git.sesse.net Git - ffmpeg/blob - libavcodec/mpeg4videodec.c

   1 /*
   2  * MPEG4 decoder.
   3  * Copyright (c) 2000,2001 Fabrice Bellard
   4  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "error_resilience.h"
  24 #include "idctdsp.h"
  25 #include "internal.h"
  26 #include "mpegutils.h"
  27 #include "mpegvideo.h"
  28 #include "mpeg4video.h"
  29 #include "h263.h"
  30 #include "thread.h"
  31 #include "xvididct.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 static VLC dc_lum, dc_chrom;
  42 static VLC sprite_trajectory;
  43 static VLC mb_type_b_vlc;
  44
  45 static const int mb_type_b_map[4] = {
  46     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
  47     MB_TYPE_L0L1    | MB_TYPE_16x16,
  48     MB_TYPE_L1      | MB_TYPE_16x16,
  49     MB_TYPE_L0      | MB_TYPE_16x16,
  50 };
  51
  52 /**
  53  * Predict the ac.
  54  * @param n block index (0-3 are luma, 4-5 are chroma)
  55  * @param dir the ac prediction direction
  56  */
  57 void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n, int dir)
  58 {
  59     int i;
  60     int16_t *ac_val, *ac_val1;
  61     int8_t *const qscale_table = s->current_picture.qscale_table;
  62
  63     /* find prediction */
  64     ac_val  = s->ac_val[0][0] + s->block_index[n] * 16;
  65     ac_val1 = ac_val;
  66     if (s->ac_pred) {
  67         if (dir == 0) {
  68             const int xy = s->mb_x - 1 + s->mb_y * s->mb_stride;
  69             /* left prediction */
  70             ac_val -= 16;
  71
  72             if (s->mb_x == 0 || s->qscale == qscale_table[xy] ||
  73                 n == 1 || n == 3) {
  74                 /* same qscale */
  75                 for (i = 1; i < 8; i++)
  76                     block[s->idsp.idct_permutation[i << 3]] += ac_val[i];
  77             } else {
  78                 /* different qscale, we must rescale */
  79                 for (i = 1; i < 8; i++)
  80                     block[s->idsp.idct_permutation[i << 3]] += ROUNDED_DIV(ac_val[i] * qscale_table[xy], s->qscale);
  81             }
  82         } else {
  83             const int xy = s->mb_x + s->mb_y * s->mb_stride - s->mb_stride;
  84             /* top prediction */
  85             ac_val -= 16 * s->block_wrap[n];
  86
  87             if (s->mb_y == 0 || s->qscale == qscale_table[xy] ||
  88                 n == 2 || n == 3) {
  89                 /* same qscale */
  90                 for (i = 1; i < 8; i++)
  91                     block[s->idsp.idct_permutation[i]] += ac_val[i + 8];
  92             } else {
  93                 /* different qscale, we must rescale */
  94                 for (i = 1; i < 8; i++)
  95                     block[s->idsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8] * qscale_table[xy], s->qscale);
  96             }
  97         }
  98     }
  99     /* left copy */
 100     for (i = 1; i < 8; i++)
 101         ac_val1[i] = block[s->idsp.idct_permutation[i << 3]];
 102
 103     /* top copy */
 104     for (i = 1; i < 8; i++)
 105         ac_val1[8 + i] = block[s->idsp.idct_permutation[i]];
 106 }
 107
 108 /**
 109  * check if the next stuff is a resync marker or the end.
 110  * @return 0 if not
 111  */
 112 static inline int mpeg4_is_resync(MpegEncContext *s)
 113 {
 114     int bits_count = get_bits_count(&s->gb);
 115     int v          = show_bits(&s->gb, 16);
 116
 117     if (s->workaround_bugs & FF_BUG_NO_PADDING)
 118         return 0;
 119
 120     while (v <= 0xFF) {
 121         if (s->pict_type == AV_PICTURE_TYPE_B ||
 122             (v >> (8 - s->pict_type) != 1) || s->partitioned_frame)
 123             break;
 124         skip_bits(&s->gb, 8 + s->pict_type);
 125         bits_count += 8 + s->pict_type;
 126         v = show_bits(&s->gb, 16);
 127     }
 128
 129     if (bits_count + 8 >= s->gb.size_in_bits) {
 130         v >>= 8;
 131         v  |= 0x7F >> (7 - (bits_count & 7));
 132
 133         if (v == 0x7F)
 134             return 1;
 135     } else {
 136         if (v == ff_mpeg4_resync_prefix[bits_count & 7]) {
 137             int len;
 138             GetBitContext gb = s->gb;
 139
 140             skip_bits(&s->gb, 1);
 141             align_get_bits(&s->gb);
 142
 143             for (len = 0; len < 32; len++)
 144                 if (get_bits1(&s->gb))
 145                     break;
 146
 147             s->gb = gb;
 148
 149             if (len >= ff_mpeg4_get_video_packet_prefix_length(s))
 150                 return 1;
 151         }
 152     }
 153     return 0;
 154 }
 155
 156 static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *gb)
 157 {
 158     MpegEncContext *s = &ctx->m;
 159     int a     = 2 << s->sprite_warping_accuracy;
 160     int rho   = 3  - s->sprite_warping_accuracy;
 161     int r     = 16 / a;
 162     int alpha = 0;
 163     int beta  = 0;
 164     int w     = s->width;
 165     int h     = s->height;
 166     int min_ab, i, w2, h2, w3, h3;
 167     int sprite_ref[4][2];
 168     int virtual_ref[2][2];
 169
 170     // only true for rectangle shapes
 171     const int vop_ref[4][2] = { { 0, 0 },         { s->width, 0 },
 172                                 { 0, s->height }, { s->width, s->height } };
 173     int d[4][2]             = { { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } };
 174
 175     if (w <= 0 || h <= 0)
 176         return AVERROR_INVALIDDATA;
 177
 178     for (i = 0; i < ctx->num_sprite_warping_points; i++) {
 179         int length;
 180         int x = 0, y = 0;
 181
 182         length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 183         if (length)
 184             x = get_xbits(gb, length);
 185
 186         if (!(ctx->divx_version == 500 && ctx->divx_build == 413))
 187             skip_bits1(gb);     /* marker bit */
 188
 189         length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
 190         if (length)
 191             y = get_xbits(gb, length);
 192
 193         skip_bits1(gb);         /* marker bit */
 194         ctx->sprite_traj[i][0] = d[i][0] = x;
 195         ctx->sprite_traj[i][1] = d[i][1] = y;
 196     }
 197     for (; i < 4; i++)
 198         ctx->sprite_traj[i][0] = ctx->sprite_traj[i][1] = 0;
 199
 200     while ((1 << alpha) < w)
 201         alpha++;
 202     while ((1 << beta) < h)
 203         beta++;  /* typo in the mpeg4 std for the definition of w' and h' */
 204     w2 = 1 << alpha;
 205     h2 = 1 << beta;
 206
 207     // Note, the 4th point isn't used for GMC
 208     if (ctx->divx_version == 500 && ctx->divx_build == 413) {
 209         sprite_ref[0][0] = a * vop_ref[0][0] + d[0][0];
 210         sprite_ref[0][1] = a * vop_ref[0][1] + d[0][1];
 211         sprite_ref[1][0] = a * vop_ref[1][0] + d[0][0] + d[1][0];
 212         sprite_ref[1][1] = a * vop_ref[1][1] + d[0][1] + d[1][1];
 213         sprite_ref[2][0] = a * vop_ref[2][0] + d[0][0] + d[2][0];
 214         sprite_ref[2][1] = a * vop_ref[2][1] + d[0][1] + d[2][1];
 215     } else {
 216         sprite_ref[0][0] = (a >> 1) * (2 * vop_ref[0][0] + d[0][0]);
 217         sprite_ref[0][1] = (a >> 1) * (2 * vop_ref[0][1] + d[0][1]);
 218         sprite_ref[1][0] = (a >> 1) * (2 * vop_ref[1][0] + d[0][0] + d[1][0]);
 219         sprite_ref[1][1] = (a >> 1) * (2 * vop_ref[1][1] + d[0][1] + d[1][1]);
 220         sprite_ref[2][0] = (a >> 1) * (2 * vop_ref[2][0] + d[0][0] + d[2][0]);
 221         sprite_ref[2][1] = (a >> 1) * (2 * vop_ref[2][1] + d[0][1] + d[2][1]);
 222     }
 223     /* sprite_ref[3][0] = (a >> 1) * (2 * vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
 224      * sprite_ref[3][1] = (a >> 1) * (2 * vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
 225
 226     /* this is mostly identical to the mpeg4 std (and is totally unreadable
 227      * because of that...). Perhaps it should be reordered to be more readable.
 228      * The idea behind this virtual_ref mess is to be able to use shifts later
 229      * per pixel instead of divides so the distance between points is converted
 230      * from w&h based to w2&h2 based which are of the 2^x form. */
 231     virtual_ref[0][0] = 16 * (vop_ref[0][0] + w2) +
 232                          ROUNDED_DIV(((w - w2) *
 233                                       (r * sprite_ref[0][0] - 16 * vop_ref[0][0]) +
 234                                       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) *
 237                                      (r * sprite_ref[0][1] - 16 * vop_ref[0][1]) +
 238                                      w2 * (r * sprite_ref[1][1] - 16 * vop_ref[1][1])), w);
 239     virtual_ref[1][0] = 16 * vop_ref[0][0] +
 240                         ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][0] - 16 * vop_ref[0][0]) +
 241                                      h2 * (r * sprite_ref[2][0] - 16 * vop_ref[2][0])), h);
 242     virtual_ref[1][1] = 16 * (vop_ref[0][1] + h2) +
 243                         ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][1] - 16 * vop_ref[0][1]) +
 244                                      h2 * (r * sprite_ref[2][1] - 16 * vop_ref[2][1])), h);
 245
 246     switch (ctx->num_sprite_warping_points) {
 247     case 0:
 248         s->sprite_offset[0][0] =
 249         s->sprite_offset[0][1] =
 250         s->sprite_offset[1][0] =
 251         s->sprite_offset[1][1] = 0;
 252         s->sprite_delta[0][0]  = a;
 253         s->sprite_delta[0][1]  =
 254         s->sprite_delta[1][0]  = 0;
 255         s->sprite_delta[1][1]  = a;
 256         ctx->sprite_shift[0]   =
 257         ctx->sprite_shift[1]   = 0;
 258         break;
 259     case 1:     // GMC only
 260         s->sprite_offset[0][0] = sprite_ref[0][0] - a * vop_ref[0][0];
 261         s->sprite_offset[0][1] = sprite_ref[0][1] - a * vop_ref[0][1];
 262         s->sprite_offset[1][0] = ((sprite_ref[0][0] >> 1) | (sprite_ref[0][0] & 1)) -
 263                                  a * (vop_ref[0][0] / 2);
 264         s->sprite_offset[1][1] = ((sprite_ref[0][1] >> 1) | (sprite_ref[0][1] & 1)) -
 265                                  a * (vop_ref[0][1] / 2);
 266         s->sprite_delta[0][0]  = a;
 267         s->sprite_delta[0][1]  =
 268         s->sprite_delta[1][0]  = 0;
 269         s->sprite_delta[1][1]  = a;
 270         ctx->sprite_shift[0]   =
 271         ctx->sprite_shift[1]   = 0;
 272         break;
 273     case 2:
 274         s->sprite_offset[0][0] = (sprite_ref[0][0] << (alpha + rho)) +
 275                                  (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
 276                                  (-vop_ref[0][0]) +
 277                                  (r * sprite_ref[0][1] - virtual_ref[0][1]) *
 278                                  (-vop_ref[0][1]) + (1 << (alpha + rho - 1));
 279         s->sprite_offset[0][1] = (sprite_ref[0][1] << (alpha + rho)) +
 280                                  (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
 281                                  (-vop_ref[0][0]) +
 282                                  (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
 283                                  (-vop_ref[0][1]) + (1 << (alpha + rho - 1));
 284         s->sprite_offset[1][0] = ((-r * sprite_ref[0][0] + virtual_ref[0][0]) *
 285                                   (-2 * vop_ref[0][0] + 1) +
 286                                   (r * sprite_ref[0][1] - virtual_ref[0][1]) *
 287                                   (-2 * vop_ref[0][1] + 1) + 2 * w2 * r *
 288                                   sprite_ref[0][0] - 16 * w2 + (1 << (alpha + rho + 1)));
 289         s->sprite_offset[1][1] = ((-r * sprite_ref[0][1] + virtual_ref[0][1]) *
 290                                   (-2 * vop_ref[0][0] + 1) +
 291                                   (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
