ffmpeg/libavcodec/hevc_mvs.c

817 lines
28 KiB
C

/*
* HEVC video decoder
*
* Copyright (C) 2012 - 2013 Guillaume Martres
* Copyright (C) 2013 Anand Meher Kotra
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "hevc.h"
static const uint8_t l0_l1_cand_idx[12][2] = {
{ 0, 1, },
{ 1, 0, },
{ 0, 2, },
{ 2, 0, },
{ 1, 2, },
{ 2, 1, },
{ 0, 3, },
{ 3, 0, },
{ 1, 3, },
{ 3, 1, },
{ 2, 3, },
{ 3, 2, },
};
void ff_hevc_set_neighbour_available(HEVCContext *s, int x0, int y0,
int nPbW, int nPbH)
{
HEVCLocalContext *lc = &s->HEVClc;
int x0b = x0 & ((1 << s->sps->log2_ctb_size) - 1);
int y0b = y0 & ((1 << s->sps->log2_ctb_size) - 1);
lc->na.cand_up = (lc->ctb_up_flag || y0b);
lc->na.cand_left = (lc->ctb_left_flag || x0b);
lc->na.cand_up_left = (!x0b && !y0b) ? lc->ctb_up_left_flag : lc->na.cand_left && lc->na.cand_up;
lc->na.cand_up_right_sap =
((x0b + nPbW) == (1 << s->sps->log2_ctb_size)) ?
lc->ctb_up_right_flag && !y0b : lc->na.cand_up;
lc->na.cand_up_right =
((x0b + nPbW) == (1 << s->sps->log2_ctb_size) ?
lc->ctb_up_right_flag && !y0b : lc->na.cand_up )
&& (x0 + nPbW) < lc->end_of_tiles_x;
lc->na.cand_bottom_left = ((y0 + nPbH) >= lc->end_of_tiles_y) ? 0 : lc->na.cand_left;
}
/*
* 6.4.1 Derivation process for z-scan order block availability
*/
static int z_scan_block_avail(HEVCContext *s, int xCurr, int yCurr,
int xN, int yN)
{
#define MIN_TB_ADDR_ZS(x, y) \
s->pps->min_tb_addr_zs[(y) * s->sps->min_tb_width + (x)]
int Curr = MIN_TB_ADDR_ZS(xCurr >> s->sps->log2_min_tb_size,
yCurr >> s->sps->log2_min_tb_size);
int N;
if (xN < 0 || yN < 0 ||
xN >= s->sps->width ||
yN >= s->sps->height)
return 0;
N = MIN_TB_ADDR_ZS(xN >> s->sps->log2_min_tb_size,
yN >> s->sps->log2_min_tb_size);
return N <= Curr;
}
static int same_prediction_block(HEVCLocalContext *lc, int log2_cb_size,
int x0, int y0, int nPbW, int nPbH,
int xA1, int yA1, int partIdx)
{
return !(nPbW << 1 == 1 << log2_cb_size &&
nPbH << 1 == 1 << log2_cb_size && partIdx == 1 &&
lc->cu.x + nPbW > xA1 &&
lc->cu.y + nPbH <= yA1);
}
/*
* 6.4.2 Derivation process for prediction block availability
*/
static int check_prediction_block_available(HEVCContext *s, int log2_cb_size,
int x0, int y0, int nPbW, int nPbH,
int xA1, int yA1, int partIdx)
{
HEVCLocalContext *lc = &s->HEVClc;
if (lc->cu.x < xA1 && lc->cu.y < yA1 &&
(lc->cu.x + (1 << log2_cb_size)) > xA1 &&
(lc->cu.y + (1 << log2_cb_size)) > yA1)
return same_prediction_block(lc, log2_cb_size, x0, y0,
nPbW, nPbH, xA1, yA1, partIdx);
else
return z_scan_block_avail(s, x0, y0, xA1, yA1);
}
//check if the two luma locations belong to the same mostion estimation region
static int isDiffMER(HEVCContext *s, int xN, int yN, int xP, int yP)
{
uint8_t plevel = s->pps->log2_parallel_merge_level;
return xN >> plevel == xP >> plevel &&
yN >> plevel == yP >> plevel;
}
#define MATCH(x) (A.x == B.x)
// check if the mv's and refidx are the same between A and B
static int compareMVrefidx(struct MvField A, struct MvField B)
{
if (A.pred_flag[0] && A.pred_flag[1] && B.pred_flag[0] && B.pred_flag[1])
