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h264_refs.c
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1 /*
2  * H.26L/H.264/AVC/JVT/14496-10/... reference picture handling
3  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * H.264 / AVC / MPEG4 part10 reference picture handling.
25  * @author Michael Niedermayer <michaelni@gmx.at>
26  */
27 
28 #include "libavutil/avassert.h"
29 #include "internal.h"
30 #include "avcodec.h"
31 #include "h264.h"
32 #include "golomb.h"
33 
34 #include <assert.h>
35 
36 #define COPY_PICTURE(dst, src) \
37 do {\
38  *(dst) = *(src);\
39  (dst)->f.extended_data = (dst)->f.data;\
40  (dst)->tf.f = &(dst)->f;\
41 } while (0)
42 
43 
44 static void pic_as_field(Picture *pic, const int parity){
45  int i;
46  for (i = 0; i < 4; ++i) {
47  if (parity == PICT_BOTTOM_FIELD)
48  pic->f.data[i] += pic->f.linesize[i];
49  pic->reference = parity;
50  pic->f.linesize[i] *= 2;
51  }
52  pic->poc= pic->field_poc[parity == PICT_BOTTOM_FIELD];
53 }
54 
55 static int split_field_copy(Picture *dest, Picture *src, int parity, int id_add)
56 {
57  int match = !!(src->reference & parity);
58 
59  if (match) {
60  COPY_PICTURE(dest, src);
61  if (parity != PICT_FRAME) {
62  pic_as_field(dest, parity);
63  dest->pic_id *= 2;
64  dest->pic_id += id_add;
65  }
66  }
67 
68  return match;
69 }
70 
71 static int build_def_list(Picture *def, int def_len,
72  Picture **in, int len, int is_long, int sel)
73 {
74  int i[2] = { 0 };
75  int index = 0;
76 
77  while (i[0] < len || i[1] < len) {
78  while (i[0] < len && !(in[i[0]] && (in[i[0]]->reference & sel)))
79  i[0]++;
80  while (i[1] < len && !(in[i[1]] && (in[i[1]]->reference & (sel ^ 3))))
81  i[1]++;
82  if (i[0] < len) {
83  av_assert0(index < def_len);
84  in[i[0]]->pic_id = is_long ? i[0] : in[i[0]]->frame_num;
85  split_field_copy(&def[index++], in[i[0]++], sel, 1);
86  }
87  if (i[1] < len) {
88  av_assert0(index < def_len);
89  in[i[1]]->pic_id = is_long ? i[1] : in[i[1]]->frame_num;
90  split_field_copy(&def[index++], in[i[1]++], sel ^ 3, 0);
91  }
92  }
93 
94  return index;
95 }
96 
97 static int add_sorted(Picture **sorted, Picture **src, int len, int limit, int dir)
98 {
99  int i, best_poc;
100  int out_i = 0;
101 
102  for (;;) {
103  best_poc = dir ? INT_MIN : INT_MAX;
104 
105  for (i = 0; i < len; i++) {
106  const int poc = src[i]->poc;
107  if (((poc > limit) ^ dir) && ((poc < best_poc) ^ dir)) {
108  best_poc = poc;
109  sorted[out_i] = src[i];
110  }
111  }
112  if (best_poc == (dir ? INT_MIN : INT_MAX))
113  break;
114  limit = sorted[out_i++]->poc - dir;
115  }
116  return out_i;
117 }
118 
120 {
121  int i, len;
122 
123  if (h->slice_type_nos == AV_PICTURE_TYPE_B) {
124  Picture *sorted[32];
125  int cur_poc, list;
126  int lens[2];
127 
128  if (FIELD_PICTURE(h))
130  else
131  cur_poc = h->cur_pic_ptr->poc;
132 
133  for (list = 0; list < 2; list++) {
134  len = add_sorted(sorted, h->short_ref, h->short_ref_count, cur_poc, 1 ^ list);
135  len += add_sorted(sorted + len, h->short_ref, h->short_ref_count, cur_poc, 0 ^ list);
136  av_assert0(len <= 32);
137 