 292                                   (-2 * vop_ref[0][1] + 1) + 2 * w2 * r *
 293                                   sprite_ref[0][1] - 16 * w2 + (1 << (alpha + rho + 1)));
 294         s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
 295         s->sprite_delta[0][1] = (+r * sprite_ref[0][1] - virtual_ref[0][1]);
 296         s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]);
 297         s->sprite_delta[1][1] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
 298
 299         ctx->sprite_shift[0]  = alpha + rho;
 300         ctx->sprite_shift[1]  = alpha + rho + 2;
 301         break;
 302     case 3:
 303         min_ab = FFMIN(alpha, beta);
 304         w3     = w2 >> min_ab;
 305         h3     = h2 >> min_ab;
 306         s->sprite_offset[0][0] = (sprite_ref[0][0] << (alpha + beta + rho - min_ab)) +
 307                                  (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
 308                                  h3 * (-vop_ref[0][0]) +
 309                                  (-r * sprite_ref[0][0] + virtual_ref[1][0]) *
 310                                  w3 * (-vop_ref[0][1]) +
 311                                  (1 << (alpha + beta + rho - min_ab - 1));
 312         s->sprite_offset[0][1] = (sprite_ref[0][1] << (alpha + beta + rho - min_ab)) +
 313                                  (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
 314                                  h3 * (-vop_ref[0][0]) +
 315                                  (-r * sprite_ref[0][1] + virtual_ref[1][1]) *
 316                                  w3 * (-vop_ref[0][1]) +
 317                                  (1 << (alpha + beta + rho - min_ab - 1));
 318         s->sprite_offset[1][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
 319                                  h3 * (-2 * vop_ref[0][0] + 1) +
 320                                  (-r * sprite_ref[0][0] + virtual_ref[1][0]) *
 321                                  w3 * (-2 * vop_ref[0][1] + 1) + 2 * w2 * h3 *
 322                                  r * sprite_ref[0][0] - 16 * w2 * h3 +
 323                                  (1 << (alpha + beta + rho - min_ab + 1));
 324         s->sprite_offset[1][1] = (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
 325                                  h3 * (-2 * vop_ref[0][0] + 1) +
 326                                  (-r * sprite_ref[0][1] + virtual_ref[1][1]) *
 327                                  w3 * (-2 * vop_ref[0][1] + 1) + 2 * w2 * h3 *
 328                                  r * sprite_ref[0][1] - 16 * w2 * h3 +
 329                                  (1 << (alpha + beta + rho - min_ab + 1));
 330         s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]) * h3;
 331         s->sprite_delta[0][1] = (-r * sprite_ref[0][0] + virtual_ref[1][0]) * w3;
 332         s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]) * h3;
 333         s->sprite_delta[1][1] = (-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3;
 334
 335         ctx->sprite_shift[0]  = alpha + beta + rho - min_ab;
 336         ctx->sprite_shift[1]  = alpha + beta + rho - min_ab + 2;
 337         break;
 338     }
 339     /* try to simplify the situation */
 340     if (s->sprite_delta[0][0] == a << ctx->sprite_shift[0] &&
 341         s->sprite_delta[0][1] == 0 &&
 342         s->sprite_delta[1][0] == 0 &&
 343         s->sprite_delta[1][1] == a << ctx->sprite_shift[0]) {
 344         s->sprite_offset[0][0] >>= ctx->sprite_shift[0];
 345         s->sprite_offset[0][1] >>= ctx->sprite_shift[0];
 346         s->sprite_offset[1][0] >>= ctx->sprite_shift[1];
 347         s->sprite_offset[1][1] >>= ctx->sprite_shift[1];
 348         s->sprite_delta[0][0] = a;
 349         s->sprite_delta[0][1] = 0;
 350         s->sprite_delta[1][0] = 0;
 351         s->sprite_delta[1][1] = a;
 352         ctx->sprite_shift[0] = 0;
 353         ctx->sprite_shift[1] = 0;
 354         s->real_sprite_warping_points = 1;
 355     } else {
 356         int shift_y = 16 - ctx->sprite_shift[0];
 357         int shift_c = 16 - ctx->sprite_shift[1];
 358         for (i = 0; i < 2; i++) {
 359             s->sprite_offset[0][i] <<= shift_y;
 360             s->sprite_offset[1][i] <<= shift_c;
 361             s->sprite_delta[0][i]  <<= shift_y;
 362             s->sprite_delta[1][i]  <<= shift_y;
 363             ctx->sprite_shift[i]     = 16;
 364         }
 365         s->real_sprite_warping_points = ctx->num_sprite_warping_points;
 366     }
 367
 368     return 0;
 369 }
 370
 371 /**
 372  * Decode the next video packet.
 373  * @return <0 if something went wrong
 374  */
 375 int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
 376 {
 377     MpegEncContext *s = &ctx->m;
 378
 379     int mb_num_bits      = av_log2(s->mb_num - 1) + 1;
 380     int header_extension = 0, mb_num, len;
 381
 382     /* is there enough space left for a video packet + header */
 383     if (get_bits_count(&s->gb) > s->gb.size_in_bits - 20)
 384         return -1;
 385
 386     for (len = 0; len < 32; len++)
 387         if (get_bits1(&s->gb))
 388             break;
 389
 390     if (len != ff_mpeg4_get_video_packet_prefix_length(s)) {
 391         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
 392         return -1;
 393     }
 394
 395     if (ctx->shape != RECT_SHAPE) {
 396         header_extension = get_bits1(&s->gb);
 397         // FIXME more stuff here
 398     }
 399
 400     mb_num = get_bits(&s->gb, mb_num_bits);
 401     if (mb_num >= s->mb_num) {
 402         av_log(s->avctx, AV_LOG_ERROR,
 403                "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
 404         return -1;
 405     }
 406     if (s->pict_type == AV_PICTURE_TYPE_B) {
 407         int mb_x = 0, mb_y = 0;
 408
 409         while (s->next_picture.mbskip_table[s->mb_index2xy[mb_num]]) {
 410             if (!mb_x)
 411                 ff_thread_await_progress(&s->next_picture_ptr->tf, mb_y++, 0);
 412             mb_num++;
 413             if (++mb_x == s->mb_width)
 414                 mb_x = 0;
 415         }
 416         if (mb_num >= s->mb_num)
 417             return -1;  // slice contains just skipped MBs (already decoded)
 418     }
 419
 420     s->mb_x = mb_num % s->mb_width;
 421     s->mb_y = mb_num / s->mb_width;
 422
 423     if (ctx->shape != BIN_ONLY_SHAPE) {
 424         int qscale = get_bits(&s->gb, s->quant_precision);
 425         if (qscale)
 426             s->chroma_qscale = s->qscale = qscale;
 427     }
 428
 429     if (ctx->shape == RECT_SHAPE)
 430         header_extension = get_bits1(&s->gb);
 431
 432     if (header_extension) {
 433         int time_incr = 0;
 434
 435         while (get_bits1(&s->gb) != 0)
 436             time_incr++;
 437
 438         check_marker(&s->gb, "before time_increment in video packed header");
 439         skip_bits(&s->gb, ctx->time_increment_bits);      /* time_increment */
 440         check_marker(&s->gb, "before vop_coding_type in video packed header");
 441
 442         skip_bits(&s->gb, 2); /* vop coding type */
 443         // FIXME not rect stuff here
 444
 445         if (ctx->shape != BIN_ONLY_SHAPE) {
 446             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
 447             // FIXME don't just ignore everything
 448             if (s->pict_type == AV_PICTURE_TYPE_S &&
 449                 ctx->vol_sprite_usage == GMC_SPRITE) {
 450                 if (mpeg4_decode_sprite_trajectory(ctx, &s->gb) < 0)
 451                     return AVERROR_INVALIDDATA;
 452                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
 453             }
 454
 455             // FIXME reduced res stuff here
 456
 457             if (s->pict_type != AV_PICTURE_TYPE_I) {
 458                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
 459                 if (f_code == 0)
 460                     av_log(s->avctx, AV_LOG_ERROR,
 461                            "Error, video packet header damaged (f_code=0)\n");
 462             }
 463             if (s->pict_type == AV_PICTURE_TYPE_B) {
 464                 int b_code = get_bits(&s->gb, 3);
 465                 if (b_code == 0)
 466                     av_log(s->avctx, AV_LOG_ERROR,
 467                            "Error, video packet header damaged (b_code=0)\n");
 468             }
 469         }
 470     }
 471     // FIXME new-pred stuff
 472
 473     return 0;
 474 }
 475
 476 /**
 477  * Get the average motion vector for a GMC MB.
 478  * @param n either 0 for the x component or 1 for y
 479  * @return the average MV for a GMC MB
 480  */
 481 static inline int get_amv(Mpeg4DecContext *ctx, int n)
 482 {
 483     MpegEncContext *s = &ctx->m;
 484     int x, y, mb_v, sum, dx, dy, shift;
 485     int len     = 1 << (s->f_code + 4);
 486     const int a = s->sprite_warping_accuracy;
 487
 488     if (s->workaround_bugs & FF_BUG_AMV)
 489         len >>= s->quarter_sample;
 490
 491     if (s->real_sprite_warping_points == 1) {
 492         if (ctx->divx_version == 500 && ctx->divx_build == 413)
 493             sum = s->sprite_offset[0][n] / (1 << (a - s->quarter_sample));
 494         else
 495             sum = RSHIFT(s->sprite_offset[0][n] << s->quarter_sample, a);
 496     } else {
 497         dx    = s->sprite_delta[n][0];
 498         dy    = s->sprite_delta[n][1];
 499         shift = ctx->sprite_shift[0];
 500         if (n)
 501             dy -= 1 << (shift + a + 1);
 502         else
 503             dx -= 1 << (shift + a + 1);
 504         mb_v = s->sprite_offset[0][n] + dx * s->mb_x * 16 + dy * s->mb_y * 16;
 505
 506         sum = 0;
 507         for (y = 0; y < 16; y++) {
 508             int v;
 509
 510             v = mb_v + dy * y;
 511             // FIXME optimize
 512             for (x = 0; x < 16; x++) {
 513                 sum += v >> shift;
 514                 v   += dx;
 515             }
 516         }
 517         sum = RSHIFT(sum, a + 8 - s->quarter_sample);
 518     }
 519
 520     if (sum < -len)
 521         sum = -len;
 522     else if (sum >= len)
 523         sum = len - 1;
 524
 525     return sum;
 526 }
 527
 528 /**
 529  * Decode the dc value.
 530  * @param n block index (0-3 are luma, 4-5 are chroma)
 531  * @param dir_ptr the prediction direction will be stored here
 532  * @return the quantized dc
 533  */
 534 static inline int mpeg4_decode_dc(MpegEncContext *s, int n, int *dir_ptr)
 535 {
 536     int level, code;
 537
 538     if (n < 4)
 539         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
 540     else
 541         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
 542
 543     if (code < 0 || code > 9 /* && s->nbit < 9 */) {
 544         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
 545         return -1;
 546     }
 547
 548     if (code == 0) {
 549         level = 0;
 550     } else {
 551         if (IS_3IV1) {
 552             if (code == 1)
 553                 level = 2 * get_bits1(&s->gb) - 1;
 554             else {
 555                 if (get_bits1(&s->gb))
 556                     level = get_bits(&s->gb, code - 1) + (1 << (code - 1));
 557                 else
 558                     level = -get_bits(&s->gb, code - 1) - (1 << (code - 1));
 559             }
 560         } else {
 561             level = get_xbits(&s->gb, code);
 562         }
 563
 564         if (code > 8) {
 565             if (get_bits1(&s->gb) == 0) { /* marker */
 566                 if (s->err_recognition & AV_EF_BITSTREAM) {
 567                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
 568                     return -1;
 569                 }
 570             }
 571         }
 572     }
 573
 574     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
 575 }
 576
 577 /**
 578  * Decode first partition.
