Libav
hevc_mvs.c
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1 /*
2  * HEVC video decoder
3  *
4  * Copyright (C) 2012 - 2013 Guillaume Martres
5  * Copyright (C) 2013 Anand Meher Kotra
6  *
7  * This file is part of Libav.
8  *
9  * Libav is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * Libav is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with Libav; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 #include "hevc.h"
25 
26 static const uint8_t l0_l1_cand_idx[12][2] = {
27  { 0, 1, },
28  { 1, 0, },
29  { 0, 2, },
30  { 2, 0, },
31  { 1, 2, },
32  { 2, 1, },
33  { 0, 3, },
34  { 3, 0, },
35  { 1, 3, },
36  { 3, 1, },
37  { 2, 3, },
38  { 3, 2, },
39 };
40 
42  int nPbW, int nPbH)
43 {
44  HEVCLocalContext *lc = &s->HEVClc;
45  int x0b = x0 & ((1 << s->sps->log2_ctb_size) - 1);
46  int y0b = y0 & ((1 << s->sps->log2_ctb_size) - 1);
47 
48  lc->na.cand_up = (lc->ctb_up_flag || y0b);
49  lc->na.cand_left = (lc->ctb_left_flag || x0b);
50  lc->na.cand_up_left = (!x0b && !y0b) ? lc->ctb_up_left_flag : lc->na.cand_left && lc->na.cand_up;
51  lc->na.cand_up_right_sap =
52  ((x0b + nPbW) == (1 << s->sps->log2_ctb_size)) ?
53  lc->ctb_up_right_flag && !y0b : lc->na.cand_up;
54  lc->na.cand_up_right =
55  ((x0b + nPbW) == (1 << s->sps->log2_ctb_size) ?
56  lc->ctb_up_right_flag && !y0b : lc->na.cand_up )
57  && (x0 + nPbW) < lc->end_of_tiles_x;
58  lc->na.cand_bottom_left = ((y0 + nPbH) >= lc->end_of_tiles_y) ? 0 : lc->na.cand_left;
59 }
60 
61 /*
62  * 6.4.1 Derivation process for z-scan order block availability
63  */
64 static int z_scan_block_avail(HEVCContext *s, int xCurr, int yCurr,
65  int xN, int yN)
66 {
67 #define MIN_TB_ADDR_ZS(x, y) \
68  s->pps->min_tb_addr_zs[(y) * s->sps->min_tb_width + (x)]
69  int Curr = MIN_TB_ADDR_ZS(xCurr >> s->sps->log2_min_tb_size,
70  yCurr >> s->sps->log2_min_tb_size);
71  int N;
72 
73  if (xN < 0 || yN < 0 ||
74  xN >= s->sps->width ||
75  yN >= s->sps->height)
76  return 0;
77 
78  N = MIN_TB_ADDR_ZS(xN >> s->sps->log2_min_tb_size,
79  yN >> s->sps->log2_min_tb_size);
80 
81  return N <= Curr;
82 }
83 
84 static int same_prediction_block(HEVCLocalContext *lc, int log2_cb_size,
85  int x0, int y0, int nPbW, int nPbH,
86  int xA1, int yA1, int partIdx)
87 {
88  return !(nPbW << 1 == 1 << log2_cb_size &&
89  nPbH << 1 == 1 << log2_cb_size && partIdx == 1 &&
90  lc->cu.x + nPbW > xA1 &&
91  lc->cu.y + nPbH <= yA1);
92 }
93 
94 /*
95  * 6.4.2 Derivation process for prediction block availability
96  */
97 static int check_prediction_block_available(HEVCContext *s, int log2_cb_size,
98  int x0, int y0, int nPbW, int nPbH,
99  int xA1, int yA1, int partIdx)
100 {
101  HEVCLocalContext *lc = &s->HEVClc;
102 
103  if (lc->cu.x < xA1 && lc->cu.y < yA1 &&
104  (lc->cu.x + (1 << log2_cb_size)) > xA1 &&
105  (lc->cu.y + (1 << log2_cb_size)) > yA1)
106  return same_prediction_block(lc, log2_cb_size, x0, y0,
107  nPbW, nPbH, xA1, yA1, partIdx);
108  else
109  return z_scan_block_avail(s, x0, y0, xA1, yA1);
110 }
111 
112 //check if the two luma locations belong to the same mostion estimation region
113 static int isDiffMER(HEVCContext *s, int xN, int yN, int xP, int yP)
114 {
116 
117  return xN >> plevel == xP >> plevel &&
118  yN >> plevel == yP >> plevel;
119 }
120 
121 #define MATCH(x) (A.x == B.x)
122 
123 // check if the mv's and refidx are the same between A and B
124 static int compareMVrefidx(struct MvField A, struct MvField B)
125 {
126  if (A.pred_flag[0] && A.pred_flag[1] && B.pred_flag[0] && B.pred_flag[1])
