNTER(re, &s->gb, 1+11+5+1);
 973
 974                 i+= run + 1;
 975                 if(last) i+=192;
 976           }else{
 977             int cache;
 978             cache= GET_CACHE(re, &s->gb);
 979
 980             if(IS_3IV1)
 981                 cache ^= 0xC0000000;
 982
 983             if (cache&0x80000000) {
 984                 if (cache&0x40000000) {
 985                     /* third escape */
 986                     SKIP_CACHE(re, &s->gb, 2);
 987                     last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
 988                     run=   SHOW_UBITS(re, &s->gb, 6);
 989                     SKIP_COUNTER(re, &s->gb, 2+1+6);
 990                     UPDATE_CACHE(re, &s->gb);
 991
 992                     if(IS_3IV1){
 993                         level= SHOW_SBITS(re, &s->gb, 12); LAST_SKIP_BITS(re, &s->gb, 12);
 994                     }else{
 995                         if(SHOW_UBITS(re, &s->gb, 1)==0){
 996                             av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in 3. esc\n");
 997                             return -1;
 998                         }; SKIP_CACHE(re, &s->gb, 1);
 999
1000                         level= SHOW_SBITS(re, &s->gb, 12); SKIP_CACHE(re, &s->gb, 12);
1001
1002                         if(SHOW_UBITS(re, &s->gb, 1)==0){
1003                             av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in 3. esc\n");
1004                             return -1;
1005                         }
1006
1007                         SKIP_COUNTER(re, &s->gb, 1+12+1);
1008                     }
1009
1010 #if 0
1011                     if(s->error_recognition >= FF_ER_COMPLIANT){
1012                         const int abs_level= FFABS(level);
1013                         if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
1014                             const int run1= run - rl->max_run[last][abs_level] - 1;
1015                             if(abs_level <= rl->max_level[last][run]){
1016                                 av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
1017                                 return -1;
1018                             }
1019                             if(s->error_recognition > FF_ER_COMPLIANT){
1020                                 if(abs_level <= rl->max_level[last][run]*2){
1021                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
1022                                     return -1;
1023                                 }
1024                                 if(run1 >= 0 && abs_level <= rl->max_level[last][run1]){
1025                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
1026                                     return -1;
1027                                 }
1028                             }
1029                         }
1030                     }
1031 #endif
1032                     if (level>0) level= level * qmul + qadd;
1033                     else         level= level * qmul - qadd;
1034
1035                     if((unsigned)(level + 2048) > 4095){
1036                         if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_AGGRESSIVE)){
1037                             if(level > 2560 || level<-2560){
1038                                 av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
1039                                 return -1;
1040                             }
1041                         }
1042                         level= level<0 ? -2048 : 2047;
1043                     }
1044
1045                     i+= run + 1;
1046                     if(last) i+=192;
1047                 } else {
1048                     /* second escape */
1049                     SKIP_BITS(re, &s->gb, 2);
1050                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1051                     i+= run + rl->max_run[run>>7][level/qmul] +1; //FIXME opt indexing
1052                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1053                     LAST_SKIP_BITS(re, &s->gb, 1);
1054                 }
1055             } else {
1056                 /* first escape */
1057                 SKIP_BITS(re, &s->gb, 1);
1058                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1059                 i+= run;
1060                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
1061                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1062                 LAST_SKIP_BITS(re, &s->gb, 1);
1063             }
1064           }
1065         } else {
1066             i+= run;
1067             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1068             LAST_SKIP_BITS(re, &s->gb, 1);
1069         }
1070         if (i > 62){
1071             i-= 192;
1072             if(i&(~63)){
1073                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1074                 return -1;
1075             }
1076
1077             block[scan_table[i]] = level;
1078             break;
1079         }
1080
1081         block[scan_table[i]] = level;
1082     }
1083     CLOSE_READER(re, &s->gb);
1084   }
1085  not_coded:
1086     if (intra) {
1087         if(!s->use_intra_dc_vlc){
1088             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1089
1090             i -= i>>31; //if(i == -1) i=0;
1091         }
1092
1093         ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
1094         if (s->ac_pred) {
1095             i = 63; /* XXX: not optimal */
1096         }
1097     }
1098     s->block_last_index[n] = i;
1099     return 0;
1100 }
1101
1102 /**
1103  * decode partition C of one MB.
1104  * @return <0 if an error occurred
1105  */
1106 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, int16_t block[6][64])
1107 {
1108     int cbp, mb_type;
1109     const int xy= s->mb_x + s->mb_y*s->mb_stride;
1110
1111     mb_type = s->current_picture.mb_type[xy];
1112     cbp = s->cbp_table[xy];
1113
1114     s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1115
1116     if (s->current_picture.qscale_table[xy] != s->qscale) {
1117         ff_set_qscale(s, s->current_picture.qscale_table[xy]);
1118     }
1119
1120     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1121         int i;
1122         for(i=0; i<4; i++){
1123             s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0];
1124             s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1];
1125         }
1126         s->mb_intra = IS_INTRA(mb_type);
1127
1128         if (IS_SKIP(mb_type)) {
1129             /* skip mb */
1130             for(i=0;i<6;i++)
1131                 s->block_last_index[i] = -1;
1132             s->mv_dir = MV_DIR_FORWARD;
1133             s->mv_type = MV_TYPE_16X16;
1134             if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1135                 s->mcsel=1;
1136                 s->mb_skipped = 0;
1137             }else{
1138                 s->mcsel=0;
1139                 s->mb_skipped = 1;
1140             }
1141         }else if(s->mb_intra){
1142             s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1143         }else if(!s->mb_intra){
1144 //            s->mcsel= 0; //FIXME do we need to init that
1145
1146             s->mv_dir = MV_DIR_FORWARD;
1147             if (IS_8X8(mb_type)) {
1148                 s->mv_type = MV_TYPE_8X8;
1149             } else {
1150                 s->mv_type = MV_TYPE_16X16;
1151             }
1152         }
1153     } else { /* I-Frame */
1154         s->mb_intra = 1;
1155         s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1156     }
1157
1158     if (!IS_SKIP(mb_type)) {
1159         int i;
1160         s->dsp.clear_blocks(s->block[0]);