return MATCH(ref_idx[0]) && MATCH(mv[0].x) && MATCH(mv[0].y) &&
MATCH(ref_idx[1]) && MATCH(mv[1].x) && MATCH(mv[1].y);
if (A.pred_flag[0] && !A.pred_flag[1] && B.pred_flag[0] && !B.pred_flag[1])
return MATCH(ref_idx[0]) && MATCH(mv[0].x) && MATCH(mv[0].y);
if (!A.pred_flag[0] && A.pred_flag[1] && !B.pred_flag[0] && B.pred_flag[1])
return MATCH(ref_idx[1]) && MATCH(mv[1].x) && MATCH(mv[1].y);
return 0;
}
static av_always_inline void mv_scale(Mv *dst, Mv *src, int td, int tb)
{
int tx, scale_factor;
td = av_clip_int8_c(td);
tb = av_clip_int8_c(tb);
tx = (0x4000 + abs(td / 2)) / td;
scale_factor = av_clip_c((tb * tx + 32) >> 6, -4096, 4095);
dst->x = av_clip_int16_c((scale_factor * src->x + 127 +
(scale_factor * src->x < 0)) >> 8);
dst->y = av_clip_int16_c((scale_factor * src->y + 127 +
(scale_factor * src->y < 0)) >> 8);
}
static int check_mvset(Mv *mvLXCol, Mv *mvCol,
int colPic, int poc,
RefPicList *refPicList, int X, int refIdxLx,
RefPicList *refPicList_col, int listCol, int refidxCol)
{
int cur_lt = refPicList[X].isLongTerm[refIdxLx];
int col_lt = refPicList_col[listCol].isLongTerm[refidxCol];
int col_poc_diff, cur_poc_diff;
if (cur_lt != col_lt) {
mvLXCol->x = 0;
mvLXCol->y = 0;
return 0;
}
col_poc_diff = colPic - refPicList_col[listCol].list[refidxCol];
cur_poc_diff = poc - refPicList[X].list[refIdxLx];
if (!col_poc_diff)
col_poc_diff = 1; // error resilience
if (cur_lt || col_poc_diff == cur_poc_diff) {
mvLXCol->x = mvCol->x;
mvLXCol->y = mvCol->y;
} else {
mv_scale(mvLXCol, mvCol, col_poc_diff, cur_poc_diff);
}
return 1;
}
#define CHECK_MVSET(l) \
check_mvset(mvLXCol, temp_col.mv + l, \
colPic, s->poc, \
refPicList, X, refIdxLx, \
refPicList_col, L ## l, temp_col.ref_idx[l])
// derive the motion vectors section 8.5.3.1.8
static int derive_temporal_colocated_mvs(HEVCContext *s, MvField temp_col,
int refIdxLx, Mv *mvLXCol, int X,
int colPic, RefPicList *refPicList_col)
{
RefPicList *refPicList = s->ref->refPicList;
if (temp_col.is_intra) {
mvLXCol->x = 0;
mvLXCol->y = 0;
return 0;
}
if (temp_col.pred_flag[0] == 0)
return CHECK_MVSET(1);
else if (temp_col.pred_flag[0] == 1 && temp_col.pred_flag[1] == 0)
return CHECK_MVSET(0);
else if (temp_col.pred_flag[0] == 1 && temp_col.pred_flag[1] == 1) {
int check_diffpicount = 0;
int i = 0;
for (i = 0; i < refPicList[0].nb_refs; i++) {
if (refPicList[0].list[i] > s->poc)
check_diffpicount++;
}
for (i = 0; i < refPicList[1].nb_refs; i++) {
if (refPicList[1].list[i] > s->poc)
check_diffpicount++;
}
if (check_diffpicount == 0 && X == 0)
return CHECK_MVSET(0);
else if (check_diffpicount == 0 && X == 1)
return CHECK_MVSET(1);
else {
if (s->sh.collocated_list == L1)
return CHECK_MVSET(0);
else
return CHECK_MVSET(1);
}
}
return 0;
}
#define TAB_MVF(x, y) \
tab_mvf[(y) * min_pu_width + x]
#define TAB_MVF_PU(v) \
TAB_MVF(x ## v ## _pu, y ## v ## _pu)
#define DERIVE_TEMPORAL_COLOCATED_MVS \
derive_temporal_colocated_mvs(s, temp_col, \
refIdxLx, mvLXCol, X, colPic, \