139  sorted, len, 0, h->picture_structure);
140  len += build_def_list(h->default_ref_list[list] + len,
141  FF_ARRAY_ELEMS(h->default_ref_list[0]) - len,
142  h->long_ref, 16, 1, h->picture_structure);
143  av_assert0(len <= 32);
144 
145  if (len < h->ref_count[list])
146  memset(&h->default_ref_list[list][len], 0, sizeof(Picture) * (h->ref_count[list] - len));
147  lens[list] = len;
148  }
149 
150  if (lens[0] == lens[1] && lens[1] > 1) {
151  for (i = 0; i < lens[0] &&
152  h->default_ref_list[0][i].f.buf[0]->buffer ==
153  h->default_ref_list[1][i].f.buf[0]->buffer; i++);
154  if (i == lens[0]) {
155  Picture tmp;
156  COPY_PICTURE(&tmp, &h->default_ref_list[1][0]);
157  COPY_PICTURE(&h->default_ref_list[1][0], &h->default_ref_list[1][1]);
158  COPY_PICTURE(&h->default_ref_list[1][1], &tmp);
159  }
160  }
161  } else {
164  len += build_def_list(h->default_ref_list[0] + len,
165  FF_ARRAY_ELEMS(h->default_ref_list[0]) - len,
166  h-> long_ref, 16, 1, h->picture_structure);
167  av_assert0(len <= 32);
168 
169  if (len < h->ref_count[0])
170  memset(&h->default_ref_list[0][len], 0, sizeof(Picture) * (h->ref_count[0] - len));
171  }
172 #ifdef TRACE
173  for (i = 0; i < h->ref_count[0]; i++) {
174  tprintf(h->avctx, "List0: %s fn:%d 0x%p\n",
175  (h->default_ref_list[0][i].long_ref ? "LT" : "ST"),
176  h->default_ref_list[0][i].pic_id,
177  h->default_ref_list[0][i].f.data[0]);
178  }
179  if (h->slice_type_nos == AV_PICTURE_TYPE_B) {
180  for (i = 0; i < h->ref_count[1]; i++) {
181  tprintf(h->avctx, "List1: %s fn:%d 0x%p\n",
182  (h->default_ref_list[1][i].long_ref ? "LT" : "ST"),
183  h->default_ref_list[1][i].pic_id,
184  h->default_ref_list[1][i].f.data[0]);
185  }
186  }
187 #endif
188  return 0;
189 }
190 
191 static void print_short_term(H264Context *h);
192 static void print_long_term(H264Context *h);
193 
194 /**
195  * Extract structure information about the picture described by pic_num in
196  * the current decoding context (frame or field). Note that pic_num is
197  * picture number without wrapping (so, 0<=pic_num<max_pic_num).
198  * @param pic_num picture number for which to extract structure information
199  * @param structure one of PICT_XXX describing structure of picture
200  * with pic_num
201  * @return frame number (short term) or long term index of picture
202  * described by pic_num
203  */
204 static int pic_num_extract(H264Context *h, int pic_num, int *structure)
205 {
206  *structure = h->picture_structure;
207  if (FIELD_PICTURE(h)) {
208  if (!(pic_num & 1))
209  /* opposite field */
210  *structure ^= PICT_FRAME;
211  pic_num >>= 1;
212  }
213 
214  return pic_num;
215 }
216 
218 {
219  int list, index, pic_structure, i;
220 
221  print_short_term(h);
222  print_long_term(h);
223 
224  for (list = 0; list < h->list_count; list++) {
225  for (i = 0; i < h->ref_count[list]; i++)
226  COPY_PICTURE(&h->ref_list[list][i], &h->default_ref_list[list][i]);
227 
228  if (get_bits1(&h->gb)) {
229  int pred = h->curr_pic_num;
230 
231  for (index = 0; ; index++) {
232  unsigned int reordering_of_pic_nums_idc = get_ue_golomb_31(&h->gb);