 579  * @return number of MBs decoded or <0 if an error occurred
 580  */
 581 static int mpeg4_decode_partition_a(Mpeg4DecContext *ctx)
 582 {
 583     MpegEncContext *s = &ctx->m;
 584     int mb_num = 0;
 585     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 586
 587     /* decode first partition */
 588     s->first_slice_line = 1;
 589     for (; s->mb_y < s->mb_height; s->mb_y++) {
 590         ff_init_block_index(s);
 591         for (; s->mb_x < s->mb_width; s->mb_x++) {
 592             const int xy = s->mb_x + s->mb_y * s->mb_stride;
 593             int cbpc;
 594             int dir = 0;
 595
 596             mb_num++;
 597             ff_update_block_index(s);
 598             if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
 599                 s->first_slice_line = 0;
 600
 601             if (s->pict_type == AV_PICTURE_TYPE_I) {
 602                 int i;
 603
 604                 do {
 605                     if (show_bits_long(&s->gb, 19) == DC_MARKER)
 606                         return mb_num - 1;
 607
 608                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
 609                     if (cbpc < 0) {
 610                         av_log(s->avctx, AV_LOG_ERROR,
 611                                "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 612                         return -1;
 613                     }
 614                 } while (cbpc == 8);
 615
 616                 s->cbp_table[xy]               = cbpc & 3;
 617                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 618                 s->mb_intra                    = 1;
 619
 620                 if (cbpc & 4)
 621                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 622
 623                 s->current_picture.qscale_table[xy] = s->qscale;
 624
 625                 s->mbintra_table[xy] = 1;
 626                 for (i = 0; i < 6; i++) {
 627                     int dc_pred_dir;
 628                     int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
 629                     if (dc < 0) {
 630                         av_log(s->avctx, AV_LOG_ERROR,
 631                                "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 632                         return -1;
 633                     }
 634                     dir <<= 1;
 635                     if (dc_pred_dir)
 636                         dir |= 1;
 637                 }
 638                 s->pred_dir_table[xy] = dir;
 639             } else { /* P/S_TYPE */
 640                 int mx, my, pred_x, pred_y, bits;
 641                 int16_t *const mot_val = s->current_picture.motion_val[0][s->block_index[0]];
 642                 const int stride       = s->b8_stride * 2;
 643
 644 try_again:
 645                 bits = show_bits(&s->gb, 17);
 646                 if (bits == MOTION_MARKER)
 647                     return mb_num - 1;
 648
 649                 skip_bits1(&s->gb);
 650                 if (bits & 0x10000) {
 651                     /* skip mb */
 652                     if (s->pict_type == AV_PICTURE_TYPE_S &&
 653                         ctx->vol_sprite_usage == GMC_SPRITE) {
 654                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
 655                                                          MB_TYPE_16x16 |
 656                                                          MB_TYPE_GMC   |
 657                                                          MB_TYPE_L0;
 658                         mx = get_amv(ctx, 0);
 659                         my = get_amv(ctx, 1);
 660                     } else {
 661                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
 662                                                          MB_TYPE_16x16 |
 663                                                          MB_TYPE_L0;
 664                         mx = my = 0;
 665                     }
 666                     mot_val[0]          =
 667                     mot_val[2]          =
 668                     mot_val[0 + stride] =
 669                     mot_val[2 + stride] = mx;
 670                     mot_val[1]          =
 671                     mot_val[3]          =
 672                     mot_val[1 + stride] =
 673                     mot_val[3 + stride] = my;
 674
 675                     if (s->mbintra_table[xy])
 676                         ff_clean_intra_table_entries(s);
 677                     continue;
 678                 }
 679
 680                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
 681                 if (cbpc < 0) {
 682                     av_log(s->avctx, AV_LOG_ERROR,
 683                            "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
 684                     return -1;
 685                 }
 686                 if (cbpc == 20)
 687                     goto try_again;
 688
 689                 s->cbp_table[xy] = cbpc & (8 + 3);  // 8 is dquant
 690
 691                 s->mb_intra = ((cbpc & 4) != 0);
 692
 693                 if (s->mb_intra) {
 694                     s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
 695                     s->mbintra_table[xy] = 1;
 696                     mot_val[0]          =
 697                     mot_val[2]          =
 698                     mot_val[0 + stride] =
 699                     mot_val[2 + stride] = 0;
 700                     mot_val[1]          =
 701                     mot_val[3]          =
 702                     mot_val[1 + stride] =
 703                     mot_val[3 + stride] = 0;
 704                 } else {
 705                     if (s->mbintra_table[xy])
 706                         ff_clean_intra_table_entries(s);
 707
 708                     if (s->pict_type == AV_PICTURE_TYPE_S &&
 709                         ctx->vol_sprite_usage == GMC_SPRITE &&
 710                         (cbpc & 16) == 0)
 711                         s->mcsel = get_bits1(&s->gb);
 712                     else
 713                         s->mcsel = 0;
 714
 715                     if ((cbpc & 16) == 0) {
 716                         /* 16x16 motion prediction */
 717
 718                         ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
 719                         if (!s->mcsel) {
 720                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
 721                             if (mx >= 0xffff)
 722                                 return -1;
 723
 724                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
 725                             if (my >= 0xffff)
 726                                 return -1;
 727                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
 728                                                              MB_TYPE_L0;
 729                         } else {
 730                             mx = get_amv(ctx, 0);
 731                             my = get_amv(ctx, 1);
 732                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
 733                                                              MB_TYPE_GMC   |
 734                                                              MB_TYPE_L0;
 735                         }
 736
 737                         mot_val[0]          =
 738                         mot_val[2]          =
 739                         mot_val[0 + stride] =
 740                         mot_val[2 + stride] = mx;
 741                         mot_val[1]          =
 742                         mot_val[3]          =
 743                         mot_val[1 + stride] =
 744                         mot_val[3 + stride] = my;
 745                     } else {
 746                         int i;
 747                         s->current_picture.mb_type[xy] = MB_TYPE_8x8 |
 748                                                          MB_TYPE_L0;
 749                         for (i = 0; i < 4; i++) {
 750                             int16_t *mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
 751                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
 752                             if (mx >= 0xffff)
 753                                 return -1;
 754
 755                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
 756                             if (my >= 0xffff)
 757                                 return -1;
 758                             mot_val[0] = mx;
 759                             mot_val[1] = my;
 760                         }
 761                     }
 762                 }
 763             }
 764         }
 765         s->mb_x = 0;
 766     }
 767
 768     return mb_num;
 769 }
 770
 771 /**
 772  * decode second partition.
 773  * @return <0 if an error occurred
 774  */
 775 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count)
 776 {
 777     int mb_num = 0;
 778     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
 779
 780     s->mb_x = s->resync_mb_x;
 781     s->first_slice_line = 1;
 782     for (s->mb_y = s->resync_mb_y; mb_num < mb_count; s->mb_y++) {
 783         ff_init_block_index(s);
 784         for (; mb_num < mb_count && s->mb_x < s->mb_width; s->mb_x++) {
 785             const int xy = s->mb_x + s->mb_y * s->mb_stride;
 786
 787             mb_num++;
 788             ff_update_block_index(s);
 789             if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
 790                 s->first_slice_line = 0;
 791
 792             if (s->pict_type == AV_PICTURE_TYPE_I) {
 793                 int ac_pred = get_bits1(&s->gb);
 794                 int cbpy    = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 795                 if (cbpy < 0) {
 796                     av_log(s->avctx, AV_LOG_ERROR,
 797                            "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 798                     return -1;
 799                 }
 800
 801                 s->cbp_table[xy]               |= cbpy << 2;
 802                 s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
 803             } else { /* P || S_TYPE */
 804                 if (IS_INTRA(s->current_picture.mb_type[xy])) {
 805                     int i;
 806                     int dir     = 0;
 807                     int ac_pred = get_bits1(&s->gb);
 808                     int cbpy    = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 809
 810                     if (cbpy < 0) {
 811                         av_log(s->avctx, AV_LOG_ERROR,
 812                                "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 813                         return -1;
 814                     }
 815
 816                     if (s->cbp_table[xy] & 8)
 817                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 818                     s->current_picture.qscale_table[xy] = s->qscale;
 819
 820                     for (i = 0; i < 6; i++) {
 821                         int dc_pred_dir;
 822                         int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
 823                         if (dc < 0) {
 824                             av_log(s->avctx, AV_LOG_ERROR,
 825                                    "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
 826                             return -1;
 827                         }
 828                         dir <<= 1;
 829                         if (dc_pred_dir)
 830                             dir |= 1;
 831                     }
 832                     s->cbp_table[xy]               &= 3;  // remove dquant
 833                     s->cbp_table[xy]               |= cbpy << 2;
 834                     s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
 835                     s->pred_dir_table[xy]           = dir;
 836                 } else if (IS_SKIP(s->current_picture.mb_type[xy])) {
 837                     s->current_picture.qscale_table[xy] = s->qscale;
 838                     s->cbp_table[xy]                    = 0;
 839                 } else {
 840                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
 841
 842                     if (cbpy < 0) {
 843                         av_log(s->avctx, AV_LOG_ERROR,
 844                                "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
 845                         return -1;
 846                     }
 847
 848                     if (s->cbp_table[xy] & 8)
 849                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
 850                     s->current_picture.qscale_table[xy] = s->qscale;
 851
 852                     s->cbp_table[xy] &= 3;  // remove dquant
 853                     s->cbp_table[xy] |= (cbpy ^ 0xf) << 2;
 854                 }
 855             }
 856         }
 857         if (mb_num >= mb_count)
 858             return 0;
 859         s->mb_x = 0;
 860     }
 861     return 0;
 862 }
 863
 864 /**
 865  * Decode the first and second partition.
 866  * @return <0 if error (and sets error type in the error_status_table)
 867  */
 868 int ff_mpeg4_decode_partitions(Mpeg4DecContext *ctx)
 869 {
 870     MpegEncContext *s = &ctx->m;
 871     int mb_num;
 872     const int part_a_error = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_ERROR | ER_MV_ERROR) : ER_MV_ERROR;
 873     const int part_a_end   = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_END   | ER_MV_END)   : ER_MV_END;
 874
 875     mb_num = mpeg4_decode_partition_a(ctx);
 876     if (mb_num < 0) {
 877         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
 878                         s->mb_x, s->mb_y, part_a_error);
 879         return -1;
 880     }
 881
 882     if (s->resync_mb_x + s->resync_mb_y * s->mb_width + mb_num > s->mb_num) {
 883         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
 884         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
 885                         s->mb_x, s->mb_y, part_a_error);
 886         return -1;
 887     }
 888
 889     s->mb_num_left = mb_num;
 890
 891     if (s->pict_type == AV_PICTURE_TYPE_I) {
 892         while (show_bits(&s->gb, 9) == 1)
 893             skip_bits(&s->gb, 9);
 894         if (get_bits_long(&s->gb, 19) != DC_MARKER) {
 895             av_log(s->avctx, AV_LOG_ERROR,
 896                    "marker missing after first I partition at %d %d\n",
 897                    s->mb_x, s->mb_y);
 898             return -1;
 899         }
 900     } else {
 901         while (show_bits(&s->gb, 10) == 1)
 902             skip_bits(&s->gb, 10);
 903         if (get_bits(&s->gb, 17) != MOTION_MARKER) {
 904             av_log(s->avctx, AV_LOG_ERROR,
 905                    "marker missing after first P partition at %d %d\n",
 906                    s->mb_x, s->mb_y);
 907             return -1;
 908         }
 909     }
 910     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
 911                     s->mb_x - 1, s->mb_y, part_a_end);
 912
 913     if (mpeg4_decode_partition_b(s, mb_num) < 0) {
 914         if (s->pict_type == AV_PICTURE_TYPE_P)
 915             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
 916                             s->mb_x, s->mb_y, ER_DC_ERROR);
 917         return -1;
 918     } else {
 919         if (s->pict_type == AV_PICTURE_TYPE_P)
 920             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
 921                             s->mb_x - 1, s->mb_y, ER_DC_END);
 922     }
 923
 924     return 0;
 925 }
 926
 927 /**
 928  * Decode a block.
