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FFmpeg/libavcodec/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 FFmpeg.

  8.  *

  9.  * FFmpeg 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.  * FFmpeg 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 FFmpeg; 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. 

  41. void ff_hevc_set_neighbour_available(HEVCContext *s, int x0, int y0, int nPbW, int nPbH)

  42. {

  43.     HEVCLocalContext *lc = s->HEVClc;

  44.     int x0b = x0 & ((1 << s->sps->log2_ctb_size) - 1);

  45.     int y0b = y0 & ((1 << s->sps->log2_ctb_size) - 1);

  46. 

  47.     lc->na.cand_up       = (lc->ctb_up_flag   || y0b);

  48.     lc->na.cand_left     = (lc->ctb_left_flag || x0b);

  49.     lc->na.cand_up_left  = (!x0b && !y0b) ? lc->ctb_up_left_flag : lc->na.cand_left && lc->na.cand_up;

  50.     lc->na.cand_up_right_sap =

  51.             ((x0b + nPbW) == (1 << s->sps->log2_ctb_size)) ?

  52.                     lc->ctb_up_right_flag && !y0b : lc->na.cand_up;

  53.     lc->na.cand_up_right =

  54.             ((x0b + nPbW) == (1 << s->sps->log2_ctb_size) ?

  55.                     lc->ctb_up_right_flag && !y0b : lc->na.cand_up )

  56.                      && (x0 + nPbW) < lc->end_of_tiles_x;

  57.     lc->na.cand_bottom_left = ((y0 + nPbH) >= lc->end_of_tiles_y) ? 0 : lc->na.cand_left;

  58. }

  59. 

  60. /*

  61.  * 6.4.1 Derivation process for z-scan order block availability

  62.  */

  63. static int z_scan_block_avail(HEVCContext *s, int xCurr, int yCurr,

  64.                               int xN, int yN)

  65. {

  66. #define MIN_TB_ADDR_ZS(x, y)                                            \

  67.     s->pps->min_tb_addr_zs[(y) * s->sps->min_tb_width + (x)]

  68.     int Curr =  MIN_TB_ADDR_ZS(xCurr >> s->sps->log2_min_tb_size,

  69.                                yCurr >> s->sps->log2_min_tb_size);

  70.     int N;

  71. 

  72.     if ((xN < 0) || (yN < 0) ||

  73.         (xN >= s->sps->width) ||

  74.         (yN >= s->sps->height))

  75.         return 0;

  76. 

  77.     N = MIN_TB_ADDR_ZS(xN >> s->sps->log2_min_tb_size,

  78.                        yN >> s->sps->log2_min_tb_size);

  79. 

  80.     return N <= Curr;

  81. }

  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. {

  115.     uint8_t plevel = s->pps->log2_parallel_merge_level;

  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

  190. static int derive_temporal_colocated_mvs(HEVCContext *s, MvField temp_col,

  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;

  253.     int x_pu, y_pu;

  254.     int min_pu_width = s->sps->min_pu_width;

  255.     int availableFlagLXCol = 0;

  256.     int colPic;

  257. 

  258.     HEVCFrame *ref = s->ref->collocated_ref;

  259. 

  260.     if (!ref)

  261.         return 0;

  262. 

  263.     tab_mvf = ref->tab_mvf;

  264.     colPic  = ref->poc;

  265. 

  266.     //bottom right collocated motion vector

  267.     x = x0 + nPbW;

  268.     y = y0 + nPbH;

  269. 

  270.     if (s->threads_type == FF_THREAD_FRAME )

  271.         ff_thread_await_progress(&ref->tf, INT_MAX, 0);

  272.     if (tab_mvf &&

  273.         (y0 >> s->sps->log2_ctb_size) == (y >> s->sps->log2_ctb_size) &&

  274.         y < s->sps->height &&

  275.         x < s->sps->width) {

  276.         x = ((x >> 4) << 4);

  277.         y = ((y >> 4) << 4);

  278.         x_pu = x >> s->sps->log2_min_pu_size;

  279.         y_pu = y >> s->sps->log2_min_pu_size;

  280.         temp_col = TAB_MVF(x_pu, y_pu);

  281.         availableFlagLXCol = DERIVE_TEMPORAL_COLOCATED_MVS;

  282.     }

  283. 