233  unsigned int pic_id;
234  int i;
235  Picture *ref = NULL;
236 
237  if (reordering_of_pic_nums_idc == 3)
238  break;
239 
240  if (index >= h->ref_count[list]) {
241  av_log(h->avctx, AV_LOG_ERROR, "reference count overflow\n");
242  return -1;
243  }
244 
245  switch (reordering_of_pic_nums_idc) {
246  case 0:
247  case 1: {
248  const unsigned int abs_diff_pic_num = get_ue_golomb(&h->gb) + 1;
249  int frame_num;
250 
251  if (abs_diff_pic_num > h->max_pic_num) {
253  "abs_diff_pic_num overflow\n");
254  return AVERROR_INVALIDDATA;
255  }
256 
257  if (reordering_of_pic_nums_idc == 0)
258  pred -= abs_diff_pic_num;
259  else
260  pred += abs_diff_pic_num;
261  pred &= h->max_pic_num - 1;
262 
263  frame_num = pic_num_extract(h, pred, &pic_structure);
264 
265  for (i = h->short_ref_count - 1; i >= 0; i--) {
266  ref = h->short_ref[i];
267  assert(ref->reference);
268  assert(!ref->long_ref);
269  if (ref->frame_num == frame_num &&
270  (ref->reference & pic_structure))
271  break;
272  }
273  if (i >= 0)
274  ref->pic_id = pred;
275  break;
276  }
277  case 2: {
278  int long_idx;
279  pic_id = get_ue_golomb(&h->gb); // long_term_pic_idx
280 
281  long_idx = pic_num_extract(h, pic_id, &pic_structure);
282 
283  if (long_idx > 31) {
285  "long_term_pic_idx overflow\n");
286  return AVERROR_INVALIDDATA;
287  }
288  ref = h->long_ref[long_idx];
289  assert(!(ref && !ref->reference));
290  if (ref && (ref->reference & pic_structure)) {
291  ref->pic_id = pic_id;
292  assert(ref->long_ref);
293  i = 0;
294  } else {
295  i = -1;
296  }
297  break;
298  }
299  default:
301  "illegal reordering_of_pic_nums_idc\n");
302  return AVERROR_INVALIDDATA;
303  }
304 
305  if (i < 0) {
307  "reference picture missing during reorder\n");
308  memset(&h->ref_list[list][index], 0, sizeof(Picture)); // FIXME
309  } else {
310  for (i = index; i + 1 < h->ref_count[list]; i++) {
311  if (ref->long_ref == h->ref_list[list][i].long_ref &&
312  ref->pic_id == h->ref_list[list][i].pic_id)
313  break;
314  }
315  for (; i > index; i--) {
316  COPY_PICTURE(&h->ref_list[list][i], &h->ref_list[list][i - 1]);
317  }
318  COPY_PICTURE(&h->ref_list[list][index], ref);
319  if (FIELD_PICTURE(h)) {
320  pic_as_field(&h->ref_list[list][index], pic_structure);
321  }
322  }
323  }
324  }
325  }
326  for (list = 0; list < h->list_count; list++) {
327  for (index = 0; index < h->ref_count[list]; index++) {
328  if ( !h->ref_list[list][index].f.buf[0]
329  || (!FIELD_PICTURE(h) && (h->ref_list[list][index].reference&3) != 3)) {
330  int i;
331  av_log(h->avctx, AV_LOG_ERROR, "Missing reference picture, default is %d\n", h->default_ref_list[list][0].poc);
332  for (i = 0; i < FF_ARRAY_ELEMS(h->last_pocs); i++)
333  h->last_pocs[i] = INT_MIN;
334  if (h->default_ref_list[list][0].f.buf[0]
335  && !(!FIELD_PICTURE(h) && (h->default_ref_list[list][0].reference&3) != 3))
336  COPY_PICTURE(&h->ref_list[list][index], &h->default_ref_list[list][0]);
337  else
338  return -1;
339  }
340  av_assert0(av_buffer_get_ref_count(h->ref_list[list][index].f.buf[0]) > 0);
341  }
342  }
343 
344  return 0;
345 }
346 