1161         /* decode each block */
1162         for (i = 0; i < 6; i++) {
1163             if(mpeg4_decode_block(s, block[i], i, cbp&32, s->mb_intra, s->rvlc) < 0){
1164                 av_log(s->avctx, AV_LOG_ERROR, "texture corrupted at %d %d %d\n", s->mb_x, s->mb_y, s->mb_intra);
1165                 return -1;
1166             }
1167             cbp+=cbp;
1168         }
1169     }
1170
1171     /* per-MB end of slice check */
1172
1173     if(--s->mb_num_left <= 0){
1174         if(mpeg4_is_resync(s))
1175             return SLICE_END;
1176         else
1177             return SLICE_NOEND;
1178     }else{
1179         if(mpeg4_is_resync(s)){
1180             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1181             if(s->cbp_table[xy+delta])
1182                 return SLICE_END;
1183         }
1184         return SLICE_OK;
1185     }
1186 }
1187
1188 static int mpeg4_decode_mb(MpegEncContext *s,
1189                       int16_t block[6][64])
1190 {
1191     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1192     int16_t *mot_val;
1193     static int8_t quant_tab[4] = { -1, -2, 1, 2 };
1194     const int xy= s->mb_x + s->mb_y * s->mb_stride;
1195
1196     av_assert2(s->h263_pred);
1197
1198     if (s->pict_type == AV_PICTURE_TYPE_P || s->pict_type==AV_PICTURE_TYPE_S) {
1199         do{
1200             if (get_bits1(&s->gb)) {
1201                 /* skip mb */
1202                 s->mb_intra = 0;
1203                 for(i=0;i<6;i++)
1204                     s->block_last_index[i] = -1;
1205                 s->mv_dir = MV_DIR_FORWARD;
1206                 s->mv_type = MV_TYPE_16X16;
1207                 if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE){
1208                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1209                     s->mcsel=1;
1210                     s->mv[0][0][0]= get_amv(s, 0);
1211                     s->mv[0][0][1]= get_amv(s, 1);
1212
1213                     s->mb_skipped = 0;
1214                 }else{
1215                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1216                     s->mcsel=0;
1217                     s->mv[0][0][0] = 0;
1218                     s->mv[0][0][1] = 0;
1219                     s->mb_skipped = 1;
1220                 }
1221                 goto end;
1222             }
1223             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1224             if (cbpc < 0){
1225                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1226                 return -1;
1227             }
1228         }while(cbpc == 20);
1229
1230         s->dsp.clear_blocks(s->block[0]);
1231         dquant = cbpc & 8;
1232         s->mb_intra = ((cbpc & 4) != 0);
1233         if (s->mb_intra) goto intra;
1234
1235         if(s->pict_type==AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
1236             s->mcsel= get_bits1(&s->gb);
1237         else s->mcsel= 0;
1238         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1239
1240         cbp = (cbpc & 3) | (cbpy << 2);
1241         if (dquant) {
1242             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1243         }
1244         if((!s->progressive_sequence) && (cbp || (s->workaround_bugs&FF_BUG_XVID_ILACE)))
1245             s->interlaced_dct= get_bits1(&s->gb);
1246
1247         s->mv_dir = MV_DIR_FORWARD;
1248         if ((cbpc & 16) == 0) {
1249             if(s->mcsel){
1250                 s->current_picture.mb_type[xy] = MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
1251                 /* 16x16 global motion prediction */
1252                 s->mv_type = MV_TYPE_16X16;
1253                 mx= get_amv(s, 0);
1254                 my= get_amv(s, 1);
1255                 s->mv[0][0][0] = mx;
1256                 s->mv[0][0][1] = my;
1257             }else if((!s->progressive_sequence) && get_bits1(&s->gb)){
1258                 s->current_picture.mb_type[xy] = MB_TYPE_16x8 | MB_TYPE_L0 | MB_TYPE_INTERLACED;
1259                 /* 16x8 field motion prediction */
1260                 s->mv_type= MV_TYPE_FIELD;
1261
1262                 s->field_select[0][0]= get_bits1(&s->gb);
1263                 s->field_select[0][1]= get_bits1(&s->gb);
1264
1265                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1266
1267                 for(i=0; i<2; i++){
1268                     mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1269                     if (mx >= 0xffff)
1270                         return -1;
1271
1272                     my = ff_h263_decode_motion(s, pred_y/2, s->f_code);
1273                     if (my >= 0xffff)
1274                         return -1;
1275
1276                     s->mv[0][i][0] = mx;
1277                     s->mv[0][i][1] = my;
1278                 }
1279             }else{
1280                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1281                 /* 16x16 motion prediction */
1282                 s->mv_type = MV_TYPE_16X16;
1283                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1284                 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1285
1286                 if (mx >= 0xffff)
1287                     return -1;
1288
1289                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1290
1291                 if (my >= 0xffff)
1292                     return -1;
1293                 s->mv[0][0][0] = mx;
1294                 s->mv[0][0][1] = my;
1295             }
1296         } else {
1297             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1298             s->mv_type = MV_TYPE_8X8;
1299             for(i=0;i<4;i++) {
1300                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1301                 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1302                 if (mx >= 0xffff)
1303                     return -1;
1304
1305                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1306                 if (my >= 0xffff)
1307                     return -1;
1308                 s->mv[0][i][0] = mx;
1309                 s->mv[0][i][1] = my;
1310                 mot_val[0] = mx;
1311                 mot_val[1] = my;
1312             }
1313         }
1314     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
1315         int modb1; // first bit of modb
1316         int modb2; // second bit of modb
1317         int mb_type;
1318
1319         s->mb_intra = 0; //B-frames never contain intra blocks
1320         s->mcsel=0;      //     ...               true gmc blocks
1321
1322         if(s->mb_x==0){
1323             for(i=0; i<2; i++){
1324                 s->last_mv[i][0][0]=
1325                 s->last_mv[i][0][1]=
1326                 s->last_mv[i][1][0]=
1327                 s->last_mv[i][1][1]= 0;
1328             }
1329
1330             ff_thread_await_progress(&s->next_picture_ptr->tf, s->mb_y, 0);
1331         }
1332
1333         /* if we skipped it in the future P Frame than skip it now too */
1334         s->mb_skipped = s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x]; // Note, skiptab=0 if last was GMC
1335
1336         if(s->mb_skipped){
1337                 /* skip mb */
1338             for(i=0;i<6;i++)
1339                 s->block_last_index[i] = -1;
1340
1341             s->mv_dir = MV_DIR_FORWARD;
1342             s->mv_type = MV_TYPE_16X16;
1343             s->mv[0][0][0] = 0;
1344             s->mv[0][0][1] = 0;
1345             s->mv[1][0][0] = 0;
1346             s->mv[1][0][1] = 0;
1347             s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
1348             goto end;
1349         }
1350
1351         modb1= get_bits1(&s->gb);
1352         if(modb1){