ff_hevc_get_ref_list(s, ref, x, y))
/*
* 8.5.3.1.7 temporal luma motion vector prediction
*/
static int temporal_luma_motion_vector(HEVCContext *s, int x0, int y0,
int nPbW, int nPbH, int refIdxLx,
Mv *mvLXCol, int X)
{
MvField *tab_mvf;
MvField temp_col;
int x, y, x_pu, y_pu;
int min_pu_width = s->sps->min_pu_width;
int availableFlagLXCol = 0;
int colPic;
HEVCFrame *ref = s->ref->collocated_ref;
if (!ref)
return 0;
tab_mvf = ref->tab_mvf;
colPic = ref->poc;
//bottom right collocated motion vector
x = x0 + nPbW;
y = y0 + nPbH;
ff_thread_await_progress(&ref->tf, y, 0);
if (tab_mvf &&
(y0 >> s->sps->log2_ctb_size) == (y >> s->sps->log2_ctb_size) &&
y < s->sps->height &&
x < s->sps->width) {
x = ((x >> 4) << 4);
y = ((y >> 4) << 4);
x_pu = x >> s->sps->log2_min_pu_size;
y_pu = y >> s->sps->log2_min_pu_size;
temp_col = TAB_MVF(x_pu, y_pu);
availableFlagLXCol = DERIVE_TEMPORAL_COLOCATED_MVS;
}
// derive center collocated motion vector
if (tab_mvf && !availableFlagLXCol) {
x = x0 + (nPbW >> 1);
y = y0 + (nPbH >> 1);
x = ((x >> 4) << 4);
y = ((y >> 4) << 4);
x_pu = x >> s->sps->log2_min_pu_size;
y_pu = y >> s->sps->log2_min_pu_size;
temp_col = TAB_MVF(x_pu, y_pu);
availableFlagLXCol = DERIVE_TEMPORAL_COLOCATED_MVS;
}
return availableFlagLXCol;
}
#define AVAILABLE(cand, v) \
(cand && !TAB_MVF_PU(v).is_intra)
#define PRED_BLOCK_AVAILABLE(v) \
check_prediction_block_available(s, log2_cb_size, \
x0, y0, nPbW, nPbH, \
x ## v, y ## v, part_idx)
#define COMPARE_MV_REFIDX(a, b) \
compareMVrefidx(TAB_MVF_PU(a), TAB_MVF_PU(b))
/*
* 8.5.3.1.2 Derivation process for spatial merging candidates
*/
static void derive_spatial_merge_candidates(HEVCContext *s, int x0, int y0,
int nPbW, int nPbH,
int log2_cb_size,
int singleMCLFlag, int part_idx,
struct MvField mergecandlist[])
{
HEVCLocalContext *lc = &s->HEVClc;
RefPicList *refPicList = s->ref->refPicList;
MvField *tab_mvf = s->ref->tab_mvf;
const int min_pu_width = s->sps->min_pu_width;
const int cand_bottom_left = lc->na.cand_bottom_left;
const int cand_left = lc->na.cand_left;
const int cand_up_left = lc->na.cand_up_left;
const int cand_up = lc->na.cand_up;
const int cand_up_right = lc->na.cand_up_right_sap;
const int xA1 = x0 - 1;
const int yA1 = y0 + nPbH - 1;
const int xA1_pu = xA1 >> s->sps->log2_min_pu_size;
const int yA1_pu = yA1 >> s->sps->log2_min_pu_size;
const int xB1 = x0 + nPbW - 1;
const int yB1 = y0 - 1;
const int xB1_pu = xB1 >> s->sps->log2_min_pu_size;
const int yB1_pu = yB1 >> s->sps->log2_min_pu_size;
const int xB0 = x0 + nPbW;
const int yB0 = y0 - 1;
const int xB0_pu = xB0 >> s->sps->log2_min_pu_size;
const int yB0_pu = yB0 >> s->sps->log2_min_pu_size;
const int xA0 = x0 - 1;
const int yA0 = y0 + nPbH;
const int xA0_pu = xA0 >> s->sps->log2_min_pu_size;
const int yA0_pu = yA0 >> s->sps->log2_min_pu_size;
const int xB2 = x0 - 1;
const int yB2 = y0 - 1;
const int xB2_pu = xB2 >> s->sps->log2_min_pu_size;
const int yB2_pu = yB2 >> s->sps->log2_min_pu_size;
const int nb_refs = (s->sh.slice_type == P_SLICE) ?
