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mpeg4videodec.c
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1 /*
2  * MPEG4 decoder.
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #define UNCHECKED_BITSTREAM_READER 1
24 
25 #include "libavutil/opt.h"
26 #include "error_resilience.h"
27 #include "idctdsp.h"
28 #include "internal.h"
29 #include "mpegutils.h"
30 #include "mpegvideo.h"
31 #include "mpeg4video.h"
32 #include "h263.h"
33 #include "thread.h"
34 #include "xvididct.h"
35 
36 /* The defines below define the number of bits that are read at once for
37  * reading vlc values. Changing these may improve speed and data cache needs
38  * be aware though that decreasing them may need the number of stages that is
39  * passed to get_vlc* to be increased. */
40 #define SPRITE_TRAJ_VLC_BITS 6
41 #define DC_VLC_BITS 9
42 #define MB_TYPE_B_VLC_BITS 4
43 
44 static VLC dc_lum, dc_chrom;
45 static VLC sprite_trajectory;
46 static VLC mb_type_b_vlc;
47 
48 static const int mb_type_b_map[4] = {
49  MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
50  MB_TYPE_L0L1 | MB_TYPE_16x16,
51  MB_TYPE_L1 | MB_TYPE_16x16,
52  MB_TYPE_L0 | MB_TYPE_16x16,
53 };
54 
55 /**
56  * Predict the ac.
57  * @param n block index (0-3 are luma, 4-5 are chroma)
58  * @param dir the ac prediction direction
59  */
60 void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n, int dir)
61 {
62  int i;
63  int16_t *ac_val, *ac_val1;
64  int8_t *const qscale_table = s->current_picture.qscale_table;
65 
66  /* find prediction */
67  ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
68  ac_val1 = ac_val;
69  if (s->ac_pred) {
70  if (dir == 0) {
71  const int xy = s->mb_x - 1 + s->mb_y * s->mb_stride;
72  /* left prediction */
73  ac_val -= 16;
74 
75  if (s->mb_x == 0 || s->qscale == qscale_table[xy] ||
76  n == 1 || n == 3) {
77  /* same qscale */
78  for (i = 1; i < 8; i++)
79  block[s->idsp.idct_permutation[i << 3]] += ac_val[i];
80  } else {
81  /* different qscale, we must rescale */
82  for (i = 1; i < 8; i++)
83  block[s->idsp.idct_permutation[i << 3]] += ROUNDED_DIV(ac_val[i] * qscale_table[xy], s->qscale);
84  }
85  } else {
86  const int xy = s->mb_x + s->mb_y * s->mb_stride - s->mb_stride;
87  /* top prediction */
88  ac_val -= 16 * s->block_wrap[n];
89 
90  if (s->mb_y == 0 || s->qscale == qscale_table[xy] ||
91  n == 2 || n == 3) {
92  /* same qscale */
93  for (i = 1; i < 8; i++)
94  block[s->idsp.idct_permutation[i]] += ac_val[i + 8];
95  } else {
96  /* different qscale, we must rescale */
97  for (i = 1; i < 8; i++)
98  block[s->idsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8] * qscale_table[xy], s->qscale);
99  }
100  }
101  }
102  /* left copy */
103  for (i = 1; i < 8; i++)
104  ac_val1[i] = block[s->idsp.idct_permutation[i << 3]];
105 
106  /* top copy */
107  for (i = 1; i < 8; i++)
108  ac_val1[8 + i] = block[s->idsp.idct_permutation[i]];
109 }
110 
111 /**
112  * check if the next stuff is a resync marker or the end.
113  * @return 0 if not
114  */
115 static inline int mpeg4_is_resync(Mpeg4DecContext *ctx)
116 {
117  MpegEncContext *s = &ctx->m;
118  int bits_count = get_bits_count(&s->gb);
119  int v = show_bits(&s->gb, 16);
120 
121  if (s->workaround_bugs & FF_BUG_NO_PADDING && !ctx->resync_marker)
122  return 0;
123 
124  while (v <= 0xFF) {
125  if (s->pict_type == AV_PICTURE_TYPE_B ||
126  (v >> (8 - s->pict_type) != 1) || s->partitioned_frame)
127  break;
128  skip_bits(&s->gb, 8 + s->pict_type);
129  bits_count += 8 + s->pict_type;
130  v = show_bits(&s->gb, 16);
131  }
132 
133  if (bits_count + 8 >= s->gb.size_in_bits) {
134  v >>= 8;
135  v |= 0x7F >> (7 - (bits_count & 7));
136 
137  if (v == 0x7F)
138  return s->mb_num;
139  } else {
140  if (v == ff_mpeg4_resync_prefix[bits_count & 7]) {
141  int len, mb_num;
142  int mb_num_bits = av_log2(s->mb_num - 1) + 1;
143  GetBitContext gb = s->gb;
144 
145  skip_bits(&s->gb, 1);
146  align_get_bits(&s->gb);
147 
148  for (len = 0; len < 32; len++)
149  if (get_bits1(&s->gb))
150  break;
151 
152  mb_num = get_bits(&s->gb, mb_num_bits);
153  if (!mb_num || mb_num > s->mb_num || get_bits_count(&s->gb)+6 > s->gb.size_in_bits)
154  mb_num= -1;
155 
156  s->gb = gb;
157 
158  if (len >= ff_mpeg4_get_video_packet_prefix_length(s))
159  return mb_num;
160  }
161  }
162  return 0;
163 }
164 
165 static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *gb)
166 {
167  MpegEncContext *s = &ctx->m;
168  int a = 2 << s->sprite_warping_accuracy;
169  int rho = 3 - s->sprite_warping_accuracy;
170  int r = 16 / a;
171  int alpha = 0;
172  int beta = 0;
173  int w = s->width;
174  int h = s->height;
175  int min_ab, i, w2, h2, w3, h3;
176  int sprite_ref[4][2];
177  int virtual_ref[2][2];
178 
179  // only true for rectangle shapes
180  const int vop_ref[4][2] = { { 0, 0 }, { s->width, 0 },
181  { 0, s->height }, { s->width, s->height } };
182  int d[4][2] = { { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } };
183 
184  if (w <= 0 || h <= 0)
185  return AVERROR_INVALIDDATA;
186 
187  for (i = 0; i < ctx->num_sprite_warping_points; i++) {
188  int length;
189  int x = 0, y = 0;
190 
191  length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
192  if (length)
193  x = get_xbits(gb, length);
194 
195  if (!(ctx->divx_version == 500 && ctx->divx_build == 413))
196  skip_bits1(gb); /* marker bit */
197 
198  length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
199  if (length)
200  y = get_xbits(gb, length);
201 
202  skip_bits1(gb); /* marker bit */
203  ctx->sprite_traj[i][0] = d[i][0] = x;
204  ctx->sprite_traj[i][1] = d[i][1] = y;
205  }
206  for (; i < 4; i++)
207  ctx->sprite_traj[i][0] = ctx->sprite_traj[i][1] = 0;
208 
209  while ((1 << alpha) < w)
210  alpha++;
211  while ((1 << beta) < h)
212  beta++; /* typo in the mpeg4 std for the definition of w' and h' */
213  w2 = 1 << alpha;
214  h2 = 1 << beta;
215 
216  // Note, the 4th point isn't used for GMC
217  if (ctx->divx_version == 500 && ctx->divx_build == 413) {
218  sprite_ref[0][0] = a * vop_ref[0][0] + d[0][0];
219  sprite_ref[0][1] = a * vop_ref[0][1] + d[0][1];
220  sprite_ref[1][0] = a * vop_ref[1][0] + d[0][0] + d[1][0];
221  sprite_ref[1][1] = a * vop_ref[1][1] + d[0][1] + d[1][1];
222  sprite_ref[2][0] = a * vop_ref[2][0] + d[0][0] + d[2][0];
223  sprite_ref[2][1] = a * vop_ref[2][1] + d[0][1] + d[2][1];
224  } else {
225  sprite_ref[0][0] = (a >> 1) * (2 * vop_ref[0][0] + d[0][0]);
226  sprite_ref[0][1] = (a >> 1) * (2 * vop_ref[0][1] + d[0][1]);
227  sprite_ref[1][0] = (a >> 1) * (2 * vop_ref[1][0] + d[0][0] + d[1][0]);
228  sprite_ref[1][1] = (a >> 1) * (2 * vop_ref[1][1] + d[0][1] + d[1][1]);
229  sprite_ref[2][0] = (a >> 1) * (2 * vop_ref[2][0] + d[0][0] + d[2][0]);
230  sprite_ref[2][1] = (a >> 1) * (2 * vop_ref[2][1] + d[0][1] + d[2][1]);
231  }
232  /* sprite_ref[3][0] = (a >> 1) * (2 * vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
233  * sprite_ref[3][1] = (a >> 1) * (2 * vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
234 
235  /* this is mostly identical to the mpeg4 std (and is totally unreadable
236  * because of that...). Perhaps it should be reordered to be more readable.
237  * The idea behind this virtual_ref mess is to be able to use shifts later
238  * per pixel instead of divides so the distance between points is converted
239  * from w&h based to w2&h2 based which are of the 2^x form. */
240  virtual_ref[0][0] = 16 * (vop_ref[0][0] + w2) +
241  ROUNDED_DIV(((w - w2) *
242  (r * sprite_ref[0][0] - 16 * vop_ref[0][0]) +
243  w2 * (r * sprite_ref[1][0] - 16 * vop_ref[1][0])), w);
244  virtual_ref[0][1] = 16 * vop_ref[0][1] +
245  ROUNDED_DIV(((w - w2) *
246  (r * sprite_ref[0][1] - 16 * vop_ref[0][1]) +
247  w2 * (r * sprite_ref[1][1] - 16 * vop_ref[1][1])), w);
248  virtual_ref[1][0] = 16 * vop_ref[0][0] +
249  ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][0] - 16 * vop_ref[0][0]) +
250  h2 * (r * sprite_ref[2][0] - 16 * vop_ref[2][0])), h);
251  virtual_ref[1][1] = 16 * (vop_ref[0][1] + h2) +
252  ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][1] - 16 * vop_ref[0][1]) +
253  h2 * (r * sprite_ref[2][1] - 16 * vop_ref[2][1])), h);
254 
255  switch (ctx->num_sprite_warping_points) {
256  case 0:
257  s->sprite_offset[0][0] =
258  s->sprite_offset[0][1] =
259  s->sprite_offset[1][0] =
260  s->sprite_offset[1][1] = 0;
261  s->sprite_delta[0][0] = a;
262  s->sprite_delta[0][1] =
263  s->sprite_delta[1][0] = 0;
264  s->sprite_delta[1][1] = a;
265  ctx->sprite_shift[0] =
266  ctx->sprite_shift[1] = 0;
267  break;
268  case 1: // GMC only
269  s->sprite_offset[0][0] = sprite_ref[0][0] - a * vop_ref[0][0];
270  s->sprite_offset[0][1] = sprite_ref[0][1] - a * vop_ref[0][1];
271  s->sprite_offset[1][0] = ((sprite_ref[0][0] >> 1) | (sprite_ref[0][0] & 1)) -
272  a * (vop_ref[0][0] / 2);
273  s->sprite_offset[1][1] = ((sprite_ref[0][1] >> 1) | (sprite_ref[0][1] & 1)) -
274  a * (vop_ref[0][1] / 2);
275  s->sprite_delta[0][0] = a;
276  s->sprite_delta[0][1] =
277  s->sprite_delta[1][0] = 0;
278  s->sprite_delta[1][1] = a;
279  ctx->sprite_shift[0] =
280  ctx->sprite_shift[1] = 0;
281  break;
282  case 2:
283  s->sprite_offset[0][0] = (sprite_ref[0][0] << (alpha + rho)) +
284  (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
285  (-vop_ref[0][0]) +
286  (r * sprite_ref[0][1] - virtual_ref[0][1]) *
287  (-vop_ref[0][1]) + (1 << (alpha + rho - 1));
288  s->sprite_offset[0][1] = (sprite_ref[0][1] << (alpha + rho)) +
289  (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
290  (-vop_ref[0][0]) +
291  (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
292  (-vop_ref[0][1]) + (1 << (alpha + rho - 1));
293  s->sprite_offset[1][0] = ((-r * sprite_ref[0][0] + virtual_ref[0][0]) *
294  (-2 * vop_ref[0][0] + 1) +
295  (r * sprite_ref[0][1] - virtual_ref[0][1]) *
296  (-2 * vop_ref[0][1] + 1) + 2 * w2 * r *
297  sprite_ref[0][0] - 16 * w2 + (1 << (alpha + rho + 1)));
298  s->sprite_offset[1][1] = ((-r * sprite_ref[0][1] + virtual_ref[0][1]) *
299  (-2 * vop_ref[0][0] + 1) +
300  (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
301  (-2 * vop_ref[0][1] + 1) + 2 * w2 * r *
302  sprite_ref[0][1] - 16 * w2 + (1 << (alpha + rho + 1)));
303  s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
304  s->sprite_delta[0][1] = (+r * sprite_ref[0][1] - virtual_ref[0][1]);
305  s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]);
306  s->sprite_delta[1][1] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
307 
308  ctx->sprite_shift[0] = alpha + rho;
309  ctx->sprite_shift[1] = alpha + rho + 2;
310  break;
311  case 3:
312  min_ab = FFMIN(alpha, beta);
313  w3 = w2 >> min_ab;
314  h3 = h2 >> min_ab;
315  s->sprite_offset[0][0] = (sprite_ref[0][0] << (alpha + beta + rho - min_ab)) +
316  (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
317  h3 * (-vop_ref[0][0]) +
318  (-r * sprite_ref[0][0] + virtual_ref[1][0]) *
319  w3 * (-vop_ref[0][1]) +
320  (1 << (alpha + beta + rho - min_ab - 1));
321  s->sprite_offset[0][1] = (sprite_ref[0][1] << (alpha + beta + rho - min_ab)) +
322  (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
323  h3 * (-vop_ref[0][0]) +
324  (-r * sprite_ref[0][1] + virtual_ref[1][1]) *
325  w3 * (-vop_ref[0][1]) +
326  (1 << (alpha + beta + rho - min_ab - 1));
327  s->sprite_offset[1][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]) *
328  h3 * (-2 * vop_ref[0][0] + 1) +
329  (-r * sprite_ref[0][0] + virtual_ref[1][0]) *
330  w3 * (-2 * vop_ref[0][1] + 1) + 2 * w2 * h3 *
331  r * sprite_ref[0][0] - 16 * w2 * h3 +
332  (1 << (alpha + beta + rho - min_ab + 1));
333  s->sprite_offset[1][1] = (-r * sprite_ref[0][1] + virtual_ref[0][1]) *
334  h3 * (-2 * vop_ref[0][0] + 1) +
335  (-r * sprite_ref[0][1] + virtual_ref[1][1]) *
336  w3 * (-2 * vop_ref[0][1] + 1) + 2 * w2 * h3 *
337  r * sprite_ref[0][1] - 16 * w2 * h3 +
338  (1 << (alpha + beta + rho - min_ab + 1));
339  s->sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]) * h3;
340  s->sprite_delta[0][1] = (-r * sprite_ref[0][0] + virtual_ref[1][0]) * w3;
341  s->sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]) * h3;
342  s->sprite_delta[1][1] = (-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3;
343 
344  ctx->sprite_shift[0] = alpha + beta + rho - min_ab;
345  ctx->sprite_shift[1] = alpha + beta + rho - min_ab + 2;
346  break;
347  }
348  /* try to simplify the situation */
349  if (s->sprite_delta[0][0] == a << ctx->sprite_shift[0] &&
350  s->sprite_delta[0][1] == 0 &&
351  s->sprite_delta[1][0] == 0 &&
352  s->sprite_delta[1][1] == a << ctx->sprite_shift[0]) {
353  s->sprite_offset[0][0] >>= ctx->sprite_shift[0];
354  s->sprite_offset[0][1] >>= ctx->sprite_shift[0];
355  s->sprite_offset[1][0] >>= ctx->sprite_shift[1];
356  s->sprite_offset[1][1] >>= ctx->sprite_shift[1];
357  s->sprite_delta[0][0] = a;
358  s->sprite_delta[0][1] = 0;
359  s->sprite_delta[1][0] = 0;
360  s->sprite_delta[1][1] = a;
361  ctx->sprite_shift[0] = 0;
362  ctx->sprite_shift[1] = 0;
363  s->real_sprite_warping_points = 1;
364  } else {
365  int shift_y = 16 - ctx->sprite_shift[0];
366  int shift_c = 16 - ctx->sprite_shift[1];
367  for (i = 0; i < 2; i++) {
368  s->sprite_offset[0][i] <<= shift_y;
369  s->sprite_offset[1][i] <<= shift_c;
370  s->sprite_delta[0][i] <<= shift_y;
371  s->sprite_delta[1][i] <<= shift_y;
372  ctx->sprite_shift[i] = 16;
373  }
374  s->real_sprite_warping_points = ctx->num_sprite_warping_points;
375  }
376 
377  return 0;
378 }
379 
380 static int decode_new_pred(Mpeg4DecContext *ctx, GetBitContext *gb) {
381  int len = FFMIN(ctx->time_increment_bits + 3, 15);
382 
383  get_bits(gb, len);
384  if (get_bits1(gb))
385  get_bits(gb, len);
386  check_marker(gb, "after new_pred");
387 
388  return 0;
389 }
390 
391 /**
392  * Decode the next video packet.