  284.     // derive center collocated motion vector

  285.     if (tab_mvf && !availableFlagLXCol) {

  286.         x = x0 + (nPbW >> 1);

  287.         y = y0 + (nPbH >> 1);

  288.         x = ((x >> 4) << 4);

  289.         y = ((y >> 4) << 4);

  290.         x_pu = x >> s->sps->log2_min_pu_size;

  291.         y_pu = y >> s->sps->log2_min_pu_size;

  292.         temp_col = TAB_MVF(x_pu, y_pu);

  293.         availableFlagLXCol = DERIVE_TEMPORAL_COLOCATED_MVS;

  294.     }

  295.     return availableFlagLXCol;

  296. }

  297. 

  298. #define AVAILABLE(cand, v) \

  299.     (cand && !TAB_MVF_PU(v).is_intra)

  300. 

  301. #define PRED_BLOCK_AVAILABLE(v) \

  302.     check_prediction_block_available(s, log2_cb_size, \

  303.                                      x0, y0, nPbW, nPbH, \

  304.                                      x##v, y##v, part_idx)

  305. 

  306. #define COMPARE_MV_REFIDX(a, b) \

  307.     compareMVrefidx(TAB_MVF_PU(a), TAB_MVF_PU(b))

  308. 

  309. /*

  310.  * 8.5.3.1.2  Derivation process for spatial merging candidates

  311.  */

  312. static void derive_spatial_merge_candidates(HEVCContext *s, int x0, int y0,

  313.                                             int nPbW, int nPbH, int log2_cb_size,

  314.                                             int singleMCLFlag, int part_idx,

  315.                                             struct MvField mergecandlist[])

  316. {

  317.     HEVCLocalContext *lc   = s->HEVClc;

  318.     RefPicList *refPicList = s->ref->refPicList;

  319.     MvField *tab_mvf       = s->ref->tab_mvf;

  320. 

  321.     const int min_pu_width     = s->sps->min_pu_width;

  322. 

  323.     const int cand_bottom_left = lc->na.cand_bottom_left;

  324.     const int cand_left        = lc->na.cand_left;

  325.     const int cand_up_left     = lc->na.cand_up_left;

  326.     const int cand_up          = lc->na.cand_up;

  327.     const int cand_up_right    = lc->na.cand_up_right_sap;

  328. 

  329.     const int xA1    = x0 - 1;

  330.     const int yA1    = y0 + nPbH - 1;

  331.     const int xA1_pu = xA1 >> s->sps->log2_min_pu_size;

  332.     const int yA1_pu = yA1 >> s->sps->log2_min_pu_size;

  333. 

  334.     const int xB1    = x0 + nPbW - 1;

  335.     const int yB1    = y0 - 1;

  336.     const int xB1_pu = xB1 >> s->sps->log2_min_pu_size;

  337.     const int yB1_pu = yB1 >> s->sps->log2_min_pu_size;

  338. 

  339.     const int xB0    = x0 + nPbW;

  340.     const int yB0    = y0 - 1;

  341.     const int xB0_pu = xB0 >> s->sps->log2_min_pu_size;

  342.     const int yB0_pu = yB0 >> s->sps->log2_min_pu_size;

  343. 

  344.     const int xA0    = x0 - 1;

  345.     const int yA0    = y0 + nPbH;

  346.     const int xA0_pu = xA0 >> s->sps->log2_min_pu_size;

  347.     const int yA0_pu = yA0 >> s->sps->log2_min_pu_size;

  348. 

  349.     const int xB2    = x0 - 1;

  350.     const int yB2    = y0 - 1;

  351.     const int xB2_pu = xB2 >> s->sps->log2_min_pu_size;

  352.     const int yB2_pu = yB2 >> s->sps->log2_min_pu_size;

  353. 

  354.     const int nb_refs = (s->sh.slice_type == P_SLICE) ?