1353             mb_type= MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1; //like MB_TYPE_B_DIRECT but no vectors coded
1354             cbp=0;
1355         }else{
1356             modb2= get_bits1(&s->gb);
1357             mb_type= get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1358             if(mb_type<0){
1359                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1360                 return -1;
1361             }
1362             mb_type= mb_type_b_map[ mb_type ];
1363             if(modb2) cbp= 0;
1364             else{
1365                 s->dsp.clear_blocks(s->block[0]);
1366                 cbp= get_bits(&s->gb, 6);
1367             }
1368
1369             if ((!IS_DIRECT(mb_type)) && cbp) {
1370                 if(get_bits1(&s->gb)){
1371                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb)*4 - 2);
1372                 }
1373             }
1374
1375             if(!s->progressive_sequence){
1376                 if(cbp)
1377                     s->interlaced_dct= get_bits1(&s->gb);
1378
1379                 if(!IS_DIRECT(mb_type) && get_bits1(&s->gb)){
1380                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1381                     mb_type &= ~MB_TYPE_16x16;
1382
1383                     if(USES_LIST(mb_type, 0)){
1384                         s->field_select[0][0]= get_bits1(&s->gb);
1385                         s->field_select[0][1]= get_bits1(&s->gb);
1386                     }
1387                     if(USES_LIST(mb_type, 1)){
1388                         s->field_select[1][0]= get_bits1(&s->gb);
1389                         s->field_select[1][1]= get_bits1(&s->gb);
1390                     }
1391                 }
1392             }
1393
1394             s->mv_dir = 0;
1395             if((mb_type & (MB_TYPE_DIRECT2|MB_TYPE_INTERLACED)) == 0){
1396                 s->mv_type= MV_TYPE_16X16;
1397
1398                 if(USES_LIST(mb_type, 0)){
1399                     s->mv_dir = MV_DIR_FORWARD;
1400
1401                     mx = ff_h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1402                     my = ff_h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1403                     s->last_mv[0][1][0]= s->last_mv[0][0][0]= s->mv[0][0][0] = mx;
1404                     s->last_mv[0][1][1]= s->last_mv[0][0][1]= s->mv[0][0][1] = my;
1405                 }
1406
1407                 if(USES_LIST(mb_type, 1)){
1408                     s->mv_dir |= MV_DIR_BACKWARD;
1409
1410                     mx = ff_h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1411                     my = ff_h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1412                     s->last_mv[1][1][0]= s->last_mv[1][0][0]= s->mv[1][0][0] = mx;
1413                     s->last_mv[1][1][1]= s->last_mv[1][0][1]= s->mv[1][0][1] = my;
1414                 }
1415             }else if(!IS_DIRECT(mb_type)){
1416                 s->mv_type= MV_TYPE_FIELD;
1417
1418                 if(USES_LIST(mb_type, 0)){
1419                     s->mv_dir = MV_DIR_FORWARD;
1420
1421                     for(i=0; i<2; i++){
1422                         mx = ff_h263_decode_motion(s, s->last_mv[0][i][0]  , s->f_code);
1423                         my = ff_h263_decode_motion(s, s->last_mv[0][i][1]/2, s->f_code);
1424                         s->last_mv[0][i][0]=  s->mv[0][i][0] = mx;
1425                         s->last_mv[0][i][1]= (s->mv[0][i][1] = my)*2;
1426                     }
1427                 }
1428
1429                 if(USES_LIST(mb_type, 1)){
1430                     s->mv_dir |= MV_DIR_BACKWARD;
1431
1432                     for(i=0; i<2; i++){
1433                         mx = ff_h263_decode_motion(s, s->last_mv[1][i][0]  , s->b_code);
1434                         my = ff_h263_decode_motion(s, s->last_mv[1][i][1]/2, s->b_code);
1435                         s->last_mv[1][i][0]=  s->mv[1][i][0] = mx;
1436                         s->last_mv[1][i][1]= (s->mv[1][i][1] = my)*2;
1437                     }
1438                 }
1439             }
1440         }
1441
1442         if(IS_DIRECT(mb_type)){
1443             if(IS_SKIP(mb_type))
1444                 mx=my=0;
1445             else{
1446                 mx = ff_h263_decode_motion(s, 0, 1);
1447                 my = ff_h263_decode_motion(s, 0, 1);
1448             }
1449
1450             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1451             mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
1452         }
1453         s->current_picture.mb_type[xy] = mb_type;
1454     } else { /* I-Frame */
1455         do{
1456             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1457             if (cbpc < 0){
1458                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1459                 return -1;
1460             }
1461         }while(cbpc == 8);
1462
1463         dquant = cbpc & 4;
1464         s->mb_intra = 1;
1465 intra:
1466         s->ac_pred = get_bits1(&s->gb);
1467         if(s->ac_pred)
1468             s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1469         else
1470             s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
1471
1472         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1473         if(cbpy<0){
1474             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1475             return -1;
1476         }
1477         cbp = (cbpc & 3) | (cbpy << 2);
1478
1479         s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
1480
1481         if (dquant) {
1482             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1483         }
1484
1485         if(!s->progressive_sequence)
1486             s->interlaced_dct= get_bits1(&s->gb);
1487
1488         s->dsp.clear_blocks(s->block[0]);
1489         /* decode each block */
1490         for (i = 0; i < 6; i++) {
1491             if (mpeg4_decode_block(s, block[i], i, cbp&32, 1, 0) < 0)
1492                 return -1;
1493             cbp+=cbp;
1494         }
1495         goto end;
1496     }
1497
1498     /* decode each block */
1499     for (i = 0; i < 6; i++) {
1500         if (mpeg4_decode_block(s, block[i], i, cbp&32, 0, 0) < 0)
1501             return -1;
1502         cbp+=cbp;
1503     }
1504 end:
1505
1506         /* per-MB end of slice check */
1507     if(s->codec_id==AV_CODEC_ID_MPEG4){
1508         int next= mpeg4_is_resync(s);
1509         if(next) {
1510             if        (s->mb_x + s->mb_y*s->mb_width + 1 >  next && (s->avctx->err_recognition & AV_EF_AGGRESSIVE)) {
1511                 return -1;
1512             } else if (s->mb_x + s->mb_y*s->mb_width + 1 >= next)
1513                 return SLICE_END;
1514
1515             if(s->pict_type==AV_PICTURE_TYPE_B){
1516                 const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1517                 ff_thread_await_progress(&s->next_picture_ptr->tf,
1518                                         (s->mb_x + delta >= s->mb_width) ? FFMIN(s->mb_y+1, s->mb_height-1) : s->mb_y, 0);
1519                 if (s->next_picture.mbskip_table[xy + delta])
1520                     return SLICE_OK;
1521             }
1522
1523             return SLICE_END;
1524         }
1525     }
1526
1527     return SLICE_OK;
1528 }
1529
1530
1531 static int mpeg4_decode_gop_header(MpegEncContext * s, GetBitContext *gb){
1532     int hours, minutes, seconds;
1533
1534     if(!show_bits(gb, 23)){
1535         av_log(s->avctx, AV_LOG_WARNING, "GOP header invalid\n");
1536         return -1;
1537     }
1538
1539     hours= get_bits(gb, 5);
1540     minutes= get_bits(gb, 6);
1541     skip_bits1(gb);
1542     seconds= get_bits(gb, 6);