348 {
349  int list, i, j;
350  for (list = 0; list < h->list_count; list++) {
351  for (i = 0; i < h->ref_count[list]; i++) {
352  Picture *frame = &h->ref_list[list][i];
353  Picture *field = &h->ref_list[list][16 + 2 * i];
354  COPY_PICTURE(field, frame);
355  for (j = 0; j < 3; j++)
356  field[0].f.linesize[j] <<= 1;
357  field[0].reference = PICT_TOP_FIELD;
358  field[0].poc = field[0].field_poc[0];
359  COPY_PICTURE(field + 1, field);
360  for (j = 0; j < 3; j++)
361  field[1].f.data[j] += frame->f.linesize[j];
362  field[1].reference = PICT_BOTTOM_FIELD;
363  field[1].poc = field[1].field_poc[1];
364 
365  h->luma_weight[16 + 2 * i][list][0] = h->luma_weight[16 + 2 * i + 1][list][0] = h->luma_weight[i][list][0];
366  h->luma_weight[16 + 2 * i][list][1] = h->luma_weight[16 + 2 * i + 1][list][1] = h->luma_weight[i][list][1];
367  for (j = 0; j < 2; j++) {
368  h->chroma_weight[16 + 2 * i][list][j][0] = h->chroma_weight[16 + 2 * i + 1][list][j][0] = h->chroma_weight[i][list][j][0];
369  h->chroma_weight[16 + 2 * i][list][j][1] = h->chroma_weight[16 + 2 * i + 1][list][j][1] = h->chroma_weight[i][list][j][1];
370  }
371  }
372  }
373 }
374 
375 /**
376  * Mark a picture as no longer needed for reference. The refmask
377  * argument allows unreferencing of individual fields or the whole frame.
378  * If the picture becomes entirely unreferenced, but is being held for
379  * display purposes, it is marked as such.
380  * @param refmask mask of fields to unreference; the mask is bitwise
381  * anded with the reference marking of pic
382  * @return non-zero if pic becomes entirely unreferenced (except possibly
383  * for display purposes) zero if one of the fields remains in
384  * reference
385  */
386 static inline int unreference_pic(H264Context *h, Picture *pic, int refmask)
387 {
388  int i;
389  if (pic->reference &= refmask) {
390  return 0;
391  } else {
392  for(i = 0; h->delayed_pic[i]; i++)
393  if(pic == h->delayed_pic[i]){
394  pic->reference = DELAYED_PIC_REF;
395  break;
396  }
397  return 1;
398  }
399 }
400 
401 /**
402  * Find a Picture in the short term reference list by frame number.
403  * @param frame_num frame number to search for
404  * @param idx the index into h->short_ref where returned picture is found
405  * undefined if no picture found.
406  * @return pointer to the found picture, or NULL if no pic with the provided
407  * frame number is found
408  */
409 static Picture *find_short(H264Context *h, int frame_num, int *idx)
410 {
411  int i;
412 
413  for (i = 0; i < h->short_ref_count; i++) {
414  Picture *pic = h->short_ref[i];
415  if (h->avctx->debug & FF_DEBUG_MMCO)
416  av_log(h->avctx, AV_LOG_DEBUG, "%d %d %p\n", i, pic->frame_num, pic);
417  if (pic->frame_num == frame_num) {
418  *idx = i;
419  return pic;
420  }
421  }
422  return NULL;
423 }
424 
425 /**
426  * Remove a picture from the short term reference list by its index in
427  * that list. This does no checking on the provided index; it is assumed
428  * to be valid. Other list entries are shifted down.
429  * @param i index into h->short_ref of picture to remove.