  355.                         s->sh.nb_refs[0] : FFMIN(s->sh.nb_refs[0], s->sh.nb_refs[1]);

  356.     int check_MER   = 1;

  357.     int check_MER_1 = 1;

  358. 

  359.     int zero_idx = 0;

  360. 

  361.     int nb_merge_cand = 0;

  362.     int nb_orig_merge_cand = 0;

  363. 

  364.     int is_available_a0;

  365.     int is_available_a1;

  366.     int is_available_b0;

  367.     int is_available_b1;

  368.     int is_available_b2;

  369.     int check_B0;

  370.     int check_A0;

  371. 

  372.     //first left spatial merge candidate

  373.     is_available_a1 = AVAILABLE(cand_left, A1);

  374. 

  375.     if (!singleMCLFlag && part_idx == 1 &&

  376.         (lc->cu.part_mode == PART_Nx2N ||

  377.          lc->cu.part_mode == PART_nLx2N ||

  378.          lc->cu.part_mode == PART_nRx2N) ||

  379.         isDiffMER(s, xA1, yA1, x0, y0)) {

  380.         is_available_a1 = 0;

  381.     }

  382. 

  383.     if (is_available_a1)

  384.         mergecandlist[nb_merge_cand++] = TAB_MVF_PU(A1);

  385. 

  386.     // above spatial merge candidate

  387.     is_available_b1 = AVAILABLE(cand_up, B1);

  388. 

  389.     if (!singleMCLFlag && part_idx == 1 &&

  390.         (lc->cu.part_mode == PART_2NxN ||

  391.          lc->cu.part_mode == PART_2NxnU ||

  392.          lc->cu.part_mode == PART_2NxnD) ||

  393.         isDiffMER(s, xB1, yB1, x0, y0)) {

  394.         is_available_b1 = 0;

  395.     }

  396. 

  397.     if (is_available_a1 && is_available_b1)

  398.         check_MER = !COMPARE_MV_REFIDX(B1, A1);

  399. 

  400.     if (is_available_b1 && check_MER)

  401.         mergecandlist[nb_merge_cand++] = TAB_MVF_PU(B1);

  402. 

  403.     // above right spatial merge candidate

  404.     check_MER = 1;

  405.     check_B0 = PRED_BLOCK_AVAILABLE(B0);

  406. 

  407.     is_available_b0 = check_B0 && AVAILABLE(cand_up_right, B0);

  408. 

  409.     if (isDiffMER(s, xB0, yB0, x0, y0))

  410.         is_available_b0 = 0;

  411. 

  412.     if (is_available_b1 && is_available_b0)

  413.         check_MER = !COMPARE_MV_REFIDX(B0, B1);

  414. 

  415.     if (is_available_b0 && check_MER)

  416.         mergecandlist[nb_merge_cand++] = TAB_MVF_PU(B0);

  417. 

  418.     // left bottom spatial merge candidate

  419.     check_MER = 1;

  420.     check_A0 = PRED_BLOCK_AVAILABLE(A0);

  421. 

  422.     is_available_a0 = check_A0 && AVAILABLE(cand_bottom_left, A0);

  423. 

  424.     if (isDiffMER(s, xA0, yA0, x0, y0))

  425.         is_available_a0 = 0;

  426. 

  427.     if (is_available_a1 && is_available_a0)

  428.         check_MER = !COMPARE_MV_REFIDX(A0, A1);

  429. 

  430.     if (is_available_a0 && check_MER)

  431.         mergecandlist[nb_merge_cand++] = TAB_MVF_PU(A0);

  432. 

  433.     // above left spatial merge candidate

  434.     check_MER = 1;

  435. 

  436.     is_available_b2 = AVAILABLE(cand_up_left, B2);

  437. 

  438.     if (isDiffMER(s, xB2, yB2, x0, y0))

  439.         is_available_b2 = 0;

  440. 

  441.     if (is_available_a1 && is_available_b2)

  442.         check_MER = !COMPARE_MV_REFIDX(B2, A1);

  443. 

  444.     if (is_available_b1 && is_available_b2)

  445.         check_MER_1 = !COMPARE_MV_REFIDX(B2, B1);

  446. 