 929  * @return <0 if an error occurred
 930  */
 931 static inline int mpeg4_decode_block(Mpeg4DecContext *ctx, int16_t *block,
 932                                      int n, int coded, int intra, int rvlc)
 933 {
 934     MpegEncContext *s = &ctx->m;
 935     int level, i, last, run, qmul, qadd, dc_pred_dir;
 936     RLTable *rl;
 937     RL_VLC_ELEM *rl_vlc;
 938     const uint8_t *scan_table;
 939
 940     // Note intra & rvlc should be optimized away if this is inlined
 941
 942     if (intra) {
 943         if (ctx->use_intra_dc_vlc) {
 944             /* DC coef */
 945             if (s->partitioned_frame) {
 946                 level = s->dc_val[0][s->block_index[n]];
 947                 if (n < 4)
 948                     level = FASTDIV((level + (s->y_dc_scale >> 1)), s->y_dc_scale);
 949                 else
 950                     level = FASTDIV((level + (s->c_dc_scale >> 1)), s->c_dc_scale);
 951                 dc_pred_dir = (s->pred_dir_table[s->mb_x + s->mb_y * s->mb_stride] << n) & 32;
 952             } else {
 953                 level = mpeg4_decode_dc(s, n, &dc_pred_dir);
 954                 if (level < 0)
 955                     return -1;
 956             }
 957             block[0] = level;
 958             i        = 0;
 959         } else {
 960             i = -1;
 961             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
 962         }
 963         if (!coded)
 964             goto not_coded;
 965
 966         if (rvlc) {
 967             rl     = &ff_rvlc_rl_intra;
 968             rl_vlc = ff_rvlc_rl_intra.rl_vlc[0];
 969         } else {
 970             rl     = &ff_mpeg4_rl_intra;
 971             rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
 972         }
 973         if (s->ac_pred) {
 974             if (dc_pred_dir == 0)
 975                 scan_table = s->intra_v_scantable.permutated;  /* left */
 976             else
 977                 scan_table = s->intra_h_scantable.permutated;  /* top */
 978         } else {
 979             scan_table = s->intra_scantable.permutated;
 980         }
 981         qmul = 1;
 982         qadd = 0;
 983     } else {
 984         i = -1;
 985         if (!coded) {
 986             s->block_last_index[n] = i;
 987             return 0;
 988         }
 989         if (rvlc)
 990             rl = &ff_rvlc_rl_inter;
 991         else
 992             rl = &ff_h263_rl_inter;
 993
 994         scan_table = s->intra_scantable.permutated;
 995
 996         if (s->mpeg_quant) {
 997             qmul = 1;
 998             qadd = 0;
 999             if (rvlc)
1000                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[0];
1001             else
1002                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
1003         } else {
1004             qmul = s->qscale << 1;
1005             qadd = (s->qscale - 1) | 1;
1006             if (rvlc)
1007                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[s->qscale];
1008             else
1009                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
1010         }
1011     }
1012     {
1013         OPEN_READER(re, &s->gb);
1014         for (;;) {
1015             UPDATE_CACHE(re, &s->gb);
1016             GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
1017             if (level == 0) {
1018                 /* escape */
1019                 if (rvlc) {
1020                     if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1021                         av_log(s->avctx, AV_LOG_ERROR,
1022                                "1. marker bit missing in rvlc esc\n");
1023                         return -1;
1024                     }
1025                     SKIP_CACHE(re, &s->gb, 1);
1026
1027                     last = SHOW_UBITS(re, &s->gb, 1);
1028                     SKIP_CACHE(re, &s->gb, 1);
1029                     run = SHOW_UBITS(re, &s->gb, 6);
1030                     SKIP_COUNTER(re, &s->gb, 1 + 1 + 6);
1031                     UPDATE_CACHE(re, &s->gb);
1032
1033                     if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1034                         av_log(s->avctx, AV_LOG_ERROR,
1035                                "2. marker bit missing in rvlc esc\n");
1036                         return -1;
1037                     }
1038                     SKIP_CACHE(re, &s->gb, 1);
1039
1040                     level = SHOW_UBITS(re, &s->gb, 11);
1041                     SKIP_CACHE(re, &s->gb, 11);
1042
1043                     if (SHOW_UBITS(re, &s->gb, 5) != 0x10) {
1044                         av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
1045                         return -1;
1046                     }
1047                     SKIP_CACHE(re, &s->gb, 5);
1048
1049                     level = level * qmul + qadd;
1050                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1051                     SKIP_COUNTER(re, &s->gb, 1 + 11 + 5 + 1);
1052
1053                     i += run + 1;
1054                     if (last)
1055                         i += 192;
1056                 } else {
1057                     int cache;
1058                     cache = GET_CACHE(re, &s->gb);
1059
1060                     if (IS_3IV1)
1061                         cache ^= 0xC0000000;
1062
1063                     if (cache & 0x80000000) {
1064                         if (cache & 0x40000000) {
1065                             /* third escape */
1066                             SKIP_CACHE(re, &s->gb, 2);
1067                             last = SHOW_UBITS(re, &s->gb, 1);
1068                             SKIP_CACHE(re, &s->gb, 1);
1069                             run = SHOW_UBITS(re, &s->gb, 6);
1070                             SKIP_COUNTER(re, &s->gb, 2 + 1 + 6);
1071                             UPDATE_CACHE(re, &s->gb);
1072
1073                             if (IS_3IV1) {
1074                                 level = SHOW_SBITS(re, &s->gb, 12);
1075                                 LAST_SKIP_BITS(re, &s->gb, 12);
1076                             } else {
1077                                 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1078                                     av_log(s->avctx, AV_LOG_ERROR,
1079                                            "1. marker bit missing in 3. esc\n");
1080                                     return -1;
1081                                 }
1082                                 SKIP_CACHE(re, &s->gb, 1);
1083
1084                                 level = SHOW_SBITS(re, &s->gb, 12);
1085                                 SKIP_CACHE(re, &s->gb, 12);
1086
1087                                 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1088                                     av_log(s->avctx, AV_LOG_ERROR,
1089                                            "2. marker bit missing in 3. esc\n");
1090                                     return -1;
1091                                 }
1092
1093                                 SKIP_COUNTER(re, &s->gb, 1 + 12 + 1);
1094                             }
1095
1096                             if (level > 0)
1097                                 level = level * qmul + qadd;
1098                             else
1099                                 level = level * qmul - qadd;
1100
1101                             if ((unsigned)(level + 2048) > 4095) {
1102                                 if (s->err_recognition & AV_EF_BITSTREAM) {
1103                                     if (level > 2560 || level < -2560) {
1104                                         av_log(s->avctx, AV_LOG_ERROR,
1105                                                "|level| overflow in 3. esc, qp=%d\n",
1106                                                s->qscale);
1107                                         return -1;
1108                                     }
1109                                 }
1110                                 level = level < 0 ? -2048 : 2047;
1111                             }
1112
1113                             i += run + 1;
1114                             if (last)
1115                                 i += 192;
1116                         } else {
1117                             /* second escape */
1118                             SKIP_BITS(re, &s->gb, 2);
1119                             GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1120                             i    += run + rl->max_run[run >> 7][level / qmul] + 1;  // FIXME opt indexing
1121                             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1122                             LAST_SKIP_BITS(re, &s->gb, 1);
1123                         }
1124                     } else {
1125                         /* first escape */
1126                         SKIP_BITS(re, &s->gb, 1);
1127                         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1128                         i    += run;
1129                         level = level + rl->max_level[run >> 7][(run - 1) & 63] * qmul;  // FIXME opt indexing
1130                         level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1131                         LAST_SKIP_BITS(re, &s->gb, 1);
1132                     }
1133                 }
1134             } else {
1135                 i    += run;
1136                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1137                 LAST_SKIP_BITS(re, &s->gb, 1);
1138             }
1139             if (i > 62) {
1140                 i -= 192;
1141                 if (i & (~63)) {
1142                     av_log(s->avctx, AV_LOG_ERROR,
1143                            "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1144                     return -1;
1145                 }
1146
1147                 block[scan_table[i]] = level;
1148                 break;
1149             }
1150
1151             block[scan_table[i]] = level;
1152         }
1153         CLOSE_READER(re, &s->gb);
1154     }
1155
1156 not_coded:
1157     if (intra) {
1158         if (!ctx->use_intra_dc_vlc) {
1159             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1160
1161             i -= i >> 31;  // if (i == -1) i = 0;
1162         }
1163
1164         ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
1165         if (s->ac_pred)
1166             i = 63;  // FIXME not optimal
1167     }
1168     s->block_last_index[n] = i;
1169     return 0;
1170 }
1171
1172 /**
1173  * decode partition C of one MB.
1174  * @return <0 if an error occurred
1175  */
1176 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, int16_t block[6][64])
1177 {
1178     Mpeg4DecContext *ctx = (Mpeg4DecContext *)s;
1179     int cbp, mb_type;
1180     const int xy = s->mb_x + s->mb_y * s->mb_stride;
1181
1182     mb_type = s->current_picture.mb_type[xy];
1183     cbp     = s->cbp_table[xy];
1184
1185     ctx->use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1186
1187     if (s->current_picture.qscale_table[xy] != s->qscale)
1188         ff_set_qscale(s, s->current_picture.qscale_table[xy]);
1189
1190     if (s->pict_type == AV_PICTURE_TYPE_P ||
1191         s->pict_type == AV_PICTURE_TYPE_S) {
1192         int i;
1193         for (i = 0; i < 4; i++) {
1194             s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0];
1195             s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1];
1196         }
1197         s->mb_intra = IS_INTRA(mb_type);
1198
1199         if (IS_SKIP(mb_type)) {
1200             /* skip mb */
1201             for (i = 0; i < 6; i++)
1202                 s->block_last_index[i] = -1;
1203             s->mv_dir  = MV_DIR_FORWARD;
1204             s->mv_type = MV_TYPE_16X16;
1205             if (s->pict_type == AV_PICTURE_TYPE_S
1206                 && ctx->vol_sprite_usage == GMC_SPRITE) {
1207                 s->mcsel      = 1;
1208                 s->mb_skipped = 0;
1209             } else {
1210                 s->mcsel      = 0;
1211                 s->mb_skipped = 1;
1212             }
1213         } else if (s->mb_intra) {
1214             s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1215         } else if (!s->mb_intra) {
1216             // s->mcsel = 0;  // FIXME do we need to init that?
1217
1218             s->mv_dir = MV_DIR_FORWARD;
1219             if (IS_8X8(mb_type)) {
1220                 s->mv_type = MV_TYPE_8X8;
1221             } else {
1222                 s->mv_type = MV_TYPE_16X16;
1223             }
1224         }
1225     } else { /* I-Frame */
1226         s->mb_intra = 1;
1227         s->ac_pred  = IS_ACPRED(s->current_picture.mb_type[xy]);
1228     }
1229
1230     if (!IS_SKIP(mb_type)) {
1231         int i;
1232         s->bdsp.clear_blocks(s->block[0]);
1233         /* decode each block */
1234         for (i = 0; i < 6; i++) {
1235             if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, s->mb_intra, ctx->rvlc) < 0) {
1236                 av_log(s->avctx, AV_LOG_ERROR,
1237                        "texture corrupted at %d %d %d\n",
1238                        s->mb_x, s->mb_y, s->mb_intra);
1239                 return -1;
1240             }
1241             cbp += cbp;
1242         }
1243     }
1244
1245     /* per-MB end of slice check */
1246     if (--s->mb_num_left <= 0) {
1247         if (mpeg4_is_resync(s))
1248             return SLICE_END;
1249         else
1250             return SLICE_NOEND;
1251     } else {
1252         if (mpeg4_is_resync(s)) {
1253             const int delta = s->mb_x + 1 == s->mb_width ? 2 : 1;
1254             if (s->cbp_table[xy + delta])
1255                 return SLICE_END;
1256         }
1257         return SLICE_OK;
1258     }
1259 }
1260
1261 static int mpeg4_decode_mb(MpegEncContext *s, int16_t block[6][64])
1262 {
1263     Mpeg4DecContext *ctx = (Mpeg4DecContext *)s;
1264     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1265     int16_t *mot_val;
1266     static int8_t quant_tab[4] = { -1, -2, 1, 2 };
1267     const int xy = s->mb_x + s->mb_y * s->mb_stride;
1268
1269     assert(s->h263_pred);
1270
1271     if (s->pict_type == AV_PICTURE_TYPE_P ||
1272         s->pict_type == AV_PICTURE_TYPE_S) {
1273         do {
1274             if (get_bits1(&s->gb)) {
1275                 /* skip mb */
1276                 s->mb_intra = 0;
1277                 for (i = 0; i < 6; i++)
1278                     s->block_last_index[i] = -1;
1279                 s->mv_dir  = MV_DIR_FORWARD;
1280                 s->mv_type = MV_TYPE_16X16;
1281                 if (s->pict_type == AV_PICTURE_TYPE_S &&
1282                     ctx->vol_sprite_usage == GMC_SPRITE) {
1283                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
1284                                                      MB_TYPE_GMC   |
1285                                                      MB_TYPE_16x16 |
1286                                                      MB_TYPE_L0;
1287                     s->mcsel       = 1;
1288                     s->mv[0][0][0] = get_amv(ctx, 0);
1289                     s->mv[0][0][1] = get_amv(ctx, 1);
1290                     s->mb_skipped  = 0;
1291                 } else {
1292                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
1293                                                      MB_TYPE_16x16 |
1294                                                      MB_TYPE_L0;
1295                     s->mcsel       = 0;
1296                     s->mv[0][0][0] = 0;
1297                     s->mv[0][0][1] = 0;
1298                     s->mb_skipped  = 1;
1299                 }
1300                 goto end;
1301             }
1302             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1303             if (cbpc < 0) {
1304                 av_log(s->avctx, AV_LOG_ERROR,
1305                        "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1306                 return -1;
1307             }
1308         } while (cbpc == 20);
1309
1310         s->bdsp.clear_blocks(s->block[0]);
1311         dquant      = cbpc & 8;
1312         s->mb_intra = ((cbpc & 4) != 0);
1313         if (s->mb_intra)
1314             goto intra;
1315
1316         if (s->pict_type == AV_PICTURE_TYPE_S &&
1317             ctx->vol_sprite_usage == GMC_SPRITE && (cbpc & 16) == 0)