393  * @return <0 if something went wrong
394  */
395 int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
396 {
397  MpegEncContext *s = &ctx->m;
398 
399  int mb_num_bits = av_log2(s->mb_num - 1) + 1;
400  int header_extension = 0, mb_num, len;
401 
402  /* is there enough space left for a video packet + header */
403  if (get_bits_count(&s->gb) > s->gb.size_in_bits - 20)
404  return -1;
405 
406  for (len = 0; len < 32; len++)
407  if (get_bits1(&s->gb))
408  break;
409 
410  if (len != ff_mpeg4_get_video_packet_prefix_length(s)) {
411  av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
412  return -1;
413  }
414 
415  if (ctx->shape != RECT_SHAPE) {
416  header_extension = get_bits1(&s->gb);
417  // FIXME more stuff here
418  }
419 
420  mb_num = get_bits(&s->gb, mb_num_bits);
421  if (mb_num >= s->mb_num) {
422  av_log(s->avctx, AV_LOG_ERROR,
423  "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
424  return -1;
425  }
426 
427  s->mb_x = mb_num % s->mb_width;
428  s->mb_y = mb_num / s->mb_width;
429 
430  if (ctx->shape != BIN_ONLY_SHAPE) {
431  int qscale = get_bits(&s->gb, s->quant_precision);
432  if (qscale)
433  s->chroma_qscale = s->qscale = qscale;
434  }
435 
436  if (ctx->shape == RECT_SHAPE)
437  header_extension = get_bits1(&s->gb);
438 
439  if (header_extension) {
440  int time_incr = 0;
441 
442  while (get_bits1(&s->gb) != 0)
443  time_incr++;
444 
445  check_marker(&s->gb, "before time_increment in video packed header");
446  skip_bits(&s->gb, ctx->time_increment_bits); /* time_increment */
447  check_marker(&s->gb, "before vop_coding_type in video packed header");
448 
449  skip_bits(&s->gb, 2); /* vop coding type */
450  // FIXME not rect stuff here
451 
452  if (ctx->shape != BIN_ONLY_SHAPE) {
453  skip_bits(&s->gb, 3); /* intra dc vlc threshold */
454  // FIXME don't just ignore everything
455  if (s->pict_type == AV_PICTURE_TYPE_S &&
456  ctx->vol_sprite_usage == GMC_SPRITE) {
457  if (mpeg4_decode_sprite_trajectory(ctx, &s->gb) < 0)
458  return AVERROR_INVALIDDATA;
459  av_log(s->avctx, AV_LOG_ERROR, "untested\n");
460  }
461 
462  // FIXME reduced res stuff here
463 
464  if (s->pict_type != AV_PICTURE_TYPE_I) {
465  int f_code = get_bits(&s->gb, 3); /* fcode_for */
466  if (f_code == 0)
467  av_log(s->avctx, AV_LOG_ERROR,
468  "Error, video packet header damaged (f_code=0)\n");
469  }
470  if (s->pict_type == AV_PICTURE_TYPE_B) {
471  int b_code = get_bits(&s->gb, 3);
472  if (b_code == 0)
473  av_log(s->avctx, AV_LOG_ERROR,
474  "Error, video packet header damaged (b_code=0)\n");
475  }
476  }
477  }
478  if (ctx->new_pred)
479  decode_new_pred(ctx, &s->gb);
480 
481  return 0;
482 }
483 
484 /**
485  * Get the average motion vector for a GMC MB.
486  * @param n either 0 for the x component or 1 for y
487  * @return the average MV for a GMC MB
488  */
489 static inline int get_amv(Mpeg4DecContext *ctx, int n)
490 {
491  MpegEncContext *s = &ctx->m;
492  int x, y, mb_v, sum, dx, dy, shift;
493  int len = 1 << (s->f_code + 4);
494  const int a = s->sprite_warping_accuracy;
495 
496  if (s->workaround_bugs & FF_BUG_AMV)
497  len >>= s->quarter_sample;
498 
499  if (s->real_sprite_warping_points == 1) {
500  if (ctx->divx_version == 500 && ctx->divx_build == 413)
501  sum = s->sprite_offset[0][n] / (1 << (a - s->quarter_sample));
502  else
503  sum = RSHIFT(s->sprite_offset[0][n] << s->quarter_sample, a);
504  } else {
505  dx = s->sprite_delta[n][0];
506  dy = s->sprite_delta[n][1];
507  shift = ctx->sprite_shift[0];
508  if (n)
509  dy -= 1 << (shift + a + 1);
510  else
511  dx -= 1 << (shift + a + 1);
512  mb_v = s->sprite_offset[0][n] + dx * s->mb_x * 16 + dy * s->mb_y * 16;
513 
514  sum = 0;
515  for (y = 0; y < 16; y++) {
516  int v;
517 
518  v = mb_v + dy * y;
519  // FIXME optimize
520  for (x = 0; x < 16; x++) {
521  sum += v >> shift;
522  v += dx;
523  }
524  }
525  sum = RSHIFT(sum, a + 8 - s->quarter_sample);
526  }
527 
528  if (sum < -len)
529  sum = -len;
530  else if (sum >= len)
531  sum = len - 1;
532 
533  return sum;
534 }
535 
536 /**
537  * Decode the dc value.
538  * @param n block index (0-3 are luma, 4-5 are chroma)
539  * @param dir_ptr the prediction direction will be stored here
540  * @return the quantized dc
541  */
542 static inline int mpeg4_decode_dc(MpegEncContext *s, int n, int *dir_ptr)
543 {
544  int level, code;
545 
546  if (n < 4)
547  code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
548  else
549  code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
550 
551  if (code < 0 || code > 9 /* && s->nbit < 9 */) {
552  av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
553  return -1;
554  }
555 
556  if (code == 0) {
557  level = 0;
558  } else {
559  if (IS_3IV1) {
560  if (code == 1)
561  level = 2 * get_bits1(&s->gb) - 1;
562  else {
563  if (get_bits1(&s->gb))
564  level = get_bits(&s->gb, code - 1) + (1 << (code - 1));
565  else
566  level = -get_bits(&s->gb, code - 1) - (1 << (code - 1));
567  }
568  } else {
569  level = get_xbits(&s->gb, code);
570  }
571 
572  if (code > 8) {
573  if (get_bits1(&s->gb) == 0) { /* marker */
574  if (s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)) {
575  av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
576  return -1;
577  }
578  }
579  }
580  }
581 
582  return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
583 }
584 
585 /**
586  * Decode first partition.
587  * @return number of MBs decoded or <0 if an error occurred
588  */
589 static int mpeg4_decode_partition_a(Mpeg4DecContext *ctx)
590 {
591  MpegEncContext *s = &ctx->m;
592  int mb_num = 0;
593  static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
594 
595  /* decode first partition */
596  s->first_slice_line = 1;
597  for (; s->mb_y < s->mb_height; s->mb_y++) {
598  ff_init_block_index(s);
599  for (; s->mb_x < s->mb_width; s->mb_x++) {
600  const int xy = s->mb_x + s->mb_y * s->mb_stride;
601  int cbpc;
602  int dir = 0;
603 
604  mb_num++;
605  ff_update_block_index(s);
606  if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
607  s->first_slice_line = 0;
608 
609  if (s->pict_type == AV_PICTURE_TYPE_I) {
610  int i;
611 
612  do {
613  if (show_bits_long(&s->gb, 19) == DC_MARKER)
614  return mb_num - 1;
615 
616  cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
617  if (cbpc < 0) {
618  av_log(s->avctx, AV_LOG_ERROR,
619  "mcbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
620  return -1;
621  }
622  } while (cbpc == 8);
623 
624  s->cbp_table[xy] = cbpc & 3;
625  s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
626  s->mb_intra = 1;
627 
628  if (cbpc & 4)
629  ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
630 
631  s->current_picture.qscale_table[xy] = s->qscale;
632 
633  s->mbintra_table[xy] = 1;
634  for (i = 0; i < 6; i++) {
635  int dc_pred_dir;
636  int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
637  if (dc < 0) {
638  av_log(s->avctx, AV_LOG_ERROR,
639  "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
640  return -1;
641  }
642  dir <<= 1;
643  if (dc_pred_dir)
644  dir |= 1;
645  }
646  s->pred_dir_table[xy] = dir;
647  } else { /* P/S_TYPE */
648  int mx, my, pred_x, pred_y, bits;
649  int16_t *const mot_val = s->current_picture.motion_val[0][s->block_index[0]];
650  const int stride = s->b8_stride * 2;
651 
652 try_again:
653  bits = show_bits(&s->gb, 17);
654  if (bits == MOTION_MARKER)
655  return mb_num - 1;
656 
657  skip_bits1(&s->gb);
658  if (bits & 0x10000) {
659  /* skip mb */
660  if (s->pict_type == AV_PICTURE_TYPE_S &&
661  ctx->vol_sprite_usage == GMC_SPRITE) {
662  s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
663  MB_TYPE_16x16 |
664  MB_TYPE_GMC |
665  MB_TYPE_L0;
666  mx = get_amv(ctx, 0);
667  my = get_amv(ctx, 1);
668  } else {
669  s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
670  MB_TYPE_16x16 |
671  MB_TYPE_L0;
672  mx = my = 0;
673  }
674  mot_val[0] =
675  mot_val[2] =
676  mot_val[0 + stride] =
677  mot_val[2 + stride] = mx;
678  mot_val[1] =
679  mot_val[3] =
680  mot_val[1 + stride] =
681  mot_val[3 + stride] = my;
682 
683  if (s->mbintra_table[xy])
684  ff_clean_intra_table_entries(s);
685  continue;
686  }
687 
688  cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
689  if (cbpc < 0) {
690  av_log(s->avctx, AV_LOG_ERROR,
691  "mcbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
692  return -1;
693  }
694  if (cbpc == 20)
695  goto try_again;
696 
697  s->cbp_table[xy] = cbpc & (8 + 3); // 8 is dquant
698 
699  s->mb_intra = ((cbpc & 4) != 0);
700 
701  if (s->mb_intra) {
702  s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
703  s->mbintra_table[xy] = 1;
704  mot_val[0] =
705  mot_val[2] =
706  mot_val[0 + stride] =
707  mot_val[2 + stride] = 0;
708  mot_val[1] =
709  mot_val[3] =
710  mot_val[1 + stride] =
711  mot_val[3 + stride] = 0;
712  } else {
713  if (s->mbintra_table[xy])
714  ff_clean_intra_table_entries(s);
715 
716  if (s->pict_type == AV_PICTURE_TYPE_S &&
717  ctx->vol_sprite_usage == GMC_SPRITE &&
718  (cbpc & 16) == 0)
719  s->mcsel = get_bits1(&s->gb);
720  else
721  s->mcsel = 0;
722 
723  if ((cbpc & 16) == 0) {
724  /* 16x16 motion prediction */
725 
726  ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
727  if (!s->mcsel) {
728  mx = ff_h263_decode_motion(s, pred_x, s->f_code);
729  if (mx >= 0xffff)
730  return -1;
731 
732  my = ff_h263_decode_motion(s, pred_y, s->f_code);
733  if (my >= 0xffff)
734  return -1;
735  s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
736  MB_TYPE_L0;
737  } else {
738  mx = get_amv(ctx, 0);
739  my = get_amv(ctx, 1);
740  s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
741  MB_TYPE_GMC |
742  MB_TYPE_L0;
743  }
744 
745  mot_val[0] =
746  mot_val[2] =
747  mot_val[0 + stride] =
748  mot_val[2 + stride] = mx;
749  mot_val[1] =
750  mot_val[3] =
751  mot_val[1 + stride] =
752  mot_val[3 + stride] = my;
753  } else {
754  int i;
755  s->current_picture.mb_type[xy] = MB_TYPE_8x8 |
756  MB_TYPE_L0;
757  for (i = 0; i < 4; i++) {
758  int16_t *mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
759  mx = ff_h263_decode_motion(s, pred_x, s->f_code);
760  if (mx >= 0xffff)
761  return -1;
762 
763  my = ff_h263_decode_motion(s, pred_y, s->f_code);
764  if (my >= 0xffff)
765  return -1;
766  mot_val[0] = mx;
767  mot_val[1] = my;
768  }
769  }
770  }
771  }
772  }
773  s->mb_x = 0;
774  }
775 
776  return mb_num;
777 }
778 
779 /**
780  * decode second partition.
