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 neighborhood of a given MB/SB 15 // to try and find candidate reference vectors. 16 static void find_mv_refs_idx(const VP9_COMMON *cm, const MACROBLOCKD *xd, 17 MODE_INFO *mi, MV_REFERENCE_FRAME ref_frame, 18 int_mv *mv_ref_list, int block, int mi_row, 19 int mi_col, uint8_t *mode_context) { 20 const int *ref_sign_bias = cm->ref_frame_sign_bias; 21 int i, refmv_count = 0; 22 const POSITION *const mv_ref_search = mv_ref_blocks[mi->sb_type]; 23 int different_ref_found = 0; 24 int context_counter = 0; 25 const MV_REF *const prev_frame_mvs = 26 cm->use_prev_frame_mvs 27 ? cm->prev_frame->mvs + mi_row * cm->mi_cols + mi_col 28 : NULL; 29 const TileInfo *const tile = &xd->tile; 30 31 // Blank the reference vector list 32 memset(mv_ref_list, 0, sizeof(*mv_ref_list) * MAX_MV_REF_CANDIDATES); 33 34 // The nearest 2 blocks are treated differently 35 // if the size < 8x8 we get the mv from the bmi substructure, 36 // and we also need to keep a mode count. 37 for (i = 0; i < 2; ++i) { 38 const POSITION *const mv_ref = &mv_ref_search[i]; 39 if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) { 40 const MODE_INFO *const candidate_mi = 41 xd->mi[mv_ref->col + mv_ref->row * xd->mi_stride]; 42 // Keep counts for entropy encoding. 43 context_counter += mode_2_counter[candidate_mi->mode]; 44 different_ref_found = 1; 45 46 if (candidate_mi->ref_frame[0] == ref_frame) 47 ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, 0, mv_ref->col, block), 48 refmv_count, mv_ref_list, Done); 49 else if (candidate_mi->ref_frame[1] == ref_frame) 50 ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, 1, mv_ref->col, block), 51 refmv_count, mv_ref_list, Done); 52 } 53 } 54 55 // Check the rest of the neighbors in much the same way 56 // as before except we don't need to keep track of sub blocks or 57 // mode counts. 58 for (; i < MVREF_NEIGHBOURS; ++i) { 59 const POSITION *const mv_ref = &mv_ref_search[i]; 60 if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) { 61 const MODE_INFO *const candidate_mi = 62 xd->mi[mv_ref->col + mv_ref->row * xd->mi_stride]; 63 different_ref_found = 1; 64 65 if (candidate_mi->ref_frame[0] == ref_frame) 66 ADD_MV_REF_LIST(candidate_mi->mv[0], refmv_count, mv_ref_list, Done); 67 else if (candidate_mi->ref_frame[1] == ref_frame) 68 ADD_MV_REF_LIST(candidate_mi->mv[1], refmv_count, mv_ref_list, Done); 69 } 70 } 71 72 // Check the last frame's mode and mv info. 73 if (cm->use_prev_frame_mvs) { 74 if (prev_frame_mvs->ref_frame[0] == ref_frame) { 75 ADD_MV_REF_LIST(prev_frame_mvs->mv[0], refmv_count, mv_ref_list, Done); 76 } else if (prev_frame_mvs->ref_frame[1] == ref_frame) { 77 ADD_MV_REF_LIST(prev_frame_mvs->mv[1], refmv_count, mv_ref_list, Done); 78 } 79 } 80 81 // Since we couldn't find 2 mvs from the same reference frame 82 // go back through the neighbors and find motion vectors from 83 // different reference frames. 84 if (different_ref_found) { 85 for (i = 0; i < MVREF_NEIGHBOURS; ++i) { 86 const POSITION *mv_ref = &mv_ref_search[i]; 87 if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) { 88 const MODE_INFO *const candidate_mi = 89 xd->mi[mv_ref->col + mv_ref->row * xd->mi_stride]; 90 91 // If the candidate is INTRA we don't want to consider its mv. 92 IF_DIFF_REF_FRAME_ADD_MV(candidate_mi, ref_frame, ref_sign_bias, 93 refmv_count, mv_ref_list, Done); 94 } 95 } 96 } 97 98 // Since we still don't have a candidate we'll try the last frame. 