127  return MATCH(ref_idx[0]) && MATCH(mv[0].x) && MATCH(mv[0].y) &&
128  MATCH(ref_idx[1]) && MATCH(mv[1].x) && MATCH(mv[1].y);
129 
130  if (A.pred_flag[0] && !A.pred_flag[1] && B.pred_flag[0] && !B.pred_flag[1])
131  return MATCH(ref_idx[0]) && MATCH(mv[0].x) && MATCH(mv[0].y);
132 
133  if (!A.pred_flag[0] && A.pred_flag[1] && !B.pred_flag[0] && B.pred_flag[1])
134  return MATCH(ref_idx[1]) && MATCH(mv[1].x) && MATCH(mv[1].y);
135 
136  return 0;
137 }
138 
139 static av_always_inline void mv_scale(Mv *dst, Mv *src, int td, int tb)
140 {
141  int tx, scale_factor;
142 
143  td = av_clip_int8_c(td);
144  tb = av_clip_int8_c(tb);
145  tx = (0x4000 + abs(td / 2)) / td;
146  scale_factor = av_clip_c((tb * tx + 32) >> 6, -4096, 4095);
147  dst->x = av_clip_int16_c((scale_factor * src->x + 127 +
148  (scale_factor * src->x < 0)) >> 8);
149  dst->y = av_clip_int16_c((scale_factor * src->y + 127 +
150  (scale_factor * src->y < 0)) >> 8);
151 }
152 
153 static int check_mvset(Mv *mvLXCol, Mv *mvCol,
154  int colPic, int poc,
155  RefPicList *refPicList, int X, int refIdxLx,
156  RefPicList *refPicList_col, int listCol, int refidxCol)
157 {
158  int cur_lt = refPicList[X].isLongTerm[refIdxLx];
159  int col_lt = refPicList_col[listCol].isLongTerm[refidxCol];
160  int col_poc_diff, cur_poc_diff;
161 
162  if (cur_lt != col_lt) {
163  mvLXCol->x = 0;
164  mvLXCol->y = 0;
165  return 0;
166  }
167 
168  col_poc_diff = colPic - refPicList_col[listCol].list[refidxCol];
169  cur_poc_diff = poc - refPicList[X].list[refIdxLx];
170 
171  if (!col_poc_diff)
172  col_poc_diff = 1; // error resilience
173 
174  if (cur_lt || col_poc_diff == cur_poc_diff) {
175  mvLXCol->x = mvCol->x;
176  mvLXCol->y = mvCol->y;
177  } else {
178  mv_scale(mvLXCol, mvCol, col_poc_diff, cur_poc_diff);
179  }
180  return 1;
181 }
182 
183 #define CHECK_MVSET(l) \
184  check_mvset(mvLXCol, temp_col.mv + l, \
185  colPic, s->poc, \
186  refPicList, X, refIdxLx, \
187  refPicList_col, L ## l, temp_col.ref_idx[l])
188 
189 // derive the motion vectors section 8.5.3.1.8
191  int refIdxLx, Mv *mvLXCol, int X,
192  int colPic, RefPicList *refPicList_col)
193 {
194  RefPicList *refPicList = s->ref->refPicList;
195 
196  if (temp_col.is_intra) {
197  mvLXCol->x = 0;
198  mvLXCol->y = 0;
199  return 0;
200  }
201 
202  if (temp_col.pred_flag[0] == 0)
203  return CHECK_MVSET(1);
204  else if (temp_col.pred_flag[0] == 1 && temp_col.pred_flag[1] == 0)
205  return CHECK_MVSET(0);
206  else if (temp_col.pred_flag[0] == 1 && temp_col.pred_flag[1] == 1) {
207  int check_diffpicount = 0;
208  int i = 0;
209  for (i = 0; i < refPicList[0].nb_refs; i++) {
210  if (refPicList[0].list[i] > s->poc)
211  check_diffpicount++;
212  }
213  for (i = 0; i < refPicList[1].nb_refs; i++) {
214  if (refPicList[1].list[i] > s->poc)
215  check_diffpicount++;
216  }
217  if (check_diffpicount == 0 && X == 0)
218  return CHECK_MVSET(0);
219  else if (check_diffpicount == 0 && X == 1)
220  return CHECK_MVSET(1);
221  else {
222  if (s->sh.collocated_list == L1)
223  return CHECK_MVSET(0);
224  else
225  return CHECK_MVSET(1);
226  }
227  }
228 
229  return 0;
230 }
231 
232 #define TAB_MVF(x, y) \
233  tab_mvf[(y) * min_pu_width + x]
234 
235 #define TAB_MVF_PU(v) \
236  TAB_MVF(x ## v ## _pu, y ## v ## _pu)
237 
238 #define DERIVE_TEMPORAL_COLOCATED_MVS \
239  derive_temporal_colocated_mvs(s, temp_col, \
240  refIdxLx, mvLXCol, X, colPic, \
241  ff_hevc_get_ref_list(s, ref, x, y))
242 
243 /*