781  * @return <0 if an error occurred
782  */
783 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count)
784 {
785  int mb_num = 0;
786  static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
787 
788  s->mb_x = s->resync_mb_x;
789  s->first_slice_line = 1;
790  for (s->mb_y = s->resync_mb_y; mb_num < mb_count; s->mb_y++) {
791  ff_init_block_index(s);
792  for (; mb_num < mb_count && s->mb_x < s->mb_width; s->mb_x++) {
793  const int xy = s->mb_x + s->mb_y * s->mb_stride;
794 
795  mb_num++;
796  ff_update_block_index(s);
797  if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
798  s->first_slice_line = 0;
799 
800  if (s->pict_type == AV_PICTURE_TYPE_I) {
801  int ac_pred = get_bits1(&s->gb);
802  int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
803  if (cbpy < 0) {
804  av_log(s->avctx, AV_LOG_ERROR,
805  "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
806  return -1;
807  }
808 
809  s->cbp_table[xy] |= cbpy << 2;
810  s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
811  } else { /* P || S_TYPE */
812  if (IS_INTRA(s->current_picture.mb_type[xy])) {
813  int i;
814  int dir = 0;
815  int ac_pred = get_bits1(&s->gb);
816  int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
817 
818  if (cbpy < 0) {
819  av_log(s->avctx, AV_LOG_ERROR,
820  "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
821  return -1;
822  }
823 
824  if (s->cbp_table[xy] & 8)
825  ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
826  s->current_picture.qscale_table[xy] = s->qscale;
827 
828  for (i = 0; i < 6; i++) {
829  int dc_pred_dir;
830  int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
831  if (dc < 0) {
832  av_log(s->avctx, AV_LOG_ERROR,
833  "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
834  return -1;
835  }
836  dir <<= 1;
837  if (dc_pred_dir)
838  dir |= 1;
839  }
840  s->cbp_table[xy] &= 3; // remove dquant
841  s->cbp_table[xy] |= cbpy << 2;
842  s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
843  s->pred_dir_table[xy] = dir;
844  } else if (IS_SKIP(s->current_picture.mb_type[xy])) {
845  s->current_picture.qscale_table[xy] = s->qscale;
846  s->cbp_table[xy] = 0;
847  } else {
848  int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
849 
850  if (cbpy < 0) {
851  av_log(s->avctx, AV_LOG_ERROR,
852  "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
853  return -1;
854  }
855 
856  if (s->cbp_table[xy] & 8)
857  ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
858  s->current_picture.qscale_table[xy] = s->qscale;
859 
860  s->cbp_table[xy] &= 3; // remove dquant
861  s->cbp_table[xy] |= (cbpy ^ 0xf) << 2;
862  }
863  }
864  }
865  if (mb_num >= mb_count)
866  return 0;
867  s->mb_x = 0;
868  }
869  return 0;
870 }
871 
872 /**
873  * Decode the first and second partition.
874  * @return <0 if error (and sets error type in the error_status_table)
875  */
876 int ff_mpeg4_decode_partitions(Mpeg4DecContext *ctx)
877 {
878  MpegEncContext *s = &ctx->m;
879  int mb_num;
880  const int part_a_error = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_ERROR | ER_MV_ERROR) : ER_MV_ERROR;
881  const int part_a_end = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_END | ER_MV_END) : ER_MV_END;
882 
883  mb_num = mpeg4_decode_partition_a(ctx);
884  if (mb_num < 0) {
885  ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
886  s->mb_x, s->mb_y, part_a_error);
887  return -1;
888  }
889 
890  if (s->resync_mb_x + s->resync_mb_y * s->mb_width + mb_num > s->mb_num) {
891  av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
892  ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
893  s->mb_x, s->mb_y, part_a_error);
894  return -1;
895  }
896 
897  s->mb_num_left = mb_num;
898 
899  if (s->pict_type == AV_PICTURE_TYPE_I) {
900  while (show_bits(&s->gb, 9) == 1)
901  skip_bits(&s->gb, 9);
902  if (get_bits_long(&s->gb, 19) != DC_MARKER) {
903  av_log(s->avctx, AV_LOG_ERROR,
904  "marker missing after first I partition at %d %d\n",
905  s->mb_x, s->mb_y);
906  return -1;
907  }
908  } else {
909  while (show_bits(&s->gb, 10) == 1)
910  skip_bits(&s->gb, 10);
911  if (get_bits(&s->gb, 17) != MOTION_MARKER) {
912  av_log(s->avctx, AV_LOG_ERROR,
913  "marker missing after first P partition at %d %d\n",
914  s->mb_x, s->mb_y);
915  return -1;
916  }
917  }
918  ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
919  s->mb_x - 1, s->mb_y, part_a_end);
920 
921  if (mpeg4_decode_partition_b(s, mb_num) < 0) {
922  if (s->pict_type == AV_PICTURE_TYPE_P)
923  ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
924  s->mb_x, s->mb_y, ER_DC_ERROR);
925  return -1;
926  } else {
927  if (s->pict_type == AV_PICTURE_TYPE_P)
928  ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
929  s->mb_x - 1, s->mb_y, ER_DC_END);
930  }
931 
932  return 0;
933 }
934 
935 /**
936  * Decode a block.
937  * @return <0 if an error occurred
938  */
939 static inline int mpeg4_decode_block(Mpeg4DecContext *ctx, int16_t *block,
940  int n, int coded, int intra, int rvlc)
941 {
942  MpegEncContext *s = &ctx->m;
943  int level, i, last, run, qmul, qadd;
944  int av_uninit(dc_pred_dir);
945  RLTable *rl;
946  RL_VLC_ELEM *rl_vlc;
947  const uint8_t *scan_table;
948 
949  // Note intra & rvlc should be optimized away if this is inlined
950 
951  if (intra) {
952  if (ctx->use_intra_dc_vlc) {
953  /* DC coef */
954  if (s->partitioned_frame) {
955  level = s->dc_val[0][s->block_index[n]];
956  if (n < 4)
957  level = FASTDIV((level + (s->y_dc_scale >> 1)), s->y_dc_scale);
958  else
959  level = FASTDIV((level + (s->c_dc_scale >> 1)), s->c_dc_scale);
960  dc_pred_dir = (s->pred_dir_table[s->mb_x + s->mb_y * s->mb_stride] << n) & 32;
961  } else {
962  level = mpeg4_decode_dc(s, n, &dc_pred_dir);
963  if (level < 0)
964  return -1;
965  }
966  block[0] = level;
967  i = 0;
968  } else {
969  i = -1;
970  ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
971  }
972  if (!coded)
973  goto not_coded;
974 
975  if (rvlc) {
976  rl = &ff_rvlc_rl_intra;
977  rl_vlc = ff_rvlc_rl_intra.rl_vlc[0];
978  } else {
979  rl = &ff_mpeg4_rl_intra;
980  rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
981  }
982  if (s->ac_pred) {
983  if (dc_pred_dir == 0)
984  scan_table = s->intra_v_scantable.permutated; /* left */
985  else
986  scan_table = s->intra_h_scantable.permutated; /* top */
987  } else {
988  scan_table = s->intra_scantable.permutated;
989  }
990  qmul = 1;
991  qadd = 0;
992  } else {
993  i = -1;
994  if (!coded) {
995  s->block_last_index[n] = i;
996  return 0;
997  }
998  if (rvlc)
999  rl = &ff_rvlc_rl_inter;
1000  else
1001  rl = &ff_h263_rl_inter;
1002 
1003  scan_table = s->intra_scantable.permutated;
1004 
1005  if (s->mpeg_quant) {
1006  qmul = 1;
1007  qadd = 0;
1008  if (rvlc)
1009  rl_vlc = ff_rvlc_rl_inter.rl_vlc[0];
1010  else
1011  rl_vlc = ff_h263_rl_inter.rl_vlc[0];
1012  } else {
1013  qmul = s->qscale << 1;
1014  qadd = (s->qscale - 1) | 1;
1015  if (rvlc)
1016  rl_vlc = ff_rvlc_rl_inter.rl_vlc[s->qscale];
1017  else
1018  rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
1019  }
1020  }
1021  {
1022  OPEN_READER(re, &s->gb);
1023  for (;;) {
1024  UPDATE_CACHE(re, &s->gb);
1025  GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
1026  if (level == 0) {
1027  /* escape */
1028  if (rvlc) {
1029  if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1030  av_log(s->avctx, AV_LOG_ERROR,
1031  "1. marker bit missing in rvlc esc\n");
1032  return -1;
1033  }
1034  SKIP_CACHE(re, &s->gb, 1);
1035 
1036  last = SHOW_UBITS(re, &s->gb, 1);
1037  SKIP_CACHE(re, &s->gb, 1);
1038  run = SHOW_UBITS(re, &s->gb, 6);
1039  SKIP_COUNTER(re, &s->gb, 1 + 1 + 6);
1040  UPDATE_CACHE(re, &s->gb);
1041 
1042  if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1043  av_log(s->avctx, AV_LOG_ERROR,
1044  "2. marker bit missing in rvlc esc\n");
1045  return -1;
1046  }
1047  SKIP_CACHE(re, &s->gb, 1);
1048 
1049  level = SHOW_UBITS(re, &s->gb, 11);
1050  SKIP_CACHE(re, &s->gb, 11);
1051 
1052  if (SHOW_UBITS(re, &s->gb, 5) != 0x10) {
1053  av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
1054  return -1;
1055  }
1056  SKIP_CACHE(re, &s->gb, 5);
1057 
1058  level = level * qmul + qadd;
1059  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1060  SKIP_COUNTER(re, &s->gb, 1 + 11 + 5 + 1);
1061 
1062  i += run + 1;
1063  if (last)
1064  i += 192;
1065  } else {
1066  int cache;
1067  cache = GET_CACHE(re, &s->gb);
1068 
1069  if (IS_3IV1)
1070  cache ^= 0xC0000000;
1071 
1072  if (cache & 0x80000000) {
1073  if (cache & 0x40000000) {
1074  /* third escape */
1075  SKIP_CACHE(re, &s->gb, 2);
1076  last = SHOW_UBITS(re, &s->gb, 1);
1077  SKIP_CACHE(re, &s->gb, 1);
1078  run = SHOW_UBITS(re, &s->gb, 6);
1079  SKIP_COUNTER(re, &s->gb, 2 + 1 + 6);
1080  UPDATE_CACHE(re, &s->gb);
1081 
1082  if (IS_3IV1) {
1083  level = SHOW_SBITS(re, &s->gb, 12);
1084  LAST_SKIP_BITS(re, &s->gb, 12);
1085  } else {
1086  if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1087  av_log(s->avctx, AV_LOG_ERROR,
1088  "1. marker bit missing in 3. esc\n");
1089  if (!(s->err_recognition & AV_EF_IGNORE_ERR))
1090  return -1;
1091  }
1092  SKIP_CACHE(re, &s->gb, 1);
1093 
1094  level = SHOW_SBITS(re, &s->gb, 12);
1095  SKIP_CACHE(re, &s->gb, 12);
1096 
1097  if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1098  av_log(s->avctx, AV_LOG_ERROR,
1099  "2. marker bit missing in 3. esc\n");
1100  if (!(s->err_recognition & AV_EF_IGNORE_ERR))
1101  return -1;
1102  }
1103 
1104  SKIP_COUNTER(re, &s->gb, 1 + 12 + 1);
1105  }
1106 
1107 #if 0
1108  if (s->error_recognition >= FF_ER_COMPLIANT) {
1109  const int abs_level= FFABS(level);
1110  if (abs_level<=MAX_LEVEL && run<=MAX_RUN) {
1111  const int run1= run - rl->max_run[last][abs_level] - 1;
1112  if (abs_level <= rl->max_level[last][run]) {
1113  av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
1114  return -1;
1115  }
1116  if (s->error_recognition > FF_ER_COMPLIANT) {
1117  if (abs_level <= rl->max_level[last][run]*2) {
1118  av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
1119  return -1;
1120  }
1121  if (run1 >= 0 && abs_level <= rl->max_level[last][run1]) {
1122  av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
1123  return -1;
1124  }
1125  }
1126  }
1127  }
1128 #endif
1129  if (level > 0)
1130  level = level * qmul + qadd;
1131  else
1132  level = level * qmul - qadd;
1133 
1134  if ((unsigned)(level + 2048) > 4095) {
1135  if (s->err_recognition & (AV_EF_BITSTREAM|AV_EF_AGGRESSIVE)) {
1136  if (level > 2560 || level < -2560) {
1137  av_log(s->avctx, AV_LOG_ERROR,
1138  "|level| overflow in 3. esc, qp=%d\n",
1139  s->qscale);
1140  return -1;
1141  }
1142  }
1143  level = level < 0 ? -2048 : 2047;
1144  }
1145 
1146  i += run + 1;
1147  if (last)
1148  i += 192;
1149  } else {
1150  /* second escape */
1151  SKIP_BITS(re, &s->gb, 2);
1152  GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1153  i += run + rl->max_run[run >> 7][level / qmul] + 1; // FIXME opt indexing
1154  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1155  LAST_SKIP_BITS(re, &s->gb, 1);
1156  }
1157  } else {
1158  /* first escape */
1159  SKIP_BITS(re, &s->gb, 1);
1160  GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1161  i += run;
1162  level = level + rl->max_level[run >> 7][(run - 1) & 63] * qmul; // FIXME opt indexing
1163  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1164  LAST_SKIP_BITS(re, &s->gb, 1);
1165  }
1166  }
1167  } else {
1168  i += run;
1169  level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1170  LAST_SKIP_BITS(re, &s->gb, 1);
1171  }
1172  tprintf(s->avctx, "dct[%d][%d] = %- 4d end?:%d\n", scan_table[i&63]&7, scan_table[i&63] >> 3, level, i>62);
1173  if (i > 62) {
1174  i -= 192;
1175  if (i & (~63)) {
1176  av_log(s->avctx, AV_LOG_ERROR,
1177  "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1178  return -1;
1179  }
1180 
1181  block[scan_table[i]] = level;
1182  break;
1183  }
1184 
1185  block[scan_table[i]] = level;
1186  }
1187  CLOSE_READER(re, &s->gb);
1188  }
1189 
1190 not_coded:
1191  if (intra) {
1192  if (!ctx->use_intra_dc_vlc) {
1193  block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1194 
1195  i -= i >> 31; // if (i == -1) i = 0;
1196  }
1197 
1198  ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
1199  if (s->ac_pred)
1200  i = 63; // FIXME not optimal
1201  }
1202  s->block_last_index[n] = i;
1203  return 0;
1204 }
1205 
1206 /**
1207  * decode partition C of one MB.