1543
1544     s->time_base= seconds + 60*(minutes + 60*hours);
1545
1546     skip_bits1(gb);
1547     skip_bits1(gb);
1548
1549     return 0;
1550 }
1551
1552 static int mpeg4_decode_profile_level(MpegEncContext * s, GetBitContext *gb){
1553
1554     s->avctx->profile = get_bits(gb, 4);
1555     s->avctx->level   = get_bits(gb, 4);
1556
1557     // for Simple profile, level 0
1558     if (s->avctx->profile == 0 && s->avctx->level == 8) {
1559         s->avctx->level = 0;
1560     }
1561
1562     return 0;
1563 }
1564
1565 static int decode_vol_header(MpegEncContext *s, GetBitContext *gb){
1566     int width, height, vo_ver_id;
1567
1568     /* vol header */
1569     skip_bits(gb, 1); /* random access */
1570     s->vo_type= get_bits(gb, 8);
1571     if (get_bits1(gb) != 0) { /* is_ol_id */
1572         vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
1573         skip_bits(gb, 3); /* vo_priority */
1574     } else {
1575         vo_ver_id = 1;
1576     }
1577     s->aspect_ratio_info= get_bits(gb, 4);
1578     if(s->aspect_ratio_info == FF_ASPECT_EXTENDED){
1579         s->avctx->sample_aspect_ratio.num= get_bits(gb, 8); // par_width
1580         s->avctx->sample_aspect_ratio.den= get_bits(gb, 8); // par_height
1581     }else{
1582         s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1583     }
1584
1585     if ((s->vol_control_parameters=get_bits1(gb))) { /* vol control parameter */
1586         int chroma_format= get_bits(gb, 2);
1587         if(chroma_format!=CHROMA_420){
1588             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1589         }
1590         s->low_delay= get_bits1(gb);
1591         if(get_bits1(gb)){ /* vbv parameters */
1592             get_bits(gb, 15);   /* first_half_bitrate */
1593             skip_bits1(gb);     /* marker */
1594             get_bits(gb, 15);   /* latter_half_bitrate */
1595             skip_bits1(gb);     /* marker */
1596             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
1597             skip_bits1(gb);     /* marker */
1598             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
1599             get_bits(gb, 11);   /* first_half_vbv_occupancy */
1600             skip_bits1(gb);     /* marker */
1601             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
1602             skip_bits1(gb);     /* marker */
1603         }
1604     }else{
1605         // set low delay flag only once the smartest? low delay detection won't be overridden
1606         if(s->picture_number==0)
1607             s->low_delay=0;
1608     }
1609
1610     s->shape = get_bits(gb, 2); /* vol shape */
1611     if(s->shape != RECT_SHAPE) av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1612     if(s->shape == GRAY_SHAPE && vo_ver_id != 1){
1613         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1614         skip_bits(gb, 4);  //video_object_layer_shape_extension
1615     }
1616
1617     check_marker(gb, "before time_increment_resolution");
1618
1619     s->avctx->time_base.den = get_bits(gb, 16);
1620     if(!s->avctx->time_base.den){
1621         av_log(s->avctx, AV_LOG_ERROR, "time_base.den==0\n");
1622         s->avctx->time_base.num = 0;
1623         return -1;
1624     }
1625
1626     s->time_increment_bits = av_log2(s->avctx->time_base.den - 1) + 1;
1627     if (s->time_increment_bits < 1)
1628         s->time_increment_bits = 1;
1629
1630     check_marker(gb, "before fixed_vop_rate");
1631
1632     if (get_bits1(gb) != 0) {   /* fixed_vop_rate  */
1633         s->avctx->time_base.num = get_bits(gb, s->time_increment_bits);
1634     }else
1635         s->avctx->time_base.num = 1;
1636
1637     s->t_frame=0;
1638
1639     if (s->shape != BIN_ONLY_SHAPE) {
1640         if (s->shape == RECT_SHAPE) {
1641             check_marker(gb, "before width");
1642             width = get_bits(gb, 13);
1643             check_marker(gb, "before height");
1644             height = get_bits(gb, 13);
1645             check_marker(gb, "after height");
1646             if(width && height && !(s->width && s->codec_tag == AV_RL32("MP4S"))){ /* they should be non zero but who knows ... */
1647                 if (s->width && s->height &&
1648                     (s->width != width || s->height != height))
1649                     s->context_reinit = 1;
1650                 s->width = width;
1651                 s->height = height;
1652             }
1653         }
1654
1655         s->progressive_sequence=
1656         s->progressive_frame= get_bits1(gb)^1;
1657         s->interlaced_dct=0;
1658         if(!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1659             av_log(s->avctx, AV_LOG_INFO, "MPEG4 OBMC not supported (very likely buggy encoder)\n");   /* OBMC Disable */
1660         if (vo_ver_id == 1) {
1661             s->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
1662         } else {
1663             s->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
1664         }
1665         if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1666         if(s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE){
1667             if(s->vol_sprite_usage==STATIC_SPRITE){
1668                 s->sprite_width = get_bits(gb, 13);
1669                 skip_bits1(gb); /* marker */
1670                 s->sprite_height= get_bits(gb, 13);
1671                 skip_bits1(gb); /* marker */
1672                 s->sprite_left  = get_bits(gb, 13);
1673                 skip_bits1(gb); /* marker */
1674                 s->sprite_top   = get_bits(gb, 13);
1675                 skip_bits1(gb); /* marker */
1676             }
1677             s->num_sprite_warping_points= get_bits(gb, 6);
1678             if(s->num_sprite_warping_points > 3){
1679                 av_log(s->avctx, AV_LOG_ERROR, "%d sprite_warping_points\n", s->num_sprite_warping_points);
1680                 s->num_sprite_warping_points= 0;
1681                 return -1;
1682             }
1683             s->sprite_warping_accuracy = get_bits(gb, 2);
1684             s->sprite_brightness_change= get_bits1(gb);
1685             if(s->vol_sprite_usage==STATIC_SPRITE)
1686                 s->low_latency_sprite= get_bits1(gb);
1687         }
1688         // FIXME sadct disable bit if verid!=1 && shape not rect
1689
1690         if (get_bits1(gb) == 1) {   /* not_8_bit */
1691             s->quant_precision = get_bits(gb, 4); /* quant_precision */
1692             if(get_bits(gb, 4)!=8) av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n"); /* bits_per_pixel */
1693             if(s->quant_precision!=5) av_log(s->avctx, AV_LOG_ERROR, "quant precision %d\n", s->quant_precision);
1694             if(s->quant_precision<3 || s->quant_precision>9) {
1695                 s->quant_precision = 5;
1696             }
1697         } else {
1698             s->quant_precision = 5;
1699         }
1700
1701         // FIXME a bunch of grayscale shape things
1702
1703         if((s->mpeg_quant=get_bits1(gb))){ /* vol_quant_type */
1704             int i, v;
1705
1706             /* load default matrixes */
1707             for(i=0; i<64; i++){
1708                 int j= s->dsp.idct_permutation[i];
1709                 v= ff_mpeg4_default_intra_matrix[i];
1710                 s->intra_matrix[j]= v;
1711                 s->chroma_intra_matrix[j]= v;
1712
1713                 v= ff_mpeg4_default_non_intra_matrix[i];
1714                 s->inter_matrix[j]= v;
1715                 s->chroma_inter_matrix[j]= v;
1716             }
1717
1718             /* load custom intra matrix */
1719             if(get_bits1(gb)){
1720                 int last=0;
1721                 for(i=0; i<64; i++){