  447.     if (is_available_b2 && check_MER && check_MER_1 && nb_merge_cand != 4)

  448.         mergecandlist[nb_merge_cand++] = TAB_MVF_PU(B2);

  449. 

  450.     // temporal motion vector candidate

  451.     if (s->sh.slice_temporal_mvp_enabled_flag &&

  452.         nb_merge_cand < s->sh.max_num_merge_cand) {

  453.         Mv mv_l0_col, mv_l1_col;

  454.         int available_l0 = temporal_luma_motion_vector(s, x0, y0, nPbW, nPbH,

  455.                                                        0, &mv_l0_col, 0);

  456.         int available_l1 = (s->sh.slice_type == B_SLICE) ?

  457.                            temporal_luma_motion_vector(s, x0, y0, nPbW, nPbH,

  458.                                                        0, &mv_l1_col, 1) : 0;

  459. 

  460.         if (available_l0 || available_l1) {

  461.             mergecandlist[nb_merge_cand].is_intra     = 0;

  462.             mergecandlist[nb_merge_cand].pred_flag[0] = available_l0;

  463.             mergecandlist[nb_merge_cand].pred_flag[1] = available_l1;

  464.             if (available_l0) {

  465.                 mergecandlist[nb_merge_cand].mv[0]      = mv_l0_col;

  466.                 mergecandlist[nb_merge_cand].ref_idx[0] = 0;

  467.             }

  468.             if (available_l1) {

  469.                 mergecandlist[nb_merge_cand].mv[1]      = mv_l1_col;

  470.                 mergecandlist[nb_merge_cand].ref_idx[1] = 0;

  471.             }

  472.             nb_merge_cand++;

  473.         }

  474.     }

  475. 

  476.     nb_orig_merge_cand = nb_merge_cand;

  477. 

  478.     // combined bi-predictive merge candidates  (applies for B slices)

  479.     if (s->sh.slice_type == B_SLICE && nb_orig_merge_cand > 1 &&

  480.         nb_orig_merge_cand < s->sh.max_num_merge_cand) {

  481.         int comb_idx = 0;

  482. 

  483.         for (comb_idx = 0; nb_merge_cand < s->sh.max_num_merge_cand &&

  484.                            comb_idx < nb_orig_merge_cand * (nb_orig_merge_cand - 1); comb_idx++) {

  485.             int l0_cand_idx = l0_l1_cand_idx[comb_idx][0];

  486.             int l1_cand_idx = l0_l1_cand_idx[comb_idx][1];

  487.             MvField l0_cand = mergecandlist[l0_cand_idx];

  488.             MvField l1_cand = mergecandlist[l1_cand_idx];

  489. 

  490.             if (l0_cand.pred_flag[0] && l1_cand.pred_flag[1] &&

  491.                 (refPicList[0].list[l0_cand.ref_idx[0]] !=

  492.                  refPicList[1].list[l1_cand.ref_idx[1]] ||

  493.                  l0_cand.mv[0].x != l1_cand.mv[1].x ||

  494.                  l0_cand.mv[0].y != l1_cand.mv[1].y)) {

  495.                 mergecandlist[nb_merge_cand].ref_idx[0]   = l0_cand.ref_idx[0];

  496.                 mergecandlist[nb_merge_cand].ref_idx[1]   = l1_cand.ref_idx[1];

  497.                 mergecandlist[nb_merge_cand].pred_flag[0] = 1;

  498.                 mergecandlist[nb_merge_cand].pred_flag[1] = 1;

  499.                 mergecandlist[nb_merge_cand].mv[0].x      = l0_cand.mv[0].x;

  500.                 mergecandlist[nb_merge_cand].mv[0].y      = l0_cand.mv[0].y;

  501.                 mergecandlist[nb_merge_cand].mv[1].x      = l1_cand.mv[1].x;

  502.                 mergecandlist[nb_merge_cand].mv[1].y      = l1_cand.mv[1].y;

  503.                 mergecandlist[nb_merge_cand].is_intra     = 0;

  504.                 nb_merge_cand++;

  505.             }

  506.         }

  507.     }

  508. 