1208  * @return <0 if an error occurred
1209  */
1210 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, int16_t block[6][64])
1211 {
1212  Mpeg4DecContext *ctx = (Mpeg4DecContext *)s;
1213  int cbp, mb_type;
1214  const int xy = s->mb_x + s->mb_y * s->mb_stride;
1215 
1216  mb_type = s->current_picture.mb_type[xy];
1217  cbp = s->cbp_table[xy];
1218 
1219  ctx->use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1220 
1221  if (s->current_picture.qscale_table[xy] != s->qscale)
1222  ff_set_qscale(s, s->current_picture.qscale_table[xy]);
1223 
1224  if (s->pict_type == AV_PICTURE_TYPE_P ||
1225  s->pict_type == AV_PICTURE_TYPE_S) {
1226  int i;
1227  for (i = 0; i < 4; i++) {
1228  s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0];
1229  s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1];
1230  }
1231  s->mb_intra = IS_INTRA(mb_type);
1232 
1233  if (IS_SKIP(mb_type)) {
1234  /* skip mb */
1235  for (i = 0; i < 6; i++)
1236  s->block_last_index[i] = -1;
1237  s->mv_dir = MV_DIR_FORWARD;
1238  s->mv_type = MV_TYPE_16X16;
1239  if (s->pict_type == AV_PICTURE_TYPE_S
1240  && ctx->vol_sprite_usage == GMC_SPRITE) {
1241  s->mcsel = 1;
1242  s->mb_skipped = 0;
1243  } else {
1244  s->mcsel = 0;
1245  s->mb_skipped = 1;
1246  }
1247  } else if (s->mb_intra) {
1248  s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1249  } else if (!s->mb_intra) {
1250  // s->mcsel = 0; // FIXME do we need to init that?
1251 
1252  s->mv_dir = MV_DIR_FORWARD;
1253  if (IS_8X8(mb_type)) {
1254  s->mv_type = MV_TYPE_8X8;
1255  } else {
1256  s->mv_type = MV_TYPE_16X16;
1257  }
1258  }
1259  } else { /* I-Frame */
1260  s->mb_intra = 1;
1261  s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1262  }
1263 
1264  if (!IS_SKIP(mb_type)) {
1265  int i;
1266  s->bdsp.clear_blocks(s->block[0]);
1267  /* decode each block */
1268  for (i = 0; i < 6; i++) {
1269  if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, s->mb_intra, ctx->rvlc) < 0) {
1270  av_log(s->avctx, AV_LOG_ERROR,
1271  "texture corrupted at %d %d %d\n",
1272  s->mb_x, s->mb_y, s->mb_intra);
1273  return -1;
1274  }
1275  cbp += cbp;
1276  }
1277  }
1278 
1279  /* per-MB end of slice check */
1280  if (--s->mb_num_left <= 0) {
1281  if (mpeg4_is_resync(ctx))
1282  return SLICE_END;
1283  else
1284  return SLICE_NOEND;
1285  } else {
1286  if (mpeg4_is_resync(ctx)) {
1287  const int delta = s->mb_x + 1 == s->mb_width ? 2 : 1;
1288  if (s->cbp_table[xy + delta])
1289  return SLICE_END;
1290  }
1291  return SLICE_OK;
1292  }
1293 }
1294 
1295 static int mpeg4_decode_mb(MpegEncContext *s, int16_t block[6][64])
1296 {
1297  Mpeg4DecContext *ctx = (Mpeg4DecContext *)s;
1298  int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1299  int16_t *mot_val;
1300  static int8_t quant_tab[4] = { -1, -2, 1, 2 };
1301  const int xy = s->mb_x + s->mb_y * s->mb_stride;
1302 
1303  av_assert2(s->h263_pred);
1304 
1305  if (s->pict_type == AV_PICTURE_TYPE_P ||
1306  s->pict_type == AV_PICTURE_TYPE_S) {
1307  do {
1308  if (get_bits1(&s->gb)) {
1309  /* skip mb */
1310  s->mb_intra = 0;
1311  for (i = 0; i < 6; i++)
1312  s->block_last_index[i] = -1;
1313  s->mv_dir = MV_DIR_FORWARD;
1314  s->mv_type = MV_TYPE_16X16;
1315  if (s->pict_type == AV_PICTURE_TYPE_S &&
1316  ctx->vol_sprite_usage == GMC_SPRITE) {
1317  s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
1318  MB_TYPE_GMC |
1319  MB_TYPE_16x16 |
1320  MB_TYPE_L0;
1321  s->mcsel = 1;
1322  s->mv[0][0][0] = get_amv(ctx, 0);
1323  s->mv[0][0][1] = get_amv(ctx, 1);
1324  s->mb_skipped = 0;
1325  } else {
1326  s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
1327  MB_TYPE_16x16 |
1328  MB_TYPE_L0;
1329  s->mcsel = 0;
1330  s->mv[0][0][0] = 0;
1331  s->mv[0][0][1] = 0;
1332  s->mb_skipped = 1;
1333  }
1334  goto end;
1335  }
1336  cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1337  if (cbpc < 0) {
1338  av_log(s->avctx, AV_LOG_ERROR,
1339  "mcbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1340  return -1;
1341  }
1342  } while (cbpc == 20);
1343 
1344  s->bdsp.clear_blocks(s->block[0]);
1345  dquant = cbpc & 8;
1346  s->mb_intra = ((cbpc & 4) != 0);
1347  if (s->mb_intra)
1348  goto intra;
1349 
1350  if (s->pict_type == AV_PICTURE_TYPE_S &&
1351  ctx->vol_sprite_usage == GMC_SPRITE && (cbpc & 16) == 0)
1352  s->mcsel = get_bits1(&s->gb);
1353  else
1354  s->mcsel = 0;
1355  cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1356 
1357  cbp = (cbpc & 3) | (cbpy << 2);
1358  if (dquant)
1359  ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1360  if ((!s->progressive_sequence) &&
1361  (cbp || (s->workaround_bugs & FF_BUG_XVID_ILACE)))
1362  s->interlaced_dct = get_bits1(&s->gb);
1363 
1364  s->mv_dir = MV_DIR_FORWARD;
1365  if ((cbpc & 16) == 0) {
1366  if (s->mcsel) {
1367  s->current_picture.mb_type[xy] = MB_TYPE_GMC |
1368  MB_TYPE_16x16 |
1369  MB_TYPE_L0;
1370  /* 16x16 global motion prediction */
1371  s->mv_type = MV_TYPE_16X16;
1372  mx = get_amv(ctx, 0);
1373  my = get_amv(ctx, 1);
1374  s->mv[0][0][0] = mx;
1375  s->mv[0][0][1] = my;
1376  } else if ((!s->progressive_sequence) && get_bits1(&s->gb)) {
1377  s->current_picture.mb_type[xy] = MB_TYPE_16x8 |
1378  MB_TYPE_L0 |
1379  MB_TYPE_INTERLACED;
1380  /* 16x8 field motion prediction */
1381  s->mv_type = MV_TYPE_FIELD;
1382 
1383  s->field_select[0][0] = get_bits1(&s->gb);
1384  s->field_select[0][1] = get_bits1(&s->gb);
1385 
1386  ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1387 
1388  for (i = 0; i < 2; i++) {
1389  mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1390  if (mx >= 0xffff)
1391  return -1;
1392 
1393  my = ff_h263_decode_motion(s, pred_y / 2, s->f_code);
1394  if (my >= 0xffff)
1395  return -1;
1396 
1397  s->mv[0][i][0] = mx;
1398  s->mv[0][i][1] = my;
1399  }
1400  } else {
1401  s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1402  /* 16x16 motion prediction */
1403  s->mv_type = MV_TYPE_16X16;
1404  ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1405  mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1406 
1407  if (mx >= 0xffff)
1408  return -1;
1409 
1410  my = ff_h263_decode_motion(s, pred_y, s->f_code);
1411 
1412  if (my >= 0xffff)
1413  return -1;
1414  s->mv[0][0][0] = mx;
1415  s->mv[0][0][1] = my;
1416  }
1417  } else {
1418  s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1419  s->mv_type = MV_TYPE_8X8;
1420  for (i = 0; i < 4; i++) {
1421  mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1422  mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1423  if (mx >= 0xffff)
1424  return -1;
1425 
1426  my = ff_h263_decode_motion(s, pred_y, s->f_code);
1427  if (my >= 0xffff)
1428  return -1;
1429  s->mv[0][i][0] = mx;
1430  s->mv[0][i][1] = my;
1431  mot_val[0] = mx;
1432  mot_val[1] = my;
1433  }
1434  }
1435  } else if (s->pict_type == AV_PICTURE_TYPE_B) {
1436  int modb1; // first bit of modb
1437  int modb2; // second bit of modb
1438  int mb_type;
1439 
1440  s->mb_intra = 0; // B-frames never contain intra blocks
1441  s->mcsel = 0; // ... true gmc blocks
1442 
1443  if (s->mb_x == 0) {
1444  for (i = 0; i < 2; i++) {
1445  s->last_mv[i][0][0] =
1446  s->last_mv[i][0][1] =
1447  s->last_mv[i][1][0] =
1448  s->last_mv[i][1][1] = 0;
1449  }
1450 
1451  ff_thread_await_progress(&s->next_picture_ptr->tf, s->mb_y, 0);
1452  }
1453 
1454  /* if we skipped it in the future P Frame than skip it now too */
1455  s->mb_skipped = s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x]; // Note, skiptab=0 if last was GMC
1456 
1457  if (s->mb_skipped) {
1458  /* skip mb */
1459  for (i = 0; i < 6; i++)
1460  s->block_last_index[i] = -1;
1461 
1462  s->mv_dir = MV_DIR_FORWARD;
1463  s->mv_type = MV_TYPE_16X16;
1464  s->mv[0][0][0] =
1465  s->mv[0][0][1] =
1466  s->mv[1][0][0] =
1467  s->mv[1][0][1] = 0;
1468  s->current_picture.mb_type[xy] = MB_TYPE_SKIP |
1469  MB_TYPE_16x16 |
1470  MB_TYPE_L0;
1471  goto end;
1472  }
1473 
1474  modb1 = get_bits1(&s->gb);
1475  if (modb1) {
1476  // like MB_TYPE_B_DIRECT but no vectors coded
1477  mb_type = MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1;
1478  cbp = 0;
1479  } else {