1722                     int j;
1723                     v= get_bits(gb, 8);
1724                     if(v==0) break;
1725
1726                     last= v;
1727                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1728                     s->intra_matrix[j]= v;
1729                     s->chroma_intra_matrix[j]= v;
1730                 }
1731
1732                 /* replicate last value */
1733                 for(; i<64; i++){
1734                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1735                     s->intra_matrix[j]= last;
1736                     s->chroma_intra_matrix[j]= last;
1737                 }
1738             }
1739
1740             /* load custom non intra matrix */
1741             if(get_bits1(gb)){
1742                 int last=0;
1743                 for(i=0; i<64; i++){
1744                     int j;
1745                     v= get_bits(gb, 8);
1746                     if(v==0) break;
1747
1748                     last= v;
1749                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1750                     s->inter_matrix[j]= v;
1751                     s->chroma_inter_matrix[j]= v;
1752                 }
1753
1754                 /* replicate last value */
1755                 for(; i<64; i++){
1756                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1757                     s->inter_matrix[j]= last;
1758                     s->chroma_inter_matrix[j]= last;
1759                 }
1760             }
1761
1762             // FIXME a bunch of grayscale shape things
1763         }
1764
1765         if(vo_ver_id != 1)
1766              s->quarter_sample= get_bits1(gb);
1767         else s->quarter_sample=0;
1768
1769         if(!get_bits1(gb)){
1770             int pos= get_bits_count(gb);
1771             int estimation_method= get_bits(gb, 2);
1772             if(estimation_method<2){
1773                 if(!get_bits1(gb)){
1774                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //opaque
1775                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //transparent
1776                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_cae
1777                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //inter_cae
1778                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //no_update
1779                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //upampling
1780                 }
1781                 if(!get_bits1(gb)){
1782                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_blocks
1783                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter_blocks
1784                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter4v_blocks
1785                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //not coded blocks
1786                 }
1787                 if(!check_marker(gb, "in complexity estimation part 1")){
1788                     skip_bits_long(gb, pos - get_bits_count(gb));
1789                     goto no_cplx_est;
1790                 }
1791                 if(!get_bits1(gb)){
1792                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_coeffs
1793                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_lines
1794                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //vlc_syms
1795                     s->cplx_estimation_trash_i += 4*get_bits1(gb); //vlc_bits
1796                 }
1797                 if(!get_bits1(gb)){
1798                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //apm
1799                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //npm
1800                     s->cplx_estimation_trash_b += 8*get_bits1(gb); //interpolate_mc_q
1801                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //forwback_mc_q
1802                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel2
1803                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel4
1804                 }
1805                 if(!check_marker(gb, "in complexity estimation part 2")){
1806                     skip_bits_long(gb, pos - get_bits_count(gb));
1807                     goto no_cplx_est;
1808                 }
1809                 if(estimation_method==1){
1810                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //sadct
1811                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //qpel
1812                 }
1813             }else
1814                 av_log(s->avctx, AV_LOG_ERROR, "Invalid Complexity estimation method %d\n", estimation_method);
1815         }else{
1816 no_cplx_est:
1817             s->cplx_estimation_trash_i=
1818             s->cplx_estimation_trash_p=
1819             s->cplx_estimation_trash_b= 0;
1820         }
1821
1822         s->resync_marker= !get_bits1(gb); /* resync_marker_disabled */
1823
1824         s->data_partitioning= get_bits1(gb);
1825         if(s->data_partitioning){
1826             s->rvlc= get_bits1(gb);
1827         }
1828
1829         if(vo_ver_id != 1) {
1830             s->new_pred= get_bits1(gb);
1831             if(s->new_pred){
1832                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
1833                 skip_bits(gb, 2); /* requested upstream message type */
1834                 skip_bits1(gb); /* newpred segment type */
1835             }
1836             s->reduced_res_vop= get_bits1(gb);
1837             if(s->reduced_res_vop) av_log(s->avctx, AV_LOG_ERROR, "reduced resolution VOP not supported\n");
1838         }
1839         else{
1840             s->new_pred=0;
1841             s->reduced_res_vop= 0;
1842         }
1843
1844         s->scalability= get_bits1(gb);
1845
1846         if (s->scalability) {
1847             GetBitContext bak= *gb;
1848             int h_sampling_factor_n;
1849             int h_sampling_factor_m;
1850             int v_sampling_factor_n;
1851             int v_sampling_factor_m;
1852
1853             s->hierachy_type= get_bits1(gb);
1854             skip_bits(gb, 4);  /* ref_layer_id */
1855             skip_bits1(gb);    /* ref_layer_sampling_dir */
1856             h_sampling_factor_n= get_bits(gb, 5);
1857             h_sampling_factor_m= get_bits(gb, 5);
1858             v_sampling_factor_n= get_bits(gb, 5);
1859             v_sampling_factor_m= get_bits(gb, 5);
1860             s->enhancement_type= get_bits1(gb);
1861
1862             if(   h_sampling_factor_n==0 || h_sampling_factor_m==0
1863                || v_sampling_factor_n==0 || v_sampling_factor_m==0){
1864                 /* illegal scalability header (VERY broken encoder),
1865                  * trying to workaround */
1866                 s->scalability=0;
1867                 *gb= bak;
1868             }else
1869                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
1870
1871             // bin shape stuff FIXME
1872         }
1873     }
1874
1875     if(s->avctx->debug&FF_DEBUG_PICT_INFO) {
1876         av_log(s->avctx, AV_LOG_DEBUG, "tb %d/%d, tincrbits:%d, qp_prec:%d, ps:%d,  %s%s%s%s\n",
1877                s->avctx->time_base.num, s->avctx->time_base.den,
1878                s->time_increment_bits,
1879                s->quant_precision,
1880                s->progressive_sequence,
1881                s->scalability ? "scalability " :"" , s->quarter_sample ? "qpel " : "",
1882                s->data_partitioning ? "partition " : "", s->rvlc ? "rvlc " : ""
1883         );
1884     }
1885
1886     return 0;
1887 }
1888
1889 /**
1890  * Decode the user data stuff in the header.
1891  * Also initializes divx/xvid/lavc_version/build.