244  * 8.5.3.1.7 temporal luma motion vector prediction
245  */
246 static int temporal_luma_motion_vector(HEVCContext *s, int x0, int y0,
247  int nPbW, int nPbH, int refIdxLx,
248  Mv *mvLXCol, int X)
249 {
250  MvField *tab_mvf;
251  MvField temp_col;
252  int x, y, x_pu, y_pu;
253  int min_pu_width = s->sps->min_pu_width;
254  int availableFlagLXCol = 0;
255  int colPic;
256 
257  HEVCFrame *ref = s->ref->collocated_ref;
258 
259  if (!ref)
260  return 0;
261 
262  tab_mvf = ref->tab_mvf;
263  colPic = ref->poc;
264 
265  //bottom right collocated motion vector
266  x = x0 + nPbW;
267  y = y0 + nPbH;
268 
269  ff_thread_await_progress(&ref->tf, y, 0);
270  if (tab_mvf &&
271  (y0 >> s->sps->log2_ctb_size) == (y >> s->sps->log2_ctb_size) &&
272  y < s->sps->height &&
273  x < s->sps->width) {
274  x = ((x >> 4) << 4);
275  y = ((y >> 4) << 4);
276  x_pu = x >> s->sps->log2_min_pu_size;
277  y_pu = y >> s->sps->log2_min_pu_size;
278  temp_col = TAB_MVF(x_pu, y_pu);
279  availableFlagLXCol = DERIVE_TEMPORAL_COLOCATED_MVS;
280  }
281 
282  // derive center collocated motion vector
283  if (tab_mvf && !availableFlagLXCol) {
284  x = x0 + (nPbW >> 1);
285  y = y0 + (nPbH >> 1);
286  x = ((x >> 4) << 4);
287  y = ((y >> 4) << 4);
288  x_pu = x >> s->sps->log2_min_pu_size;
289  y_pu = y >> s->sps->log2_min_pu_size;
290  temp_col = TAB_MVF(x_pu, y_pu);
291  availableFlagLXCol = DERIVE_TEMPORAL_COLOCATED_MVS;
292  }
293  return availableFlagLXCol;
294 }
295 
296 #define AVAILABLE(cand, v) \
297  (cand && !TAB_MVF_PU(v).is_intra)
298 
299 #define PRED_BLOCK_AVAILABLE(v) \
300  check_prediction_block_available(s, log2_cb_size, \
301  x0, y0, nPbW, nPbH, \
302  x ## v, y ## v, part_idx)
303 
304 #define COMPARE_MV_REFIDX(a, b) \
305  compareMVrefidx(TAB_MVF_PU(a), TAB_MVF_PU(b))
306 
307 /*
308  * 8.5.3.1.2 Derivation process for spatial merging candidates
309  */
310 static void derive_spatial_merge_candidates(HEVCContext *s, int x0, int y0,
311  int nPbW, int nPbH,
312  int log2_cb_size,
313  int singleMCLFlag, int part_idx,
314  struct MvField mergecandlist[])
315 {
316  HEVCLocalContext *lc = &s->HEVClc;
317  RefPicList *refPicList = s->ref->refPicList;
318  MvField *tab_mvf = s->ref->tab_mvf;
319 
320  const int min_pu_width = s->sps->min_pu_width;
321 
322  const int cand_bottom_left = lc->na.cand_bottom_left;
323  const int cand_left = lc->na.cand_left;
324  const int cand_up_left = lc->na.cand_up_left;
325  const int cand_up = lc->na.cand_up;
326  const int cand_up_right = lc->na.cand_up_right_sap;
327 
328  const int xA1 = x0 - 1;
329  const int yA1 = y0 + nPbH - 1;
330  const int xA1_pu = xA1 >> s->sps->log2_min_pu_size;
331  const int yA1_pu = yA1 >> s->sps->log2_min_pu_size;
332 
333  const int xB1 = x0 + nPbW - 1;
334  const int yB1 = y0 - 1;
335  const int xB1_pu = xB1 >> s->sps->log2_min_pu_size;
336  const int yB1_pu = yB1 >> s->sps->log2_min_pu_size;
337 
338  const int xB0 = x0 + nPbW;
339  const int yB0 = y0 - 1;
340  const int xB0_pu = xB0 >> s->sps->log2_min_pu_size;
341  const int yB0_pu = yB0 >> s->sps->log2_min_pu_size;
342 
343  const int xA0 = x0 - 1;
344  const int yA0 = y0 + nPbH;
345  const int xA0_pu = xA0 >> s->sps->log2_min_pu_size;
346  const int yA0_pu = yA0 >> s->sps->log2_min_pu_size;
347 
348  const int xB2 = x0 - 1;
349  const int yB2 = y0 - 1;
350  const int xB2_pu = xB2 >> s->sps->log2_min_pu_size;
351  const int yB2_pu = yB2 >> s->sps->log2_min_pu_size;
352 
353  const int nb_refs = (s->sh.slice_type == P_SLICE) ?