1318             s->mcsel = get_bits1(&s->gb);
1319         else
1320             s->mcsel = 0;
1321         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1322
1323         cbp = (cbpc & 3) | (cbpy << 2);
1324         if (dquant)
1325             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1326         if ((!s->progressive_sequence) &&
1327             (cbp || (s->workaround_bugs & FF_BUG_XVID_ILACE)))
1328             s->interlaced_dct = get_bits1(&s->gb);
1329
1330         s->mv_dir = MV_DIR_FORWARD;
1331         if ((cbpc & 16) == 0) {
1332             if (s->mcsel) {
1333                 s->current_picture.mb_type[xy] = MB_TYPE_GMC   |
1334                                                  MB_TYPE_16x16 |
1335                                                  MB_TYPE_L0;
1336                 /* 16x16 global motion prediction */
1337                 s->mv_type     = MV_TYPE_16X16;
1338                 mx             = get_amv(ctx, 0);
1339                 my             = get_amv(ctx, 1);
1340                 s->mv[0][0][0] = mx;
1341                 s->mv[0][0][1] = my;
1342             } else if ((!s->progressive_sequence) && get_bits1(&s->gb)) {
1343                 s->current_picture.mb_type[xy] = MB_TYPE_16x8 |
1344                                                  MB_TYPE_L0   |
1345                                                  MB_TYPE_INTERLACED;
1346                 /* 16x8 field motion prediction */
1347                 s->mv_type = MV_TYPE_FIELD;
1348
1349                 s->field_select[0][0] = get_bits1(&s->gb);
1350                 s->field_select[0][1] = get_bits1(&s->gb);
1351
1352                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1353
1354                 for (i = 0; i < 2; i++) {
1355                     mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1356                     if (mx >= 0xffff)
1357                         return -1;
1358
1359                     my = ff_h263_decode_motion(s, pred_y / 2, s->f_code);
1360                     if (my >= 0xffff)
1361                         return -1;
1362
1363                     s->mv[0][i][0] = mx;
1364                     s->mv[0][i][1] = my;
1365                 }
1366             } else {
1367                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1368                 /* 16x16 motion prediction */
1369                 s->mv_type = MV_TYPE_16X16;
1370                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1371                 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1372
1373                 if (mx >= 0xffff)
1374                     return -1;
1375
1376                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1377
1378                 if (my >= 0xffff)
1379                     return -1;
1380                 s->mv[0][0][0] = mx;
1381                 s->mv[0][0][1] = my;
1382             }
1383         } else {
1384             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1385             s->mv_type                     = MV_TYPE_8X8;
1386             for (i = 0; i < 4; i++) {
1387                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1388                 mx      = ff_h263_decode_motion(s, pred_x, s->f_code);
1389                 if (mx >= 0xffff)
1390                     return -1;
1391
1392                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1393                 if (my >= 0xffff)
1394                     return -1;
1395                 s->mv[0][i][0] = mx;
1396                 s->mv[0][i][1] = my;
1397                 mot_val[0]     = mx;
1398                 mot_val[1]     = my;
1399             }
1400         }
1401     } else if (s->pict_type == AV_PICTURE_TYPE_B) {
1402         int modb1;   // first bit of modb
1403         int modb2;   // second bit of modb
1404         int mb_type;
1405
1406         s->mb_intra = 0;  // B-frames never contain intra blocks
1407         s->mcsel    = 0;  //      ...               true gmc blocks
1408
1409         if (s->mb_x == 0) {
1410             for (i = 0; i < 2; i++) {
1411                 s->last_mv[i][0][0] =
1412                 s->last_mv[i][0][1] =
1413                 s->last_mv[i][1][0] =
1414                 s->last_mv[i][1][1] = 0;
1415             }
1416
1417             ff_thread_await_progress(&s->next_picture_ptr->tf, s->mb_y, 0);
1418         }
1419
1420         /* if we skipped it in the future P Frame than skip it now too */
1421         s->mb_skipped = s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x];  // Note, skiptab=0 if last was GMC
1422
1423         if (s->mb_skipped) {
1424             /* skip mb */
1425             for (i = 0; i < 6; i++)
1426                 s->block_last_index[i] = -1;
1427
1428             s->mv_dir      = MV_DIR_FORWARD;
1429             s->mv_type     = MV_TYPE_16X16;
1430             s->mv[0][0][0] =
1431             s->mv[0][0][1] =
1432             s->mv[1][0][0] =
1433             s->mv[1][0][1] = 0;
1434             s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
1435                                              MB_TYPE_16x16 |
1436                                              MB_TYPE_L0;
1437             goto end;
1438         }
1439
1440         modb1 = get_bits1(&s->gb);
1441         if (modb1) {
1442             // like MB_TYPE_B_DIRECT but no vectors coded
1443             mb_type = MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1;
1444             cbp     = 0;
1445         } else {
1446             modb2   = get_bits1(&s->gb);
1447             mb_type = get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1448             if (mb_type < 0) {
1449                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1450                 return -1;
1451             }
1452             mb_type = mb_type_b_map[mb_type];
1453             if (modb2) {
1454                 cbp = 0;
1455             } else {
1456                 s->bdsp.clear_blocks(s->block[0]);
1457                 cbp = get_bits(&s->gb, 6);
1458             }
1459
1460             if ((!IS_DIRECT(mb_type)) && cbp) {
1461                 if (get_bits1(&s->gb))
1462                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb) * 4 - 2);
1463             }
1464
1465             if (!s->progressive_sequence) {
1466                 if (cbp)
1467                     s->interlaced_dct = get_bits1(&s->gb);
1468
1469                 if (!IS_DIRECT(mb_type) && get_bits1(&s->gb)) {
1470                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1471                     mb_type &= ~MB_TYPE_16x16;
1472
1473                     if (USES_LIST(mb_type, 0)) {
1474                         s->field_select[0][0] = get_bits1(&s->gb);
1475                         s->field_select[0][1] = get_bits1(&s->gb);
1476                     }
1477                     if (USES_LIST(mb_type, 1)) {
1478                         s->field_select[1][0] = get_bits1(&s->gb);
1479                         s->field_select[1][1] = get_bits1(&s->gb);
1480                     }
1481                 }
1482             }
1483
1484             s->mv_dir = 0;
1485             if ((mb_type & (MB_TYPE_DIRECT2 | MB_TYPE_INTERLACED)) == 0) {
1486                 s->mv_type = MV_TYPE_16X16;
1487
1488                 if (USES_LIST(mb_type, 0)) {
1489                     s->mv_dir = MV_DIR_FORWARD;
1490
1491                     mx = ff_h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1492                     my = ff_h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1493                     s->last_mv[0][1][0] =
1494                     s->last_mv[0][0][0] =
1495                     s->mv[0][0][0]      = mx;
1496                     s->last_mv[0][1][1] =
1497                     s->last_mv[0][0][1] =
1498                     s->mv[0][0][1]      = my;
1499                 }
1500
1501                 if (USES_LIST(mb_type, 1)) {
1502                     s->mv_dir |= MV_DIR_BACKWARD;
1503
1504                     mx = ff_h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1505                     my = ff_h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1506                     s->last_mv[1][1][0] =
1507                     s->last_mv[1][0][0] =
1508                     s->mv[1][0][0]      = mx;
1509                     s->last_mv[1][1][1] =
1510                     s->last_mv[1][0][1] =
1511                     s->mv[1][0][1]      = my;
1512                 }
1513             } else if (!IS_DIRECT(mb_type)) {
1514                 s->mv_type = MV_TYPE_FIELD;
1515
1516                 if (USES_LIST(mb_type, 0)) {
1517                     s->mv_dir = MV_DIR_FORWARD;
1518
1519                     for (i = 0; i < 2; i++) {
1520                         mx = ff_h263_decode_motion(s, s->last_mv[0][i][0], s->f_code);
1521                         my = ff_h263_decode_motion(s, s->last_mv[0][i][1] / 2, s->f_code);
1522                         s->last_mv[0][i][0] =
1523                         s->mv[0][i][0]      = mx;
1524                         s->last_mv[0][i][1] = (s->mv[0][i][1] = my) * 2;
1525                     }
1526                 }
1527
1528                 if (USES_LIST(mb_type, 1)) {
1529                     s->mv_dir |= MV_DIR_BACKWARD;
1530
1531                     for (i = 0; i < 2; i++) {
1532                         mx = ff_h263_decode_motion(s, s->last_mv[1][i][0], s->b_code);
1533                         my = ff_h263_decode_motion(s, s->last_mv[1][i][1] / 2, s->b_code);
1534                         s->last_mv[1][i][0] =
1535                         s->mv[1][i][0]      = mx;
1536                         s->last_mv[1][i][1] = (s->mv[1][i][1] = my) * 2;
1537                     }
1538                 }
1539             }
1540         }
1541
1542         if (IS_DIRECT(mb_type)) {
1543             if (IS_SKIP(mb_type)) {
1544                 mx =
1545                 my = 0;
1546             } else {
1547                 mx = ff_h263_decode_motion(s, 0, 1);
1548                 my = ff_h263_decode_motion(s, 0, 1);
1549             }
1550
1551             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1552             mb_type  |= ff_mpeg4_set_direct_mv(s, mx, my);
1553         }
1554         s->current_picture.mb_type[xy] = mb_type;
1555     } else { /* I-Frame */
1556         do {
1557             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1558             if (cbpc < 0) {
1559                 av_log(s->avctx, AV_LOG_ERROR,
1560                        "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1561                 return -1;
1562             }
1563         } while (cbpc == 8);
1564
1565         dquant = cbpc & 4;
1566         s->mb_intra = 1;
1567
1568 intra:
1569         s->ac_pred = get_bits1(&s->gb);
1570         if (s->ac_pred)
1571             s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1572         else
1573             s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
1574
1575         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1576         if (cbpy < 0) {
1577             av_log(s->avctx, AV_LOG_ERROR,
1578                    "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1579             return -1;
1580         }
1581         cbp = (cbpc & 3) | (cbpy << 2);
1582
1583         ctx->use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1584
1585         if (dquant)
1586             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1587
1588         if (!s->progressive_sequence)
1589             s->interlaced_dct = get_bits1(&s->gb);
1590
1591         s->bdsp.clear_blocks(s->block[0]);
1592         /* decode each block */
1593         for (i = 0; i < 6; i++) {
1594             if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, 1, 0) < 0)
1595                 return -1;
1596             cbp += cbp;
1597         }
1598         goto end;
1599     }
1600
1601     /* decode each block */
1602     for (i = 0; i < 6; i++) {
1603         if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, 0, 0) < 0)
1604             return -1;
1605         cbp += cbp;
1606     }
1607
1608 end:
1609     /* per-MB end of slice check */
1610     if (s->codec_id == AV_CODEC_ID_MPEG4) {
1611         if (mpeg4_is_resync(s)) {
1612             const int delta = s->mb_x + 1 == s->mb_width ? 2 : 1;
1613
1614             if (s->pict_type == AV_PICTURE_TYPE_B &&
1615                 s->next_picture.mbskip_table[xy + delta]) {
1616                 ff_thread_await_progress(&s->next_picture_ptr->tf,
1617                                          (s->mb_x + delta >= s->mb_width)
1618                                          ? FFMIN(s->mb_y + 1, s->mb_height - 1)
1619                                          : s->mb_y, 0);
1620             }
1621
1622             if (s->pict_type == AV_PICTURE_TYPE_B &&
1623                 s->next_picture.mbskip_table[xy + delta])
1624                 return SLICE_OK;
1625             return SLICE_END;
1626         }
1627     }
1628
1629     return SLICE_OK;
1630 }
1631
1632 static int mpeg4_decode_gop_header(MpegEncContext *s, GetBitContext *gb)
1633 {
1634     int hours, minutes, seconds;
1635     unsigned time_code = show_bits(gb, 18);
1636
1637     if (time_code & 0x40) {     /* marker_bit */
1638         hours   = time_code >> 13;
1639         minutes = time_code >> 7 & 0x3f;
1640         seconds = time_code & 0x3f;
1641         s->time_base = seconds + 60 * (minutes + 60 * hours);
1642         skip_bits(gb, 20);      /* time_code, closed_gov, broken_link */
1643     } else {
1644         av_log(s->avctx, AV_LOG_WARNING, "GOP header missing marker_bit\n");
1645     }
1646
1647     return 0;
1648 }
1649
1650 static int mpeg4_decode_profile_level(MpegEncContext *s, GetBitContext *gb)
1651 {
1652     int profile_and_level_indication;
1653
1654     profile_and_level_indication = get_bits(gb, 8);
1655
1656     s->avctx->profile = (profile_and_level_indication & 0xf0) >> 4;
1657     s->avctx->level   = (profile_and_level_indication & 0x0f);
1658
1659     // for Simple profile, level 0
1660     if (s->avctx->profile == 0 && s->avctx->level == 8) {
1661         s->avctx->level = 0;
1662     }
1663
1664     return 0;
1665 }
1666
1667 static int decode_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
1668 {
1669     MpegEncContext *s = &ctx->m;
1670     int width, height, vo_ver_id;
1671
1672     /* vol header */
1673     skip_bits(gb, 1);                   /* random access */
1674     s->vo_type = get_bits(gb, 8);
1675     if (get_bits1(gb) != 0) {           /* is_ol_id */
1676         vo_ver_id = get_bits(gb, 4);    /* vo_ver_id */
1677         skip_bits(gb, 3);               /* vo_priority */
1678     } else {
1679         vo_ver_id = 1;
1680     }
1681     s->aspect_ratio_info = get_bits(gb, 4);
1682     if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1683         s->avctx->sample_aspect_ratio.num = get_bits(gb, 8);  // par_width
1684         s->avctx->sample_aspect_ratio.den = get_bits(gb, 8);  // par_height
1685     } else {
1686         s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[s->aspect_ratio_info];
1687     }
1688
1689     if ((ctx->vol_control_parameters = get_bits1(gb))) { /* vol control parameter */
1690         int chroma_format = get_bits(gb, 2);
1691         if (chroma_format != CHROMA_420)
1692             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1693
1694         s->low_delay = get_bits1(gb);
1695         if (get_bits1(gb)) {    /* vbv parameters */
1696             get_bits(gb, 15);   /* first_half_bitrate */
1697             skip_bits1(gb);     /* marker */
1698             get_bits(gb, 15);   /* latter_half_bitrate */
1699             skip_bits1(gb);     /* marker */
1700             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
1701             skip_bits1(gb);     /* marker */
1702             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
1703             get_bits(gb, 11);   /* first_half_vbv_occupancy */
1704             skip_bits1(gb);     /* marker */
1705             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
1706             skip_bits1(gb);     /* marker */
1707         }
1708     } else {
1709         /* is setting low delay flag only once the smartest thing to do?
