1
2 /*
3 * Copyright (c) 2012 The WebM project authors. All Rights Reserved.
4 *
5 * Use of this source code is governed by a BSD-style license
6 * that can be found in the LICENSE file in the root of the source
7 * tree. An additional intellectual property rights grant can be found
8 * in the file PATENTS. All contributing project authors may
9 * be found in the AUTHORS file in the root of the source tree.
10 */
11
12 #include "vp9/common/vp9_mvref_common.h"
13
14 // This function searches the neighbourhood of a given MB/SB
15 // to try and find candidate reference vectors.
find_mv_refs_idx(const VP9_COMMON * cm,const MACROBLOCKD * xd,const TileInfo * const tile,MODE_INFO * mi,MV_REFERENCE_FRAME ref_frame,int_mv * mv_ref_list,int block,int mi_row,int mi_col)16 static void find_mv_refs_idx(const VP9_COMMON *cm, const MACROBLOCKD *xd,
17 const TileInfo *const tile,
18 MODE_INFO *mi, MV_REFERENCE_FRAME ref_frame,
19 int_mv *mv_ref_list,
20 int block, int mi_row, int mi_col) {
21 const int *ref_sign_bias = cm->ref_frame_sign_bias;
22 int i, refmv_count = 0;
23 const MODE_INFO *prev_mi = !cm->error_resilient_mode && cm->prev_mi
24 ? cm->prev_mi_grid_visible[mi_row * xd->mi_stride + mi_col]
25 : NULL;
26 const MB_MODE_INFO *const prev_mbmi = prev_mi ? &prev_mi->mbmi : NULL;
27
28
29 const POSITION *const mv_ref_search = mv_ref_blocks[mi->mbmi.sb_type];
30
31 int different_ref_found = 0;
32 int context_counter = 0;
33
34 // Blank the reference vector list
35 vpx_memset(mv_ref_list, 0, sizeof(*mv_ref_list) * MAX_MV_REF_CANDIDATES);
36
37 // The nearest 2 blocks are treated differently
38 // if the size < 8x8 we get the mv from the bmi substructure,
39 // and we also need to keep a mode count.
40 for (i = 0; i < 2; ++i) {
41 const POSITION *const mv_ref = &mv_ref_search[i];
42 if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) {
43 const MODE_INFO *const candidate_mi = xd->mi[mv_ref->col + mv_ref->row *
44 xd->mi_stride];
45 const MB_MODE_INFO *const candidate = &candidate_mi->mbmi;
46 // Keep counts for entropy encoding.
47 context_counter += mode_2_counter[candidate->mode];
48 different_ref_found = 1;
49
50 if (candidate->ref_frame[0] == ref_frame)
51 ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, 0, mv_ref->col, block));
52 else if (candidate->ref_frame[1] == ref_frame)
53 ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, 1, mv_ref->col, block));
54 }
55 }
56
57 // Check the rest of the neighbors in much the same way
58 // as before except we don't need to keep track of sub blocks or
59 // mode counts.
60 for (; i < MVREF_NEIGHBOURS; ++i) {
61 const POSITION *const mv_ref = &mv_ref_search[i];
62 if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) {
63 const MB_MODE_INFO *const candidate = &xd->mi[mv_ref->col + mv_ref->row *
64 xd->mi_stride]->mbmi;
65 different_ref_found = 1;
66
67 if (candidate->ref_frame[0] == ref_frame)
68 ADD_MV_REF_LIST(candidate->mv[0]);
69 else if (candidate->ref_frame[1] == ref_frame)
70 ADD_MV_REF_LIST(candidate->mv[1]);
71 }
72 }
73
74 // Check the last frame's mode and mv info.
75 if (prev_mbmi) {
76 if (prev_mbmi->ref_frame[0] == ref_frame)
77 ADD_MV_REF_LIST(prev_mbmi->mv[0]);
78 else if (prev_mbmi->ref_frame[1] == ref_frame)
79 ADD_MV_REF_LIST(prev_mbmi->mv[1]);
80 }
81
82 // Since we couldn't find 2 mvs from the same reference frame
83 // go back through the neighbors and find motion vectors from
84 // different reference frames.
85 if (different_ref_found) {
86 for (i = 0; i < MVREF_NEIGHBOURS; ++i) {
87 const POSITION *mv_ref = &mv_ref_search[i];
88 if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) {
89 const MB_MODE_INFO *const candidate = &xd->mi[mv_ref->col + mv_ref->row
90 * xd->mi_stride]->mbmi;
91
92 // If the candidate is INTRA we don't want to consider its mv.