354  s->sh.nb_refs[0] : FFMIN(s->sh.nb_refs[0], s->sh.nb_refs[1]);
355  int check_MER = 1;
356  int check_MER_1 = 1;
357 
358  int zero_idx = 0;
359 
360  int nb_merge_cand = 0;
361  int nb_orig_merge_cand = 0;
362 
363  int is_available_a0;
364  int is_available_a1;
365  int is_available_b0;
366  int is_available_b1;
367  int is_available_b2;
368  int check_B0;
369  int check_A0;
370 
371  //first left spatial merge candidate
372  is_available_a1 = AVAILABLE(cand_left, A1);
373 
374  if (!singleMCLFlag && part_idx == 1 &&
375  (lc->cu.part_mode == PART_Nx2N ||
376  lc->cu.part_mode == PART_nLx2N ||
377  lc->cu.part_mode == PART_nRx2N) ||
378  isDiffMER(s, xA1, yA1, x0, y0)) {
379  is_available_a1 = 0;
380  }
381 
382  if (is_available_a1)
383  mergecandlist[nb_merge_cand++] = TAB_MVF_PU(A1);
384 
385  // above spatial merge candidate
386  is_available_b1 = AVAILABLE(cand_up, B1);
387 
388  if (!singleMCLFlag && part_idx == 1 &&
389  (lc->cu.part_mode == PART_2NxN ||
390  lc->cu.part_mode == PART_2NxnU ||
391  lc->cu.part_mode == PART_2NxnD) ||
392  isDiffMER(s, xB1, yB1, x0, y0)) {
393  is_available_b1 = 0;
394  }
395 
396  if (is_available_a1 && is_available_b1)
397  check_MER = !COMPARE_MV_REFIDX(B1, A1);
398 
399  if (is_available_b1 && check_MER)
400  mergecandlist[nb_merge_cand++] = TAB_MVF_PU(B1);
401 
402  // above right spatial merge candidate
403  check_MER = 1;
404  check_B0 = PRED_BLOCK_AVAILABLE(B0);
405 
406  is_available_b0 = check_B0 && AVAILABLE(cand_up_right, B0);
407 
408  if (isDiffMER(s, xB0, yB0, x0, y0))
409  is_available_b0 = 0;
410 
411  if (is_available_b1 && is_available_b0)
412  check_MER = !COMPARE_MV_REFIDX(B0, B1);
413 
414  if (is_available_b0 && check_MER)
415  mergecandlist[nb_merge_cand++] = TAB_MVF_PU(B0);
416 
417  // left bottom spatial merge candidate
418  check_MER = 1;
419  check_A0 = PRED_BLOCK_AVAILABLE(A0);
420 
421  is_available_a0 = check_A0 && AVAILABLE(cand_bottom_left, A0);
422 
423  if (isDiffMER(s, xA0, yA0, x0, y0))
424  is_available_a0 = 0;
425 
426  if (is_available_a1 && is_available_a0)
427  check_MER = !COMPARE_MV_REFIDX(A0, A1);
428 
429  if (is_available_a0 && check_MER)
430  mergecandlist[nb_merge_cand++] = TAB_MVF_PU(A0);
431 
432  // above left spatial merge candidate
433  check_MER = 1;
434 
435  is_available_b2 = AVAILABLE(cand_up_left, B2);
436 
437  if (isDiffMER(s, xB2, yB2, x0, y0))
438  is_available_b2 = 0;
439 
440  if (is_available_a1 && is_available_b2)
441  check_MER = !COMPARE_MV_REFIDX(B2, A1);
442 
443  if (is_available_b1 && is_available_b2)
444  check_MER_1 = !COMPARE_MV_REFIDX(B2, B1);
445 
446  if (is_available_b2 && check_MER && check_MER_1 && nb_merge_cand != 4)
447  mergecandlist[nb_merge_cand++] = TAB_MVF_PU(B2);
448 
449  // temporal motion vector candidate
451  nb_merge_cand < s->sh.max_num_merge_cand) {
452  Mv mv_l0_col, mv_l1_col;
453  int available_l0 = temporal_luma_motion_vector(s, x0, y0, nPbW, nPbH,
454  0, &mv_l0_col, 0);
455  int available_l1 = (s->sh.slice_type == B_SLICE) ?
