1 /*
2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "findnearmv.h"
12
13 const unsigned char vp8_mbsplit_offset[4][16] = {
14 { 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
15 { 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
16 { 0, 2, 8, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
17 { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 }
18 };
19
20 /* Predict motion vectors using those from already-decoded nearby blocks.
21 Note that we only consider one 4x4 subblock from each candidate 16x16
22 macroblock. */
vp8_find_near_mvs(MACROBLOCKD * xd,const MODE_INFO * here,int_mv * nearest,int_mv * nearby,int_mv * best_mv,int cnt[4],int refframe,int * ref_frame_sign_bias)23 void vp8_find_near_mvs(MACROBLOCKD *xd, const MODE_INFO *here, int_mv *nearest,
24 int_mv *nearby, int_mv *best_mv, int cnt[4],
25 int refframe, int *ref_frame_sign_bias) {
26 const MODE_INFO *above = here - xd->mode_info_stride;
27 const MODE_INFO *left = here - 1;
28 const MODE_INFO *aboveleft = above - 1;
29 int_mv near_mvs[4];
30 int_mv *mv = near_mvs;
31 int *cntx = cnt;
32 enum { CNT_INTRA, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV };
33
34 /* Zero accumulators */
35 mv[0].as_int = mv[1].as_int = mv[2].as_int = 0;
36 cnt[0] = cnt[1] = cnt[2] = cnt[3] = 0;
37
38 /* Process above */
39 if (above->mbmi.ref_frame != INTRA_FRAME) {
40 if (above->mbmi.mv.as_int) {
41 (++mv)->as_int = above->mbmi.mv.as_int;
42 mv_bias(ref_frame_sign_bias[above->mbmi.ref_frame], refframe, mv,
43 ref_frame_sign_bias);
44 ++cntx;
45 }
46
47 *cntx += 2;
48 }
49
50 /* Process left */
51 if (left->mbmi.ref_frame != INTRA_FRAME) {
52 if (left->mbmi.mv.as_int) {
53 int_mv this_mv;
54
55 this_mv.as_int = left->mbmi.mv.as_int;
56 mv_bias(ref_frame_sign_bias[left->mbmi.ref_frame], refframe, &this_mv,
57 ref_frame_sign_bias);
58
59 if (this_mv.as_int != mv->as_int) {
60 (++mv)->as_int = this_mv.as_int;
61 ++cntx;
62 }
63
64 *cntx += 2;
65 } else {
66 cnt[CNT_INTRA] += 2;
67 }
68 }
69
70 /* Process above left */
71 if (aboveleft->mbmi.ref_frame != INTRA_FRAME) {
72 if (aboveleft->mbmi.mv.as_int) {
73 int_mv this_mv;
74
75 this_mv.as_int = aboveleft->mbmi.mv.as_int;
76 mv_bias(ref_frame_sign_bias[aboveleft->mbmi.ref_frame], refframe,
77 &this_mv, ref_frame_sign_bias);
78
79 if (this_mv.as_int != mv->as_int) {
80 (++mv)->as_int = this_mv.as_int;
81 ++cntx;
82 }
83
84 *cntx += 1;
85 } else {
86 cnt[CNT_INTRA] += 1;
87 }
88 }
89
90 /* If we have three distinct MV's ... */
91 if (cnt[CNT_SPLITMV]) {
92 /* See if above-left MV can be merged with NEAREST */
93 if (mv->as_int == near_mvs[CNT_NEAREST].as_int) cnt[CNT_NEAREST] += 1;
94 }
95
96 cnt[CNT_SPLITMV] =
97 ((above->mbmi.mode == SPLITMV) + (left->mbmi.mode == SPLITMV)) * 2 +
98 (aboveleft->mbmi.mode == SPLITMV);
99
100 /* Swap near and nearest if necessary */
101 if (cnt[CNT_NEAR] > cnt[CNT_NEAREST]) {
102 int tmp;
103 tmp = cnt[CNT_NEAREST];
104 cnt[CNT_NEAREST] = cnt[CNT_NEAR];
105 cnt[CNT_NEAR] = tmp;
106 tmp = near_mvs[CNT_NEAREST].as_int;
107 near_mvs[CNT_NEAREST].as_int = near_mvs[CNT_NEAR].as_int;
108 near_mvs[CNT_NEAR].as_int = tmp;
109 }
110
111 /* Use near_mvs[0] to store the "best" MV */
112 if (cnt[CNT_NEAREST] >= cnt[CNT_INTRA]) {
113 near_mvs[CNT_INTRA] = near_mvs[CNT_NEAREST];
114 }
115
116 /* Set up return values */
117 best_mv->as_int = near_mvs[0].as_int;
118 nearest->as_int = near_mvs[CNT_NEAREST].as_int;
119 nearby->as_int = near_mvs[CNT_NEAR].as_int;
120 }
121
invert_and_clamp_mvs(int_mv * inv,int_mv * src,MACROBLOCKD * xd)122 static void invert_and_clamp_mvs(int_mv *inv, int_mv *src, MACROBLOCKD *xd) {
123 inv->as_mv.row = src->as_mv.row * -1;
124 inv->as_mv.col = src->as_mv.col * -1;
125 vp8_clamp_mv2(inv, xd);
126 vp8_clamp_mv2(src, xd);
127 }
128
vp8_find_near_mvs_bias(MACROBLOCKD * xd,const MODE_INFO * here,int_mv mode_mv_sb[2][MB_MODE_COUNT],int_mv best_mv_sb[2],int cnt[4],int refframe,int * ref_frame_sign_bias)129 int vp8_find_near_mvs_bias(MACROBLOCKD *xd, const MODE_INFO *here,
130 int_mv mode_mv_sb[2][MB_MODE_COUNT],
131 int_mv best_mv_sb[2], int cnt[4], int refframe,
132 int *ref_frame_sign_bias) {
133 int sign_bias = ref_frame_sign_bias[refframe];
134
135 vp8_find_near_mvs(xd, here, &mode_mv_sb[sign_bias][NEARESTMV],
136 &mode_mv_sb[sign_bias][NEARMV], &best_mv_sb[sign_bias], cnt,
137 refframe, ref_frame_sign_bias);
138
139 invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARESTMV],
140 &mode_mv_sb[sign_bias][NEARESTMV], xd);
141 invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARMV],
142 &mode_mv_sb[sign_bias][NEARMV], xd);
143 invert_and_clamp_mvs(&best_mv_sb[!sign_bias], &best_mv_sb[sign_bias], xd);
144
145 return sign_bias;
146 }
147
vp8_mv_ref_probs(vp8_prob p[VP8_MVREFS-1],const int near_mv_ref_ct[4])148 vp8_prob *vp8_mv_ref_probs(vp8_prob p[VP8_MVREFS - 1],
149 const int near_mv_ref_ct[4]) {
150 p[0] = vp8_mode_contexts[near_mv_ref_ct[0]][0];
151 p[1] = vp8_mode_contexts[near_mv_ref_ct[1]][1];
152 p[2] = vp8_mode_contexts[near_mv_ref_ct[2]][2];
153 p[3] = vp8_mode_contexts[near_mv_ref_ct[3]][3];
154 /* p[3] = vp8_mode_contexts[near_mv_ref_ct[1] + near_mv_ref_ct[2] +
155 near_mv_ref_ct[3]][3]; */
156 return p;
157 }
158