1480  modb2 = get_bits1(&s->gb);
1481  mb_type = get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1482  if (mb_type < 0) {
1483  av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1484  return -1;
1485  }
1486  mb_type = mb_type_b_map[mb_type];
1487  if (modb2) {
1488  cbp = 0;
1489  } else {
1490  s->bdsp.clear_blocks(s->block[0]);
1491  cbp = get_bits(&s->gb, 6);
1492  }
1493 
1494  if ((!IS_DIRECT(mb_type)) && cbp) {
1495  if (get_bits1(&s->gb))
1496  ff_set_qscale(s, s->qscale + get_bits1(&s->gb) * 4 - 2);
1497  }
1498 
1499  if (!s->progressive_sequence) {
1500  if (cbp)
1501  s->interlaced_dct = get_bits1(&s->gb);
1502 
1503  if (!IS_DIRECT(mb_type) && get_bits1(&s->gb)) {
1504  mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1505  mb_type &= ~MB_TYPE_16x16;
1506 
1507  if (USES_LIST(mb_type, 0)) {
1508  s->field_select[0][0] = get_bits1(&s->gb);
1509  s->field_select[0][1] = get_bits1(&s->gb);
1510  }
1511  if (USES_LIST(mb_type, 1)) {
1512  s->field_select[1][0] = get_bits1(&s->gb);
1513  s->field_select[1][1] = get_bits1(&s->gb);
1514  }
1515  }
1516  }
1517 
1518  s->mv_dir = 0;
1519  if ((mb_type & (MB_TYPE_DIRECT2 | MB_TYPE_INTERLACED)) == 0) {
1520  s->mv_type = MV_TYPE_16X16;
1521 
1522  if (USES_LIST(mb_type, 0)) {
1523  s->mv_dir = MV_DIR_FORWARD;
1524 
1525  mx = ff_h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1526  my = ff_h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1527  s->last_mv[0][1][0] =
1528  s->last_mv[0][0][0] =
1529  s->mv[0][0][0] = mx;
1530  s->last_mv[0][1][1] =
1531  s->last_mv[0][0][1] =
1532  s->mv[0][0][1] = my;
1533  }
1534 
1535  if (USES_LIST(mb_type, 1)) {
1536  s->mv_dir |= MV_DIR_BACKWARD;
1537 
1538  mx = ff_h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1539  my = ff_h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1540  s->last_mv[1][1][0] =
1541  s->last_mv[1][0][0] =
1542  s->mv[1][0][0] = mx;
1543  s->last_mv[1][1][1] =
1544  s->last_mv[1][0][1] =
1545  s->mv[1][0][1] = my;
1546  }
1547  } else if (!IS_DIRECT(mb_type)) {
1548  s->mv_type = MV_TYPE_FIELD;
1549 
1550  if (USES_LIST(mb_type, 0)) {
1551  s->mv_dir = MV_DIR_FORWARD;
1552 
1553  for (i = 0; i < 2; i++) {
1554  mx = ff_h263_decode_motion(s, s->last_mv[0][i][0], s->f_code);
1555  my = ff_h263_decode_motion(s, s->last_mv[0][i][1] / 2, s->f_code);
1556  s->last_mv[0][i][0] =
1557  s->mv[0][i][0] = mx;
1558  s->last_mv[0][i][1] = (s->mv[0][i][1] = my) * 2;
1559  }
1560  }
1561 
1562  if (USES_LIST(mb_type, 1)) {
1563  s->mv_dir |= MV_DIR_BACKWARD;
1564 
1565  for (i = 0; i < 2; i++) {
1566  mx = ff_h263_decode_motion(s, s->last_mv[1][i][0], s->b_code);
1567  my = ff_h263_decode_motion(s, s->last_mv[1][i][1] / 2, s->b_code);
1568  s->last_mv[1][i][0] =
1569  s->mv[1][i][0] = mx;
1570  s->last_mv[1][i][1] = (s->mv[1][i][1] = my) * 2;
1571  }
1572  }
1573  }
1574  }
1575 
1576  if (IS_DIRECT(mb_type)) {
1577  if (IS_SKIP(mb_type)) {
1578  mx =
1579  my = 0;
1580  } else {
1581  mx = ff_h263_decode_motion(s, 0, 1);
1582  my = ff_h263_decode_motion(s, 0, 1);
1583  }
1584 
1585  s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1586  mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
1587  }
1588  s->current_picture.mb_type[xy] = mb_type;
1589  } else { /* I-Frame */
1590  do {
1591  cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1592  if (cbpc < 0) {
1593  av_log(s->avctx, AV_LOG_ERROR,
1594  "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1595  return -1;
1596  }
1597  } while (cbpc == 8);
1598 
1599  dquant = cbpc & 4;
1600  s->mb_intra = 1;
1601 
1602 intra:
1603  s->ac_pred = get_bits1(&s->gb);
1604  if (s->ac_pred)
1605  s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1606  else
1607  s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
1608 
1609  cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1610  if (cbpy < 0) {
1611  av_log(s->avctx, AV_LOG_ERROR,
1612  "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1613  return -1;
1614  }
1615  cbp = (cbpc & 3) | (cbpy << 2);
1616 
1617  ctx->use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1618 
1619  if (dquant)
1620  ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1621 
1622  if (!s->progressive_sequence)
1623  s->interlaced_dct = get_bits1(&s->gb);
1624 
1625  s->bdsp.clear_blocks(s->block[0]);
1626  /* decode each block */
1627  for (i = 0; i < 6; i++) {
1628  if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, 1, 0) < 0)
1629  return -1;
1630  cbp += cbp;
1631  }
1632  goto end;
1633  }
1634 
1635  /* decode each block */
1636  for (i = 0; i < 6; i++) {
1637  if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, 0, 0) < 0)
1638  return -1;
1639  cbp += cbp;
1640  }
1641 
1642 end:
1643  /* per-MB end of slice check */
1644  if (s->codec_id == AV_CODEC_ID_MPEG4) {
1645  int next = mpeg4_is_resync(ctx);
1646  if (next) {
1647  if (s->mb_x + s->mb_y*s->mb_width + 1 > next && (s->avctx->err_recognition & AV_EF_AGGRESSIVE)) {
1648  return -1;
1649  } else if (s->mb_x + s->mb_y*s->mb_width + 1 >= next)
1650  return SLICE_END;
1651 
1652  if (s->pict_type == AV_PICTURE_TYPE_B) {
1653  const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1654  ff_thread_await_progress(&s->next_picture_ptr->tf,
1655  (s->mb_x + delta >= s->mb_width)
1656  ? FFMIN(s->mb_y + 1, s->mb_height - 1)
1657  : s->mb_y, 0);
1658  if (s->next_picture.mbskip_table[xy + delta])
1659  return SLICE_OK;
1660  }
1661 
1662  return SLICE_END;
1663  }
1664  }
1665 
1666  return SLICE_OK;
1667 }
1668 
1669 static int mpeg4_decode_gop_header(MpegEncContext *s, GetBitContext *gb)
1670 {
1671  int hours, minutes, seconds;
1672 
1673  if (!show_bits(gb, 23)) {
1674  av_log(s->avctx, AV_LOG_WARNING, "GOP header invalid\n");
1675  return -1;
1676  }
1677 
1678  hours = get_bits(gb, 5);
1679  minutes = get_bits(gb, 6);
1680  skip_bits1(gb);
1681  seconds = get_bits(gb, 6);
1682 
1683  s->time_base = seconds + 60*(minutes + 60*hours);
1684 
1685  skip_bits1(gb);
1686  skip_bits1(gb);
1687 
1688  return 0;
1689 }
1690 
1691 static int mpeg4_decode_profile_level(MpegEncContext *s, GetBitContext *gb)
1692 {
1693 
1694  s->avctx->profile = get_bits(gb, 4);
1695  s->avctx->level = get_bits(gb, 4);
1696 
1697  // for Simple profile, level 0
1698  if (s->avctx->profile == 0 && s->avctx->level == 8) {
1699  s->avctx->level = 0;
1700  }
1701 
1702  return 0;
1703 }
1704 
1705 static int decode_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
1706 {
1707  MpegEncContext *s = &ctx->m;
1708  int width, height, vo_ver_id;
1709 
1710  /* vol header */
1711  skip_bits(gb, 1); /* random access */
1712  s->vo_type = get_bits(gb, 8);
1713  if (get_bits1(gb) != 0) { /* is_ol_id */
1714  vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
1715  skip_bits(gb, 3); /* vo_priority */
1716  } else {
1717  vo_ver_id = 1;
1718  }
1719  s->aspect_ratio_info = get_bits(gb, 4);
1720  if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1721  s->avctx->sample_aspect_ratio.num = get_bits(gb, 8); // par_width
1722  s->avctx->sample_aspect_ratio.den = get_bits(gb, 8); // par_height
1723  } else {
1724  s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[s->aspect_ratio_info];
1725  }
1726 
1727  if ((ctx->vol_control_parameters = get_bits1(gb))) { /* vol control parameter */
1728  int chroma_format = get_bits(gb, 2);
1729  if (chroma_format != CHROMA_420)
1730  av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
1731 
1732  s->low_delay = get_bits1(gb);
1733  if (get_bits1(gb)) { /* vbv parameters */
1734  get_bits(gb, 15); /* first_half_bitrate */
1735  skip_bits1(gb); /* marker */
1736  get_bits(gb, 15); /* latter_half_bitrate */
1737  skip_bits1(gb); /* marker */
1738  get_bits(gb, 15); /* first_half_vbv_buffer_size */
1739  skip_bits1(gb); /* marker */
1740  get_bits(gb, 3); /* latter_half_vbv_buffer_size */
1741  get_bits(gb, 11); /* first_half_vbv_occupancy */
1742  skip_bits1(gb); /* marker */
1743  get_bits(gb, 15); /* latter_half_vbv_occupancy */
1744  skip_bits1(gb); /* marker */
1745  }
1746  } else {
1747  /* is setting low delay flag only once the smartest thing to do?