456  temporal_luma_motion_vector(s, x0, y0, nPbW, nPbH,
457  0, &mv_l1_col, 1) : 0;
458 
459  if (available_l0 || available_l1) {
460  mergecandlist[nb_merge_cand].is_intra = 0;
461  mergecandlist[nb_merge_cand].pred_flag[0] = available_l0;
462  mergecandlist[nb_merge_cand].pred_flag[1] = available_l1;
463  if (available_l0) {
464  mergecandlist[nb_merge_cand].mv[0] = mv_l0_col;
465  mergecandlist[nb_merge_cand].ref_idx[0] = 0;
466  }
467  if (available_l1) {
468  mergecandlist[nb_merge_cand].mv[1] = mv_l1_col;
469  mergecandlist[nb_merge_cand].ref_idx[1] = 0;
470  }
471  nb_merge_cand++;
472  }
473  }
474 
475  nb_orig_merge_cand = nb_merge_cand;
476 
477  // combined bi-predictive merge candidates (applies for B slices)
478  if (s->sh.slice_type == B_SLICE && nb_orig_merge_cand > 1 &&
479  nb_orig_merge_cand < s->sh.max_num_merge_cand) {
480  int comb_idx;
481 
482  for (comb_idx = 0; nb_merge_cand < s->sh.max_num_merge_cand &&
483  comb_idx < nb_orig_merge_cand * (nb_orig_merge_cand - 1); comb_idx++) {
484  int l0_cand_idx = l0_l1_cand_idx[comb_idx][0];
485  int l1_cand_idx = l0_l1_cand_idx[comb_idx][1];
486  MvField l0_cand = mergecandlist[l0_cand_idx];
487  MvField l1_cand = mergecandlist[l1_cand_idx];
488 
489  if (l0_cand.pred_flag[0] && l1_cand.pred_flag[1] &&
490  (refPicList[0].list[l0_cand.ref_idx[0]] !=
491  refPicList[1].list[l1_cand.ref_idx[1]] ||
492  l0_cand.mv[0].x != l1_cand.mv[1].x ||
493  l0_cand.mv[0].y != l1_cand.mv[1].y)) {
494  mergecandlist[nb_merge_cand].ref_idx[0] = l0_cand.ref_idx[0];
495  mergecandlist[nb_merge_cand].ref_idx[1] = l1_cand.ref_idx[1];
496  mergecandlist[nb_merge_cand].pred_flag[0] = 1;
497  mergecandlist[nb_merge_cand].pred_flag[1] = 1;
498  mergecandlist[nb_merge_cand].mv[0].x = l0_cand.mv[0].x;
499  mergecandlist[nb_merge_cand].mv[0].y = l0_cand.mv[0].y;
500  mergecandlist[nb_merge_cand].mv[1].x = l1_cand.mv[1].x;
501  mergecandlist[nb_merge_cand].mv[1].y = l1_cand.mv[1].y;
502  mergecandlist[nb_merge_cand].is_intra = 0;
503  nb_merge_cand++;
504  }
505  }
506  }
507 
508  // append Zero motion vector candidates
509  while (nb_merge_cand < s->sh.max_num_merge_cand) {
510  mergecandlist[nb_merge_cand].pred_flag[0] = 1;
511  mergecandlist[nb_merge_cand].pred_flag[1] = s->sh.slice_type == B_SLICE;
512  mergecandlist[nb_merge_cand].mv[0].x = 0;
513  mergecandlist[nb_merge_cand].mv[0].y = 0;
514  mergecandlist[nb_merge_cand].mv[1].x = 0;
515  mergecandlist[nb_merge_cand].mv[1].y = 0;
516  mergecandlist[nb_merge_cand].is_intra = 0;
517  mergecandlist[nb_merge_cand].ref_idx[0] = zero_idx < nb_refs ? zero_idx : 0;
518  mergecandlist[nb_merge_cand].ref_idx[1] = zero_idx < nb_refs ? zero_idx : 0;
519 
520  nb_merge_cand++;
521  zero_idx++;
522  }
523 }
524 
525 /*
526  * 8.5.3.1.1 Derivation process of luma Mvs for merge mode
527  */
528 void ff_hevc_luma_mv_merge_mode(HEVCContext *s, int x0, int y0, int nPbW,
529  int nPbH, int log2_cb_size, int part_idx,
530  int merge_idx, MvField *mv)
531 {
532  int singleMCLFlag = 0;
533  int nCS = 1 << log2_cb_size;