  509.     // append Zero motion vector candidates

  510.     while (nb_merge_cand < s->sh.max_num_merge_cand) {

  511.         mergecandlist[nb_merge_cand].pred_flag[0] = 1;

  512.         mergecandlist[nb_merge_cand].pred_flag[1] = s->sh.slice_type == B_SLICE;

  513.         mergecandlist[nb_merge_cand].mv[0].x      = 0;

  514.         mergecandlist[nb_merge_cand].mv[0].y      = 0;

  515.         mergecandlist[nb_merge_cand].mv[1].x      = 0;

  516.         mergecandlist[nb_merge_cand].mv[1].y      = 0;

  517.         mergecandlist[nb_merge_cand].is_intra     = 0;

  518.         mergecandlist[nb_merge_cand].ref_idx[0]   = (zero_idx < nb_refs) ? zero_idx : 0;

  519.         mergecandlist[nb_merge_cand].ref_idx[1]   = (zero_idx < nb_refs) ? zero_idx : 0;

  520. 

  521.         nb_merge_cand++;

  522.         zero_idx++;

  523.     }

  524. }

  525. 

  526. /*

  527.  * 8.5.3.1.1 Derivation process of luma Mvs for merge mode

  528.  */

  529. void ff_hevc_luma_mv_merge_mode(HEVCContext *s, int x0, int y0, int nPbW,

  530.                                 int nPbH, int log2_cb_size, int part_idx,

  531.                                 int merge_idx, MvField *mv)

  532. {

  533.     int singleMCLFlag = 0;

  534.     int nCS = 1 << log2_cb_size;

  535.     struct MvField mergecand_list[MRG_MAX_NUM_CANDS] = { { { { 0 } } } };

  536.     int nPbW2 = nPbW;

  537.     int nPbH2 = nPbH;

  538.     HEVCLocalContext *lc = s->HEVClc;

  539. 

  540.     if (s->pps->log2_parallel_merge_level > 2 && nCS == 8) {

  541.         singleMCLFlag = 1;

  542.         x0 = lc->cu.x;

  543.         y0 = lc->cu.y;

  544.         nPbW = nCS;

  545.         nPbH = nCS;

  546.         part_idx = 0;

  547.     }

  548. 

  549.     ff_hevc_set_neighbour_available(s, x0, y0, nPbW, nPbH);

  550.     derive_spatial_merge_candidates(s, x0, y0, nPbW, nPbH, log2_cb_size,

  551.                                     singleMCLFlag, part_idx, mergecand_list);

  552. 

  553.     if (mergecand_list[merge_idx].pred_flag[0] == 1 &&

  554.         mergecand_list[merge_idx].pred_flag[1] == 1 &&

  555.         (nPbW2 + nPbH2) == 12) {

  556.         mergecand_list[merge_idx].ref_idx[1] = -1;

  557.         mergecand_list[merge_idx].pred_flag[1] = 0;

  558.     }

  559. 

  560.     *mv = mergecand_list[merge_idx];

  561. }

  562. 

  563. static av_always_inline void dist_scale(HEVCContext *s, Mv * mv,

  564.                                         int min_pu_width, int x, int y,

  565.                                         int elist, int ref_idx_curr, int ref_idx)

  566. {

  567.     RefPicList *refPicList = s->ref->refPicList;

  568.     MvField *tab_mvf = s->ref->tab_mvf;

  569.     int ref_pic_elist = refPicList[elist].list[TAB_MVF(x, y).ref_idx[elist]];

  570.     int ref_pic_curr  = refPicList[ref_idx_curr].list[ref_idx];

  571. 

  572.     if (ref_pic_elist != ref_pic_curr)

  573.         mv_scale(mv, mv, s->poc - ref_pic_elist, s->poc - ref_pic_curr);

  574. }

  575. 

  576. static int mv_mp_mode_mx(HEVCContext *s, int x, int y, int pred_flag_index,

  577.                          Mv *mv, int ref_idx_curr, int ref_idx)

  578. {

  579.     MvField *tab_mvf = s->ref->tab_mvf;

  580.     int min_pu_width = s->sps->min_pu_width;

  581. 

