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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 
119 int ff_h264_fill_default_ref_list(H264Context *h)
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))
129  cur_poc = h->cur_pic_ptr->field_poc[h->picture_structure == PICT_BOTTOM_FIELD];
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 
138  len = build_def_list(h->default_ref_list[list], FF_ARRAY_ELEMS(h->default_ref_list[0]),
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 {
162  len = build_def_list(h->default_ref_list[0], FF_ARRAY_ELEMS(h->default_ref_list[0]),
163  h->short_ref, h->short_ref_count, 0, h->picture_structure);
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 
217 int ff_h264_decode_ref_pic_list_reordering(H264Context *h)
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  if (reordering_of_pic_nums_idc < 3) {
246  if (reordering_of_pic_nums_idc < 2) {
247  const unsigned int abs_diff_pic_num = get_ue_golomb(&h->gb) + 1;
248  int frame_num;
249 
250  if (abs_diff_pic_num > h->max_pic_num) {
251  av_log(h->avctx, AV_LOG_ERROR, "abs_diff_pic_num overflow\n");
252  return -1;
253  }
254 
255  if (reordering_of_pic_nums_idc == 0)
256  pred -= abs_diff_pic_num;
257  else
258  pred += abs_diff_pic_num;
259  pred &= h->max_pic_num - 1;
260 
261  frame_num = pic_num_extract(h, pred, &pic_structure);
262 
263  for (i = h->short_ref_count - 1; i >= 0; i--) {
264  ref = h->short_ref[i];
265  assert(ref->reference);
266  assert(!ref->long_ref);
267  if (ref->frame_num == frame_num &&
268  (ref->reference & pic_structure))
269  break;
270  }
271  if (i >= 0)
272  ref->pic_id = pred;
273  } else {
274  int long_idx;
275  pic_id = get_ue_golomb(&h->gb); //long_term_pic_idx
276 
277  long_idx = pic_num_extract(h, pic_id, &pic_structure);
278 
279  if (long_idx > 31) {
280  av_log(h->avctx, AV_LOG_ERROR, "long_term_pic_idx overflow\n");
281  return -1;
282  }
283  ref = h->long_ref[long_idx];
284  assert(!(ref && !ref->reference));
285  if (ref && (ref->reference & pic_structure)) {
286  ref->pic_id = pic_id;
287  assert(ref->long_ref);
288  i = 0;
289  } else {
290  i = -1;
291  }
292  }
293 
294  if (i < 0) {
295  av_log(h->avctx, AV_LOG_ERROR, "reference picture missing during reorder\n");
296  memset(&h->ref_list[list][index], 0, sizeof(Picture)); //FIXME
297  } else {
298  for (i = index; i + 1 < h->ref_count[list]; i++) {
299  if (ref->long_ref == h->ref_list[list][i].long_ref &&
300  ref->pic_id == h->ref_list[list][i].pic_id)
301  break;
302  }
303  for (; i > index; i--) {
304  COPY_PICTURE(&h->ref_list[list][i], &h->ref_list[list][i - 1]);
305  }
306  COPY_PICTURE(&h->ref_list[list][index], ref);
307  if (FIELD_PICTURE(h)) {
308  pic_as_field(&h->ref_list[list][index], pic_structure);
309  }
310  }
311  } else {
312  av_log(h->avctx, AV_LOG_ERROR, "illegal reordering_of_pic_nums_idc\n");
313  return -1;
314  }
315  }
316  }
317  }
318  for (list = 0; list < h->list_count; list++) {
319  for (index = 0; index < h->ref_count[list]; index++) {
320  if ( !h->ref_list[list][index].f.buf[0]
321  || (!FIELD_PICTURE(h) && (h->ref_list[list][index].reference&3) != 3)) {
322  int i;
323  av_log(h->avctx, AV_LOG_ERROR, "Missing reference picture, default is %d\n", h->default_ref_list[list][0].poc);
324  for (i = 0; i < FF_ARRAY_ELEMS(h->last_pocs); i++)
325  h->last_pocs[i] = INT_MIN;
326  if (h->default_ref_list[list][0].f.buf[0]
327  && !(!FIELD_PICTURE(h) && (h->default_ref_list[list][0].reference&3) != 3))
328  COPY_PICTURE(&h->ref_list[list][index], &h->default_ref_list[list][0]);
329  else
330  return -1;
331  }
332  av_assert0(av_buffer_get_ref_count(h->ref_list[list][index].f.buf[0]) > 0);
333  }
334  }
335 
336  return 0;
337 }
338 
339 void ff_h264_fill_mbaff_ref_list(H264Context *h)
340 {
341  int list, i, j;
342  for (list = 0; list < h->list_count; list++) {