1748  * low delay detection won't be overridden. */
1749  if (s->picture_number == 0)
1750  s->low_delay = 0;
1751  }
1752 
1753  ctx->shape = get_bits(gb, 2); /* vol shape */
1754  if (ctx->shape != RECT_SHAPE)
1755  av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
1756  if (ctx->shape == GRAY_SHAPE && vo_ver_id != 1) {
1757  av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
1758  skip_bits(gb, 4); /* video_object_layer_shape_extension */
1759  }
1760 
1761  check_marker(gb, "before time_increment_resolution");
1762 
1763  s->avctx->framerate.num = get_bits(gb, 16);
1764  if (!s->avctx->framerate.num) {
1765  av_log(s->avctx, AV_LOG_ERROR, "framerate==0\n");
1766  return AVERROR_INVALIDDATA;
1767  }
1768 
1769  ctx->time_increment_bits = av_log2(s->avctx->framerate.num - 1) + 1;
1770  if (ctx->time_increment_bits < 1)
1771  ctx->time_increment_bits = 1;
1772 
1773  check_marker(gb, "before fixed_vop_rate");
1774 
1775  if (get_bits1(gb) != 0) /* fixed_vop_rate */
1776  s->avctx->framerate.den = get_bits(gb, ctx->time_increment_bits);
1777  else
1778  s->avctx->framerate.den = 1;
1779 
1780  s->avctx->time_base = av_inv_q(av_mul_q(s->avctx->framerate, (AVRational){s->avctx->ticks_per_frame, 1}));
1781 
1782  ctx->t_frame = 0;
1783 
1784  if (ctx->shape != BIN_ONLY_SHAPE) {
1785  if (ctx->shape == RECT_SHAPE) {
1786  check_marker(gb, "before width");
1787  width = get_bits(gb, 13);
1788  check_marker(gb, "before height");
1789  height = get_bits(gb, 13);
1790  check_marker(gb, "after height");
1791  if (width && height && /* they should be non zero but who knows */
1792  !(s->width && s->codec_tag == AV_RL32("MP4S"))) {
1793  if (s->width && s->height &&
1794  (s->width != width || s->height != height))
1795  s->context_reinit = 1;
1796  s->width = width;
1797  s->height = height;
1798  }
1799  }
1800 
1801  s->progressive_sequence =
1802  s->progressive_frame = get_bits1(gb) ^ 1;
1803  s->interlaced_dct = 0;
1804  if (!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
1805  av_log(s->avctx, AV_LOG_INFO, /* OBMC Disable */
1806  "MPEG4 OBMC not supported (very likely buggy encoder)\n");
1807  if (vo_ver_id == 1)
1808  ctx->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
1809  else
1810  ctx->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
1811 
1812  if (ctx->vol_sprite_usage == STATIC_SPRITE)
1813  av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
1814  if (ctx->vol_sprite_usage == STATIC_SPRITE ||
1815  ctx->vol_sprite_usage == GMC_SPRITE) {
1816  if (ctx->vol_sprite_usage == STATIC_SPRITE) {
1817  skip_bits(gb, 13); // sprite_width
1818  skip_bits1(gb); /* marker */
1819  skip_bits(gb, 13); // sprite_height
1820  skip_bits1(gb); /* marker */
1821  skip_bits(gb, 13); // sprite_left
1822  skip_bits1(gb); /* marker */
1823  skip_bits(gb, 13); // sprite_top
1824  skip_bits1(gb); /* marker */
1825  }
1826  ctx->num_sprite_warping_points = get_bits(gb, 6);
1827  if (ctx->num_sprite_warping_points > 3) {
1828  av_log(s->avctx, AV_LOG_ERROR,
1829  "%d sprite_warping_points\n",
1830  ctx->num_sprite_warping_points);
1831  ctx->num_sprite_warping_points = 0;
1832  return AVERROR_INVALIDDATA;
1833  }
1834  s->sprite_warping_accuracy = get_bits(gb, 2);
1835  ctx->sprite_brightness_change = get_bits1(gb);
1836  if (ctx->vol_sprite_usage == STATIC_SPRITE)
1837  skip_bits1(gb); // low_latency_sprite
1838  }
1839  // FIXME sadct disable bit if verid!=1 && shape not rect
1840 
1841  if (get_bits1(gb) == 1) { /* not_8_bit */
1842  s->quant_precision = get_bits(gb, 4); /* quant_precision */
1843  if (get_bits(gb, 4) != 8) /* bits_per_pixel */
1844  av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n");
1845  if (s->quant_precision != 5)
1846  av_log(s->avctx, AV_LOG_ERROR,
1847  "quant precision %d\n", s->quant_precision);
1848  if (s->quant_precision<3 || s->quant_precision>9) {
1849  s->quant_precision = 5;
1850  }
1851  } else {
1852  s->quant_precision = 5;
1853  }
1854 
1855  // FIXME a bunch of grayscale shape things
1856 
1857  if ((s->mpeg_quant = get_bits1(gb))) { /* vol_quant_type */
1858  int i, v;
1859 
1860  /* load default matrixes */
1861  for (i = 0; i < 64; i++) {
1862  int j = s->idsp.idct_permutation[i];
1863  v = ff_mpeg4_default_intra_matrix[i];
1864  s->intra_matrix[j] = v;
1865  s->chroma_intra_matrix[j] = v;
1866 
1867  v = ff_mpeg4_default_non_intra_matrix[i];
1868  s->inter_matrix[j] = v;
1869  s->chroma_inter_matrix[j] = v;
1870  }
1871 
1872  /* load custom intra matrix */
1873  if (get_bits1(gb)) {
1874  int last = 0;
1875  for (i = 0; i < 64; i++) {
1876  int j;
1877  v = get_bits(gb, 8);
1878  if (v == 0)
1879  break;
1880 
1881  last = v;
1882  j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1883  s->intra_matrix[j] = last;
1884  s->chroma_intra_matrix[j] = last;
1885  }
1886 
1887  /* replicate last value */
1888  for (; i < 64; i++) {
1889  int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1890  s->intra_matrix[j] = last;
1891  s->chroma_intra_matrix[j] = last;
1892  }
1893  }
1894 
1895  /* load custom non intra matrix */
1896  if (get_bits1(gb)) {
1897  int last = 0;
1898  for (i = 0; i < 64; i++) {
1899  int j;
1900  v = get_bits(gb, 8);
1901  if (v == 0)
1902  break;
1903 
1904  last = v;
1905  j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1906  s->inter_matrix[j] = v;
1907  s->chroma_inter_matrix[j] = v;
1908  }
1909 
1910  /* replicate last value */
1911  for (; i < 64; i++) {
1912  int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1913  s->inter_matrix[j] = last;
1914  s->chroma_inter_matrix[j] = last;
1915  }
1916  }
1917 
1918  // FIXME a bunch of grayscale shape things
1919  }
1920 
1921  if (vo_ver_id != 1)
1922  s->quarter_sample = get_bits1(gb);
1923  else
1924  s->quarter_sample = 0;
1925 
1926  if (get_bits_left(gb) < 4) {
1927  av_log(s->avctx, AV_LOG_ERROR, "VOL Header truncated\n");
1928  return AVERROR_INVALIDDATA;
1929  }
1930 
1931  if (!get_bits1(gb)) {
1932  int pos = get_bits_count(gb);
1933  int estimation_method = get_bits(gb, 2);
1934  if (estimation_method < 2) {
1935  if (!get_bits1(gb)) {
1936  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* opaque */
1937  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* transparent */
1938  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* intra_cae */
1939  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* inter_cae */
1940  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* no_update */
1941  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* upampling */
1942  }
1943  if (!get_bits1(gb)) {
1944  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* intra_blocks */
1945  ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* inter_blocks */
1946  ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* inter4v_blocks */
1947  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* not coded blocks */
1948  }
1949  if (!check_marker(gb, "in complexity estimation part 1")) {
1950  skip_bits_long(gb, pos - get_bits_count(gb));
1951  goto no_cplx_est;
1952  }
1953  if (!get_bits1(gb)) {
1954  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* dct_coeffs */
1955  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* dct_lines */
1956  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* vlc_syms */
1957  ctx->cplx_estimation_trash_i += 4 * get_bits1(gb); /* vlc_bits */
1958  }
1959  if (!get_bits1(gb)) {
1960  ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* apm */
1961  ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* npm */
1962  ctx->cplx_estimation_trash_b += 8 * get_bits1(gb); /* interpolate_mc_q */
1963  ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* forwback_mc_q */
1964  ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* halfpel2 */
1965  ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* halfpel4 */
1966  }
1967  if (!check_marker(gb, "in complexity estimation part 2")) {
1968  skip_bits_long(gb, pos - get_bits_count(gb));
1969  goto no_cplx_est;
1970  }
1971  if (estimation_method == 1) {
1972  ctx->cplx_estimation_trash_i += 8 * get_bits1(gb); /* sadct */
1973  ctx->cplx_estimation_trash_p += 8 * get_bits1(gb); /* qpel */
1974  }
1975  } else
1976  av_log(s->avctx, AV_LOG_ERROR,
1977  "Invalid Complexity estimation method %d\n",
1978  estimation_method);
1979  } else {
1980 
1981 no_cplx_est:
1982  ctx->cplx_estimation_trash_i =
1983  ctx->cplx_estimation_trash_p =
1984  ctx->cplx_estimation_trash_b = 0;
1985  }
1986 
1987  ctx->resync_marker = !get_bits1(gb); /* resync_marker_disabled */
1988 
1989  s->data_partitioning = get_bits1(gb);
1990  if (s->data_partitioning)
1991  ctx->rvlc = get_bits1(gb);
1992 
1993  if (vo_ver_id != 1) {
1994  ctx->new_pred = get_bits1(gb);
1995  if (ctx->new_pred) {
1996  av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
1997  skip_bits(gb, 2); /* requested upstream message type */
1998  skip_bits1(gb); /* newpred segment type */
1999  }
2000  if (get_bits1(gb)) // reduced_res_vop
2001  av_log(s->avctx, AV_LOG_ERROR,
2002  "reduced resolution VOP not supported\n");
2003  } else {
2004  ctx->new_pred = 0;
2005  }
2006 
2007  ctx->scalability = get_bits1(gb);
2008 
2009  if (ctx->scalability) {
2010  GetBitContext bak = *gb;
2011  int h_sampling_factor_n;
2012  int h_sampling_factor_m;
2013  int v_sampling_factor_n;
2014  int v_sampling_factor_m;
2015 
2016  skip_bits1(gb); // hierarchy_type
2017  skip_bits(gb, 4); /* ref_layer_id */
2018  skip_bits1(gb); /* ref_layer_sampling_dir */
2019  h_sampling_factor_n = get_bits(gb, 5);
2020  h_sampling_factor_m = get_bits(gb, 5);
2021  v_sampling_factor_n = get_bits(gb, 5);
2022  v_sampling_factor_m = get_bits(gb, 5);
2023  ctx->enhancement_type = get_bits1(gb);
2024 
2025  if (h_sampling_factor_n == 0 || h_sampling_factor_m == 0 ||
2026  v_sampling_factor_n == 0 || v_sampling_factor_m == 0) {
2027  /* illegal scalability header (VERY broken encoder),
2028  * trying to workaround */
2029  ctx->scalability = 0;
2030  *gb = bak;
2031  } else
2032  av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
2033 
2034  // bin shape stuff FIXME
2035  }
2036  }
2037 
2038  if (s->avctx->debug&FF_DEBUG_PICT_INFO) {
2039  av_log(s->avctx, AV_LOG_DEBUG, "tb %d/%d, tincrbits:%d, qp_prec:%d, ps:%d, %s%s%s%s\n",
2040  s->avctx->framerate.den, s->avctx->framerate.num,
2041  ctx->time_increment_bits,
2042  s->quant_precision,
2043  s->progressive_sequence,
2044  ctx->scalability ? "scalability " :"" , s->quarter_sample ? "qpel " : "",
2045  s->data_partitioning ? "partition " : "", ctx->rvlc ? "rvlc " : ""
2046  );
2047  }
2048 
2049  return 0;
2050 }
2051 
2052 /**
2053  * Decode the user data stuff in the header.
2054  * Also initializes divx/xvid/lavc_version/build.
2055  */
2056 static int decode_user_data(Mpeg4DecContext *ctx, GetBitContext *gb)
2057 {
2058  MpegEncContext *s = &ctx->m;
2059  char buf[256];
2060  int i;
2061  int e;
2062  int ver = 0, build = 0, ver2 = 0, ver3 = 0;
2063  char last;
2064 
2065  for (i = 0; i < 255 && get_bits_count(gb) < gb->size_in_bits; i++) {
2066  if (show_bits(gb, 23) == 0)
2067  break;
2068  buf[i] = get_bits(gb, 8);
2069  }
2070  buf[i] = 0;
2071 
2072  /* divx detection */
2073  e = sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
2074  if (e < 2)
2075  e = sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
2076  if (e >= 2) {
2077  ctx->divx_version = ver;
2078  ctx->divx_build = build;
2079  s->divx_packed = e == 3 && last == 'p';
2080  if (s->divx_packed && !ctx->showed_packed_warning) {
2081  av_log(s->avctx, AV_LOG_INFO, "Video uses a non-standard and "
2082  "wasteful way to store B-frames ('packed B-frames'). "
2083  "Consider using a tool like VirtualDub or avidemux to fix it.\n");
2084  ctx->showed_packed_warning = 1;
2085  }
2086  }
2087 
2088  /* libavcodec detection */
2089  e = sscanf(buf, "FFmpe%*[^b]b%d", &build) + 3;
2090  if (e != 4)
2091  e = sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
2092  if (e != 4) {
2093  e = sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3) + 1;
2094  if (e > 1)
2095  build = (ver << 16) + (ver2 << 8) + ver3;
2096  }
2097  if (e != 4) {
2098  if (strcmp(buf, "ffmpeg") == 0)
2099  ctx->lavc_build = 4600;
2100  }
2101  if (e == 4)
2102  ctx->lavc_build = build;
2103 
2104  /* Xvid detection */
2105  e = sscanf(buf, "XviD%d", &build);
2106  if (e == 1)
2107  ctx->xvid_build = build;
2108 
2109  return 0;
2110 }
2111 
2112 int ff_mpeg4_workaround_bugs(AVCodecContext *avctx)
2113 {
2114  Mpeg4DecContext *ctx = avctx->priv_data;
2115  MpegEncContext *s = &ctx->m;
2116 
2117  if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1) {
2118  if (s->codec_tag == AV_RL32("XVID") ||
2119  s->codec_tag == AV_RL32("XVIX") ||
2120  s->codec_tag == AV_RL32("RMP4") ||
2121  s->codec_tag == AV_RL32("ZMP4") ||
2122  s->codec_tag == AV_RL32("SIPP"))
2123  ctx->xvid_build = 0;
2124  }
2125 
2126  if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1)
2127  if (s->codec_tag == AV_RL32("DIVX") && s->vo_type == 0 &&
2128  ctx->vol_control_parameters == 0)
2129  ctx->divx_version = 400; // divx 4
2130 
2131  if (ctx->xvid_build >= 0 && ctx->divx_version >= 0) {
2132  ctx->divx_version =
2133  ctx->divx_build = -1;
2134  }
2135 
2136  if (s->workaround_bugs & FF_BUG_AUTODETECT) {