s->sh.nb_refs[0] : FFMIN(s->sh.nb_refs[0], s->sh.nb_refs[1]);
int check_MER = 1;
int check_MER_1 = 1;
int zero_idx = 0;
int nb_merge_cand = 0;
int nb_orig_merge_cand = 0;
int is_available_a0;
int is_available_a1;
int is_available_b0;
int is_available_b1;
int is_available_b2;
int check_B0;
int check_A0;
//first left spatial merge candidate
is_available_a1 = AVAILABLE(cand_left, A1);
if (!singleMCLFlag && part_idx == 1 &&
(lc->cu.part_mode == PART_Nx2N ||
lc->cu.part_mode == PART_nLx2N ||
lc->cu.part_mode == PART_nRx2N) ||
isDiffMER(s, xA1, yA1, x0, y0)) {
is_available_a1 = 0;
}
if (is_available_a1)
mergecandlist[nb_merge_cand++] = TAB_MVF_PU(A1);
// above spatial merge candidate
is_available_b1 = AVAILABLE(cand_up, B1);
if (!singleMCLFlag && part_idx == 1 &&
(lc->cu.part_mode == PART_2NxN ||
lc->cu.part_mode == PART_2NxnU ||
lc->cu.part_mode == PART_2NxnD) ||
isDiffMER(s, xB1, yB1, x0, y0)) {
is_available_b1 = 0;
}
if (is_available_a1 && is_available_b1)
check_MER = !COMPARE_MV_REFIDX(B1, A1);
if (is_available_b1 && check_MER)
mergecandlist[nb_merge_cand++] = TAB_MVF_PU(B1);
// above right spatial merge candidate
check_MER = 1;
check_B0 = PRED_BLOCK_AVAILABLE(B0);
is_available_b0 = check_B0 && AVAILABLE(cand_up_right, B0);
if (isDiffMER(s, xB0, yB0, x0, y0))
is_available_b0 = 0;
if (is_available_b1 && is_available_b0)
check_MER = !COMPARE_MV_REFIDX(B0, B1);
if (is_available_b0 && check_MER)
mergecandlist[nb_merge_cand++] = TAB_MVF_PU(B0);
// left bottom spatial merge candidate
check_MER = 1;
check_A0 = PRED_BLOCK_AVAILABLE(A0);
is_available_a0 = check_A0 && AVAILABLE(cand_bottom_left, A0);
if (isDiffMER(s, xA0, yA0, x0, y0))
is_available_a0 = 0;
if (is_available_a1 && is_available_a0)
check_MER = !COMPARE_MV_REFIDX(A0, A1);
if (is_available_a0 && check_MER)
mergecandlist[nb_merge_cand++] = TAB_MVF_PU(A0);
// above left spatial merge candidate
check_MER = 1;
is_available_b2 = AVAILABLE(cand_up_left, B2);
if (isDiffMER(s, xB2, yB2, x0, y0))
is_available_b2 = 0;
if (is_available_a1 && is_available_b2)
check_MER = !COMPARE_MV_REFIDX(B2, A1);
if (is_available_b1 && is_available_b2)
check_MER_1 = !COMPARE_MV_REFIDX(B2, B1);
if (is_available_b2 && check_MER && check_MER_1 && nb_merge_cand != 4)
mergecandlist[nb_merge_cand++] = TAB_MVF_PU(B2);
// temporal motion vector candidate
if (s->sh.slice_temporal_mvp_enabled_flag &&
nb_merge_cand < s->sh.max_num_merge_cand) {
Mv mv_l0_col, mv_l1_col;
int available_l0 = temporal_luma_motion_vector(s, x0, y0, nPbW, nPbH,
0, &mv_l0_col, 0);
int available_l1 = (s->sh.slice_type == B_SLICE) ?