343  for (i = 0; i < h->ref_count[list]; i++) {
344  Picture *frame = &h->ref_list[list][i];
345  Picture *field = &h->ref_list[list][16 + 2 * i];
346  COPY_PICTURE(field, frame);
347  for (j = 0; j < 3; j++)
348  field[0].f.linesize[j] <<= 1;
349  field[0].reference = PICT_TOP_FIELD;
350  field[0].poc = field[0].field_poc[0];
351  COPY_PICTURE(field + 1, field);
352  for (j = 0; j < 3; j++)
353  field[1].f.data[j] += frame->f.linesize[j];
354  field[1].reference = PICT_BOTTOM_FIELD;
355  field[1].poc = field[1].field_poc[1];
356 
357  h->luma_weight[16 + 2 * i][list][0] = h->luma_weight[16 + 2 * i + 1][list][0] = h->luma_weight[i][list][0];
358  h->luma_weight[16 + 2 * i][list][1] = h->luma_weight[16 + 2 * i + 1][list][1] = h->luma_weight[i][list][1];
359  for (j = 0; j < 2; j++) {
360  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];
361  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];
362  }
363  }
364  }
365 }
366 
367 /**
368  * Mark a picture as no longer needed for reference. The refmask
369  * argument allows unreferencing of individual fields or the whole frame.
370  * If the picture becomes entirely unreferenced, but is being held for
371  * display purposes, it is marked as such.
372  * @param refmask mask of fields to unreference; the mask is bitwise
373  * anded with the reference marking of pic
374  * @return non-zero if pic becomes entirely unreferenced (except possibly
375  * for display purposes) zero if one of the fields remains in
376  * reference
377  */
378 static inline int unreference_pic(H264Context *h, Picture *pic, int refmask)
379 {
380  int i;
381  if (pic->reference &= refmask) {
382  return 0;
383  } else {
384  for(i = 0; h->delayed_pic[i]; i++)
385  if(pic == h->delayed_pic[i]){
386  pic->reference = DELAYED_PIC_REF;
387  break;
388  }
389  return 1;
390  }
391 }
392 
393 /**
394  * Find a Picture in the short term reference list by frame number.
395  * @param frame_num frame number to search for
396  * @param idx the index into h->short_ref where returned picture is found
397  * undefined if no picture found.
398  * @return pointer to the found picture, or NULL if no pic with the provided
399  * frame number is found
400  */
401 static Picture *find_short(H264Context *h, int frame_num, int *idx)
402 {
403  int i;
404 
405  for (i = 0; i < h->short_ref_count; i++) {
406  Picture *pic = h->short_ref[i];
407  if (h->avctx->debug & FF_DEBUG_MMCO)
408  av_log(h->avctx, AV_LOG_DEBUG, "%d %d %p\n", i, pic->frame_num, pic);
409  if (pic->frame_num == frame_num) {
410  *idx = i;
411  return pic;
412  }
413  }
414  return NULL;
415 }
416 
417 /**
418  * Remove a picture from the short term reference list by its index in
419  * that list. This does no checking on the provided index; it is assumed
420  * to be valid. Other list entries are shifted down.
421  * @param i index into h->short_ref of picture to remove.
422  */
423 static void remove_short_at_index(H264Context *h, int i)
424 {
425  assert(i >= 0 && i < h->short_ref_count);
426  h->short_ref[i] = NULL;
427  if (--h->short_ref_count)
428  memmove(&h->short_ref[i], &h->short_ref[i + 1],
429  (h->short_ref_count - i) * sizeof(Picture*));
430 }
431 
432 /**
433  *
434  * @return the removed picture or NULL if an error occurs
435  */
436 static Picture *remove_short(H264Context *h, int frame_num, int ref_mask)
437 {
438  Picture *pic;
439  int i;
440 
441  if (h->avctx->debug & FF_DEBUG_MMCO)
442  av_log(h->avctx, AV_LOG_DEBUG, "remove short %d count %d\n", frame_num, h->short_ref_count);
443 
444  pic = find_short(h, frame_num, &i);
445  if (pic) {
446  if (unreference_pic(h, pic, ref_mask))
447  remove_short_at_index(h, i);
448  }
449 
450  return pic;
451 }
452 
453 /**
454  * Remove a picture from the long term reference list by its index in
455  * that list.