430  */
431 static void remove_short_at_index(H264Context *h, int i)
432 {
433  assert(i >= 0 && i < h->short_ref_count);
434  h->short_ref[i] = NULL;
435  if (--h->short_ref_count)
436  memmove(&h->short_ref[i], &h->short_ref[i + 1],
437  (h->short_ref_count - i) * sizeof(Picture*));
438 }
439 
440 /**
441  *
442  * @return the removed picture or NULL if an error occurs
443  */
444 static Picture *remove_short(H264Context *h, int frame_num, int ref_mask)
445 {
446  Picture *pic;
447  int i;
448 
449  if (h->avctx->debug & FF_DEBUG_MMCO)
450  av_log(h->avctx, AV_LOG_DEBUG, "remove short %d count %d\n", frame_num, h->short_ref_count);
451 
452  pic = find_short(h, frame_num, &i);
453  if (pic) {
454  if (unreference_pic(h, pic, ref_mask))
455  remove_short_at_index(h, i);
456  }
457 
458  return pic;
459 }
460 
461 /**
462  * Remove a picture from the long term reference list by its index in
463  * that list.
464  * @return the removed picture or NULL if an error occurs
465  */
466 static Picture *remove_long(H264Context *h, int i, int ref_mask)
467 {
468  Picture *pic;
469 
470  pic = h->long_ref[i];
471  if (pic) {
472  if (unreference_pic(h, pic, ref_mask)) {
473  assert(h->long_ref[i]->long_ref == 1);
474  h->long_ref[i]->long_ref = 0;
475  h->long_ref[i] = NULL;
476  h->long_ref_count--;
477  }
478  }
479 
480  return pic;
481 }
482 
484 {
485  int i;
486 
487  for (i = 0; i < 16; i++) {
488  remove_long(h, i, 0);
489  }
490  assert(h->long_ref_count == 0);
491 
492  for (i = 0; i < h->short_ref_count; i++) {
493  unreference_pic(h, h->short_ref[i], 0);
494  h->short_ref[i] = NULL;
495  }
496  h->short_ref_count = 0;
497 
498  memset(h->default_ref_list, 0, sizeof(h->default_ref_list));
499  memset(h->ref_list, 0, sizeof(h->ref_list));
500 }
501 
502 /**
503  * print short term list
504  */
506 {
507  uint32_t i;
508  if (h->avctx->debug & FF_DEBUG_MMCO) {
509  av_log(h->avctx, AV_LOG_DEBUG, "short term list:\n");
510  for (i = 0; i < h->short_ref_count; i++) {
511  Picture *pic = h->short_ref[i];
512  av_log(h->avctx, AV_LOG_DEBUG, "%d fn:%d poc:%d %p\n",
513  i, pic->frame_num, pic->poc, pic->f.data[0]);
514  }
515  }
516 }
517 
518 /**
519  * print long term list
520  */
522 {
523  uint32_t i;
524  if (h->avctx->debug & FF_DEBUG_MMCO) {
525  av_log(h->avctx, AV_LOG_DEBUG, "long term list:\n");
526  for (i = 0; i < 16; i++) {
527  Picture *pic = h->long_ref[i];
528  if (pic) {
529  av_log(h->avctx, AV_LOG_DEBUG, "%d fn:%d poc:%d %p\n",
530  i, pic->frame_num, pic->poc, pic->f.data[0]);
531  }
532  }
533  }
534 }
535 
536 static int check_opcodes(MMCO *mmco1, MMCO *mmco2, int n_mmcos)
537 {
538  int i;
539 
540  for (i = 0; i < n_mmcos; i++) {
541  if (mmco1[i].opcode != mmco2[i].opcode) {
542  av_log(NULL, AV_LOG_ERROR, "MMCO opcode [%d, %d] at %d mismatches between slices\n",
543  mmco1[i].opcode, mmco2[i].opcode, i);
544  return -1;
545  }
546  }
547 
548  return 0;
549 }
550 
552 {
553  MMCO mmco_temp[MAX_MMCO_COUNT], *mmco = first_slice ? h->mmco : mmco_temp;
554  int mmco_index = 0, i;
555 
556  if (h->short_ref_count &&