temporal_luma_motion_vector(s, x0, y0, nPbW, nPbH,
0, &mv_l1_col, 1) : 0;
if (available_l0 || available_l1) {
mergecandlist[nb_merge_cand].is_intra = 0;
mergecandlist[nb_merge_cand].pred_flag[0] = available_l0;
mergecandlist[nb_merge_cand].pred_flag[1] = available_l1;
if (available_l0) {
mergecandlist[nb_merge_cand].mv[0] = mv_l0_col;
mergecandlist[nb_merge_cand].ref_idx[0] = 0;
}
if (available_l1) {
mergecandlist[nb_merge_cand].mv[1] = mv_l1_col;
mergecandlist[nb_merge_cand].ref_idx[1] = 0;
}
nb_merge_cand++;
}
}
nb_orig_merge_cand = nb_merge_cand;
// combined bi-predictive merge candidates (applies for B slices)
if (s->sh.slice_type == B_SLICE && nb_orig_merge_cand > 1 &&
nb_orig_merge_cand < s->sh.max_num_merge_cand) {
int comb_idx;
for (comb_idx = 0; nb_merge_cand < s->sh.max_num_merge_cand &&
comb_idx < nb_orig_merge_cand * (nb_orig_merge_cand - 1); comb_idx++) {
int l0_cand_idx = l0_l1_cand_idx[comb_idx][0];
int l1_cand_idx = l0_l1_cand_idx[comb_idx][1];
MvField l0_cand = mergecandlist[l0_cand_idx];
MvField l1_cand = mergecandlist[l1_cand_idx];
if (l0_cand.pred_flag[0] && l1_cand.pred_flag[1] &&
(refPicList[0].list[l0_cand.ref_idx[0]] !=
refPicList[1].list[l1_cand.ref_idx[1]] ||
l0_cand.mv[0].x != l1_cand.mv[1].x ||
l0_cand.mv[0].y != l1_cand.mv[1].y)) {
mergecandlist[nb_merge_cand].ref_idx[0] = l0_cand.ref_idx[0];
mergecandlist[nb_merge_cand].ref_idx[1] = l1_cand.ref_idx[1];
mergecandlist[nb_merge_cand].pred_flag[0] = 1;
mergecandlist[nb_merge_cand].pred_flag[1] = 1;
mergecandlist[nb_merge_cand].mv[0].x = l0_cand.mv[0].x;
mergecandlist[nb_merge_cand].mv[0].y = l0_cand.mv[0].y;
mergecandlist[nb_merge_cand].mv[1].x = l1_cand.mv[1].x;
mergecandlist[nb_merge_cand].mv[1].y = l1_cand.mv[1].y;
mergecandlist[nb_merge_cand].is_intra = 0;
nb_merge_cand++;
}
}
}
// append Zero motion vector candidates
while (nb_merge_cand < s->sh.max_num_merge_cand) {
mergecandlist[nb_merge_cand].pred_flag[0] = 1;
mergecandlist[nb_merge_cand].pred_flag[1] = s->sh.slice_type == B_SLICE;
mergecandlist[nb_merge_cand].mv[0].x = 0;
mergecandlist[nb_merge_cand].mv[0].y = 0;
mergecandlist[nb_merge_cand].mv[1].x = 0;
mergecandlist[nb_merge_cand].mv[1].y = 0;
mergecandlist[nb_merge_cand].is_intra = 0;
mergecandlist[nb_merge_cand].ref_idx[0] = zero_idx < nb_refs ? zero_idx : 0;
mergecandlist[nb_merge_cand].ref_idx[1] = zero_idx < nb_refs ? zero_idx : 0;
nb_merge_cand++;
zero_idx++;
}
}
/*
* 8.5.3.1.1 Derivation process of luma Mvs for merge mode
*/
void ff_hevc_luma_mv_merge_mode(HEVCContext *s, int x0, int y0, int nPbW,
int nPbH, int log2_cb_size, int part_idx,