93 IF_DIFF_REF_FRAME_ADD_MV(candidate);
94 }
95 }
96 }
97
98 // Since we still don't have a candidate we'll try the last frame.
99 if (prev_mbmi)
100 IF_DIFF_REF_FRAME_ADD_MV(prev_mbmi);
101
102 Done:
103
104 mi->mbmi.mode_context[ref_frame] = counter_to_context[context_counter];
105
106 // Clamp vectors
107 for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i)
108 clamp_mv_ref(&mv_ref_list[i].as_mv, xd);
109 }
110
vp9_find_mv_refs(const VP9_COMMON * cm,const MACROBLOCKD * xd,const TileInfo * const tile,MODE_INFO * mi,MV_REFERENCE_FRAME ref_frame,int_mv * mv_ref_list,int mi_row,int mi_col)111 void vp9_find_mv_refs(const VP9_COMMON *cm, const MACROBLOCKD *xd,
112 const TileInfo *const tile,
113 MODE_INFO *mi, MV_REFERENCE_FRAME ref_frame,
114 int_mv *mv_ref_list,
115 int mi_row, int mi_col) {
116 find_mv_refs_idx(cm, xd, tile, mi, ref_frame, mv_ref_list, -1,
117 mi_row, mi_col);
118 }
119
lower_mv_precision(MV * mv,int allow_hp)120 static void lower_mv_precision(MV *mv, int allow_hp) {
121 const int use_hp = allow_hp && vp9_use_mv_hp(mv);
122 if (!use_hp) {
123 if (mv->row & 1)
124 mv->row += (mv->row > 0 ? -1 : 1);
125 if (mv->col & 1)
126 mv->col += (mv->col > 0 ? -1 : 1);
127 }
128 }
129
130
vp9_find_best_ref_mvs(MACROBLOCKD * xd,int allow_hp,int_mv * mvlist,int_mv * nearest,int_mv * near)131 void vp9_find_best_ref_mvs(MACROBLOCKD *xd, int allow_hp,
132 int_mv *mvlist, int_mv *nearest, int_mv *near) {
133 int i;
134 // Make sure all the candidates are properly clamped etc
135 for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i) {
136 lower_mv_precision(&mvlist[i].as_mv, allow_hp);
137 clamp_mv2(&mvlist[i].as_mv, xd);
138 }
139 *nearest = mvlist[0];
140 *near = mvlist[1];
141 }
142
vp9_append_sub8x8_mvs_for_idx(VP9_COMMON * cm,MACROBLOCKD * xd,const TileInfo * const tile,int block,int ref,int mi_row,int mi_col,int_mv * nearest,int_mv * near)143 void vp9_append_sub8x8_mvs_for_idx(VP9_COMMON *cm, MACROBLOCKD *xd,
144 const TileInfo *const tile,
145 int block, int ref, int mi_row, int mi_col,
146 int_mv *nearest, int_mv *near) {
147 int_mv mv_list[MAX_MV_REF_CANDIDATES];
148 MODE_INFO *const mi = xd->mi[0];
149 b_mode_info *bmi = mi->bmi;
150 int n;
151
152 assert(MAX_MV_REF_CANDIDATES == 2);
153
154 find_mv_refs_idx(cm, xd, tile, mi, mi->mbmi.ref_frame[ref], mv_list, block,
155 mi_row, mi_col);
156
157 near->as_int = 0;
158 switch (block) {
159 case 0:
160 nearest->as_int = mv_list[0].as_int;
161 near->as_int = mv_list[1].as_int;
162 break;
163 case 1:
164 case 2:
165 nearest->as_int = bmi[0].as_mv[ref].as_int;
166 for (n = 0; n < MAX_MV_REF_CANDIDATES; ++n)
167 if (nearest->as_int != mv_list[n].as_int) {
168 near->as_int = mv_list[n].as_int;
169 break;
170 }
171 break;
172 case 3: {
173 int_mv candidates[2 + MAX_MV_REF_CANDIDATES];
174 candidates[0] = bmi[1].as_mv[ref];
175 candidates[1] = bmi[0].as_mv[ref];
176 candidates[2] = mv_list[0];
177 candidates[3] = mv_list[1];
178
179 nearest->as_int = bmi[2].as_mv[ref].as_int;
180 for (n = 0; n < 2 + MAX_MV_REF_CANDIDATES; ++n)
181 if (nearest->as_int != candidates[n].as_int) {
182 near->as_int = candidates[n].as_int;
183 break;
184 }
185 break;
186 }
187 default:
188 assert("Invalid block index.");
189 }
190 }
191