  582.     RefPicList *refPicList = s->ref->refPicList;

  583. 

  584.     if (TAB_MVF(x, y).pred_flag[pred_flag_index] == 1 &&

  585.         refPicList[pred_flag_index].list[TAB_MVF(x, y).ref_idx[pred_flag_index]] == refPicList[ref_idx_curr].list[ref_idx]) {

  586.         *mv = TAB_MVF(x, y).mv[pred_flag_index];

  587.         return 1;

  588.     }

  589.     return 0;

  590. }

  591. 

  592. 

  593. static int mv_mp_mode_mx_lt(HEVCContext *s, int x, int y, int pred_flag_index,

  594.                             Mv *mv, int ref_idx_curr, int ref_idx)

  595. {

  596.     MvField *tab_mvf = s->ref->tab_mvf;

  597.     int min_pu_width = s->sps->min_pu_width;

  598. 

  599.     RefPicList *refPicList = s->ref->refPicList;

  600.     int currIsLongTerm = refPicList[ref_idx_curr].isLongTerm[ref_idx];

  601. 

  602.     int colIsLongTerm =

  603.         refPicList[pred_flag_index].isLongTerm[(TAB_MVF(x, y).ref_idx[pred_flag_index])];

  604. 

  605.     if (TAB_MVF(x, y).pred_flag[pred_flag_index] && colIsLongTerm == currIsLongTerm) {

  606.         *mv = TAB_MVF(x, y).mv[pred_flag_index];

  607.         if (!currIsLongTerm)

  608.             dist_scale(s, mv, min_pu_width, x, y, pred_flag_index, ref_idx_curr, ref_idx);

  609.         return 1;

  610.     }

  611.     return 0;

  612. }

  613. 

  614. #define MP_MX(v, pred, mx) \

  615.     mv_mp_mode_mx(s, x##v##_pu, y##v##_pu, pred, &mx, ref_idx_curr, ref_idx)

  616. 

  617. #define MP_MX_LT(v, pred, mx) \

  618.     mv_mp_mode_mx_lt(s, x##v##_pu, y##v##_pu, pred, &mx, ref_idx_curr, ref_idx)

  619. 

  620. void ff_hevc_luma_mv_mvp_mode(HEVCContext *s, int x0, int y0, int nPbW,

  621.                               int nPbH, int log2_cb_size, int part_idx,

  622.                               int merge_idx, MvField *mv,

  623.                               int mvp_lx_flag, int LX)

  624. {

  625.     HEVCLocalContext *lc = s->HEVClc;

  626.     MvField *tab_mvf = s->ref->tab_mvf;

  627.     int isScaledFlag_L0 = 0;

  628.     int availableFlagLXA0 = 0;

  629.     int availableFlagLXB0 = 0;

  630.     int numMVPCandLX = 0;

  631.     int min_pu_width = s->sps->min_pu_width;

  632. 

  633.     int xA0, yA0;

  634.     int xA0_pu, yA0_pu;

  635.     int is_available_a0;

  636. 

  637.     int xA1, yA1;

  638.     int xA1_pu, yA1_pu;

  639.     int is_available_a1;

  640. 

  641.     int xB0, yB0;

  642.     int xB0_pu, yB0_pu;

  643.     int is_available_b0;

  644. 

  645.     int xB1, yB1;

  646.     int xB1_pu = 0, yB1_pu = 0;

  647.     int is_available_b1 = 0;

  648. 

  649.     int xB2, yB2;

  650.     int xB2_pu = 0, yB2_pu = 0;

  651.     int is_available_b2 = 0;

  652.     Mv mvpcand_list[2] = { { 0 } };

  653.     Mv mxA = { 0 };

  654.     Mv mxB = { 0 };

  655.     int ref_idx_curr = 0;

  656.     int ref_idx = 0;

  657.     int pred_flag_index_l0;

  658.     int pred_flag_index_l1;

  659.     int x0b = x0 & ((1 << s->sps->log2_ctb_size) - 1);

  660.     int y0b = y0 & ((1 << s->sps->log2_ctb_size) - 1);

  661. 