int merge_idx, MvField *mv)
{
int singleMCLFlag = 0;
int nCS = 1 << log2_cb_size;
struct MvField mergecand_list[MRG_MAX_NUM_CANDS] = { { { { 0 } } } };
int nPbW2 = nPbW;
int nPbH2 = nPbH;
HEVCLocalContext *lc = &s->HEVClc;
if (s->pps->log2_parallel_merge_level > 2 && nCS == 8) {
singleMCLFlag = 1;
x0 = lc->cu.x;
y0 = lc->cu.y;
nPbW = nCS;
nPbH = nCS;
part_idx = 0;
}
ff_hevc_set_neighbour_available(s, x0, y0, nPbW, nPbH);
derive_spatial_merge_candidates(s, x0, y0, nPbW, nPbH, log2_cb_size,
singleMCLFlag, part_idx, mergecand_list);
if (mergecand_list[merge_idx].pred_flag[0] == 1 &&
mergecand_list[merge_idx].pred_flag[1] == 1 &&
(nPbW2 + nPbH2) == 12) {
mergecand_list[merge_idx].ref_idx[1] = -1;
mergecand_list[merge_idx].pred_flag[1] = 0;
}
*mv = mergecand_list[merge_idx];
}
static av_always_inline void dist_scale(HEVCContext *s, Mv *mv,
int min_pu_width, int x, int y,
int elist, int ref_idx_curr, int ref_idx)
{
RefPicList *refPicList = s->ref->refPicList;
MvField *tab_mvf = s->ref->tab_mvf;
int ref_pic_elist = refPicList[elist].list[TAB_MVF(x, y).ref_idx[elist]];
int ref_pic_curr = refPicList[ref_idx_curr].list[ref_idx];
if (ref_pic_elist != ref_pic_curr)
mv_scale(mv, mv, s->poc - ref_pic_elist, s->poc - ref_pic_curr);
}
static int mv_mp_mode_mx(HEVCContext *s, int x, int y, int pred_flag_index,
Mv *mv, int ref_idx_curr, int ref_idx)
{
MvField *tab_mvf = s->ref->tab_mvf;
int min_pu_width = s->sps->min_pu_width;
RefPicList *refPicList = s->ref->refPicList;
if (TAB_MVF(x, y).pred_flag[pred_flag_index] == 1 &&
refPicList[pred_flag_index].list[TAB_MVF(x, y).ref_idx[pred_flag_index]] == refPicList[ref_idx_curr].list[ref_idx]) {
*mv = TAB_MVF(x, y).mv[pred_flag_index];
return 1;
}
return 0;
}
static int mv_mp_mode_mx_lt(HEVCContext *s, int x, int y, int pred_flag_index,
Mv *mv, int ref_idx_curr, int ref_idx)
{
MvField *tab_mvf = s->ref->tab_mvf;
int min_pu_width = s->sps->min_pu_width;
RefPicList *refPicList = s->ref->refPicList;
int currIsLongTerm = refPicList[ref_idx_curr].isLongTerm[ref_idx];
int colIsLongTerm =
refPicList[pred_flag_index].isLongTerm[(TAB_MVF(x, y).ref_idx[pred_flag_index])];
if (TAB_MVF(x, y).pred_flag[pred_flag_index] &&
colIsLongTerm == currIsLongTerm) {
*mv = TAB_MVF(x, y).mv[pred_flag_index];
if (!currIsLongTerm)
dist_scale(s, mv, min_pu_width, x, y,
pred_flag_index, ref_idx_curr, ref_idx);
return 1;
}
return 0;
}
#define MP_MX(v, pred, mx) \
mv_mp_mode_mx(s, x ## v ## _pu, y ## v ## _pu, pred, \
&mx, ref_idx_curr, ref_idx)
#define MP_MX_LT(v, pred, mx) \
mv_mp_mode_mx_lt(s, x ## v ## _pu, y ## v ## _pu, pred, \
&mx, ref_idx_curr, ref_idx)