534  struct MvField mergecand_list[MRG_MAX_NUM_CANDS] = { { { { 0 } } } };
535  int nPbW2 = nPbW;
536  int nPbH2 = nPbH;
537  HEVCLocalContext *lc = &s->HEVClc;
538 
539  if (s->pps->log2_parallel_merge_level > 2 && nCS == 8) {
540  singleMCLFlag = 1;
541  x0 = lc->cu.x;
542  y0 = lc->cu.y;
543  nPbW = nCS;
544  nPbH = nCS;
545  part_idx = 0;
546  }
547 
548  ff_hevc_set_neighbour_available(s, x0, y0, nPbW, nPbH);
549  derive_spatial_merge_candidates(s, x0, y0, nPbW, nPbH, log2_cb_size,
550  singleMCLFlag, part_idx, mergecand_list);
551 
552  if (mergecand_list[merge_idx].pred_flag[0] == 1 &&
553  mergecand_list[merge_idx].pred_flag[1] == 1 &&
554  (nPbW2 + nPbH2) == 12) {
555  mergecand_list[merge_idx].ref_idx[1] = -1;
556  mergecand_list[merge_idx].pred_flag[1] = 0;
557  }
558 
559  *mv = mergecand_list[merge_idx];
560 }
561 
563  int min_pu_width, int x, int y,
564  int elist, int ref_idx_curr, int ref_idx)
565 {
566  RefPicList *refPicList = s->ref->refPicList;
567  MvField *tab_mvf = s->ref->tab_mvf;
568  int ref_pic_elist = refPicList[elist].list[TAB_MVF(x, y).ref_idx[elist]];
569  int ref_pic_curr = refPicList[ref_idx_curr].list[ref_idx];
570 
571  if (ref_pic_elist != ref_pic_curr) {
572  int poc_diff = s->poc - ref_pic_elist;
573  if (!poc_diff)
574  poc_diff = 1;
575  mv_scale(mv, mv, poc_diff, s->poc - ref_pic_curr);
576  }
577 }
578 
579 static int mv_mp_mode_mx(HEVCContext *s, int x, int y, int pred_flag_index,
580  Mv *mv, int ref_idx_curr, int ref_idx)
581 {
582  MvField *tab_mvf = s->ref->tab_mvf;
583  int min_pu_width = s->sps->min_pu_width;
584 
585  RefPicList *refPicList = s->ref->refPicList;
586 
587  if (TAB_MVF(x, y).pred_flag[pred_flag_index] == 1 &&
588  refPicList[pred_flag_index].list[TAB_MVF(x, y).ref_idx[pred_flag_index]] == refPicList[ref_idx_curr].list[ref_idx]) {
589  *mv = TAB_MVF(x, y).mv[pred_flag_index];
590  return 1;
591  }
592  return 0;
593 }
594 
595 static int mv_mp_mode_mx_lt(HEVCContext *s, int x, int y, int pred_flag_index,
596  Mv *mv, int ref_idx_curr, int ref_idx)
597 {
598  MvField *tab_mvf = s->ref->tab_mvf;
599  int min_pu_width = s->sps->min_pu_width;
600 
601  RefPicList *refPicList = s->ref->refPicList;
602  int currIsLongTerm = refPicList[ref_idx_curr].isLongTerm[ref_idx];
603 
604  int colIsLongTerm =
605  refPicList[pred_flag_index].isLongTerm[(TAB_MVF(x, y).ref_idx[pred_flag_index])];
606 
607  if (TAB_MVF(x, y).pred_flag[pred_flag_index] &&
608  colIsLongTerm == currIsLongTerm) {
609  *mv = TAB_MVF(x, y).mv[pred_flag_index];
610  if (!currIsLongTerm)
611  dist_scale(s, mv, min_pu_width, x, y,
612  pred_flag_index, ref_idx_curr, ref_idx);
613  return 1;
614  }
615  return 0;
616 }
617 
618 #define MP_MX(v, pred, mx) \
619  mv_mp_mode_mx(s, x ## v ## _pu, y ## v ## _pu, pred, \
620  &mx, ref_idx_curr, ref_idx)
621 
622 #define MP_MX_LT(v, pred, mx) \
623  mv_mp_mode_mx_lt(s, x ## v ## _pu, y ## v ## _pu, pred, \
624  &mx, ref_idx_curr, ref_idx)
625 
626 void ff_hevc_luma_mv_mvp_mode(HEVCContext *s, int x0, int y0, int nPbW,