  662.     int cand_up = (lc->ctb_up_flag || y0b);

  663.     int cand_left = (lc->ctb_left_flag || x0b);

  664.     int cand_up_left =

  665.             (!x0b && !y0b) ? lc->ctb_up_left_flag : cand_left && cand_up;

  666.     int cand_up_right =

  667.             (x0b + nPbW == (1 << s->sps->log2_ctb_size) ||

  668.              x0  + nPbW >= lc->end_of_tiles_x) ? lc->ctb_up_right_flag && !y0b

  669.                                                : cand_up;

  670.     int cand_bottom_left = (y0 + nPbH >= lc->end_of_tiles_y) ? 0 : cand_left;

  671. 

  672.     ref_idx_curr       = LX;

  673.     ref_idx            = mv->ref_idx[LX];

  674.     pred_flag_index_l0 = LX;

  675.     pred_flag_index_l1 = !LX;

  676. 

  677.     // left bottom spatial candidate

  678.     xA0 = x0 - 1;

  679.     yA0 = y0 + nPbH;

  680.     xA0_pu = xA0 >> s->sps->log2_min_pu_size;

  681.     yA0_pu = yA0 >> s->sps->log2_min_pu_size;

  682. 

  683.     is_available_a0 = PRED_BLOCK_AVAILABLE(A0) && AVAILABLE(cand_bottom_left, A0);

  684. 

  685.     //left spatial merge candidate

  686.     xA1 = x0 - 1;

  687.     yA1 = y0 + nPbH - 1;

  688.     xA1_pu = xA1 >> s->sps->log2_min_pu_size;

  689.     yA1_pu = yA1 >> s->sps->log2_min_pu_size;

  690. 

  691.     is_available_a1 = AVAILABLE(cand_left, A1);

  692.     if (is_available_a0 || is_available_a1) {

  693.         isScaledFlag_L0 = 1;

  694.     }

  695. 

  696.     if (is_available_a0) {

  697.         availableFlagLXA0 = MP_MX(A0, pred_flag_index_l0, mxA);

  698.         if (!availableFlagLXA0)

  699.             availableFlagLXA0 = MP_MX(A0, pred_flag_index_l1, mxA);

  700.     }

  701. 

  702.     if (is_available_a1 && !availableFlagLXA0) {

  703.         availableFlagLXA0 = MP_MX(A1, pred_flag_index_l0, mxA);

  704.         if (!availableFlagLXA0)

  705.             availableFlagLXA0 = MP_MX(A1, pred_flag_index_l1, mxA);

  706.     }

  707. 

  708.     if (is_available_a0 && !availableFlagLXA0) {

  709.         availableFlagLXA0 = MP_MX_LT(A0, pred_flag_index_l0, mxA);

  710.         if (!availableFlagLXA0)

  711.             availableFlagLXA0 = MP_MX_LT(A0, pred_flag_index_l1, mxA);

  712.     }

  713. 

  714.     if (is_available_a1 && !availableFlagLXA0) {

  715.         availableFlagLXA0 = MP_MX_LT(A1, pred_flag_index_l0, mxA);

  716.         if (!availableFlagLXA0)

  717.             availableFlagLXA0 = MP_MX_LT(A1, pred_flag_index_l1, mxA);

  718.     }

  719. 

  720.     // B candidates

  721.     // above right spatial merge candidate

  722.     xB0 = x0 + nPbW;

  723.     yB0 = y0 - 1;

  724.     xB0_pu = xB0 >> s->sps->log2_min_pu_size;

  725.     yB0_pu = yB0 >> s->sps->log2_min_pu_size;

  726. 

  727.     is_available_b0 = PRED_BLOCK_AVAILABLE(B0) && AVAILABLE(cand_up_right, B0);

  728. 

  729.     if (is_available_b0) {

  730.         availableFlagLXB0 = MP_MX(B0, pred_flag_index_l0, mxB);

  731.         if (!availableFlagLXB0)

  732.             availableFlagLXB0 = MP_MX(B0, pred_flag_index_l1, mxB);

  733.     }

  734. 

