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
12#include "findnearmv.h"
13
14const unsigned char vp8_mbsplit_offset[4][16] = {
15    { 0,  8,  0,  0,  0,  0,  0,  0,  0,  0,   0,  0,  0,  0,  0,  0},
16    { 0,  2,  0,  0,  0,  0,  0,  0,  0,  0,   0,  0,  0,  0,  0,  0},
17    { 0,  2,  8, 10,  0,  0,  0,  0,  0,  0,   0,  0,  0,  0,  0,  0},
18    { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15}
19};
20
21/* Predict motion vectors using those from already-decoded nearby blocks.
22   Note that we only consider one 4x4 subblock from each candidate 16x16
23   macroblock.   */
24void vp8_find_near_mvs
25(
26    MACROBLOCKD *xd,
27    const MODE_INFO *here,
28    int_mv *nearest,
29    int_mv *nearby,
30    int_mv *best_mv,
31    int cnt[4],
32    int refframe,
33    int *ref_frame_sign_bias
34)
35{
36    const MODE_INFO *above = here - xd->mode_info_stride;
37    const MODE_INFO *left = here - 1;
38    const MODE_INFO *aboveleft = above - 1;
39    int_mv            near_mvs[4];
40    int_mv           *mv = near_mvs;
41    int             *cntx = cnt;
42    enum {CNT_INTRA, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV};
43
44    /* Zero accumulators */
45    mv[0].as_int = mv[1].as_int = mv[2].as_int = 0;
46    cnt[0] = cnt[1] = cnt[2] = cnt[3] = 0;
47
48    /* Process above */
49    if (above->mbmi.ref_frame != INTRA_FRAME)
50    {
51        if (above->mbmi.mv.as_int)
52        {
53            (++mv)->as_int = above->mbmi.mv.as_int;
54            mv_bias(ref_frame_sign_bias[above->mbmi.ref_frame], refframe, mv, ref_frame_sign_bias);
55            ++cntx;
56        }
57
58        *cntx += 2;
59    }
60
61    /* Process left */
62    if (left->mbmi.ref_frame != INTRA_FRAME)
63    {
64        if (left->mbmi.mv.as_int)
65        {
66            int_mv this_mv;
67
68            this_mv.as_int = left->mbmi.mv.as_int;
69            mv_bias(ref_frame_sign_bias[left->mbmi.ref_frame], refframe, &this_mv, ref_frame_sign_bias);
70
71            if (this_mv.as_int != mv->as_int)
72            {
73                (++mv)->as_int = this_mv.as_int;
74                ++cntx;
75            }
76
77            *cntx += 2;
78        }
79        else
80            cnt[CNT_INTRA] += 2;
81    }
82
83    /* Process above left */
84    if (aboveleft->mbmi.ref_frame != INTRA_FRAME)
85    {
86        if (aboveleft->mbmi.mv.as_int)
87        {
88            int_mv this_mv;
89
90            this_mv.as_int = aboveleft->mbmi.mv.as_int;
91            mv_bias(ref_frame_sign_bias[aboveleft->mbmi.ref_frame], refframe, &this_mv, ref_frame_sign_bias);
92
93            if (this_mv.as_int != mv->as_int)
94            {
95                (++mv)->as_int = this_mv.as_int;
96                ++cntx;
97            }
98
99            *cntx += 1;
100        }
101        else
102            cnt[CNT_INTRA] += 1;
103    }
104
105    /* If we have three distinct MV's ... */
106    if (cnt[CNT_SPLITMV])
107    {
108        /* See if above-left MV can be merged with NEAREST */
109        if (mv->as_int == near_mvs[CNT_NEAREST].as_int)
110            cnt[CNT_NEAREST] += 1;
111    }
112
113    cnt[CNT_SPLITMV] = ((above->mbmi.mode == SPLITMV)
114                        + (left->mbmi.mode == SPLITMV)) * 2
115                       + (aboveleft->mbmi.mode == SPLITMV);
116
117    /* Swap near and nearest if necessary */
118    if (cnt[CNT_NEAR] > cnt[CNT_NEAREST])
119    {
120        int tmp;
121        tmp = cnt[CNT_NEAREST];
122        cnt[CNT_NEAREST] = cnt[CNT_NEAR];
123        cnt[CNT_NEAR] = tmp;
124        tmp = near_mvs[CNT_NEAREST].as_int;
125        near_mvs[CNT_NEAREST].as_int = near_mvs[CNT_NEAR].as_int;
126        near_mvs[CNT_NEAR].as_int = tmp;
127    }
128
129    /* Use near_mvs[0] to store the "best" MV */
130    if (cnt[CNT_NEAREST] >= cnt[CNT_INTRA])
131        near_mvs[CNT_INTRA] = near_mvs[CNT_NEAREST];
132
133    /* Set up return values */
134    best_mv->as_int = near_mvs[0].as_int;
135    nearest->as_int = near_mvs[CNT_NEAREST].as_int;
136    nearby->as_int = near_mvs[CNT_NEAR].as_int;
137}
138
139
140static void invert_and_clamp_mvs(int_mv *inv, int_mv *src, MACROBLOCKD *xd)
141{
142    inv->as_mv.row = src->as_mv.row * -1;
143    inv->as_mv.col = src->as_mv.col * -1;
144    vp8_clamp_mv2(inv, xd);
145    vp8_clamp_mv2(src, xd);
146}
147
148
149int vp8_find_near_mvs_bias
150(
151    MACROBLOCKD *xd,
152    const MODE_INFO *here,
153    int_mv mode_mv_sb[2][MB_MODE_COUNT],
154    int_mv best_mv_sb[2],
155    int cnt[4],
156    int refframe,
157    int *ref_frame_sign_bias
158)
159{
160    int sign_bias = ref_frame_sign_bias[refframe];
161
162    vp8_find_near_mvs(xd,
163                      here,
164                      &mode_mv_sb[sign_bias][NEARESTMV],
165                      &mode_mv_sb[sign_bias][NEARMV],
166                      &best_mv_sb[sign_bias],
167                      cnt,
168                      refframe,
169                      ref_frame_sign_bias);
170
171    invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARESTMV],
172                         &mode_mv_sb[sign_bias][NEARESTMV], xd);
173    invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARMV],
174                         &mode_mv_sb[sign_bias][NEARMV], xd);
175    invert_and_clamp_mvs(&best_mv_sb[!sign_bias],
176                         &best_mv_sb[sign_bias], xd);
177
178    return sign_bias;
179}
180
181
182vp8_prob *vp8_mv_ref_probs(
183    vp8_prob p[VP8_MVREFS-1], const int near_mv_ref_ct[4]
184)
185{
186    p[0] = vp8_mode_contexts [near_mv_ref_ct[0]] [0];
187    p[1] = vp8_mode_contexts [near_mv_ref_ct[1]] [1];
188    p[2] = vp8_mode_contexts [near_mv_ref_ct[2]] [2];
189    p[3] = vp8_mode_contexts [near_mv_ref_ct[3]] [3];
190    /*p[3] = vp8_mode_contexts [near_mv_ref_ct[1] + near_mv_ref_ct[2] + near_mv_ref_ct[3]] [3];*/
191    return p;
192}
193
194