1892  */
1893 static int decode_user_data(MpegEncContext *s, GetBitContext *gb){
1894     char buf[256];
1895     int i;
1896     int e;
1897     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
1898     char last;
1899
1900     for(i=0; i<255 && get_bits_count(gb) < gb->size_in_bits; i++){
1901         if(show_bits(gb, 23) == 0) break;
1902         buf[i]= get_bits(gb, 8);
1903     }
1904     buf[i]=0;
1905
1906     /* divx detection */
1907     e=sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
1908     if(e<2)
1909         e=sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
1910     if(e>=2){
1911         s->divx_version= ver;
1912         s->divx_build= build;
1913         s->divx_packed= e==3 && last=='p';
1914         if(s->divx_packed && !s->showed_packed_warning) {
1915             av_log(s->avctx, AV_LOG_INFO, "Video uses a non-standard and "
1916                    "wasteful way to store B-frames ('packed B-frames'). "
1917                    "Consider using a tool like VirtualDub or avidemux to fix it.\n");
1918             s->showed_packed_warning=1;
1919         }
1920     }
1921
1922     /* libavcodec detection */
1923     e=sscanf(buf, "FFmpe%*[^b]b%d", &build)+3;
1924     if(e!=4)
1925         e=sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
1926     if(e!=4){
1927         e=sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3)+1;
1928         if (e>1)
1929             build= (ver<<16) + (ver2<<8) + ver3;
1930     }
1931     if(e!=4){
1932         if(strcmp(buf, "ffmpeg")==0){
1933             s->lavc_build= 4600;
1934         }
1935     }
1936     if(e==4){
1937         s->lavc_build= build;
1938     }
1939
1940     /* Xvid detection */
1941     e=sscanf(buf, "XviD%d", &build);
1942     if(e==1){
1943         s->xvid_build= build;
1944     }
1945
1946     return 0;
1947 }
1948
1949 static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
1950     int time_incr, time_increment;
1951
1952     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I;        /* pict type: I = 0 , P = 1 */
1953     if(s->pict_type==AV_PICTURE_TYPE_B && s->low_delay && s->vol_control_parameters==0 && !(s->flags & CODEC_FLAG_LOW_DELAY)){
1954         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag incorrectly, clearing it\n");
1955         s->low_delay=0;
1956     }
1957
1958     s->partitioned_frame= s->data_partitioning && s->pict_type!=AV_PICTURE_TYPE_B;
1959     if(s->partitioned_frame)
1960         s->decode_mb= mpeg4_decode_partitioned_mb;
1961     else
1962         s->decode_mb= mpeg4_decode_mb;
1963
1964     time_incr=0;
1965     while (get_bits1(gb) != 0)
1966         time_incr++;
1967
1968     check_marker(gb, "before time_increment");
1969
1970     if(s->time_increment_bits==0 || !(show_bits(gb, s->time_increment_bits+1)&1)){
1971         av_log(s->avctx, AV_LOG_ERROR, "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
1972
1973         for(s->time_increment_bits=1 ;s->time_increment_bits<16; s->time_increment_bits++){
1974             if (    s->pict_type == AV_PICTURE_TYPE_P
1975                 || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE)) {
1976                 if((show_bits(gb, s->time_increment_bits+6)&0x37) == 0x30) break;
1977             }else
1978                 if((show_bits(gb, s->time_increment_bits+5)&0x1F) == 0x18) break;
1979         }
1980
1981         av_log(s->avctx, AV_LOG_ERROR, "my guess is %d bits ;)\n",s->time_increment_bits);
1982         if (s->avctx->time_base.den && 4*s->avctx->time_base.den < 1<<s->time_increment_bits) {
1983             s->avctx->time_base.den = 1<<s->time_increment_bits;
1984         }
1985     }
1986
1987     if(IS_3IV1) time_increment= get_bits1(gb); //FIXME investigate further
1988     else time_increment= get_bits(gb, s->time_increment_bits);
1989
1990     if(s->pict_type!=AV_PICTURE_TYPE_B){
1991         s->last_time_base= s->time_base;
1992         s->time_base+= time_incr;
1993         s->time= s->time_base*s->avctx->time_base.den + time_increment;
1994         if(s->workaround_bugs&FF_BUG_UMP4){
1995             if(s->time < s->last_non_b_time){
1996                 /* header is not mpeg-4-compatible, broken encoder,
1997                  * trying to workaround */
1998                 s->time_base++;
1999                 s->time+= s->avctx->time_base.den;
2000             }
2001         }
2002         s->pp_time= s->time - s->last_non_b_time;
2003         s->last_non_b_time= s->time;
2004     }else{
2005         s->time= (s->last_time_base + time_incr)*s->avctx->time_base.den + time_increment;
2006         s->pb_time= s->pp_time - (s->last_non_b_time - s->time);
2007         if(s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0){
2008             /* messed up order, maybe after seeking? skipping current b-frame */
2009             return FRAME_SKIPPED;
2010         }
2011         ff_mpeg4_init_direct_mv(s);
2012
2013         if(s->t_frame==0) s->t_frame= s->pb_time;
2014         if(s->t_frame==0) s->t_frame=1; // 1/0 protection
2015         s->pp_field_time= (  ROUNDED_DIV(s->last_non_b_time, s->t_frame)
2016                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
2017         s->pb_field_time= (  ROUNDED_DIV(s->time, s->t_frame)
2018                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
2019         if(!s->progressive_sequence){
2020             if(s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
2021                 return FRAME_SKIPPED;
2022         }
2023     }
2024
2025     if(s->avctx->time_base.num)
2026         s->current_picture_ptr->f.pts = ROUNDED_DIV(s->time, s->avctx->time_base.num);
2027     else
2028         s->current_picture_ptr->f.pts = AV_NOPTS_VALUE;
2029     if(s->avctx->debug&FF_DEBUG_PTS)
2030         av_log(s->avctx, AV_LOG_DEBUG, "MPEG4 PTS: %"PRId64"\n",
2031                s->current_picture_ptr->f.pts);
2032
2033     check_marker(gb, "before vop_coded");
2034
2035     /* vop coded */
2036     if (get_bits1(gb) != 1){
2037         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
2038             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
2039         return FRAME_SKIPPED;
2040     }
2041     if (s->new_pred)
2042         decode_new_pred(s, gb);
2043
2044     if (s->shape != BIN_ONLY_SHAPE && ( s->pict_type == AV_PICTURE_TYPE_P
2045                           || (s->pict_type == AV_PICTURE_TYPE_S && s->vol_sprite_usage==GMC_SPRITE))) {
2046         /* rounding type for motion estimation */
2047         s->no_rounding = get_bits1(gb);
2048     } else {
2049         s->no_rounding = 0;
2050     }
2051 //FIXME reduced res stuff
2052
2053      if (s->shape != RECT_SHAPE) {
2054          if (s->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
2055              skip_bits(gb, 13); /* width */
2056              skip_bits1(gb);   /* marker */
2057              skip_bits(gb, 13); /* height */
2058              skip_bits1(gb);   /* marker */
2059              skip_bits(gb, 13); /* hor_spat_ref */
2060              skip_bits1(gb);   /* marker */
2061              skip_bits(gb, 13); /* ver_spat_ref */
2062          }
2063          skip_bits1(gb); /* change_CR_disable */
2064
2065          if (get_bits1(gb) != 0) {
2066              skip_bits(gb, 8); /* constant_alpha_value */
2067          }
2068      }
2069 //FIXME complexity estimation stuff
2070
2071      if (s->shape != BIN_ONLY_SHAPE) {
2072          skip_bits_long(gb, s->cplx_estimation_trash_i);
2073          if(s->pict_type != AV_PICTURE_TYPE_I)
2074             skip_bits_long(gb, s->cplx_estimation_trash_p);
2075          if(s->pict_type == AV_PICTURE_TYPE_B)
2076             skip_bits_long(gb, s->cplx_estimation_trash_b);
2077
2078          if(get_bits_left(gb) < 3) {
2079              av_log(s->avctx, AV_LOG_ERROR, "Header truncated\n");
2080              return -1;
2081          }
2082          s->intra_dc_threshold= ff_mpeg4_dc_threshold[ get_bits(gb, 3) ];