void ff_hevc_luma_mv_mvp_mode(HEVCContext *s, int x0, int y0, int nPbW,
int nPbH, int log2_cb_size, int part_idx,
int merge_idx, MvField *mv,
int mvp_lx_flag, int LX)
{
HEVCLocalContext *lc = &s->HEVClc;
MvField *tab_mvf = s->ref->tab_mvf;
int isScaledFlag_L0 = 0;
int availableFlagLXA0 = 0;
int availableFlagLXB0 = 0;
int numMVPCandLX = 0;
int min_pu_width = s->sps->min_pu_width;
int xA0, yA0;
int xA0_pu, yA0_pu;
int is_available_a0;
int xA1, yA1;
int xA1_pu, yA1_pu;
int is_available_a1;
int xB0, yB0;
int xB0_pu, yB0_pu;
int is_available_b0;
int xB1, yB1;
int xB1_pu = 0, yB1_pu = 0;
int is_available_b1 = 0;
int xB2, yB2;
int xB2_pu = 0, yB2_pu = 0;
int is_available_b2 = 0;
Mv mvpcand_list[2] = { { 0 } };
Mv mxA = { 0 };
Mv mxB = { 0 };
int ref_idx_curr = 0;
int ref_idx = 0;
int pred_flag_index_l0;
int pred_flag_index_l1;
int x0b = x0 & ((1 << s->sps->log2_ctb_size) - 1);
int y0b = y0 & ((1 << s->sps->log2_ctb_size) - 1);
int cand_up = (lc->ctb_up_flag || y0b);
int cand_left = (lc->ctb_left_flag || x0b);
int cand_up_left =
(!x0b && !y0b) ? lc->ctb_up_left_flag : cand_left && cand_up;
int cand_up_right =
(x0b + nPbW == (1 << s->sps->log2_ctb_size) ||
x0 + nPbW >= lc->end_of_tiles_x) ? lc->ctb_up_right_flag && !y0b
: cand_up;
int cand_bottom_left = (y0 + nPbH >= lc->end_of_tiles_y) ? 0 : cand_left;
ref_idx_curr = LX;
ref_idx = mv->ref_idx[LX];
pred_flag_index_l0 = LX;
pred_flag_index_l1 = !LX;
// left bottom spatial candidate
xA0 = x0 - 1;
yA0 = y0 + nPbH;
xA0_pu = xA0 >> s->sps->log2_min_pu_size;
yA0_pu = yA0 >> s->sps->log2_min_pu_size;
is_available_a0 = PRED_BLOCK_AVAILABLE(A0) && AVAILABLE(cand_bottom_left, A0);
//left spatial merge candidate
xA1 = x0 - 1;
yA1 = y0 + nPbH - 1;
xA1_pu = xA1 >> s->sps->log2_min_pu_size;
yA1_pu = yA1 >> s->sps->log2_min_pu_size;
is_available_a1 = AVAILABLE(cand_left, A1);
if (is_available_a0 || is_available_a1)
isScaledFlag_L0 = 1;
if (is_available_a0) {
availableFlagLXA0 = MP_MX(A0, pred_flag_index_l0, mxA);
if (!availableFlagLXA0)
availableFlagLXA0 = MP_MX(A0, pred_flag_index_l1, mxA);
}
if (is_available_a1 && !availableFlagLXA0) {
availableFlagLXA0 = MP_MX(A1, pred_flag_index_l0, mxA);
if (!availableFlagLXA0)
availableFlagLXA0 = MP_MX(A1, pred_flag_index_l1, mxA);
}
if (is_available_a0 && !availableFlagLXA0) {
availableFlagLXA0 = MP_MX_LT(A0, pred_flag_index_l0, mxA);
if (!availableFlagLXA0)
availableFlagLXA0 = MP_MX_LT(A0, pred_flag_index_l1, mxA);
}
if (is_available_a1 && !availableFlagLXA0) {
availableFlagLXA0 = MP_MX_LT(A1, pred_flag_index_l0, mxA);
if (!availableFlagLXA0)