558  !(FIELD_PICTURE(h) && !h->first_field && h->cur_pic_ptr->reference)) {
559  mmco[0].opcode = MMCO_SHORT2UNUSED;
560  mmco[0].short_pic_num = h->short_ref[h->short_ref_count - 1]->frame_num;
561  mmco_index = 1;
562  if (FIELD_PICTURE(h)) {
563  mmco[0].short_pic_num *= 2;
564  mmco[1].opcode = MMCO_SHORT2UNUSED;
565  mmco[1].short_pic_num = mmco[0].short_pic_num + 1;
566  mmco_index = 2;
567  }
568  }
569 
570  if (first_slice) {
571  h->mmco_index = mmco_index;
572  } else if (!first_slice && mmco_index >= 0 &&
573  (mmco_index != h->mmco_index ||
574  (i = check_opcodes(h->mmco, mmco_temp, mmco_index)))) {
576  "Inconsistent MMCO state between slices [%d, %d]\n",
577  mmco_index, h->mmco_index);
578  return AVERROR_INVALIDDATA;
579  }
580  return 0;
581 }
582 
583 int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count)
584 {
585  int i, av_uninit(j);
586  int pps_count;
587  int current_ref_assigned = 0, err = 0;
588  Picture *av_uninit(pic);
589 
590  if ((h->avctx->debug & FF_DEBUG_MMCO) && mmco_count == 0)
591  av_log(h->avctx, AV_LOG_DEBUG, "no mmco here\n");
592 
593  for (i = 0; i < mmco_count; i++) {
594  int av_uninit(structure), av_uninit(frame_num);
595  if (h->avctx->debug & FF_DEBUG_MMCO)
596  av_log(h->avctx, AV_LOG_DEBUG, "mmco:%d %d %d\n", h->mmco[i].opcode,
597  h->mmco[i].short_pic_num, h->mmco[i].long_arg);
598 
599  if (mmco[i].opcode == MMCO_SHORT2UNUSED ||
600  mmco[i].opcode == MMCO_SHORT2LONG) {
601  frame_num = pic_num_extract(h, mmco[i].short_pic_num, &structure);
602  pic = find_short(h, frame_num, &j);
603  if (!pic) {
604  if (mmco[i].opcode != MMCO_SHORT2LONG ||
605  !h->long_ref[mmco[i].long_arg] ||
606  h->long_ref[mmco[i].long_arg]->frame_num != frame_num) {
607  av_log(h->avctx, h->short_ref_count ? AV_LOG_ERROR : AV_LOG_DEBUG, "mmco: unref short failure\n");
608  err = AVERROR_INVALIDDATA;
609  }
610  continue;
611  }
612  }
613 
614  switch (mmco[i].opcode) {
615  case MMCO_SHORT2UNUSED:
616  if (h->avctx->debug & FF_DEBUG_MMCO)
617  av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref short %d count %d\n",
619  remove_short(h, frame_num, structure ^ PICT_FRAME);
620  break;
621  case MMCO_SHORT2LONG:
622  if (h->long_ref[mmco[i].long_arg] != pic)
623  remove_long(h, mmco[i].long_arg, 0);
624 
625  remove_short_at_index(h, j);
626  h->long_ref[ mmco[i].long_arg ] = pic;
627  if (h->long_ref[mmco[i].long_arg]) {
628  h->long_ref[mmco[i].long_arg]->long_ref = 1;
629  h->long_ref_count++;
630  }
631  break;
632  case MMCO_LONG2UNUSED:
633  j = pic_num_extract(h, mmco[i].long_arg, &structure);
634  pic = h->long_ref[j];
635  if (pic) {
636  remove_long(h, j, structure ^ PICT_FRAME);
637  } else if (h->avctx->debug & FF_DEBUG_MMCO)
638  av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref long failure\n");
639  break;
640  case MMCO_LONG:
641  // Comment below left from previous code as it is an interresting note.
642  /* First field in pair is in short term list or
643  * at a different long term index.
644  * This is not allowed; see 7.4.3.3, notes 2 and 3.
645  * Report the problem and keep the pair where it is,
646  * and mark this field valid.