2083          if(!s->progressive_sequence){
2084              s->top_field_first= get_bits1(gb);
2085              s->alternate_scan= get_bits1(gb);
2086          }else
2087              s->alternate_scan= 0;
2088      }
2089
2090      if(s->alternate_scan){
2091          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
2092          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
2093          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2094          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2095      } else{
2096          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
2097          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
2098          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2099          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2100      }
2101
2102      if(s->pict_type == AV_PICTURE_TYPE_S && (s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE)){
2103          if (mpeg4_decode_sprite_trajectory(s, gb) < 0)
2104              return AVERROR_INVALIDDATA;
2105          if(s->sprite_brightness_change) av_log(s->avctx, AV_LOG_ERROR, "sprite_brightness_change not supported\n");
2106          if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2107      }
2108
2109      if (s->shape != BIN_ONLY_SHAPE) {
2110          s->chroma_qscale= s->qscale = get_bits(gb, s->quant_precision);
2111          if(s->qscale==0){
2112              av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (qscale=0)\n");
2113              return -1; // makes no sense to continue, as there is nothing left from the image then
2114          }
2115
2116          if (s->pict_type != AV_PICTURE_TYPE_I) {
2117              s->f_code = get_bits(gb, 3);       /* fcode_for */
2118              if(s->f_code==0){
2119                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (f_code=0)\n");
2120                  s->f_code=1;
2121                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
2122              }
2123          }else
2124              s->f_code=1;
2125
2126          if (s->pict_type == AV_PICTURE_TYPE_B) {
2127              s->b_code = get_bits(gb, 3);
2128              if(s->b_code==0){
2129                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (b_code=0)\n");
2130                  s->b_code=1;
2131                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
2132              }
2133          }else
2134              s->b_code=1;
2135
2136          if(s->avctx->debug&FF_DEBUG_PICT_INFO){
2137              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 time:%"PRId64" tincr:%d\n",
2138                  s->qscale, s->f_code, s->b_code,
2139                  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")),
2140                  gb->size_in_bits,s->progressive_sequence, s->alternate_scan, s->top_field_first,
2141                  s->quarter_sample ? "q" : "h", s->data_partitioning, s->resync_marker, s->num_sprite_warping_points,
2142                  s->sprite_warping_accuracy, 1-s->no_rounding, s->vo_type, s->vol_control_parameters ? " VOLC" : " ", s->intra_dc_threshold,
2143                  s->cplx_estimation_trash_i, s->cplx_estimation_trash_p, s->cplx_estimation_trash_b,
2144                  s->time,
2145                  time_increment
2146                    );
2147          }
2148
2149          if(!s->scalability){
2150              if (s->shape!=RECT_SHAPE && s->pict_type!=AV_PICTURE_TYPE_I) {
2151                  skip_bits1(gb); // vop shape coding type
2152              }
2153          }else{
2154              if(s->enhancement_type){
2155                  int load_backward_shape= get_bits1(gb);
2156                  if(load_backward_shape){
2157                      av_log(s->avctx, AV_LOG_ERROR, "load backward shape isn't supported\n");
2158                  }
2159              }
2160              skip_bits(gb, 2); //ref_select_code
2161          }
2162      }
2163      /* detect buggy encoders which don't set the low_delay flag (divx4/xvid/opendivx)*/
2164      // note we cannot detect divx5 without b-frames easily (although it's buggy too)
2165      if(s->vo_type==0 && s->vol_control_parameters==0 && s->divx_version==-1 && s->picture_number==0){
2166          av_log(s->avctx, AV_LOG_WARNING, "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2167          s->low_delay=1;
2168      }
2169
2170      s->picture_number++; // better than pic number==0 always ;)
2171
2172      s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table; //FIXME add short header support
2173      s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
2174
2175      if(s->workaround_bugs&FF_BUG_EDGE){
2176          s->h_edge_pos= s->width;
2177          s->v_edge_pos= s->height;
2178      }
2179      return 0;
2180 }
2181
2182 /**
2183  * Decode mpeg4 headers.
2184  * @return <0 if no VOP found (or a damaged one)
2185  *         FRAME_SKIPPED if a not coded VOP is found
2186  *         0 if a VOP is found
2187  */
2188 int ff_mpeg4_decode_picture_header(MpegEncContext * s, GetBitContext *gb)
2189 {
2190     unsigned startcode, v;
2191
2192     /* search next start code */
2193     align_get_bits(gb);
2194
2195     if(s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630){
2196         skip_bits(gb, 24);
2197         if(get_bits(gb, 8) == 0xF0)
2198             goto end;
2199     }
2200
2201     startcode = 0xff;
2202     for(;;) {
2203         if(get_bits_count(gb) >= gb->size_in_bits){
2204             if(gb->size_in_bits==8 && (s->divx_version>=0 || s->xvid_build>=0) || s->codec_tag == AV_RL32("QMP4")){
2205                 av_log(s->avctx, AV_LOG_VERBOSE, "frame skip %d\n", gb->size_in_bits);
2206                 return FRAME_SKIPPED; //divx bug
2207             }else
2208                 return -1; //end of stream
2209         }
2210
2211         /* use the bits after the test */
2212         v = get_bits(gb, 8);
2213         startcode = ((startcode << 8) | v) & 0xffffffff;
2214
2215         if((startcode&0xFFFFFF00) != 0x100)
2216             continue; //no startcode
2217
2218         if(s->avctx->debug&FF_DEBUG_STARTCODE){
2219             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2220             if     (startcode<=0x11F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2221             else if(startcode<=0x12F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2222             else if(startcode<=0x13F) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2223             else if(startcode<=0x15F) av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2224             else if(startcode<=0x1AF) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2225             else if(startcode==0x1B0) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2226             else if(startcode==0x1B1) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2227             else if(startcode==0x1B2) av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2228             else if(startcode==0x1B3) av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2229             else if(startcode==0x1B4) av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2230             else if(startcode==0x1B5) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2231             else if(startcode==0x1B6) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2232             else if(startcode==0x1B7) av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2233             else if(startcode==0x1B8) av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2234             else if(startcode==0x1B9) av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2235             else if(startcode==0x1BA) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2236             else if(startcode==0x1BB) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2237             else if(startcode==0x1BC) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2238             else if(startcode==0x1BD) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2239             else if(startcode==0x1BE) av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2240             else if(startcode==0x1BF) av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2241             else if(startcode==0x1C0) av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2242             else if(startcode==0x1C1) av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2243             else if(startcode==0x1C2) av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2244             else if(startcode==0x1C3) av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2245             else if(startcode<=0x1C5) av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2246             else if(startcode<=0x1FF) av_log(s->avctx, AV_LOG_DEBUG, "System start");