availableFlagLXA0 = MP_MX_LT(A1, pred_flag_index_l1, mxA);
}
// B candidates
// above right spatial merge candidate
xB0 = x0 + nPbW;
yB0 = y0 - 1;
xB0_pu = xB0 >> s->sps->log2_min_pu_size;
yB0_pu = yB0 >> s->sps->log2_min_pu_size;
is_available_b0 = PRED_BLOCK_AVAILABLE(B0) && AVAILABLE(cand_up_right, B0);
if (is_available_b0) {
availableFlagLXB0 = MP_MX(B0, pred_flag_index_l0, mxB);
if (!availableFlagLXB0)
availableFlagLXB0 = MP_MX(B0, pred_flag_index_l1, mxB);
}
if (!availableFlagLXB0) {
// above spatial merge candidate
xB1 = x0 + nPbW - 1;
yB1 = y0 - 1;
xB1_pu = xB1 >> s->sps->log2_min_pu_size;
yB1_pu = yB1 >> s->sps->log2_min_pu_size;
is_available_b1 = AVAILABLE(cand_up, B1);
if (is_available_b1) {
availableFlagLXB0 = MP_MX(B1, pred_flag_index_l0, mxB);
if (!availableFlagLXB0)
availableFlagLXB0 = MP_MX(B1, pred_flag_index_l1, mxB);
}
}
if (!availableFlagLXB0) {
// above left spatial merge candidate
xB2 = x0 - 1;
yB2 = y0 - 1;
xB2_pu = xB2 >> s->sps->log2_min_pu_size;
yB2_pu = yB2 >> s->sps->log2_min_pu_size;
is_available_b2 = AVAILABLE(cand_up_left, B2);
if (is_available_b2) {
availableFlagLXB0 = MP_MX(B2, pred_flag_index_l0, mxB);
if (!availableFlagLXB0)
availableFlagLXB0 = MP_MX(B2, pred_flag_index_l1, mxB);
}
}
if (isScaledFlag_L0 == 0) {
if (availableFlagLXB0) {
availableFlagLXA0 = 1;
mxA = mxB;
}
availableFlagLXB0 = 0;
// XB0 and L1
if (is_available_b0) {
availableFlagLXB0 = MP_MX_LT(B0, pred_flag_index_l0, mxB);
if (!availableFlagLXB0)
availableFlagLXB0 = MP_MX_LT(B0, pred_flag_index_l1, mxB);
}
if (is_available_b1 && !availableFlagLXB0) {
availableFlagLXB0 = MP_MX_LT(B1, pred_flag_index_l0, mxB);
if (!availableFlagLXB0)
availableFlagLXB0 = MP_MX_LT(B1, pred_flag_index_l1, mxB);
}
if (is_available_b2 && !availableFlagLXB0) {
availableFlagLXB0 = MP_MX_LT(B2, pred_flag_index_l0, mxB);
if (!availableFlagLXB0)
availableFlagLXB0 = MP_MX_LT(B2, pred_flag_index_l1, mxB);
}
}
if (availableFlagLXA0)
mvpcand_list[numMVPCandLX++] = mxA;
if (availableFlagLXB0 && (!availableFlagLXA0 || mxA.x != mxB.x || mxA.y != mxB.y))
mvpcand_list[numMVPCandLX++] = mxB;
//temporal motion vector prediction candidate
if (numMVPCandLX < 2 && s->sh.slice_temporal_mvp_enabled_flag) {
Mv mv_col;
int available_col = temporal_luma_motion_vector(s, x0, y0, nPbW,
nPbH, ref_idx,
&mv_col, LX);
if (available_col)
mvpcand_list[numMVPCandLX++] = mv_col;
}
// insert zero motion vectors when the number of available candidates are less than 2
while (numMVPCandLX < 2)
mvpcand_list[numMVPCandLX++] = (Mv){ 0, 0 };
mv->mv[LX].x = mvpcand_list[mvp_lx_flag].x;
mv->mv[LX].y = mvpcand_list[mvp_lx_flag].y;
}