1710          * low delay detection won't be overriden. */
1711         if (s->picture_number == 0)
1712             s->low_delay = 0;
1713     }
1714
1715     ctx->shape = get_bits(gb, 2); /* vol shape */
1716     if (ctx->shape != RECT_SHAPE)
1717         av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1718     if (ctx->shape == GRAY_SHAPE && vo_ver_id != 1) {
1719         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1720         skip_bits(gb, 4);  /* video_object_layer_shape_extension */
1721     }
1722
1723     check_marker(gb, "before time_increment_resolution");
1724
1725     s->avctx->framerate.num = get_bits(gb, 16);
1726     if (!s->avctx->framerate.num) {
1727         av_log(s->avctx, AV_LOG_ERROR, "framerate==0\n");
1728         return -1;
1729     }
1730
1731     ctx->time_increment_bits = av_log2(s->avctx->framerate.num - 1) + 1;
1732     if (ctx->time_increment_bits < 1)
1733         ctx->time_increment_bits = 1;
1734
1735     check_marker(gb, "before fixed_vop_rate");
1736
1737     if (get_bits1(gb) != 0)     /* fixed_vop_rate  */
1738         s->avctx->framerate.den = get_bits(gb, ctx->time_increment_bits);
1739     else
1740         s->avctx->framerate.den = 1;
1741
1742     ctx->t_frame = 0;
1743
1744     if (ctx->shape != BIN_ONLY_SHAPE) {
1745         if (ctx->shape == RECT_SHAPE) {
1746             skip_bits1(gb);   /* marker */
1747             width = get_bits(gb, 13);
1748             skip_bits1(gb);   /* marker */
1749             height = get_bits(gb, 13);
1750             skip_bits1(gb);   /* marker */
1751             if (width && height &&  /* they should be non zero but who knows */
1752                 !(s->width && s->codec_tag == AV_RL32("MP4S"))) {
1753                 if (s->width && s->height &&
1754                     (s->width != width || s->height != height))
1755                     s->context_reinit = 1;
1756                 s->width  = width;
1757                 s->height = height;
1758             }
1759         }
1760
1761         s->progressive_sequence  =
1762         s->progressive_frame     = get_bits1(gb) ^ 1;
1763         s->interlaced_dct        = 0;
1764         if (!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1765             av_log(s->avctx, AV_LOG_INFO,           /* OBMC Disable */
1766                    "MPEG4 OBMC not supported (very likely buggy encoder)\n");
1767         if (vo_ver_id == 1)
1768             ctx->vol_sprite_usage = get_bits1(gb);    /* vol_sprite_usage */
1769         else
1770             ctx->vol_sprite_usage = get_bits(gb, 2);  /* vol_sprite_usage */
1771
1772         if (ctx->vol_sprite_usage == STATIC_SPRITE)
1773             av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1774         if (ctx->vol_sprite_usage == STATIC_SPRITE ||
1775             ctx->vol_sprite_usage == GMC_SPRITE) {
1776             if (ctx->vol_sprite_usage == STATIC_SPRITE) {
1777                 skip_bits(gb, 13); // sprite_width
1778                 skip_bits1(gb); /* marker */
1779                 skip_bits(gb, 13); // sprite_height
1780                 skip_bits1(gb); /* marker */
1781                 skip_bits(gb, 13); // sprite_left
1782                 skip_bits1(gb); /* marker */
1783                 skip_bits(gb, 13); // sprite_top
1784                 skip_bits1(gb); /* marker */
1785             }
1786             ctx->num_sprite_warping_points = get_bits(gb, 6);
1787             if (ctx->num_sprite_warping_points > 3) {
1788                 av_log(s->avctx, AV_LOG_ERROR,
1789                        "%d sprite_warping_points\n",
1790                        ctx->num_sprite_warping_points);
1791                 ctx->num_sprite_warping_points = 0;
1792                 return -1;
1793             }
1794             s->sprite_warping_accuracy  = get_bits(gb, 2);
1795             ctx->sprite_brightness_change = get_bits1(gb);
1796             if (ctx->vol_sprite_usage == STATIC_SPRITE)
1797                 skip_bits1(gb); // low_latency_sprite
1798         }
1799         // FIXME sadct disable bit if verid!=1 && shape not rect
1800
1801         if (get_bits1(gb) == 1) {                   /* not_8_bit */
1802             s->quant_precision = get_bits(gb, 4);   /* quant_precision */
1803             if (get_bits(gb, 4) != 8)               /* bits_per_pixel */
1804                 av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n");
1805             if (s->quant_precision != 5)
1806                 av_log(s->avctx, AV_LOG_ERROR,
1807                        "quant precision %d\n", s->quant_precision);
1808         } else {
1809             s->quant_precision = 5;
1810         }
1811
1812         // FIXME a bunch of grayscale shape things
1813
1814         if ((s->mpeg_quant = get_bits1(gb))) { /* vol_quant_type */
1815             int i, v;
1816
1817             /* load default matrixes */
1818             for (i = 0; i < 64; i++) {
1819                 int j = s->idsp.idct_permutation[i];
1820                 v = ff_mpeg4_default_intra_matrix[i];
1821                 s->intra_matrix[j]        = v;
1822                 s->chroma_intra_matrix[j] = v;
1823
1824                 v = ff_mpeg4_default_non_intra_matrix[i];
1825                 s->inter_matrix[j]        = v;
1826                 s->chroma_inter_matrix[j] = v;
1827             }
1828
1829             /* load custom intra matrix */
1830             if (get_bits1(gb)) {
1831                 int last = 0;
1832                 for (i = 0; i < 64; i++) {
1833                     int j;
1834                     v = get_bits(gb, 8);
1835                     if (v == 0)
1836                         break;
1837
1838                     last = v;
1839                     j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1840                     s->intra_matrix[j]        = last;
1841                     s->chroma_intra_matrix[j] = last;
1842                 }
1843
1844                 /* replicate last value */
1845                 for (; i < 64; i++) {
1846                     int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1847                     s->intra_matrix[j]        = last;
1848                     s->chroma_intra_matrix[j] = last;
1849                 }
1850             }
1851
1852             /* load custom non intra matrix */
1853             if (get_bits1(gb)) {
1854                 int last = 0;
1855                 for (i = 0; i < 64; i++) {
1856                     int j;
1857                     v = get_bits(gb, 8);
1858                     if (v == 0)
1859                         break;
1860
1861                     last = v;
1862                     j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1863                     s->inter_matrix[j]        = v;
1864                     s->chroma_inter_matrix[j] = v;
1865                 }
1866
1867                 /* replicate last value */
1868                 for (; i < 64; i++) {
1869                     int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1870                     s->inter_matrix[j]        = last;
1871                     s->chroma_inter_matrix[j] = last;
1872                 }
1873             }
1874
1875             // FIXME a bunch of grayscale shape things
1876         }
1877
1878         if (vo_ver_id != 1)
1879             s->quarter_sample = get_bits1(gb);
1880         else
1881             s->quarter_sample = 0;
1882
1883         if (!get_bits1(gb)) {
1884             int pos               = get_bits_count(gb);
1885             int estimation_method = get_bits(gb, 2);
1886             if (estimation_method < 2) {
1887                 if (!get_bits1(gb)) {
1888                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* opaque */
1889                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* transparent */
1890                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* intra_cae */
1891                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* inter_cae */
1892                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* no_update */
1893                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* upampling */
1894                 }
1895                 if (!get_bits1(gb)) {
1896                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* intra_blocks */
1897                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* inter_blocks */
1898                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* inter4v_blocks */
1899                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* not coded blocks */
1900                 }
1901                 if (!check_marker(gb, "in complexity estimation part 1")) {
1902                     skip_bits_long(gb, pos - get_bits_count(gb));
1903                     goto no_cplx_est;
1904                 }
1905                 if (!get_bits1(gb)) {
1906                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* dct_coeffs */
1907                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* dct_lines */
1908                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* vlc_syms */
1909                     ctx->cplx_estimation_trash_i += 4 * get_bits1(gb);  /* vlc_bits */
1910                 }
1911                 if (!get_bits1(gb)) {
1912                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* apm */
1913                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* npm */
1914                     ctx->cplx_estimation_trash_b += 8 * get_bits1(gb);  /* interpolate_mc_q */
1915                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* forwback_mc_q */
1916                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* halfpel2 */
1917                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* halfpel4 */
1918                 }
1919                 if (!check_marker(gb, "in complexity estimation part 2")) {
1920                     skip_bits_long(gb, pos - get_bits_count(gb));
1921                     goto no_cplx_est;
1922                 }
1923                 if (estimation_method == 1) {
1924                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* sadct */
1925                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* qpel */
1926                 }
1927             } else
1928                 av_log(s->avctx, AV_LOG_ERROR,
1929                        "Invalid Complexity estimation method %d\n",
1930                        estimation_method);
1931         } else {
1932
1933 no_cplx_est:
1934             ctx->cplx_estimation_trash_i =
1935             ctx->cplx_estimation_trash_p =
1936             ctx->cplx_estimation_trash_b = 0;
1937         }
1938
1939         ctx->resync_marker = !get_bits1(gb); /* resync_marker_disabled */
1940
1941         s->data_partitioning = get_bits1(gb);
1942         if (s->data_partitioning)
1943             ctx->rvlc = get_bits1(gb);
1944
1945         if (vo_ver_id != 1) {
1946             ctx->new_pred = get_bits1(gb);
1947             if (ctx->new_pred) {
1948                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
1949                 skip_bits(gb, 2); /* requested upstream message type */
1950                 skip_bits1(gb);   /* newpred segment type */
1951             }
1952             if (get_bits1(gb)) // reduced_res_vop
1953                 av_log(s->avctx, AV_LOG_ERROR,
1954                        "reduced resolution VOP not supported\n");
1955         } else {
1956             ctx->new_pred = 0;
1957         }
1958
1959         ctx->scalability = get_bits1(gb);
1960
1961         if (ctx->scalability) {
1962             GetBitContext bak = *gb;
1963             int h_sampling_factor_n;
1964             int h_sampling_factor_m;
1965             int v_sampling_factor_n;
1966             int v_sampling_factor_m;
1967
1968             skip_bits1(gb);    // hierarchy_type
1969             skip_bits(gb, 4);  /* ref_layer_id */
1970             skip_bits1(gb);    /* ref_layer_sampling_dir */
1971             h_sampling_factor_n = get_bits(gb, 5);
1972             h_sampling_factor_m = get_bits(gb, 5);
1973             v_sampling_factor_n = get_bits(gb, 5);
1974             v_sampling_factor_m = get_bits(gb, 5);
1975             ctx->enhancement_type = get_bits1(gb);
1976
1977             if (h_sampling_factor_n == 0 || h_sampling_factor_m == 0 ||
1978                 v_sampling_factor_n == 0 || v_sampling_factor_m == 0) {
1979                 /* illegal scalability header (VERY broken encoder),
1980                  * trying to workaround */
1981                 ctx->scalability = 0;
1982                 *gb            = bak;
1983             } else
1984                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
1985
1986             // bin shape stuff FIXME
1987         }
1988     }
1989
1990     return 0;
1991 }
1992
1993 /**
1994  * Decode the user data stuff in the header.
1995  * Also initializes divx/xvid/lavc_version/build.
