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 14 #define FINDNEAR_SEARCH_SITES 3 15 16 /* Predict motion vectors using those from already-decoded nearby blocks. 17 Note that we only consider one 4x4 subblock from each candidate 16x16 18 macroblock. */ 19 20 typedef union 21 { 22 unsigned int as_int; 23 MV as_mv; 24 } int_mv; /* facilitates rapid equality tests */ 25 26 static void mv_bias(const MODE_INFO *x, int refframe, int_mv *mvp, const int *ref_frame_sign_bias) 27 { 28 MV xmv; 29 xmv = x->mbmi.mv.as_mv; 30 31 if (ref_frame_sign_bias[x->mbmi.ref_frame] != ref_frame_sign_bias[refframe]) 32 { 33 xmv.row *= -1; 34 xmv.col *= -1; 35 } 36 37 mvp->as_mv = xmv; 38 } 39 40 41 void vp8_clamp_mv(MV *mv, const MACROBLOCKD *xd) 42 { 43 if (mv->col < (xd->mb_to_left_edge - LEFT_TOP_MARGIN)) 44 mv->col = xd->mb_to_left_edge - LEFT_TOP_MARGIN; 45 else if (mv->col > xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN) 46 mv->col = xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN; 47 48 if (mv->row < (xd->mb_to_top_edge - LEFT_TOP_MARGIN)) 49 mv->row = xd->mb_to_top_edge - LEFT_TOP_MARGIN; 50 else if (mv->row > xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN) 51 mv->row = xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN; 52 } 53 54 55 void vp8_find_near_mvs 56 ( 57 MACROBLOCKD *xd, 58 const MODE_INFO *here, 59 MV *nearest, 60 MV *nearby, 61 MV *best_mv, 62 int cnt[4], 63 int refframe, 64 int *ref_frame_sign_bias 65 ) 66 { 67 const MODE_INFO *above = here - xd->mode_info_stride; 68 const MODE_INFO *left = here - 1; 69 const MODE_INFO *aboveleft = above - 1; 70 int_mv near_mvs[4]; 71 int_mv *mv = near_mvs; 72 int *cntx = cnt; 73 enum {CNT_INTRA, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV}; 74 75 /* Zero accumulators */ 76 mv[0].as_int = mv[1].as_int = mv[2].as_int = 0; 77 cnt[0] = cnt[1] = cnt[2] = cnt[3] = 0; 78 79 /* Process above */ 80 if (above->mbmi.ref_frame != INTRA_FRAME) 81 { 82 if (above->mbmi.mv.as_int) 83 { 84 (++mv)->as_int = above->mbmi.mv.as_int; 85 mv_bias(above, refframe, mv, ref_frame_sign_bias); 86 ++cntx; 87 } 88 89 *cntx += 2; 90 } 91 92 /* Process left */ 93 if (left->mbmi.ref_frame != INTRA_FRAME) 94 { 95 if (left->mbmi.mv.as_int) 96 { 97 int_mv this_mv; 98 99 this_mv.as_int = left->mbmi.mv.as_int; 100 mv_bias(left, refframe, &this_mv, ref_frame_sign_bias); 101 102 if (this_mv.as_int != mv->as_int) 103 { 104 (++mv)->as_int = this_mv.as_int; 105 ++cntx; 106 } 107 108 *cntx += 2; 109 } 110 else 111 cnt[CNT_INTRA] += 2; 112 } 113 114 /* Process above left */ 115 if (aboveleft->mbmi.ref_frame != INTRA_FRAME) 116 { 117 if (aboveleft->mbmi.mv.as_int) 118 { 119 int_mv this_mv; 120 121 this_mv.as_int = aboveleft->mbmi.mv.as_int; 122 mv_bias(aboveleft, refframe, &this_mv, ref_frame_sign_bias); 123 124 if (this_mv.as_int != mv->as_int) 125 { 126 (++mv)->as_int = this_mv.as_int; 127 ++cntx; 128 } 129 130 *cntx += 1; 131 } 132 else 133 cnt[CNT_INTRA] += 1; 134 } 135 136 /* If we have three distinct MV's ... */ 137 if (cnt[CNT_SPLITMV]) 138 { 139 /* See if above-left MV can be merged with NEAREST */ 140 if (mv->as_int == near_mvs[CNT_NEAREST].as_int) 141 cnt[CNT_NEAREST] += 1; 142 } 143 144 cnt[CNT_SPLITMV] = ((above->mbmi.mode == SPLITMV) 145 + (left->mbmi.mode == SPLITMV)) * 2 146 + (aboveleft->mbmi.mode == SPLITMV); 147 148 /* Swap near and nearest if necessary */ 149 if (cnt[CNT_NEAR] > cnt[CNT_NEAREST]) 150 { 151 int tmp; 152 tmp = cnt[CNT_NEAREST]; 153 cnt[CNT_NEAREST] = cnt[CNT_NEAR]; 154 cnt[CNT_NEAR] = tmp; 155 tmp = near_mvs[CNT_NEAREST].as_int; 156 near_mvs[CNT_NEAREST].as_int = near_mvs[CNT_NEAR].as_int; 157 near_mvs[CNT_NEAR].as_int = tmp; 158 } 159 160 /* Use near_mvs[0] to store the "best" MV */ 161 if (cnt[CNT_NEAREST] >= cnt[CNT_INTRA]) 162 near_mvs[CNT_INTRA] = near_mvs[CNT_NEAREST]; 163 164 /* Set up return values */ 165 *best_mv = near_mvs[0].as_mv; 166 *nearest = near_mvs[CNT_NEAREST].as_mv; 167 *nearby = near_mvs[CNT_NEAR].as_mv; 168 169 vp8_clamp_mv(nearest, xd); 170 vp8_clamp_mv(nearby, xd); 171 vp8_clamp_mv(best_mv, xd); /*TODO: move this up before the copy*/ 172 } 173 174 vp8_prob *vp8_mv_ref_probs( 175 vp8_prob p[VP8_MVREFS-1], const int near_mv_ref_ct[4] 176 ) 177 { 178 p[0] = vp8_mode_contexts [near_mv_ref_ct[0]] [0]; 179 p[1] = vp8_mode_contexts [near_mv_ref_ct[1]] [1]; 180 p[2] = vp8_mode_contexts [near_mv_ref_ct[2]] [2]; 181 p[3] = vp8_mode_contexts [near_mv_ref_ct[3]] [3]; 182 /*p[3] = vp8_mode_contexts [near_mv_ref_ct[1] + near_mv_ref_ct[2] + near_mv_ref_ct[3]] [3];*/ 183 return p; 184 } 185 186 const B_MODE_INFO *vp8_left_bmi(const MODE_INFO *cur_mb, int b) 187 { 188 if (!(b & 3)) 189 { 190 /* On L edge, get from MB to left of us */ 191 --cur_mb; 192 b += 4; 193 } 194 195 return cur_mb->bmi + b - 1; 196 } 197 198 const B_MODE_INFO *vp8_above_bmi(const MODE_INFO *cur_mb, int b, int mi_stride) 199 { 200 if (!(b >> 2)) 201 { 202 /* On top edge, get from MB above us */ 203 cur_mb -= mi_stride; 204 b += 16; 205 } 206 207 return cur_mb->bmi + b - 4; 208 } 209