456  * @return the removed picture or NULL if an error occurs
457  */
458 static Picture *remove_long(H264Context *h, int i, int ref_mask)
459 {
460  Picture *pic;
461 
462  pic = h->long_ref[i];
463  if (pic) {
464  if (unreference_pic(h, pic, ref_mask)) {
465  assert(h->long_ref[i]->long_ref == 1);
466  h->long_ref[i]->long_ref = 0;
467  h->long_ref[i] = NULL;
468  h->long_ref_count--;
469  }
470  }
471 
472  return pic;
473 }
474 
475 void ff_h264_remove_all_refs(H264Context *h)
476 {
477  int i;
478 
479  for (i = 0; i < 16; i++) {
480  remove_long(h, i, 0);
481  }
482  assert(h->long_ref_count == 0);
483 
484  for (i = 0; i < h->short_ref_count; i++) {
485  unreference_pic(h, h->short_ref[i], 0);
486  h->short_ref[i] = NULL;
487  }
488  h->short_ref_count = 0;
489 
490  memset(h->default_ref_list, 0, sizeof(h->default_ref_list));
491  memset(h->ref_list, 0, sizeof(h->ref_list));
492 }
493 
494 /**
495  * print short term list
496  */
497 static void print_short_term(H264Context *h)
498 {
499  uint32_t i;
500  if (h->avctx->debug & FF_DEBUG_MMCO) {
501  av_log(h->avctx, AV_LOG_DEBUG, "short term list:\n");
502  for (i = 0; i < h->short_ref_count; i++) {
503  Picture *pic = h->short_ref[i];
504  av_log(h->avctx, AV_LOG_DEBUG, "%d fn:%d poc:%d %p\n",
505  i, pic->frame_num, pic->poc, pic->f.data[0]);
506  }
507  }
508 }
509 
510 /**
511  * print long term list
512  */
513 static void print_long_term(H264Context *h)
514 {
515  uint32_t i;
516  if (h->avctx->debug & FF_DEBUG_MMCO) {
517  av_log(h->avctx, AV_LOG_DEBUG, "long term list:\n");
518  for (i = 0; i < 16; i++) {
519  Picture *pic = h->long_ref[i];
520  if (pic) {
521  av_log(h->avctx, AV_LOG_DEBUG, "%d fn:%d poc:%d %p\n",
522  i, pic->frame_num, pic->poc, pic->f.data[0]);
523  }
524  }
525  }
526 }
527 
528 static int check_opcodes(MMCO *mmco1, MMCO *mmco2, int n_mmcos)
529 {
530  int i;
531 
532  for (i = 0; i < n_mmcos; i++) {
533  if (mmco1[i].opcode != mmco2[i].opcode) {
534  av_log(NULL, AV_LOG_ERROR, "MMCO opcode [%d, %d] at %d mismatches between slices\n",
535  mmco1[i].opcode, mmco2[i].opcode, i);
536  return -1;
537  }
538  }
539 
540  return 0;
541 }
542 
543 int ff_generate_sliding_window_mmcos(H264Context *h, int first_slice)
544 {
545  MMCO mmco_temp[MAX_MMCO_COUNT], *mmco = first_slice ? h->mmco : mmco_temp;
546  int mmco_index = 0, i;
547 
548  if (h->short_ref_count &&
549  h->long_ref_count + h->short_ref_count >= h->sps.ref_frame_count &&
550  !(FIELD_PICTURE(h) && !h->first_field && h->cur_pic_ptr->reference)) {
551  mmco[0].opcode = MMCO_SHORT2UNUSED;
552  mmco[0].short_pic_num = h->short_ref[h->short_ref_count - 1]->frame_num;
553  mmco_index = 1;
554  if (FIELD_PICTURE(h)) {
555  mmco[0].short_pic_num *= 2;
556  mmco[1].opcode = MMCO_SHORT2UNUSED;
557  mmco[1].short_pic_num = mmco[0].short_pic_num + 1;
558  mmco_index = 2;