627  int nPbH, int log2_cb_size, int part_idx,
628  int merge_idx, MvField *mv,
629  int mvp_lx_flag, int LX)
630 {
631  HEVCLocalContext *lc = &s->HEVClc;
632  MvField *tab_mvf = s->ref->tab_mvf;
633  int isScaledFlag_L0 = 0;
634  int availableFlagLXA0 = 0;
635  int availableFlagLXB0 = 0;
636  int numMVPCandLX = 0;
637  int min_pu_width = s->sps->min_pu_width;
638 
639  int xA0, yA0;
640  int xA0_pu, yA0_pu;
641  int is_available_a0;
642 
643  int xA1, yA1;
644  int xA1_pu, yA1_pu;
645  int is_available_a1;
646 
647  int xB0, yB0;
648  int xB0_pu, yB0_pu;
649  int is_available_b0;
650 
651  int xB1, yB1;
652  int xB1_pu = 0, yB1_pu = 0;
653  int is_available_b1 = 0;
654 
655  int xB2, yB2;
656  int xB2_pu = 0, yB2_pu = 0;
657  int is_available_b2 = 0;
658  Mv mvpcand_list[2] = { { 0 } };
659  Mv mxA = { 0 };
660  Mv mxB = { 0 };
661  int ref_idx_curr = 0;
662  int ref_idx = 0;
663  int pred_flag_index_l0;
664  int pred_flag_index_l1;
665  int x0b = x0 & ((1 << s->sps->log2_ctb_size) - 1);
666  int y0b = y0 & ((1 << s->sps->log2_ctb_size) - 1);
667 
668  int cand_up = (lc->ctb_up_flag || y0b);
669  int cand_left = (lc->ctb_left_flag || x0b);
670  int cand_up_left =
671  (!x0b && !y0b) ? lc->ctb_up_left_flag : cand_left && cand_up;
672  int cand_up_right =
673  (x0b + nPbW == (1 << s->sps->log2_ctb_size) ||
674  x0 + nPbW >= lc->end_of_tiles_x) ? lc->ctb_up_right_flag && !y0b
675  : cand_up;
676  int cand_bottom_left = (y0 + nPbH >= lc->end_of_tiles_y) ? 0 : cand_left;
677 
678  ref_idx_curr = LX;
679  ref_idx = mv->ref_idx[LX];
680  pred_flag_index_l0 = LX;
681  pred_flag_index_l1 = !LX;
682 
683  // left bottom spatial candidate
684  xA0 = x0 - 1;
685  yA0 = y0 + nPbH;
686  xA0_pu = xA0 >> s->sps->log2_min_pu_size;
687  yA0_pu = yA0 >> s->sps->log2_min_pu_size;
688 
689  is_available_a0 = PRED_BLOCK_AVAILABLE(A0) && AVAILABLE(cand_bottom_left, A0);
690 
691  //left spatial merge candidate
692  xA1 = x0 - 1;
693  yA1 = y0 + nPbH - 1;
694  xA1_pu = xA1 >> s->sps->log2_min_pu_size;
695  yA1_pu = yA1 >> s->sps->log2_min_pu_size;
696 
697  is_available_a1 = AVAILABLE(cand_left, A1);
698  if (is_available_a0 || is_available_a1)
699  isScaledFlag_L0 = 1;
700 
701  if (is_available_a0) {
702  availableFlagLXA0 = MP_MX(A0, pred_flag_index_l0, mxA);
703  if (!availableFlagLXA0)
704  availableFlagLXA0 = MP_MX(A0, pred_flag_index_l1, mxA);
705  }
706 
707  if (is_available_a1 && !availableFlagLXA0) {
708  availableFlagLXA0 = MP_MX(A1, pred_flag_index_l0, mxA);
709  if (!availableFlagLXA0)
710  availableFlagLXA0 = MP_MX(A1, pred_flag_index_l1, mxA);
711  }
712 
713  if (is_available_a0 && !availableFlagLXA0) {
714  availableFlagLXA0 = MP_MX_LT(A0, pred_flag_index_l0, mxA);
715  if (!availableFlagLXA0)
716  availableFlagLXA0 = MP_MX_LT(A0, pred_flag_index_l1, mxA);
717  }
718 
719  if (is_available_a1 && !availableFlagLXA0) {
720  availableFlagLXA0 = MP_MX_LT(A1, pred_flag_index_l0, mxA);
721  if (!availableFlagLXA0)
722  availableFlagLXA0 = MP_MX_LT(A1, pred_flag_index_l1, mxA);