647  */
648  if (h->short_ref[0] == h->cur_pic_ptr) {
649  av_log(h->avctx, AV_LOG_ERROR, "mmco: cannot assign current picture to short and long at the same time\n");
650  remove_short_at_index(h, 0);
651  }
652 
653  if (h->long_ref[mmco[i].long_arg] != h->cur_pic_ptr) {
654  if (h->cur_pic_ptr->long_ref) {
655  for(j=0; j<16; j++) {
656  if(h->long_ref[j] == h->cur_pic_ptr) {
657  remove_long(h, j, 0);
658  av_log(h->avctx, AV_LOG_ERROR, "mmco: cannot assign current picture to 2 long term references\n");
659  }
660  }
661  }
663  remove_long(h, mmco[i].long_arg, 0);
664 
665  h->long_ref[mmco[i].long_arg] = h->cur_pic_ptr;
666  h->long_ref[mmco[i].long_arg]->long_ref = 1;
667  h->long_ref_count++;
668  }
669 
671  current_ref_assigned = 1;
672  break;
673  case MMCO_SET_MAX_LONG:
674  assert(mmco[i].long_arg <= 16);
675  // just remove the long term which index is greater than new max
676  for (j = mmco[i].long_arg; j < 16; j++) {
677  remove_long(h, j, 0);
678  }
679  break;
680  case MMCO_RESET:
681  while (h->short_ref_count) {
682  remove_short(h, h->short_ref[0]->frame_num, 0);
683  }
684  for (j = 0; j < 16; j++) {
685  remove_long(h, j, 0);
686  }
687  h->frame_num = h->cur_pic_ptr->frame_num = 0;
688  h->mmco_reset = 1;
689  h->cur_pic_ptr->mmco_reset = 1;
690  for (j = 0; j < MAX_DELAYED_PIC_COUNT; j++)
691  h->last_pocs[j] = INT_MIN;
692  break;
693  default: assert(0);
694  }
695  }
696 
697  if (!current_ref_assigned) {
698  /* Second field of complementary field pair; the first field of
699  * which is already referenced. If short referenced, it
700  * should be first entry in short_ref. If not, it must exist
701  * in long_ref; trying to put it on the short list here is an
702  * error in the encoded bit stream (ref: 7.4.3.3, NOTE 2 and 3).
703  */
704  if (h->short_ref_count && h->short_ref[0] == h->cur_pic_ptr) {
705  /* Just mark the second field valid */
707  } else if (h->cur_pic_ptr->long_ref) {
708  av_log(h->avctx, AV_LOG_ERROR, "illegal short term reference "
709  "assignment for second field "
710  "in complementary field pair "
711  "(first field is long term)\n");
712  err = AVERROR_INVALIDDATA;
713  } else {
714  pic = remove_short(h, h->cur_pic_ptr->frame_num, 0);
715  if (pic) {
716  av_log(h->avctx, AV_LOG_ERROR, "illegal short term buffer state detected\n");
717  err = AVERROR_INVALIDDATA;
718  }
719 
720  if (h->short_ref_count)
721  memmove(&h->short_ref[1], &h->short_ref[0],
722  h->short_ref_count * sizeof(Picture*));
723 
724  h->short_ref[0] = h->cur_pic_ptr;
725  h->short_ref_count++;
727  }
728  }
729 
730  if (h->long_ref_count + h->short_ref_count > FFMAX(h->sps.ref_frame_count, 1)) {
731 
732  /* We have too many reference frames, probably due to corrupted
733  * stream. Need to discard one frame. Prevents overrun of the
734  * short_ref and long_ref buffers.