559  }
560  }
561 
562  if (first_slice) {
563  h->mmco_index = mmco_index;
564  } else if (!first_slice && mmco_index >= 0 &&
565  (mmco_index != h->mmco_index ||
566  (i = check_opcodes(h->mmco, mmco_temp, mmco_index)))) {
567  av_log(h->avctx, AV_LOG_ERROR,
568  "Inconsistent MMCO state between slices [%d, %d]\n",
569  mmco_index, h->mmco_index);
570  return AVERROR_INVALIDDATA;
571  }
572  return 0;
573 }
574 
575 int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count)
576 {
577  int i, av_uninit(j);
578  int pps_count;
579  int current_ref_assigned = 0, err = 0;
580  Picture *av_uninit(pic);
581 
582  if ((h->avctx->debug & FF_DEBUG_MMCO) && mmco_count == 0)
583  av_log(h->avctx, AV_LOG_DEBUG, "no mmco here\n");
584 
585  for (i = 0; i < mmco_count; i++) {
586  int av_uninit(structure), av_uninit(frame_num);
587  if (h->avctx->debug & FF_DEBUG_MMCO)
588  av_log(h->avctx, AV_LOG_DEBUG, "mmco:%d %d %d\n", h->mmco[i].opcode,
589  h->mmco[i].short_pic_num, h->mmco[i].long_arg);
590 
591  if (mmco[i].opcode == MMCO_SHORT2UNUSED ||
592  mmco[i].opcode == MMCO_SHORT2LONG) {
593  frame_num = pic_num_extract(h, mmco[i].short_pic_num, &structure);
594  pic = find_short(h, frame_num, &j);
595  if (!pic) {
596  if (mmco[i].opcode != MMCO_SHORT2LONG ||
597  !h->long_ref[mmco[i].long_arg] ||
598  h->long_ref[mmco[i].long_arg]->frame_num != frame_num) {
599  av_log(h->avctx, h->short_ref_count ? AV_LOG_ERROR : AV_LOG_DEBUG, "mmco: unref short failure\n");
600  err = AVERROR_INVALIDDATA;
601  }
602  continue;
603  }
604  }
605 
606  switch (mmco[i].opcode) {
607  case MMCO_SHORT2UNUSED:
608  if (h->avctx->debug & FF_DEBUG_MMCO)
609  av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref short %d count %d\n",
610  h->mmco[i].short_pic_num, h->short_ref_count);
611  remove_short(h, frame_num, structure ^ PICT_FRAME);
612  break;
613  case MMCO_SHORT2LONG:
614  if (h->long_ref[mmco[i].long_arg] != pic)
615  remove_long(h, mmco[i].long_arg, 0);
616 
617  remove_short_at_index(h, j);
618  h->long_ref[ mmco[i].long_arg ] = pic;
619  if (h->long_ref[mmco[i].long_arg]) {
620  h->long_ref[mmco[i].long_arg]->long_ref = 1;
621  h->long_ref_count++;
622  }
623  break;
624  case MMCO_LONG2UNUSED:
625  j = pic_num_extract(h, mmco[i].long_arg, &structure);
626  pic = h->long_ref[j];
627  if (pic) {
628  remove_long(h, j, structure ^ PICT_FRAME);
629  } else if (h->avctx->debug & FF_DEBUG_MMCO)
630  av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref long failure\n");
631  break;
632  case MMCO_LONG:
633  // Comment below left from previous code as it is an interresting note.
634  /* First field in pair is in short term list or
635  * at a different long term index.
636  * This is not allowed; see 7.4.3.3, notes 2 and 3.
637  * Report the problem and keep the pair where it is,
638  * and mark this field valid.