723  }
724 
725  // B candidates
726  // above right spatial merge candidate
727  xB0 = x0 + nPbW;
728  yB0 = y0 - 1;
729  xB0_pu = xB0 >> s->sps->log2_min_pu_size;
730  yB0_pu = yB0 >> s->sps->log2_min_pu_size;
731 
732  is_available_b0 = PRED_BLOCK_AVAILABLE(B0) && AVAILABLE(cand_up_right, B0);
733 
734  if (is_available_b0) {
735  availableFlagLXB0 = MP_MX(B0, pred_flag_index_l0, mxB);
736  if (!availableFlagLXB0)
737  availableFlagLXB0 = MP_MX(B0, pred_flag_index_l1, mxB);
738  }
739 
740  if (!availableFlagLXB0) {
741  // above spatial merge candidate
742  xB1 = x0 + nPbW - 1;
743  yB1 = y0 - 1;
744  xB1_pu = xB1 >> s->sps->log2_min_pu_size;
745  yB1_pu = yB1 >> s->sps->log2_min_pu_size;
746 
747  is_available_b1 = AVAILABLE(cand_up, B1);
748 
749  if (is_available_b1) {
750  availableFlagLXB0 = MP_MX(B1, pred_flag_index_l0, mxB);
751  if (!availableFlagLXB0)
752  availableFlagLXB0 = MP_MX(B1, pred_flag_index_l1, mxB);
753  }
754  }
755 
756  if (!availableFlagLXB0) {
757  // above left spatial merge candidate
758  xB2 = x0 - 1;
759  yB2 = y0 - 1;
760  xB2_pu = xB2 >> s->sps->log2_min_pu_size;
761  yB2_pu = yB2 >> s->sps->log2_min_pu_size;
762  is_available_b2 = AVAILABLE(cand_up_left, B2);
763 
764  if (is_available_b2) {
765  availableFlagLXB0 = MP_MX(B2, pred_flag_index_l0, mxB);
766  if (!availableFlagLXB0)
767  availableFlagLXB0 = MP_MX(B2, pred_flag_index_l1, mxB);
768  }
769  }
770 
771  if (isScaledFlag_L0 == 0) {
772  if (availableFlagLXB0) {
773  availableFlagLXA0 = 1;
774  mxA = mxB;
775  }
776  availableFlagLXB0 = 0;
777 
778  // XB0 and L1
779  if (is_available_b0) {
780  availableFlagLXB0 = MP_MX_LT(B0, pred_flag_index_l0, mxB);
781  if (!availableFlagLXB0)
782  availableFlagLXB0 = MP_MX_LT(B0, pred_flag_index_l1, mxB);
783  }
784 
785  if (is_available_b1 && !availableFlagLXB0) {
786  availableFlagLXB0 = MP_MX_LT(B1, pred_flag_index_l0, mxB);
787  if (!availableFlagLXB0)
788  availableFlagLXB0 = MP_MX_LT(B1, pred_flag_index_l1, mxB);
789  }
790 
791  if (is_available_b2 && !availableFlagLXB0) {
792  availableFlagLXB0 = MP_MX_LT(B2, pred_flag_index_l0, mxB);
793  if (!availableFlagLXB0)
794  availableFlagLXB0 = MP_MX_LT(B2, pred_flag_index_l1, mxB);
795  }
796  }
797 
798  if (availableFlagLXA0)
799  mvpcand_list[numMVPCandLX++] = mxA;
800 
801  if (availableFlagLXB0 && (!availableFlagLXA0 || mxA.x != mxB.x || mxA.y != mxB.y))
802  mvpcand_list[numMVPCandLX++] = mxB;
803 
804  //temporal motion vector prediction candidate
805  if (numMVPCandLX < 2 && s->sh.slice_temporal_mvp_enabled_flag) {
806  Mv mv_col;
807  int available_col = temporal_luma_motion_vector(s, x0, y0, nPbW,
808  nPbH, ref_idx,
809  &mv_col, LX);
810  if (available_col)
811  mvpcand_list[numMVPCandLX++] = mv_col;
812  }
813 
814  // insert zero motion vectors when the number of available candidates are less than 2
815  while (numMVPCandLX < 2)
816  mvpcand_list[numMVPCandLX++] = (Mv){ 0, 0 };
817 
818  mv->mv[LX].x = mvpcand_list[mvp_lx_flag].x;
819  mv->mv[LX].y = mvpcand_list[mvp_lx_flag].y;
820 }