2137  if (s->codec_tag == AV_RL32("XVIX"))
2138  s->workaround_bugs |= FF_BUG_XVID_ILACE;
2139 
2140  if (s->codec_tag == AV_RL32("UMP4"))
2141  s->workaround_bugs |= FF_BUG_UMP4;
2142 
2143  if (ctx->divx_version >= 500 && ctx->divx_build < 1814)
2144  s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2145 
2146  if (ctx->divx_version > 502 && ctx->divx_build < 1814)
2147  s->workaround_bugs |= FF_BUG_QPEL_CHROMA2;
2148 
2149  if (ctx->xvid_build <= 3U)
2150  s->padding_bug_score = 256 * 256 * 256 * 64;
2151 
2152  if (ctx->xvid_build <= 1U)
2153  s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2154 
2155  if (ctx->xvid_build <= 12U)
2156  s->workaround_bugs |= FF_BUG_EDGE;
2157 
2158  if (ctx->xvid_build <= 32U)
2159  s->workaround_bugs |= FF_BUG_DC_CLIP;
2160 
2161 #define SET_QPEL_FUNC(postfix1, postfix2) \
2162  s->qdsp.put_ ## postfix1 = ff_put_ ## postfix2; \
2163  s->qdsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2; \
2164  s->qdsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
2165 
2166  if (ctx->lavc_build < 4653U)
2167  s->workaround_bugs |= FF_BUG_STD_QPEL;
2168 
2169  if (ctx->lavc_build < 4655U)
2170  s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2171 
2172  if (ctx->lavc_build < 4670U)
2173  s->workaround_bugs |= FF_BUG_EDGE;
2174 
2175  if (ctx->lavc_build <= 4712U)
2176  s->workaround_bugs |= FF_BUG_DC_CLIP;
2177 
2178  if (ctx->divx_version >= 0)
2179  s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2180  if (ctx->divx_version == 501 && ctx->divx_build == 20020416)
2181  s->padding_bug_score = 256 * 256 * 256 * 64;
2182 
2183  if (ctx->divx_version < 500U)
2184  s->workaround_bugs |= FF_BUG_EDGE;
2185 
2186  if (ctx->divx_version >= 0)
2187  s->workaround_bugs |= FF_BUG_HPEL_CHROMA;
2188  }
2189 
2190  if (s->workaround_bugs & FF_BUG_STD_QPEL) {
2191  SET_QPEL_FUNC(qpel_pixels_tab[0][5], qpel16_mc11_old_c)
2192  SET_QPEL_FUNC(qpel_pixels_tab[0][7], qpel16_mc31_old_c)
2193  SET_QPEL_FUNC(qpel_pixels_tab[0][9], qpel16_mc12_old_c)
2194  SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
2195  SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
2196  SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
2197 
2198  SET_QPEL_FUNC(qpel_pixels_tab[1][5], qpel8_mc11_old_c)
2199  SET_QPEL_FUNC(qpel_pixels_tab[1][7], qpel8_mc31_old_c)
2200  SET_QPEL_FUNC(qpel_pixels_tab[1][9], qpel8_mc12_old_c)
2201  SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
2202  SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
2203  SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
2204  }
2205 
2206  if (avctx->debug & FF_DEBUG_BUGS)
2207  av_log(s->avctx, AV_LOG_DEBUG,
2208  "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
2209  s->workaround_bugs, ctx->lavc_build, ctx->xvid_build,
2210  ctx->divx_version, ctx->divx_build, s->divx_packed ? "p" : "");
2211 
2212  if (CONFIG_MPEG4_DECODER && ctx->xvid_build >= 0 &&
2213  s->codec_id == AV_CODEC_ID_MPEG4 &&
2214  avctx->idct_algo == FF_IDCT_AUTO) {
2215  avctx->idct_algo = FF_IDCT_XVID;
2216  ff_mpv_idct_init(s);
2217  return 1;
2218  }
2219 
2220  return 0;
2221 }
2222 
2223 static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2224 {
2225  MpegEncContext *s = &ctx->m;
2226  int time_incr, time_increment;
2227  int64_t pts;
2228 
2229  s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I; /* pict type: I = 0 , P = 1 */
2230  if (s->pict_type == AV_PICTURE_TYPE_B && s->low_delay &&
2231  ctx->vol_control_parameters == 0 && !(s->flags & CODEC_FLAG_LOW_DELAY)) {
2232  av_log(s->avctx, AV_LOG_ERROR, "low_delay flag set incorrectly, clearing it\n");
2233  s->low_delay = 0;
2234  }
2235 
2236  s->partitioned_frame = s->data_partitioning && s->pict_type != AV_PICTURE_TYPE_B;
2237  if (s->partitioned_frame)
2238  s->decode_mb = mpeg4_decode_partitioned_mb;
2239  else
2240  s->decode_mb = mpeg4_decode_mb;
2241 
2242  time_incr = 0;
2243  while (get_bits1(gb) != 0)
2244  time_incr++;
2245 
2246  check_marker(gb, "before time_increment");
2247 
2248  if (ctx->time_increment_bits == 0 ||
2249  !(show_bits(gb, ctx->time_increment_bits + 1) & 1)) {
2250  av_log(s->avctx, AV_LOG_ERROR,
2251  "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
2252 
2253  for (ctx->time_increment_bits = 1;
2254  ctx->time_increment_bits < 16;
2255  ctx->time_increment_bits++) {
2256  if (s->pict_type == AV_PICTURE_TYPE_P ||
2257  (s->pict_type == AV_PICTURE_TYPE_S &&
2258  ctx->vol_sprite_usage == GMC_SPRITE)) {
2259  if ((show_bits(gb, ctx->time_increment_bits + 6) & 0x37) == 0x30)
2260  break;
2261  } else if ((show_bits(gb, ctx->time_increment_bits + 5) & 0x1F) == 0x18)
2262  break;
2263  }
2264 
2265  av_log(s->avctx, AV_LOG_ERROR,
2266  "my guess is %d bits ;)\n", ctx->time_increment_bits);
2267  if (s->avctx->framerate.num && 4*s->avctx->framerate.num < 1<<ctx->time_increment_bits) {
2268  s->avctx->framerate.num = 1<<ctx->time_increment_bits;
2269  s->avctx->time_base = av_inv_q(av_mul_q(s->avctx->framerate, (AVRational){s->avctx->ticks_per_frame, 1}));
2270  }
2271  }
2272 
2273  if (IS_3IV1)
2274  time_increment = get_bits1(gb); // FIXME investigate further
2275  else
2276  time_increment = get_bits(gb, ctx->time_increment_bits);
2277 
2278  if (s->pict_type != AV_PICTURE_TYPE_B) {
2279  s->last_time_base = s->time_base;
2280  s->time_base += time_incr;
2281  s->time = s->time_base * s->avctx->framerate.num + time_increment;
2282  if (s->workaround_bugs & FF_BUG_UMP4) {
2283  if (s->time < s->last_non_b_time) {
2284  /* header is not mpeg-4-compatible, broken encoder,
2285  * trying to workaround */
2286  s->time_base++;
2287  s->time += s->avctx->framerate.num;
2288  }
2289  }
2290  s->pp_time = s->time - s->last_non_b_time;
2291  s->last_non_b_time = s->time;
2292  } else {
2293  s->time = (s->last_time_base + time_incr) * s->avctx->framerate.num + time_increment;
2294  s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
2295  if (s->pp_time <= s->pb_time ||
2296  s->pp_time <= s->pp_time - s->pb_time ||
2297  s->pp_time <= 0) {
2298  /* messed up order, maybe after seeking? skipping current b-frame */
2299  return FRAME_SKIPPED;
2300  }
2301  ff_mpeg4_init_direct_mv(s);
2302 
2303  if (ctx->t_frame == 0)
2304  ctx->t_frame = s->pb_time;
2305  if (ctx->t_frame == 0)
2306  ctx->t_frame = 1; // 1/0 protection
2307  s->pp_field_time = (ROUNDED_DIV(s->last_non_b_time, ctx->t_frame) -
2308  ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
2309  s->pb_field_time = (ROUNDED_DIV(s->time, ctx->t_frame) -
2310  ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
2311  if (s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1) {
2312  s->pb_field_time = 2;
2313  s->pp_field_time = 4;
2314  if (!s->progressive_sequence)
2315  return FRAME_SKIPPED;
2316  }
2317  }
2318 
2319  if (s->avctx->framerate.den)
2320  pts = ROUNDED_DIV(s->time, s->avctx->framerate.den);
2321  else
2322  pts = AV_NOPTS_VALUE;
2323  if (s->avctx->debug&FF_DEBUG_PTS)
2324  av_log(s->avctx, AV_LOG_DEBUG, "MPEG4 PTS: %"PRId64"\n",
2325  pts);
2326 
2327  check_marker(gb, "before vop_coded");
2328 
2329  /* vop coded */
2330  if (get_bits1(gb) != 1) {
2331  if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2332  av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
2333  return FRAME_SKIPPED;
2334  }
2335  if (ctx->new_pred)
2336  decode_new_pred(ctx, gb);
2337 
2338  if (ctx->shape != BIN_ONLY_SHAPE &&
2339  (s->pict_type == AV_PICTURE_TYPE_P ||
2340  (s->pict_type == AV_PICTURE_TYPE_S &&
2341  ctx->vol_sprite_usage == GMC_SPRITE))) {
2342  /* rounding type for motion estimation */
2343  s->no_rounding = get_bits1(gb);
2344  } else {
2345  s->no_rounding = 0;
2346  }
2347  // FIXME reduced res stuff
2348 
2349  if (ctx->shape != RECT_SHAPE) {
2350  if (ctx->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
2351  skip_bits(gb, 13); /* width */
2352  skip_bits1(gb); /* marker */
2353  skip_bits(gb, 13); /* height */
2354  skip_bits1(gb); /* marker */
2355  skip_bits(gb, 13); /* hor_spat_ref */
2356  skip_bits1(gb); /* marker */
2357  skip_bits(gb, 13); /* ver_spat_ref */
2358  }
2359  skip_bits1(gb); /* change_CR_disable */
2360 
2361  if (get_bits1(gb) != 0)
2362  skip_bits(gb, 8); /* constant_alpha_value */
2363  }
2364 
2365  // FIXME complexity estimation stuff
2366 
2367  if (ctx->shape != BIN_ONLY_SHAPE) {
2368  skip_bits_long(gb, ctx->cplx_estimation_trash_i);
2369  if (s->pict_type != AV_PICTURE_TYPE_I)
2370  skip_bits_long(gb, ctx->cplx_estimation_trash_p);
2371  if (s->pict_type == AV_PICTURE_TYPE_B)
2372  skip_bits_long(gb, ctx->cplx_estimation_trash_b);
2373 
2374  if (get_bits_left(gb) < 3) {
2375  av_log(s->avctx, AV_LOG_ERROR, "Header truncated\n");
2376  return AVERROR_INVALIDDATA;
2377  }
2378  ctx->intra_dc_threshold = ff_mpeg4_dc_threshold[get_bits(gb, 3)];
2379  if (!s->progressive_sequence) {
2380  s->top_field_first = get_bits1(gb);
2381  s->alternate_scan = get_bits1(gb);
2382  } else
2383  s->alternate_scan = 0;
2384  }
2385 
2386  if (s->alternate_scan) {
2387  ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
2388  ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
2389  ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2390  ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2391  } else {
2392  ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
2393  ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
2394  ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2395  ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2396  }
2397 
2398  if (s->pict_type == AV_PICTURE_TYPE_S &&
2399  (ctx->vol_sprite_usage == STATIC_SPRITE ||
2400  ctx->vol_sprite_usage == GMC_SPRITE)) {
2401  if (mpeg4_decode_sprite_trajectory(ctx, gb) < 0)
2402  return AVERROR_INVALIDDATA;
2403  if (ctx->sprite_brightness_change)
2404  av_log(s->avctx, AV_LOG_ERROR,
2405  "sprite_brightness_change not supported\n");
2406  if (ctx->vol_sprite_usage == STATIC_SPRITE)
2407  av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2408  }
2409 
2410  if (ctx->shape != BIN_ONLY_SHAPE) {
2411  s->chroma_qscale = s->qscale = get_bits(gb, s->quant_precision);
2412  if (s->qscale == 0) {
2413  av_log(s->avctx, AV_LOG_ERROR,
2414  "Error, header damaged or not MPEG4 header (qscale=0)\n");
2415  return AVERROR_INVALIDDATA; // makes no sense to continue, as there is nothing left from the image then
2416  }
2417 
2418  if (s->pict_type != AV_PICTURE_TYPE_I) {
2419  s->f_code = get_bits(gb, 3); /* fcode_for */
2420  if (s->f_code == 0) {
2421  av_log(s->avctx, AV_LOG_ERROR,
2422  "Error, header damaged or not MPEG4 header (f_code=0)\n");
2423  s->f_code = 1;
2424  return AVERROR_INVALIDDATA; // makes no sense to continue, as there is nothing left from the image then
2425  }
2426  } else
2427  s->f_code = 1;
2428 
2429  if (s->pict_type == AV_PICTURE_TYPE_B) {
2430  s->b_code = get_bits(gb, 3);
2431  if (s->b_code == 0) {
2432  av_log(s->avctx, AV_LOG_ERROR,
2433  "Error, header damaged or not MPEG4 header (b_code=0)\n");
2434  s->b_code=1;
2435  return AVERROR_INVALIDDATA; // makes no sense to continue, as the MV decoding will break very quickly
2436  }
2437  } else
2438  s->b_code = 1;
2439 
2440  if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2441  av_log(s->avctx, AV_LOG_DEBUG,
2442  "qp:%d fc:%d,%d %s size:%d pro:%d alt:%d top:%d %spel part:%d resync:%d w:%d a:%d rnd:%d vot:%d%s dc:%d ce:%d/%d/%d time:%"PRId64" tincr:%d\n",
2443  s->qscale, s->f_code, s->b_code,
2444  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")),
2445  gb->size_in_bits,s->progressive_sequence, s->alternate_scan,
2446  s->top_field_first, s->quarter_sample ? "q" : "h",
2447  s->data_partitioning, ctx->resync_marker,
2448  ctx->num_sprite_warping_points, s->sprite_warping_accuracy,
2449  1 - s->no_rounding, s->vo_type,
2450  ctx->vol_control_parameters ? " VOLC" : " ", ctx->intra_dc_threshold,
2451  ctx->cplx_estimation_trash_i, ctx->cplx_estimation_trash_p,
2452  ctx->cplx_estimation_trash_b,
2453  s->time,
2454  time_increment
2455  );
2456  }
2457 
2458  if (!ctx->scalability) {
2459  if (ctx->shape != RECT_SHAPE && s->pict_type != AV_PICTURE_TYPE_I)
2460  skip_bits1(gb); // vop shape coding type
2461  } else {
2462  if (ctx->enhancement_type) {
2463  int load_backward_shape = get_bits1(gb);
2464  if (load_backward_shape)
2465  av_log(s->avctx, AV_LOG_ERROR,
2466  "load backward shape isn't supported\n");
2467  }
2468  skip_bits(gb, 2); // ref_select_code
2469  }
2470  }
2471  /* detect buggy encoders which don't set the low_delay flag
2472  * (divx4/xvid/opendivx). Note we cannot detect divx5 without b-frames
2473  * easily (although it's buggy too) */
2474  if (s->vo_type == 0 && ctx->vol_control_parameters == 0 &&
2475  ctx->divx_version == -1 && s->picture_number == 0) {
2476  av_log(s->avctx, AV_LOG_WARNING,
2477  "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2478  s->low_delay = 1;
2479  }
2480 
2481  s->picture_number++; // better than pic number==0 always ;)
2482 
2483  // FIXME add short header support
2484  s->y_dc_scale_table = ff_mpeg4_y_dc_scale_table;
2485  s->c_dc_scale_table = ff_mpeg4_c_dc_scale_table;
2486 
2487  if (s->workaround_bugs & FF_BUG_EDGE) {
2488  s->h_edge_pos = s->width;
2489  s->v_edge_pos = s->height;
2490  }
2491  return 0;
2492 }
2493 
2494 /**
2495  * Decode mpeg4 headers.