99 if (cm->use_prev_frame_mvs) { 100 if (prev_frame_mvs->ref_frame[0] != ref_frame && 101 prev_frame_mvs->ref_frame[0] > INTRA_FRAME) { 102 int_mv mv = prev_frame_mvs->mv[0]; 103 if (ref_sign_bias[prev_frame_mvs->ref_frame[0]] != 104 ref_sign_bias[ref_frame]) { 105 mv.as_mv.row *= -1; 106 mv.as_mv.col *= -1; 107 } 108 ADD_MV_REF_LIST(mv, refmv_count, mv_ref_list, Done); 109 } 110 111 if (prev_frame_mvs->ref_frame[1] > INTRA_FRAME && 112 prev_frame_mvs->ref_frame[1] != ref_frame && 113 prev_frame_mvs->mv[1].as_int != prev_frame_mvs->mv[0].as_int) { 114 int_mv mv = prev_frame_mvs->mv[1]; 115 if (ref_sign_bias[prev_frame_mvs->ref_frame[1]] != 116 ref_sign_bias[ref_frame]) { 117 mv.as_mv.row *= -1; 118 mv.as_mv.col *= -1; 119 } 120 ADD_MV_REF_LIST(mv, refmv_count, mv_ref_list, Done); 121 } 122 } 123 124 Done: 125 126 mode_context[ref_frame] = counter_to_context[context_counter]; 127 128 // Clamp vectors 129 for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i) 130 clamp_mv_ref(&mv_ref_list[i].as_mv, xd); 131 } 132 133 void vp9_find_mv_refs(const VP9_COMMON *cm, const MACROBLOCKD *xd, 134 MODE_INFO *mi, MV_REFERENCE_FRAME ref_frame, 135 int_mv *mv_ref_list, int mi_row, int mi_col, 136 uint8_t *mode_context) { 137 find_mv_refs_idx(cm, xd, mi, ref_frame, mv_ref_list, -1, mi_row, mi_col, 138 mode_context); 139 } 140 141 void vp9_find_best_ref_mvs(MACROBLOCKD *xd, int allow_hp, int_mv *mvlist, 142 int_mv *nearest_mv, int_mv *near_mv) { 143 int i; 144 // Make sure all the candidates are properly clamped etc 145 for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i) { 146 lower_mv_precision(&mvlist[i].as_mv, allow_hp); 147 clamp_mv2(&mvlist[i].as_mv, xd); 148 } 149 *nearest_mv = mvlist[0]; 150 *near_mv = mvlist[1]; 151 } 152 153 void vp9_append_sub8x8_mvs_for_idx(VP9_COMMON *cm, MACROBLOCKD *xd, int block, 154 int ref, int mi_row, int mi_col, 155 int_mv *nearest_mv, int_mv *near_mv, 156 uint8_t *mode_context) { 157 int_mv mv_list[MAX_MV_REF_CANDIDATES]; 158 MODE_INFO *const mi = xd->mi[0]; 159 b_mode_info *bmi = mi->bmi; 160 int n; 161 162 assert(MAX_MV_REF_CANDIDATES == 2); 163 164 find_mv_refs_idx(cm, xd, mi, mi->ref_frame[ref], mv_list, block, mi_row, 165 mi_col, mode_context); 166 167 near_mv->as_int = 0; 168 switch (block) { 169 case 0: 170 nearest_mv->as_int = mv_list[0].as_int; 171 near_mv->as_int = mv_list[1].as_int; 172 break; 173 case 1: 174 case 2: 175 nearest_mv->as_int = bmi[0].as_mv[ref].as_int; 176 for (n = 0; n < MAX_MV_REF_CANDIDATES; ++n) 177 if (nearest_mv->as_int != mv_list[n].as_int) { 178 near_mv->as_int = mv_list[n].as_int; 179 break; 180 } 181 break; 182 case 3: { 183 int_mv candidates[2 + MAX_MV_REF_CANDIDATES]; 184 candidates[0] = bmi[1].as_mv[ref]; 185 candidates[1] = bmi[0].as_mv[ref]; 186 candidates[2] = mv_list[0]; 187 candidates[3] = mv_list[1]; 188 189 nearest_mv->as_int = bmi[2].as_mv[ref].as_int; 190 for (n = 0; n < 2 + MAX_MV_REF_CANDIDATES; ++n) 191 if (nearest_mv->as_int != candidates[n].as_int) { 192 near_mv->as_int = candidates[n].as_int; 193 break; 194 } 195 break; 196 } 197 default: assert(0 && "Invalid block index."); 198 } 199 } 200