639  */
640 
641  if (h->long_ref[mmco[i].long_arg] != h->cur_pic_ptr) {
642  if (h->cur_pic_ptr->long_ref) {
643  for(j=0; j<16; j++) {
644  if(h->long_ref[j] == h->cur_pic_ptr) {
645  remove_long(h, j, 0);
646  av_log(h->avctx, AV_LOG_ERROR, "mmco: cannot assign current picture to 2 long term references\n");
647  }
648  }
649  }
650  av_assert0(!h->cur_pic_ptr->long_ref);
651  remove_long(h, mmco[i].long_arg, 0);
652  if (remove_short(h, h->cur_pic_ptr->frame_num, 0)) {
653  av_log(h->avctx, AV_LOG_ERROR, "mmco: cannot assign current picture to short and long at the same time\n");
654  }
655 
656  h->long_ref[mmco[i].long_arg] = h->cur_pic_ptr;
657  h->long_ref[mmco[i].long_arg]->long_ref = 1;
658  h->long_ref_count++;
659  }
660 
661  h->cur_pic_ptr->reference |= h->picture_structure;
662  current_ref_assigned = 1;
663  break;
664  case MMCO_SET_MAX_LONG:
665  assert(mmco[i].long_arg <= 16);
666  // just remove the long term which index is greater than new max
667  for (j = mmco[i].long_arg; j < 16; j++) {
668  remove_long(h, j, 0);
669  }
670  break;
671  case MMCO_RESET:
672  while (h->short_ref_count) {
673  remove_short(h, h->short_ref[0]->frame_num, 0);
674  }
675  for (j = 0; j < 16; j++) {
676  remove_long(h, j, 0);
677  }
678  h->frame_num = h->cur_pic_ptr->frame_num = 0;
679  h->mmco_reset = 1;
680  h->cur_pic_ptr->mmco_reset = 1;
681  for (j = 0; j < MAX_DELAYED_PIC_COUNT; j++)
682  h->last_pocs[j] = INT_MIN;
683  break;
684  default: assert(0);
685  }
686  }
687 
688  if (!current_ref_assigned) {
689  /* Second field of complementary field pair; the first field of
690  * which is already referenced. If short referenced, it
691  * should be first entry in short_ref. If not, it must exist
692  * in long_ref; trying to put it on the short list here is an
693  * error in the encoded bit stream (ref: 7.4.3.3, NOTE 2 and 3).
694  */
695  if (h->short_ref_count && h->short_ref[0] == h->cur_pic_ptr) {
696  /* Just mark the second field valid */
697  h->cur_pic_ptr->reference = PICT_FRAME;
698  } else if (h->cur_pic_ptr->long_ref) {
699  av_log(h->avctx, AV_LOG_ERROR, "illegal short term reference "
700  "assignment for second field "
701  "in complementary field pair "
702  "(first field is long term)\n");
703  err = AVERROR_INVALIDDATA;
704  } else {
705  pic = remove_short(h, h->cur_pic_ptr->frame_num, 0);
706  if (pic) {
707  av_log(h->avctx, AV_LOG_ERROR, "illegal short term buffer state detected\n");
708  err = AVERROR_INVALIDDATA;
709  }
710 
711  if (h->short_ref_count)
712  memmove(&h->short_ref[1], &h->short_ref[0],
713  h->short_ref_count * sizeof(Picture*));
714 
715  h->short_ref[0] = h->cur_pic_ptr;
716  h->short_ref_count++;
717  h->cur_pic_ptr->reference |= h->picture_structure;
718  }
719  }
720 
721  if (h->long_ref_count + h->short_ref_count > FFMAX(h->sps.ref_frame_count, 1)) {
722 
723  /* We have too many reference frames, probably due to corrupted
724  * stream. Need to discard one frame. Prevents overrun of the
725  * short_ref and long_ref buffers.