2247             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2248         }
2249
2250         if(startcode >= 0x120 && startcode <= 0x12F){
2251             if(decode_vol_header(s, gb) < 0)
2252                 return -1;
2253         }
2254         else if(startcode == USER_DATA_STARTCODE){
2255             decode_user_data(s, gb);
2256         }
2257         else if(startcode == GOP_STARTCODE){
2258             mpeg4_decode_gop_header(s, gb);
2259         }
2260         else if(startcode == VOS_STARTCODE){
2261             mpeg4_decode_profile_level(s, gb);
2262         }
2263         else if(startcode == VOP_STARTCODE){
2264             break;
2265         }
2266
2267         align_get_bits(gb);
2268         startcode = 0xff;
2269     }
2270 end:
2271     if(s->flags& CODEC_FLAG_LOW_DELAY)
2272         s->low_delay=1;
2273     s->avctx->has_b_frames= !s->low_delay;
2274     return decode_vop_header(s, gb);
2275 }
2276
2277 av_cold void ff_mpeg4videodec_static_init(void) {
2278     static int done = 0;
2279
2280     if (!done) {
2281         ff_init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2282         ff_init_rl(&ff_rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2283         ff_init_rl(&ff_rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2284         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2285         INIT_VLC_RL(ff_rvlc_rl_inter, 1072);
2286         INIT_VLC_RL(ff_rvlc_rl_intra, 1072);
2287         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2288                  &ff_mpeg4_DCtab_lum[0][1], 2, 1,
2289                  &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2290         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2291                  &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2292                  &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2293         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2294                  &ff_sprite_trajectory_tab[0][1], 4, 2,
2295                  &ff_sprite_trajectory_tab[0][0], 4, 2, 128);
2296         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2297                  &ff_mb_type_b_tab[0][1], 2, 1,
2298                  &ff_mb_type_b_tab[0][0], 2, 1, 16);
2299         done = 1;
2300     }
2301 }
2302
2303 static av_cold int decode_init(AVCodecContext *avctx)
2304 {
2305     MpegEncContext *s = avctx->priv_data;
2306     int ret;
2307
2308     s->divx_version=
2309     s->divx_build=
2310     s->xvid_build=
2311     s->lavc_build= -1;
2312
2313     if((ret=ff_h263_decode_init(avctx)) < 0)
2314         return ret;
2315
2316     ff_mpeg4videodec_static_init();
2317
2318     s->h263_pred = 1;
2319     s->low_delay = 0; //default, might be overridden in the vol header during header parsing
2320     s->decode_mb= mpeg4_decode_mb;
2321     s->time_increment_bits = 4; /* default value for broken headers */
2322     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2323
2324     avctx->internal->allocate_progress = 1;
2325
2326     return 0;
2327 }
2328
2329 static const AVProfile mpeg4_video_profiles[] = {
2330     { FF_PROFILE_MPEG4_SIMPLE,                    "Simple Profile" },
2331     { FF_PROFILE_MPEG4_SIMPLE_SCALABLE,           "Simple Scalable Profile" },
2332     { FF_PROFILE_MPEG4_CORE,                      "Core Profile" },
2333     { FF_PROFILE_MPEG4_MAIN,                      "Main Profile" },
2334     { FF_PROFILE_MPEG4_N_BIT,                     "N-bit Profile" },
2335     { FF_PROFILE_MPEG4_SCALABLE_TEXTURE,          "Scalable Texture Profile" },
2336     { FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION,     "Simple Face Animation Profile" },
2337     { FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE,    "Basic Animated Texture Profile" },
2338     { FF_PROFILE_MPEG4_HYBRID,                    "Hybrid Profile" },
2339     { FF_PROFILE_MPEG4_ADVANCED_REAL_TIME,        "Advanced Real Time Simple Profile" },
2340     { FF_PROFILE_MPEG4_CORE_SCALABLE,             "Code Scalable Profile" },
2341     { FF_PROFILE_MPEG4_ADVANCED_CODING,           "Advanced Coding Profile" },
2342     { FF_PROFILE_MPEG4_ADVANCED_CORE,             "Advanced Core Profile" },
2343     { FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE, "Advanced Scalable Texture Profile" },
2344     { FF_PROFILE_MPEG4_SIMPLE_STUDIO,             "Simple Studio Profile" },
2345     { FF_PROFILE_MPEG4_ADVANCED_SIMPLE,           "Advanced Simple Profile" },
2346     { FF_PROFILE_UNKNOWN },
2347 };
2348
2349 static const AVOption mpeg4_options[] = {
2350     {"quarter_sample", "1/4 subpel MC", offsetof(MpegEncContext, quarter_sample), FF_OPT_TYPE_INT, {.i64 = 0}, 0, 1, 0},
2351     {"divx_packed", "divx style packed b frames", offsetof(MpegEncContext, divx_packed), FF_OPT_TYPE_INT, {.i64 = 0}, 0, 1, 0},
2352     {NULL}
2353 };
2354
2355 static const AVClass mpeg4_class = {
2356     "MPEG4 Video Decoder",
2357     av_default_item_name,
2358     mpeg4_options,
2359     LIBAVUTIL_VERSION_INT,
2360 };
2361
2362 static const AVClass mpeg4_vdpau_class = {
2363     "MPEG4 Video VDPAU Decoder",
2364     av_default_item_name,
2365     mpeg4_options,
2366     LIBAVUTIL_VERSION_INT,
2367 };
2368
2369 AVCodec ff_mpeg4_decoder = {
2370     .name                  = "mpeg4",
2371     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2372     .type                  = AVMEDIA_TYPE_VIDEO,
2373     .id                    = AV_CODEC_ID_MPEG4,
2374     .priv_data_size        = sizeof(MpegEncContext),
2375     .init                  = decode_init,
2376     .close                 = ff_h263_decode_end,
2377     .decode                = ff_h263_decode_frame,
2378     .capabilities          = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
2379                              CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2380                              CODEC_CAP_FRAME_THREADS,
2381     .flush                 = ff_mpeg_flush,
2382     .max_lowres            = 3,
2383     .pix_fmts              = ff_h263_hwaccel_pixfmt_list_420,
2384     .profiles              = NULL_IF_CONFIG_SMALL(mpeg4_video_profiles),
2385     .update_thread_context = ONLY_IF_THREADS_ENABLED(ff_mpeg_update_thread_context),
2386     .priv_class = &mpeg4_class,
2387 };
2388
2389
2390 #if CONFIG_MPEG4_VDPAU_DECODER
2391 AVCodec ff_mpeg4_vdpau_decoder = {
2392     .name           = "mpeg4_vdpau",
2393     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
2394     .type           = AVMEDIA_TYPE_VIDEO,
2395     .id             = AV_CODEC_ID_MPEG4,
2396     .priv_data_size = sizeof(MpegEncContext),
2397     .init           = decode_init,
2398     .close          = ff_h263_decode_end,
2399     .decode         = ff_h263_decode_frame,
2400     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2401                       CODEC_CAP_HWACCEL_VDPAU,
2402     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_VDPAU_MPEG4,
2403                                                   AV_PIX_FMT_NONE },
2404     .priv_class     = &mpeg4_vdpau_class,
2405 };
2406 #endif