1996  */
1997 static int decode_user_data(Mpeg4DecContext *ctx, GetBitContext *gb)
1998 {
1999     MpegEncContext *s = &ctx->m;
2000     char buf[256];
2001     int i;
2002     int e;
2003     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
2004     char last;
2005
2006     for (i = 0; i < 255 && get_bits_count(gb) < gb->size_in_bits; i++) {
2007         if (show_bits(gb, 23) == 0)
2008             break;
2009         buf[i] = get_bits(gb, 8);
2010     }
2011     buf[i] = 0;
2012
2013     /* divx detection */
2014     e = sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
2015     if (e < 2)
2016         e = sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
2017     if (e >= 2) {
2018         ctx->divx_version = ver;
2019         ctx->divx_build   = build;
2020         s->divx_packed  = e == 3 && last == 'p';
2021         if (s->divx_packed && !ctx->showed_packed_warning) {
2022             av_log(s->avctx, AV_LOG_WARNING,
2023                    "Invalid and inefficient vfw-avi packed B frames detected\n");
2024             ctx->showed_packed_warning = 1;
2025         }
2026     }
2027
2028     /* libavcodec detection */
2029     e = sscanf(buf, "FFmpe%*[^b]b%d", &build) + 3;
2030     if (e != 4)
2031         e = sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
2032     if (e != 4) {
2033         e = sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3) + 1;
2034         if (e > 1)
2035             build = (ver << 16) + (ver2 << 8) + ver3;
2036     }
2037     if (e != 4) {
2038         if (strcmp(buf, "ffmpeg") == 0)
2039             ctx->lavc_build = 4600;
2040     }
2041     if (e == 4)
2042         ctx->lavc_build = build;
2043
2044     /* Xvid detection */
2045     e = sscanf(buf, "XviD%d", &build);
2046     if (e == 1)
2047         ctx->xvid_build = build;
2048
2049     if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1) {
2050         if (s->codec_tag        == AV_RL32("XVID") ||
2051             s->codec_tag        == AV_RL32("XVIX") ||
2052             s->codec_tag        == AV_RL32("RMP4") ||
2053             s->codec_tag        == AV_RL32("ZMP4") ||
2054             s->codec_tag        == AV_RL32("SIPP"))
2055             ctx->xvid_build = 0;
2056     }
2057
2058     if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1)
2059         if (s->codec_tag == AV_RL32("DIVX") && s->vo_type == 0 &&
2060             ctx->vol_control_parameters == 0)
2061             ctx->divx_version = 400;  // divx 4
2062
2063     if (ctx->xvid_build >= 0 && ctx->divx_version >= 0) {
2064         ctx->divx_version =
2065         ctx->divx_build   = -1;
2066     }
2067
2068     if (CONFIG_MPEG4_DECODER && ctx->xvid_build >= 0)
2069         ff_xvid_idct_init(&s->idsp, s->avctx);
2070
2071     return 0;
2072 }
2073
2074 static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2075 {
2076     MpegEncContext *s = &ctx->m;
2077     int time_incr, time_increment;
2078
2079     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I;        /* pict type: I = 0 , P = 1 */
2080     if (s->pict_type == AV_PICTURE_TYPE_B && s->low_delay &&
2081         ctx->vol_control_parameters == 0 && !(s->flags & CODEC_FLAG_LOW_DELAY)) {
2082         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag set incorrectly, clearing it\n");
2083         s->low_delay = 0;
2084     }
2085
2086     s->partitioned_frame = s->data_partitioning && s->pict_type != AV_PICTURE_TYPE_B;
2087     if (s->partitioned_frame)
2088         s->decode_mb = mpeg4_decode_partitioned_mb;
2089     else
2090         s->decode_mb = mpeg4_decode_mb;
2091
2092     time_incr = 0;
2093     while (get_bits1(gb) != 0)
2094         time_incr++;
2095
2096     check_marker(gb, "before time_increment");
2097
2098     if (ctx->time_increment_bits == 0 ||
2099         !(show_bits(gb, ctx->time_increment_bits + 1) & 1)) {
2100         av_log(s->avctx, AV_LOG_ERROR,
2101                "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
2102
2103         for (ctx->time_increment_bits = 1;
2104              ctx->time_increment_bits < 16;
2105              ctx->time_increment_bits++) {
2106             if (s->pict_type == AV_PICTURE_TYPE_P ||
2107                 (s->pict_type == AV_PICTURE_TYPE_S &&
2108                  ctx->vol_sprite_usage == GMC_SPRITE)) {
2109                 if ((show_bits(gb, ctx->time_increment_bits + 6) & 0x37) == 0x30)
2110                     break;
2111             } else if ((show_bits(gb, ctx->time_increment_bits + 5) & 0x1F) == 0x18)
2112                 break;
2113         }
2114
2115         av_log(s->avctx, AV_LOG_ERROR,
2116                "my guess is %d bits ;)\n", ctx->time_increment_bits);
2117     }
2118
2119     if (IS_3IV1)
2120         time_increment = get_bits1(gb);        // FIXME investigate further
2121     else
2122         time_increment = get_bits(gb, ctx->time_increment_bits);
2123
2124     if (s->pict_type != AV_PICTURE_TYPE_B) {
2125         s->last_time_base = s->time_base;
2126         s->time_base     += time_incr;
2127         s->time = s->time_base * s->avctx->framerate.num + time_increment;
2128         if (s->workaround_bugs & FF_BUG_UMP4) {
2129             if (s->time < s->last_non_b_time) {
2130                 /* header is not mpeg-4-compatible, broken encoder,
2131                  * trying to workaround */
2132                 s->time_base++;
2133                 s->time += s->avctx->framerate.num;
2134             }
2135         }
2136         s->pp_time         = s->time - s->last_non_b_time;
2137         s->last_non_b_time = s->time;
2138     } else {
2139         s->time    = (s->last_time_base + time_incr) * s->avctx->framerate.num + time_increment;
2140         s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
2141         if (s->pp_time <= s->pb_time ||
2142             s->pp_time <= s->pp_time - s->pb_time ||
2143             s->pp_time <= 0) {
2144             /* messed up order, maybe after seeking? skipping current b-frame */
2145             return FRAME_SKIPPED;
2146         }
2147         ff_mpeg4_init_direct_mv(s);
2148
2149         if (ctx->t_frame == 0)
2150             ctx->t_frame = s->pb_time;
2151         if (ctx->t_frame == 0)
2152             ctx->t_frame = 1;  // 1/0 protection
2153         s->pp_field_time = (ROUNDED_DIV(s->last_non_b_time, ctx->t_frame) -
2154                             ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
2155         s->pb_field_time = (ROUNDED_DIV(s->time, ctx->t_frame) -
2156                             ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
2157         if (!s->progressive_sequence) {
2158             if (s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
2159                 return FRAME_SKIPPED;
2160         }
2161     }
2162
2163     check_marker(gb, "before vop_coded");
2164
2165     /* vop coded */
2166     if (get_bits1(gb) != 1) {
2167         if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2168             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
2169         return FRAME_SKIPPED;
2170     }
2171     if (ctx->shape != BIN_ONLY_SHAPE &&
2172                     (s->pict_type == AV_PICTURE_TYPE_P ||
2173                      (s->pict_type == AV_PICTURE_TYPE_S &&
2174                       ctx->vol_sprite_usage == GMC_SPRITE))) {
2175         /* rounding type for motion estimation */
2176         s->no_rounding = get_bits1(gb);
2177     } else {
2178         s->no_rounding = 0;
2179     }
2180     // FIXME reduced res stuff
2181
2182     if (ctx->shape != RECT_SHAPE) {
2183         if (ctx->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
2184             skip_bits(gb, 13);  /* width */
2185             skip_bits1(gb);     /* marker */
2186             skip_bits(gb, 13);  /* height */
2187             skip_bits1(gb);     /* marker */
2188             skip_bits(gb, 13);  /* hor_spat_ref */
2189             skip_bits1(gb);     /* marker */
2190             skip_bits(gb, 13);  /* ver_spat_ref */
2191         }
2192         skip_bits1(gb);         /* change_CR_disable */
2193
2194         if (get_bits1(gb) != 0)
2195             skip_bits(gb, 8);   /* constant_alpha_value */
2196     }
2197
2198     // FIXME complexity estimation stuff
2199
2200     if (ctx->shape != BIN_ONLY_SHAPE) {
2201         skip_bits_long(gb, ctx->cplx_estimation_trash_i);
2202         if (s->pict_type != AV_PICTURE_TYPE_I)
2203             skip_bits_long(gb, ctx->cplx_estimation_trash_p);
2204         if (s->pict_type == AV_PICTURE_TYPE_B)
2205             skip_bits_long(gb, ctx->cplx_estimation_trash_b);
2206
2207         ctx->intra_dc_threshold = ff_mpeg4_dc_threshold[get_bits(gb, 3)];
2208         if (!s->progressive_sequence) {
2209             s->top_field_first = get_bits1(gb);
2210             s->alternate_scan  = get_bits1(gb);
2211         } else
2212             s->alternate_scan = 0;
2213     }
2214
2215     if (s->alternate_scan) {
2216         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_alternate_vertical_scan);
2217         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_alternate_vertical_scan);
2218         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2219         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2220     } else {
2221         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_zigzag_direct);
2222         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_zigzag_direct);
2223         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2224         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2225     }
2226
2227     if (s->pict_type == AV_PICTURE_TYPE_S &&
2228         (ctx->vol_sprite_usage == STATIC_SPRITE ||
2229          ctx->vol_sprite_usage == GMC_SPRITE)) {
2230         if (mpeg4_decode_sprite_trajectory(ctx, gb) < 0)
2231             return AVERROR_INVALIDDATA;
2232         if (ctx->sprite_brightness_change)
2233             av_log(s->avctx, AV_LOG_ERROR,
2234                    "sprite_brightness_change not supported\n");
2235         if (ctx->vol_sprite_usage == STATIC_SPRITE)
2236             av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2237     }
2238
2239     if (ctx->shape != BIN_ONLY_SHAPE) {
2240         s->chroma_qscale = s->qscale = get_bits(gb, s->quant_precision);
2241         if (s->qscale == 0) {
2242             av_log(s->avctx, AV_LOG_ERROR,
2243                    "Error, header damaged or not MPEG4 header (qscale=0)\n");
2244             return -1;  // makes no sense to continue, as there is nothing left from the image then
2245         }
2246
2247         if (s->pict_type != AV_PICTURE_TYPE_I) {
2248             s->f_code = get_bits(gb, 3);        /* fcode_for */
2249             if (s->f_code == 0) {
2250                 av_log(s->avctx, AV_LOG_ERROR,
2251                        "Error, header damaged or not MPEG4 header (f_code=0)\n");
2252                 return -1;  // makes no sense to continue, as there is nothing left from the image then
2253             }
2254         } else
2255             s->f_code = 1;
2256
2257         if (s->pict_type == AV_PICTURE_TYPE_B) {
2258             s->b_code = get_bits(gb, 3);
2259         } else
2260             s->b_code = 1;
2261
2262         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2263             av_log(s->avctx, AV_LOG_DEBUG,
2264                    "qp:%d fc:%d,%d %s size:%d pro:%d alt:%d top:%d %spel part:%d resync:%d w:%d a:%d rnd:%d vot:%d%s dc:%d ce:%d/%d/%d\n",
2265                    s->qscale, s->f_code, s->b_code,
2266                    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")),
2267                    gb->size_in_bits, s->progressive_sequence, s->alternate_scan,
2268                    s->top_field_first, s->quarter_sample ? "q" : "h",
2269                    s->data_partitioning, ctx->resync_marker,
2270                    ctx->num_sprite_warping_points, s->sprite_warping_accuracy,
2271                    1 - s->no_rounding, s->vo_type,
2272                    ctx->vol_control_parameters ? " VOLC" : " ", ctx->intra_dc_threshold,
2273                    ctx->cplx_estimation_trash_i, ctx->cplx_estimation_trash_p,
2274                    ctx->cplx_estimation_trash_b);
2275         }
2276
2277         if (!ctx->scalability) {
2278             if (ctx->shape != RECT_SHAPE && s->pict_type != AV_PICTURE_TYPE_I)
2279                 skip_bits1(gb);  // vop shape coding type
2280         } else {
2281             if (ctx->enhancement_type) {
2282                 int load_backward_shape = get_bits1(gb);
2283                 if (load_backward_shape)
2284                     av_log(s->avctx, AV_LOG_ERROR,
2285                            "load backward shape isn't supported\n");
2286             }
2287             skip_bits(gb, 2);  // ref_select_code
2288         }
2289     }
2290     /* detect buggy encoders which don't set the low_delay flag
2291      * (divx4/xvid/opendivx). Note we cannot detect divx5 without b-frames
2292      * easily (although it's buggy too) */
2293     if (s->vo_type == 0 && ctx->vol_control_parameters == 0 &&
2294         ctx->divx_version == -1 && s->picture_number == 0) {
2295         av_log(s->avctx, AV_LOG_WARNING,
2296                "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2297         s->low_delay = 1;
2298     }
2299
2300     s->picture_number++;  // better than pic number==0 always ;)
2301
2302     // FIXME add short header support
2303     s->y_dc_scale_table = ff_mpeg4_y_dc_scale_table;
2304     s->c_dc_scale_table = ff_mpeg4_c_dc_scale_table;
2305
2306     if (s->workaround_bugs & FF_BUG_EDGE) {
2307         s->h_edge_pos = s->width;
2308         s->v_edge_pos = s->height;
2309     }
2310     return 0;
2311 }
2312
2313 /**
2314  * Decode mpeg4 headers.