726  */
727  av_log(h->avctx, AV_LOG_ERROR,
728  "number of reference frames (%d+%d) exceeds max (%d; probably "
729  "corrupt input), discarding one\n",
730  h->long_ref_count, h->short_ref_count, h->sps.ref_frame_count);
731  err = AVERROR_INVALIDDATA;
732 
733  if (h->long_ref_count && !h->short_ref_count) {
734  for (i = 0; i < 16; ++i)
735  if (h->long_ref[i])
736  break;
737 
738  assert(i < 16);
739  remove_long(h, i, 0);
740  } else {
741  pic = h->short_ref[h->short_ref_count - 1];
742  remove_short(h, pic->frame_num, 0);
743  }
744  }
745 
746  print_short_term(h);
747  print_long_term(h);
748 
749  pps_count = 0;
750  for (i = 0; i < FF_ARRAY_ELEMS(h->pps_buffers); i++)
751  pps_count += !!h->pps_buffers[i];
752 
753  if ( err >= 0
754  && h->long_ref_count==0
755  && (h->short_ref_count<=2 || h->pps.ref_count[0] <= 1 && h->pps.ref_count[1] <= 1 && pps_count == 1)
756  && h->pps.ref_count[0]<=2 + (h->picture_structure != PICT_FRAME)
757  && h->cur_pic_ptr->f.pict_type == AV_PICTURE_TYPE_I){
758  h->cur_pic_ptr->recovered |= 1;
759  if(!h->avctx->has_b_frames)
760  h->frame_recovered |= FRAME_RECOVERED_SEI;
761  }
762 
763  return (h->avctx->err_recognition & AV_EF_EXPLODE) ? err : 0;
764 }
765 
766 int ff_h264_decode_ref_pic_marking(H264Context *h, GetBitContext *gb,
767  int first_slice)
768 {
769  int i, ret;
770  MMCO mmco_temp[MAX_MMCO_COUNT], *mmco = mmco_temp;
771  int mmco_index = 0;
772 
773  if (h->nal_unit_type == NAL_IDR_SLICE) { // FIXME fields
774  skip_bits1(gb); // broken_link
775  if (get_bits1(gb)) {
776  mmco[0].opcode = MMCO_LONG;
777  mmco[0].long_arg = 0;
778  mmco_index = 1;
779  }
780  } else {
781  if (get_bits1(gb)) { // adaptive_ref_pic_marking_mode_flag
782  for (i = 0; i < MAX_MMCO_COUNT; i++) {
783  MMCOOpcode opcode = get_ue_golomb_31(gb);
784 
785  mmco[i].opcode = opcode;
786  if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG) {
787  mmco[i].short_pic_num =
788  (h->curr_pic_num - get_ue_golomb(gb) - 1) &
789  (h->max_pic_num - 1);
790 #if 0
791  if (mmco[i].short_pic_num >= h->short_ref_count ||
792  h->short_ref[ mmco[i].short_pic_num ] == NULL){
793  av_log(s->avctx, AV_LOG_ERROR,
794  "illegal short ref in memory management control "
795  "operation %d\n", mmco);
796  return -1;
797  }
798 #endif
799  }
800  if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED ||
801  opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG) {
802  unsigned int long_arg = get_ue_golomb_31(gb);
803  if (long_arg >= 32 ||
804  (long_arg >= 16 && !(opcode == MMCO_SET_MAX_LONG &&
805  long_arg == 16) &&
806  !(opcode == MMCO_LONG2UNUSED && FIELD_PICTURE(h)))) {
807  av_log(h->avctx, AV_LOG_ERROR,
808  "illegal long ref in memory management control "
809  "operation %d\n", opcode);
810  return -1;
811  }
812  mmco[i].long_arg = long_arg;
813  }
814 
815  if (opcode > (unsigned) MMCO_LONG) {
816  av_log(h->avctx, AV_LOG_ERROR,
817  "illegal memory management control operation %d\n",
818  opcode);
819  return -1;
820  }
821  if (opcode == MMCO_END)
822  break;
823  }
824  mmco_index = i;
825  } else {
826  if (first_slice) {
827  ret = ff_generate_sliding_window_mmcos(h, first_slice);
828  if (ret < 0 && h->avctx->err_recognition & AV_EF_EXPLODE)
829  return ret;
830  }
831  mmco_index = -1;
832  }
833  }
834 
835  if (first_slice && mmco_index != -1) {
836  memcpy(h->mmco, mmco_temp, sizeof(h->mmco));
837  h->mmco_index = mmco_index;
838  } else if (!first_slice && mmco_index >= 0 &&
839  (mmco_index != h->mmco_index ||
840  check_opcodes(h->mmco, mmco_temp, mmco_index))) {
841  av_log(h->avctx, AV_LOG_ERROR,
842  "Inconsistent MMCO state between slices [%d, %d]\n",
843  mmco_index, h->mmco_index);
844  return AVERROR_INVALIDDATA;
845  }
846 
847  return 0;
848 }
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