  735.     if (!availableFlagLXB0) {

  736.         // above spatial merge candidate

  737.         xB1 = x0 + nPbW - 1;

  738.         yB1 = y0 - 1;

  739.         xB1_pu = xB1 >> s->sps->log2_min_pu_size;

  740.         yB1_pu = yB1 >> s->sps->log2_min_pu_size;

  741. 

  742.         is_available_b1 = AVAILABLE(cand_up, B1);

  743. 

  744.         if (is_available_b1) {

  745.             availableFlagLXB0 = MP_MX(B1, pred_flag_index_l0, mxB);

  746.             if (!availableFlagLXB0)

  747.                 availableFlagLXB0 = MP_MX(B1, pred_flag_index_l1, mxB);

  748.         }

  749.     }

  750. 

  751.     if (!availableFlagLXB0) {

  752.         // above left spatial merge candidate

  753.         xB2 = x0 - 1;

  754.         yB2 = y0 - 1;

  755.         xB2_pu = xB2 >> s->sps->log2_min_pu_size;

  756.         yB2_pu = yB2 >> s->sps->log2_min_pu_size;

  757.         is_available_b2 = AVAILABLE(cand_up_left, B2);

  758. 

  759.         if (is_available_b2) {

  760.             availableFlagLXB0 = MP_MX(B2, pred_flag_index_l0, mxB);

  761.             if (!availableFlagLXB0)

  762.                 availableFlagLXB0 = MP_MX(B2, pred_flag_index_l1, mxB);

  763.         }

  764.     }

  765. 

  766.     if (isScaledFlag_L0 == 0) {

  767.         if (availableFlagLXB0) {

  768.             availableFlagLXA0 = 1;

  769.             mxA = mxB;

  770.         }

  771.         availableFlagLXB0 = 0;

  772. 

  773.         // XB0 and L1

  774.         if (is_available_b0) {

  775.             availableFlagLXB0 = MP_MX_LT(B0, pred_flag_index_l0, mxB);

  776.             if (!availableFlagLXB0)

  777.                 availableFlagLXB0 = MP_MX_LT(B0, pred_flag_index_l1, mxB);

  778.         }

  779. 

  780.         if (is_available_b1 && !availableFlagLXB0) {

  781.             availableFlagLXB0 = MP_MX_LT(B1, pred_flag_index_l0, mxB);

  782.             if (!availableFlagLXB0)

  783.                 availableFlagLXB0 = MP_MX_LT(B1, pred_flag_index_l1, mxB);

  784.         }

  785. 

  786.         if (is_available_b2 && !availableFlagLXB0) {

  787.             availableFlagLXB0 = MP_MX_LT(B2, pred_flag_index_l0, mxB);

  788.             if (!availableFlagLXB0)

  789.                 availableFlagLXB0 = MP_MX_LT(B2, pred_flag_index_l1, mxB);

  790.         }

  791.     }

  792. 

  793.     if (availableFlagLXA0)

  794.         mvpcand_list[numMVPCandLX++] = mxA;

  795. 

  796.     if (availableFlagLXB0 && (!availableFlagLXA0 || mxA.x != mxB.x || mxA.y != mxB.y))

  797.         mvpcand_list[numMVPCandLX++] = mxB;

  798. 

  799.     //temporal motion vector prediction candidate

  800.     if (numMVPCandLX < 2 && s->sh.slice_temporal_mvp_enabled_flag) {

  801.         Mv mv_col;

  802.         int available_col = temporal_luma_motion_vector(s, x0, y0, nPbW,

  803.                                                         nPbH, ref_idx, &mv_col, LX);

  804.         if (available_col)

  805.             mvpcand_list[numMVPCandLX++] = mv_col;

  806.     }

  807. 

  808.     // insert zero motion vectors when the number of available candidates are less than 2

  809.     while (numMVPCandLX < 2)

  810.         mvpcand_list[numMVPCandLX++] = (Mv){ 0, 0 };

  811. 

  812.     mv->mv[LX].x = mvpcand_list[mvp_lx_flag].x;

  813.     mv->mv[LX].y = mvpcand_list[mvp_lx_flag].y;

  814. }