2315  * @return <0 if no VOP found (or a damaged one)
2316  *         FRAME_SKIPPED if a not coded VOP is found
2317  *         0 if a VOP is found
2318  */
2319 int ff_mpeg4_decode_picture_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2320 {
2321     MpegEncContext *s = &ctx->m;
2322     unsigned startcode, v;
2323
2324     /* search next start code */
2325     align_get_bits(gb);
2326
2327     if (s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630) {
2328         skip_bits(gb, 24);
2329         if (get_bits(gb, 8) == 0xF0)
2330             goto end;
2331     }
2332
2333     startcode = 0xff;
2334     for (;;) {
2335         if (get_bits_count(gb) >= gb->size_in_bits) {
2336             if (gb->size_in_bits == 8 &&
2337                 (ctx->divx_version >= 0 || ctx->xvid_build >= 0)) {
2338                 av_log(s->avctx, AV_LOG_WARNING, "frame skip %d\n", gb->size_in_bits);
2339                 return FRAME_SKIPPED;  // divx bug
2340             } else
2341                 return -1;  // end of stream
2342         }
2343
2344         /* use the bits after the test */
2345         v = get_bits(gb, 8);
2346         startcode = ((startcode << 8) | v) & 0xffffffff;
2347
2348         if ((startcode & 0xFFFFFF00) != 0x100)
2349             continue;  // no startcode
2350
2351         if (s->avctx->debug & FF_DEBUG_STARTCODE) {
2352             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2353             if (startcode <= 0x11F)
2354                 av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2355             else if (startcode <= 0x12F)
2356                 av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2357             else if (startcode <= 0x13F)
2358                 av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2359             else if (startcode <= 0x15F)
2360                 av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2361             else if (startcode <= 0x1AF)
2362                 av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2363             else if (startcode == 0x1B0)
2364                 av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2365             else if (startcode == 0x1B1)
2366                 av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2367             else if (startcode == 0x1B2)
2368                 av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2369             else if (startcode == 0x1B3)
2370                 av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2371             else if (startcode == 0x1B4)
2372                 av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2373             else if (startcode == 0x1B5)
2374                 av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2375             else if (startcode == 0x1B6)
2376                 av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2377             else if (startcode == 0x1B7)
2378                 av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2379             else if (startcode == 0x1B8)
2380                 av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2381             else if (startcode == 0x1B9)
2382                 av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2383             else if (startcode == 0x1BA)
2384                 av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2385             else if (startcode == 0x1BB)
2386                 av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2387             else if (startcode == 0x1BC)
2388                 av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2389             else if (startcode == 0x1BD)
2390                 av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2391             else if (startcode == 0x1BE)
2392                 av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2393             else if (startcode == 0x1BF)
2394                 av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2395             else if (startcode == 0x1C0)
2396                 av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2397             else if (startcode == 0x1C1)
2398                 av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2399             else if (startcode == 0x1C2)
2400                 av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2401             else if (startcode == 0x1C3)
2402                 av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2403             else if (startcode <= 0x1C5)
2404                 av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2405             else if (startcode <= 0x1FF)
2406                 av_log(s->avctx, AV_LOG_DEBUG, "System start");
2407             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2408         }
2409
2410         if (startcode >= 0x120 && startcode <= 0x12F) {
2411             if (decode_vol_header(ctx, gb) < 0)
2412                 return -1;
2413         } else if (startcode == USER_DATA_STARTCODE) {
2414             decode_user_data(ctx, gb);
2415         } else if (startcode == GOP_STARTCODE) {
2416             mpeg4_decode_gop_header(s, gb);
2417         } else if (startcode == VOS_STARTCODE) {
2418             mpeg4_decode_profile_level(s, gb);
2419         } else if (startcode == VOP_STARTCODE) {
2420             break;
2421         }
2422
2423         align_get_bits(gb);
2424         startcode = 0xff;
2425     }
2426
2427 end:
2428     if (s->flags & CODEC_FLAG_LOW_DELAY)
2429         s->low_delay = 1;
2430     s->avctx->has_b_frames = !s->low_delay;
2431
2432     if (s->workaround_bugs & FF_BUG_AUTODETECT) {
2433         if (s->codec_tag == AV_RL32("XVIX"))
2434             s->workaround_bugs |= FF_BUG_XVID_ILACE;
2435
2436         if (s->codec_tag == AV_RL32("UMP4"))
2437             s->workaround_bugs |= FF_BUG_UMP4;
2438
2439         if (ctx->divx_version >= 500 && ctx->divx_build < 1814)
2440             s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2441
2442         if (ctx->divx_version > 502 && ctx->divx_build < 1814)
2443             s->workaround_bugs |= FF_BUG_QPEL_CHROMA2;
2444
2445         if (ctx->xvid_build <= 3U)
2446             s->padding_bug_score = 256 * 256 * 256 * 64;
2447
2448         if (ctx->xvid_build <= 1U)
2449             s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2450
2451         if (ctx->xvid_build <= 12U)
2452             s->workaround_bugs |= FF_BUG_EDGE;
2453
2454         if (ctx->xvid_build <= 32U)
2455             s->workaround_bugs |= FF_BUG_DC_CLIP;
2456
2457         if (ctx->lavc_build < 4653U)
2458             s->workaround_bugs |= FF_BUG_STD_QPEL;
2459
2460         if (ctx->lavc_build < 4655U)
2461             s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2462
2463         if (ctx->lavc_build < 4670U)
2464             s->workaround_bugs |= FF_BUG_EDGE;
2465
2466         if (ctx->lavc_build <= 4712U)
2467             s->workaround_bugs |= FF_BUG_DC_CLIP;
2468
2469         if (ctx->divx_version >= 0)
2470             s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2471
2472         if (ctx->divx_version == 501 && ctx->divx_build == 20020416)
2473             s->padding_bug_score = 256 * 256 * 256 * 64;
2474
2475         if (ctx->divx_version < 500U)
2476             s->workaround_bugs |= FF_BUG_EDGE;
2477
2478         if (ctx->divx_version >= 0)
2479             s->workaround_bugs |= FF_BUG_HPEL_CHROMA;
2480     }
2481
2482
2483     if (s->avctx->debug & FF_DEBUG_BUGS)
2484         av_log(s->avctx, AV_LOG_DEBUG,
2485                "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
2486                s->workaround_bugs, ctx->lavc_build, ctx->xvid_build,
2487                ctx->divx_version, ctx->divx_build, s->divx_packed ? "p" : "");
2488
2489     return decode_vop_header(ctx, gb);
2490 }
2491
2492 int ff_mpeg4_frame_end(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
2493 {
2494     Mpeg4DecContext *ctx = avctx->priv_data;
2495     MpegEncContext    *s = &ctx->m;
2496
2497     /* divx 5.01+ bistream reorder stuff */
2498     if (s->divx_packed) {
2499         int current_pos     = get_bits_count(&s->gb) >> 3;
2500         int startcode_found = 0;
2501
2502         if (buf_size - current_pos > 5) {
2503             int i;
2504             for (i = current_pos; i < buf_size - 3; i++)
2505                 if (buf[i]     == 0 &&
2506                     buf[i + 1] == 0 &&
2507                     buf[i + 2] == 1 &&
2508                     buf[i + 3] == 0xB6) {
2509                     startcode_found = 1;
2510                     break;
2511                 }
2512         }
2513         if (s->gb.buffer == s->bitstream_buffer && buf_size > 7 &&
2514             ctx->xvid_build >= 0) {       // xvid style
2515             startcode_found = 1;
2516             current_pos     = 0;
2517         }
2518
2519         if (startcode_found) {
2520             av_fast_malloc(&s->bitstream_buffer,
2521                            &s->allocated_bitstream_buffer_size,
2522                            buf_size - current_pos +
2523                            FF_INPUT_BUFFER_PADDING_SIZE);
2524             if (!s->bitstream_buffer)
2525                 return AVERROR(ENOMEM);
2526             memcpy(s->bitstream_buffer, buf + current_pos,
2527                    buf_size - current_pos);
2528             s->bitstream_buffer_size = buf_size - current_pos;
2529         }
2530     }
2531
2532     return 0;
2533 }
2534
2535 static int mpeg4_update_thread_context(AVCodecContext *dst,
2536                                        const AVCodecContext *src)
2537 {
2538     Mpeg4DecContext *s = dst->priv_data;
2539     const Mpeg4DecContext *s1 = src->priv_data;
2540     int init = s->m.context_initialized;
2541
2542     int ret = ff_mpeg_update_thread_context(dst, src);
2543
2544     if (ret < 0)
2545         return ret;
2546
2547     if (CONFIG_MPEG4_DECODER && !init && s1->xvid_build >= 0)
2548         ff_xvid_idct_init(&s->m.idsp, dst);
2549
2550     s->shape               = s1->shape;
2551     s->time_increment_bits = s1->time_increment_bits;
2552     s->xvid_build          = s1->xvid_build;
2553
2554     return 0;
2555 }
2556
2557 static av_cold int decode_init(AVCodecContext *avctx)
2558 {
2559     Mpeg4DecContext *ctx = avctx->priv_data;
2560     MpegEncContext *s = &ctx->m;
2561     int ret;
2562     static int done = 0;
2563
2564     ctx->divx_version =
2565     ctx->divx_build   =
2566     ctx->xvid_build   =
2567     ctx->lavc_build   = -1;
2568
2569     if ((ret = ff_h263_decode_init(avctx)) < 0)
2570         return ret;
2571
2572     if (!done) {
2573         done = 1;
2574
2575         ff_init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2576         ff_init_rl(&ff_rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2577         ff_init_rl(&ff_rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2578         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2579         INIT_VLC_RL(ff_rvlc_rl_inter, 1072);
2580         INIT_VLC_RL(ff_rvlc_rl_intra, 1072);
2581         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2582                         &ff_mpeg4_DCtab_lum[0][1], 2, 1,
2583                         &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2584         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2585                         &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2586                         &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2587         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2588                         &ff_sprite_trajectory_tab[0][1], 4, 2,
2589                         &ff_sprite_trajectory_tab[0][0], 4, 2, 128);
2590         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2591                         &ff_mb_type_b_tab[0][1], 2, 1,
2592                         &ff_mb_type_b_tab[0][0], 2, 1, 16);
2593     }
2594
2595     s->h263_pred = 1;
2596     s->low_delay = 0; /* default, might be overriden in the vol header during header parsing */
2597     s->decode_mb = mpeg4_decode_mb;
2598     ctx->time_increment_bits = 4; /* default value for broken headers */
2599
2600     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2601     avctx->internal->allocate_progress = 1;
2602
2603     return 0;
2604 }
2605
2606 static const AVProfile mpeg4_video_profiles[] = {
2607     { FF_PROFILE_MPEG4_SIMPLE,                    "Simple Profile" },
2608     { FF_PROFILE_MPEG4_SIMPLE_SCALABLE,           "Simple Scalable Profile" },
2609     { FF_PROFILE_MPEG4_CORE,                      "Core Profile" },
2610     { FF_PROFILE_MPEG4_MAIN,                      "Main Profile" },
2611     { FF_PROFILE_MPEG4_N_BIT,                     "N-bit Profile" },
2612     { FF_PROFILE_MPEG4_SCALABLE_TEXTURE,          "Scalable Texture Profile" },
2613     { FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION,     "Simple Face Animation Profile" },
2614     { FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE,    "Basic Animated Texture Profile" },
2615     { FF_PROFILE_MPEG4_HYBRID,                    "Hybrid Profile" },
2616     { FF_PROFILE_MPEG4_ADVANCED_REAL_TIME,        "Advanced Real Time Simple Profile" },
2617     { FF_PROFILE_MPEG4_CORE_SCALABLE,             "Code Scalable Profile" },
2618     { FF_PROFILE_MPEG4_ADVANCED_CODING,           "Advanced Coding Profile" },
2619     { FF_PROFILE_MPEG4_ADVANCED_CORE,             "Advanced Core Profile" },
2620     { FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE, "Advanced Scalable Texture Profile" },
2621     { FF_PROFILE_MPEG4_SIMPLE_STUDIO,             "Simple Studio Profile" },
2622     { FF_PROFILE_MPEG4_ADVANCED_SIMPLE,           "Advanced Simple Profile" },
2623 };
2624
2625 AVCodec ff_mpeg4_decoder = {
2626     .name                  = "mpeg4",
2627     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2628     .type                  = AVMEDIA_TYPE_VIDEO,
2629     .id                    = AV_CODEC_ID_MPEG4,
2630     .priv_data_size        = sizeof(Mpeg4DecContext),
2631     .init                  = decode_init,
2632     .close                 = ff_h263_decode_end,
2633     .decode                = ff_h263_decode_frame,
2634     .capabilities          = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
2635                              CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2636                              CODEC_CAP_FRAME_THREADS,
2637     .flush                 = ff_mpeg_flush,
2638     .pix_fmts              = ff_h263_hwaccel_pixfmt_list_420,
2639     .profiles              = NULL_IF_CONFIG_SMALL(mpeg4_video_profiles),
2640     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg4_update_thread_context),
2641 };