735  */
737  "number of reference frames (%d+%d) exceeds max (%d; probably "
738  "corrupt input), discarding one\n",
740  err = AVERROR_INVALIDDATA;
741 
742  if (h->long_ref_count && !h->short_ref_count) {
743  for (i = 0; i < 16; ++i)
744  if (h->long_ref[i])
745  break;
746 
747  assert(i < 16);
748  remove_long(h, i, 0);
749  } else {
750  pic = h->short_ref[h->short_ref_count - 1];
751  remove_short(h, pic->frame_num, 0);
752  }
753  }
754 
755  for (i = 0; i<h->short_ref_count; i++) {
756  pic = h->short_ref[i];
757  if (pic->invalid_gap) {
758  int d = (h->cur_pic_ptr->frame_num - pic->frame_num) & ((1 << h->sps.log2_max_frame_num)-1);
759  if (d > h->sps.ref_frame_count)
760  remove_short(h, pic->frame_num, 0);
761  }
762  }
763 
764  print_short_term(h);
765  print_long_term(h);
766 
767  pps_count = 0;
768  for (i = 0; i < FF_ARRAY_ELEMS(h->pps_buffers); i++)
769  pps_count += !!h->pps_buffers[i];
770 
771  if ( err >= 0
772  && h->long_ref_count==0
773  && (h->short_ref_count<=2 || h->pps.ref_count[0] <= 1 && h->pps.ref_count[1] <= 1 && pps_count == 1)
774  && h->pps.ref_count[0]<=2 + (h->picture_structure != PICT_FRAME)
776  h->cur_pic_ptr->recovered |= 1;
777  if(!h->avctx->has_b_frames)
779  }
780 
781  return (h->avctx->err_recognition & AV_EF_EXPLODE) ? err : 0;
782 }
783 
785  int first_slice)
786 {
787  int i, ret;
788  MMCO mmco_temp[MAX_MMCO_COUNT], *mmco = mmco_temp;
789  int mmco_index = 0;
790 
791  if (h->nal_unit_type == NAL_IDR_SLICE) { // FIXME fields
792  skip_bits1(gb); // broken_link
793  if (get_bits1(gb)) {
794  mmco[0].opcode = MMCO_LONG;
795  mmco[0].long_arg = 0;
796  mmco_index = 1;
797  }
798  } else {
799  if (get_bits1(gb)) { // adaptive_ref_pic_marking_mode_flag
800  for (i = 0; i < MAX_MMCO_COUNT; i++) {
801  MMCOOpcode opcode = get_ue_golomb_31(gb);
802 
803  mmco[i].opcode = opcode;
804  if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG) {
805  mmco[i].short_pic_num =
806  (h->curr_pic_num - get_ue_golomb(gb) - 1) &
807  (h->max_pic_num - 1);
808 #if 0
809  if (mmco[i].short_pic_num >= h->short_ref_count ||
810  h->short_ref[ mmco[i].short_pic_num ] == NULL){
811  av_log(s->avctx, AV_LOG_ERROR,
812  "illegal short ref in memory management control "
813  "operation %d\n", mmco);
814  return -1;
815  }
816 #endif
817  }
818  if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED ||
819  opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG) {
820  unsigned int long_arg = get_ue_golomb_31(gb);
821  if (long_arg >= 32 ||
822  (long_arg >= 16 && !(opcode == MMCO_SET_MAX_LONG &&
823  long_arg == 16) &&
824  !(opcode == MMCO_LONG2UNUSED && FIELD_PICTURE(h)))) {
826  "illegal long ref in memory management control "
827  "operation %d\n", opcode);
828  return -1;
829  }
830  mmco[i].long_arg = long_arg;
831  }
832 
833  if (opcode > (unsigned) MMCO_LONG) {
835  "illegal memory management control operation %d\n",
836  opcode);
837  return -1;
838  }
839  if (opcode == MMCO_END)
840  break;
841  }
842  mmco_index = i;
843  } else {
844  if (first_slice) {
845  ret = ff_generate_sliding_window_mmcos(h, first_slice);
846  if (ret < 0 && h->avctx->err_recognition & AV_EF_EXPLODE)
847  return ret;
848  }
849  mmco_index = -1;
850  }
851  }
852 
853  if (first_slice && mmco_index != -1) {
854  memcpy(h->mmco, mmco_temp, sizeof(h->mmco));
855  h->mmco_index = mmco_index;
856  } else if (!first_slice && mmco_index >= 0 &&
857  (mmco_index != h->mmco_index ||
858  check_opcodes(h->mmco, mmco_temp, mmco_index))) {
860  "Inconsistent MMCO state between slices [%d, %d]\n",
861  mmco_index, h->mmco_index);
862  return AVERROR_INVALIDDATA;
863  }
864 
865  return 0;
866 }