2496  * @return <0 if no VOP found (or a damaged one)
2497  * FRAME_SKIPPED if a not coded VOP is found
2498  * 0 if a VOP is found
2499  */
2500 int ff_mpeg4_decode_picture_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2501 {
2502  MpegEncContext *s = &ctx->m;
2503  unsigned startcode, v;
2504  int ret;
2505 
2506  /* search next start code */
2507  align_get_bits(gb);
2508 
2509  if (s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630) {
2510  skip_bits(gb, 24);
2511  if (get_bits(gb, 8) == 0xF0)
2512  goto end;
2513  }
2514 
2515  startcode = 0xff;
2516  for (;;) {
2517  if (get_bits_count(gb) >= gb->size_in_bits) {
2518  if (gb->size_in_bits == 8 &&
2519  (ctx->divx_version >= 0 || ctx->xvid_build >= 0) || s->codec_tag == AV_RL32("QMP4")) {
2520  av_log(s->avctx, AV_LOG_VERBOSE, "frame skip %d\n", gb->size_in_bits);
2521  return FRAME_SKIPPED; // divx bug
2522  } else
2523  return -1; // end of stream
2524  }
2525 
2526  /* use the bits after the test */
2527  v = get_bits(gb, 8);
2528  startcode = ((startcode << 8) | v) & 0xffffffff;
2529 
2530  if ((startcode & 0xFFFFFF00) != 0x100)
2531  continue; // no startcode
2532 
2533  if (s->avctx->debug & FF_DEBUG_STARTCODE) {
2534  av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
2535  if (startcode <= 0x11F)
2536  av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
2537  else if (startcode <= 0x12F)
2538  av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
2539  else if (startcode <= 0x13F)
2540  av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2541  else if (startcode <= 0x15F)
2542  av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
2543  else if (startcode <= 0x1AF)
2544  av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
2545  else if (startcode == 0x1B0)
2546  av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
2547  else if (startcode == 0x1B1)
2548  av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
2549  else if (startcode == 0x1B2)
2550  av_log(s->avctx, AV_LOG_DEBUG, "User Data");
2551  else if (startcode == 0x1B3)
2552  av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
2553  else if (startcode == 0x1B4)
2554  av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
2555  else if (startcode == 0x1B5)
2556  av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
2557  else if (startcode == 0x1B6)
2558  av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
2559  else if (startcode == 0x1B7)
2560  av_log(s->avctx, AV_LOG_DEBUG, "slice start");
2561  else if (startcode == 0x1B8)
2562  av_log(s->avctx, AV_LOG_DEBUG, "extension start");
2563  else if (startcode == 0x1B9)
2564  av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
2565  else if (startcode == 0x1BA)
2566  av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
2567  else if (startcode == 0x1BB)
2568  av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
2569  else if (startcode == 0x1BC)
2570  av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
2571  else if (startcode == 0x1BD)
2572  av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
2573  else if (startcode == 0x1BE)
2574  av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
2575  else if (startcode == 0x1BF)
2576  av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
2577  else if (startcode == 0x1C0)
2578  av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
2579  else if (startcode == 0x1C1)
2580  av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
2581  else if (startcode == 0x1C2)
2582  av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
2583  else if (startcode == 0x1C3)
2584  av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
2585  else if (startcode <= 0x1C5)
2586  av_log(s->avctx, AV_LOG_DEBUG, "reserved");
2587  else if (startcode <= 0x1FF)
2588  av_log(s->avctx, AV_LOG_DEBUG, "System start");
2589  av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
2590  }
2591 
2592  if (startcode >= 0x120 && startcode <= 0x12F) {
2593  if ((ret = decode_vol_header(ctx, gb)) < 0)
2594  return ret;
2595  } else if (startcode == USER_DATA_STARTCODE) {
2596  decode_user_data(ctx, gb);
2597  } else if (startcode == GOP_STARTCODE) {
2598  mpeg4_decode_gop_header(s, gb);
2599  } else if (startcode == VOS_STARTCODE) {
2600  mpeg4_decode_profile_level(s, gb);
2601  } else if (startcode == VOP_STARTCODE) {
2602  break;
2603  }
2604 
2605  align_get_bits(gb);
2606  startcode = 0xff;
2607  }
2608 
2609 end:
2610  if (s->flags & CODEC_FLAG_LOW_DELAY)
2611  s->low_delay = 1;
2612  s->avctx->has_b_frames = !s->low_delay;
2613 
2614  return decode_vop_header(ctx, gb);
2615 }
2616 
2617 av_cold void ff_mpeg4videodec_static_init(void) {
2618  static int done = 0;
2619 
2620  if (!done) {
2621  ff_init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
2622  ff_init_rl(&ff_rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
2623  ff_init_rl(&ff_rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
2624  INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
2625  INIT_VLC_RL(ff_rvlc_rl_inter, 1072);
2626  INIT_VLC_RL(ff_rvlc_rl_intra, 1072);
2627  INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
2628  &ff_mpeg4_DCtab_lum[0][1], 2, 1,
2629  &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
2630  INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
2631  &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
2632  &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
2633  INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
2634  &ff_sprite_trajectory_tab[0][1], 4, 2,
2635  &ff_sprite_trajectory_tab[0][0], 4, 2, 128);
2636  INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
2637  &ff_mb_type_b_tab[0][1], 2, 1,
2638  &ff_mb_type_b_tab[0][0], 2, 1, 16);
2639  done = 1;
2640  }
2641 }
2642 
2643 int ff_mpeg4_frame_end(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
2644 {
2645  Mpeg4DecContext *ctx = avctx->priv_data;
2646  MpegEncContext *s = &ctx->m;
2647 
2648  /* divx 5.01+ bitstream reorder stuff */
2649  /* Since this clobbers the input buffer and hwaccel codecs still need the
2650  * data during hwaccel->end_frame we should not do this any earlier */
2651  if (s->divx_packed) {
2652  int current_pos = s->gb.buffer == s->bitstream_buffer ? 0 : (get_bits_count(&s->gb) >> 3);
2653  int startcode_found = 0;
2654 
2655  if (buf_size - current_pos > 7) {
2656 
2657  int i;
2658  for (i = current_pos; i < buf_size - 4; i++)
2659 
2660  if (buf[i] == 0 &&
2661  buf[i + 1] == 0 &&
2662  buf[i + 2] == 1 &&
2663  buf[i + 3] == 0xB6) {
2664  startcode_found = !(buf[i + 4] & 0x40);
2665  break;
2666  }
2667  }
2668 
2669  if (startcode_found) {
2670  av_fast_padded_malloc(&s->bitstream_buffer,
2671  &s->allocated_bitstream_buffer_size,
2672  buf_size - current_pos);
2673  if (!s->bitstream_buffer)
2674  return AVERROR(ENOMEM);
2675  memcpy(s->bitstream_buffer, buf + current_pos,
2676  buf_size - current_pos);
2677  s->bitstream_buffer_size = buf_size - current_pos;
2678  }
2679  }
2680 
2681  return 0;
2682 }
2683 
2684 static int mpeg4_update_thread_context(AVCodecContext *dst,
2685  const AVCodecContext *src)
2686 {
2687  Mpeg4DecContext *s = dst->priv_data;
2688  const Mpeg4DecContext *s1 = src->priv_data;
2689  int init = s->m.context_initialized;
2690 
2691  int ret = ff_mpeg_update_thread_context(dst, src);
2692 
2693  if (ret < 0)
2694  return ret;
2695 
2696  memcpy(((uint8_t*)s) + sizeof(MpegEncContext), ((uint8_t*)s1) + sizeof(MpegEncContext), sizeof(Mpeg4DecContext) - sizeof(MpegEncContext));
2697 
2698  if (CONFIG_MPEG4_DECODER && !init && s1->xvid_build >= 0)
2699  ff_xvid_idct_init(&s->m.idsp, dst);
2700 
2701  return 0;
2702 }
2703 
2704 static av_cold int decode_init(AVCodecContext *avctx)
2705 {
2706  Mpeg4DecContext *ctx = avctx->priv_data;
2707  MpegEncContext *s = &ctx->m;
2708  int ret;
2709 
2710  ctx->divx_version =
2711  ctx->divx_build =
2712  ctx->xvid_build =
2713  ctx->lavc_build = -1;
2714 
2715  if ((ret = ff_h263_decode_init(avctx)) < 0)
2716  return ret;
2717 
2718  ff_mpeg4videodec_static_init();
2719 
2720  s->h263_pred = 1;
2721  s->low_delay = 0; /* default, might be overridden in the vol header during header parsing */
2722  s->decode_mb = mpeg4_decode_mb;
2723  ctx->time_increment_bits = 4; /* default value for broken headers */
2724 
2725  avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
2726  avctx->internal->allocate_progress = 1;
2727 
2728  return 0;
2729 }
2730 
2731 static const AVProfile mpeg4_video_profiles[] = {
2732  { FF_PROFILE_MPEG4_SIMPLE, "Simple Profile" },
2733  { FF_PROFILE_MPEG4_SIMPLE_SCALABLE, "Simple Scalable Profile" },
2734  { FF_PROFILE_MPEG4_CORE, "Core Profile" },
2735  { FF_PROFILE_MPEG4_MAIN, "Main Profile" },
2736  { FF_PROFILE_MPEG4_N_BIT, "N-bit Profile" },
2737  { FF_PROFILE_MPEG4_SCALABLE_TEXTURE, "Scalable Texture Profile" },
2738  { FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION, "Simple Face Animation Profile" },
2739  { FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE, "Basic Animated Texture Profile" },
2740  { FF_PROFILE_MPEG4_HYBRID, "Hybrid Profile" },
2741  { FF_PROFILE_MPEG4_ADVANCED_REAL_TIME, "Advanced Real Time Simple Profile" },
2742  { FF_PROFILE_MPEG4_CORE_SCALABLE, "Code Scalable Profile" },
2743  { FF_PROFILE_MPEG4_ADVANCED_CODING, "Advanced Coding Profile" },
2744  { FF_PROFILE_MPEG4_ADVANCED_CORE, "Advanced Core Profile" },
2745  { FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE, "Advanced Scalable Texture Profile" },
2746  { FF_PROFILE_MPEG4_SIMPLE_STUDIO, "Simple Studio Profile" },
2747  { FF_PROFILE_MPEG4_ADVANCED_SIMPLE, "Advanced Simple Profile" },
2748  { FF_PROFILE_UNKNOWN },
2749 };
2750 
2751 static const AVOption mpeg4_options[] = {
2752  {"quarter_sample", "1/4 subpel MC", offsetof(MpegEncContext, quarter_sample), FF_OPT_TYPE_INT, {.i64 = 0}, 0, 1, 0},
2753  {"divx_packed", "divx style packed b frames", offsetof(MpegEncContext, divx_packed), FF_OPT_TYPE_INT, {.i64 = 0}, 0, 1, 0},
2754  {NULL}
2755 };
2756 
2757 static const AVClass mpeg4_class = {
2758  "MPEG4 Video Decoder",
2759  av_default_item_name,
2760  mpeg4_options,
2761  LIBAVUTIL_VERSION_INT,
2762 };
2763 
2764 AVCodec ff_mpeg4_decoder = {
2765  .name = "mpeg4",
2766  .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
2767  .type = AVMEDIA_TYPE_VIDEO,
2768  .id = AV_CODEC_ID_MPEG4,
2769  .priv_data_size = sizeof(Mpeg4DecContext),
2770  .init = decode_init,
2771  .close = ff_h263_decode_end,
2772  .decode = ff_h263_decode_frame,
2773  .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
2774  CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2775  CODEC_CAP_FRAME_THREADS,
2776  .flush = ff_mpeg_flush,
2777  .max_lowres = 3,
2778  .pix_fmts = ff_h263_hwaccel_pixfmt_list_420,
2779  .profiles = NULL_IF_CONFIG_SMALL(mpeg4_video_profiles),
2780  .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg4_update_thread_context),
2781  .priv_class = &mpeg4_class,
2782 };
2783 
2784 
2785 #if CONFIG_MPEG4_VDPAU_DECODER
2786 static const AVClass mpeg4_vdpau_class = {
2787  "MPEG4 Video VDPAU Decoder",
2788  av_default_item_name,
2789  mpeg4_options,
2790  LIBAVUTIL_VERSION_INT,
2791 };
2792 
2793 AVCodec ff_mpeg4_vdpau_decoder = {
2794  .name = "mpeg4_vdpau",
2795  .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
2796  .type = AVMEDIA_TYPE_VIDEO,
2797  .id = AV_CODEC_ID_MPEG4,
2798  .priv_data_size = sizeof(Mpeg4DecContext),
2799  .init = decode_init,
2800  .close = ff_h263_decode_end,
2801  .decode = ff_h263_decode_frame,
2802  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY |
2803  CODEC_CAP_HWACCEL_VDPAU,
2804  .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_VDPAU_MPEG4,
2805  AV_PIX_FMT_NONE },
2806  .priv_class = &mpeg4_vdpau_class,
2807 };
2808 #endif
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