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 #define MVREF_NEIGHBOURS 8 15 16 typedef enum { 17 BOTH_ZERO = 0, 18 ZERO_PLUS_PREDICTED = 1, 19 BOTH_PREDICTED = 2, 20 NEW_PLUS_NON_INTRA = 3, 21 BOTH_NEW = 4, 22 INTRA_PLUS_NON_INTRA = 5, 23 BOTH_INTRA = 6, 24 INVALID_CASE = 9 25 } motion_vector_context; 26 27 // This is used to figure out a context for the ref blocks. The code flattens 28 // an array that would have 3 possible counts (0, 1 & 2) for 3 choices by 29 // adding 9 for each intra block, 3 for each zero mv and 1 for each new 30 // motion vector. This single number is then converted into a context 31 // with a single lookup ( counter_to_context ). 32 static const int mode_2_counter[MB_MODE_COUNT] = { 33 9, // DC_PRED 34 9, // V_PRED 35 9, // H_PRED 36 9, // D45_PRED 37 9, // D135_PRED 38 9, // D117_PRED 39 9, // D153_PRED 40 9, // D207_PRED 41 9, // D63_PRED 42 9, // TM_PRED 43 0, // NEARESTMV 44 0, // NEARMV 45 3, // ZEROMV 46 1, // NEWMV 47 }; 48 49 // There are 3^3 different combinations of 3 counts that can be either 0,1 or 50 // 2. However the actual count can never be greater than 2 so the highest 51 // counter we need is 18. 9 is an invalid counter that's never used. 52 static const int counter_to_context[19] = { 53 BOTH_PREDICTED, // 0 54 NEW_PLUS_NON_INTRA, // 1 55 BOTH_NEW, // 2 56 ZERO_PLUS_PREDICTED, // 3 57 NEW_PLUS_NON_INTRA, // 4 58 INVALID_CASE, // 5 59 BOTH_ZERO, // 6 60 INVALID_CASE, // 7 61 INVALID_CASE, // 8 62 INTRA_PLUS_NON_INTRA, // 9 63 INTRA_PLUS_NON_INTRA, // 10 64 INVALID_CASE, // 11 65 INTRA_PLUS_NON_INTRA, // 12 66 INVALID_CASE, // 13 67 INVALID_CASE, // 14 68 INVALID_CASE, // 15 69 INVALID_CASE, // 16 70 INVALID_CASE, // 17 71 BOTH_INTRA // 18 72 }; 73 74 static const MV mv_ref_blocks[BLOCK_SIZES][MVREF_NEIGHBOURS] = { 75 // 4X4 76 {{-1, 0}, {0, -1}, {-1, -1}, {-2, 0}, {0, -2}, {-2, -1}, {-1, -2}, {-2, -2}}, 77 // 4X8 78 {{-1, 0}, {0, -1}, {-1, -1}, {-2, 0}, {0, -2}, {-2, -1}, {-1, -2}, {-2, -2}}, 79 // 8X4 80 {{-1, 0}, {0, -1}, {-1, -1}, {-2, 0}, {0, -2}, {-2, -1}, {-1, -2}, {-2, -2}}, 81 // 8X8 82 {{-1, 0}, {0, -1}, {-1, -1}, {-2, 0}, {0, -2}, {-2, -1}, {-1, -2}, {-2, -2}}, 83 // 8X16 84 {{0, -1}, {-1, 0}, {1, -1}, {-1, -1}, {0, -2}, {-2, 0}, {-2, -1}, {-1, -2}}, 85 // 16X8 86 {{-1, 0}, {0, -1}, {-1, 1}, {-1, -1}, {-2, 0}, {0, -2}, {-1, -2}, {-2, -1}}, 87 // 16X16 88 {{-1, 0}, {0, -1}, {-1, 1}, {1, -1}, {-1, -1}, {-3, 0}, {0, -3}, {-3, -3}}, 89 // 16X32 90 {{0, -1}, {-1, 0}, {2, -1}, {-1, -1}, {-1, 1}, {0, -3}, {-3, 0}, {-3, -3}}, 91 // 32X16 92 {{-1, 0}, {0, -1}, {-1, 2}, {-1, -1}, {1, -1}, {-3, 0}, {0, -3}, {-3, -3}}, 93 // 32X32 94 {{-1, 1}, {1, -1}, {-1, 2}, {2, -1}, {-1, -1}, {-3, 0}, {0, -3}, {-3, -3}}, 95 // 32X64 96 {{0, -1}, {-1, 0}, {4, -1}, {-1, 2}, {-1, -1}, {0, -3}, {-3, 0}, {2, -1}}, 97 // 64X32 98 {{-1, 0}, {0, -1}, {-1, 4}, {2, -1}, {-1, -1}, {-3, 0}, {0, -3}, {-1, 2}}, 99 // 64X64 100 {{-1, 3}, {3, -1}, {-1, 4}, {4, -1}, {-1, -1}, {-1, 0}, {0, -1}, {-1, 6}} 101 }; 102 103 static const int idx_n_column_to_subblock[4][2] = { 104 {1, 2}, 105 {1, 3}, 106 {3, 2}, 107 {3, 3} 108 }; 109 110 // clamp_mv_ref 111 #define MV_BORDER (16 << 3) // Allow 16 pels in 1/8th pel units 112 113 static void clamp_mv_ref(MV *mv, const MACROBLOCKD *xd) { 114 clamp_mv(mv, xd->mb_to_left_edge - MV_BORDER, 115 xd->mb_to_right_edge + MV_BORDER, 116 xd->mb_to_top_edge - MV_BORDER, 117 xd->mb_to_bottom_edge + MV_BORDER); 118 } 119 120 // This function returns either the appropriate sub block or block's mv 121 // on whether the block_size < 8x8 and we have check_sub_blocks set. 122 static INLINE int_mv get_sub_block_mv(const MODE_INFO *candidate, 123 int check_sub_blocks, int which_mv, 124 int search_col, int block_idx) { 125 return check_sub_blocks && candidate->mbmi.sb_type < BLOCK_8X8 126 ? candidate->bmi[idx_n_column_to_subblock[block_idx][search_col == 0]] 127 .as_mv[which_mv] 128 : candidate->mbmi.mv[which_mv]; 129 } 130 131 132 // Performs mv sign inversion if indicated by the reference frame combination. 133 static INLINE int_mv scale_mv(const MB_MODE_INFO *mbmi, int ref, 134 const MV_REFERENCE_FRAME this_ref_frame, 135 const int *ref_sign_bias) { 136 int_mv mv = mbmi->mv[ref]; 137 if (ref_sign_bias[mbmi->ref_frame[ref]] != ref_sign_bias[this_ref_frame]) { 138 mv.as_mv.row *= -1; 139 mv.as_mv.col *= -1; 140 } 141 return mv; 142 } 143 144 // This macro is used to add a motion vector mv_ref list if it isn't 145 // already in the list. If it's the second motion vector it will also 146 // skip all additional processing and jump to done! 147 #define ADD_MV_REF_LIST(MV) \ 148 do { \ 149 if (refmv_count) { \ 150 if ((MV).as_int != mv_ref_list[0].as_int) { \ 151 mv_ref_list[refmv_count] = (MV); \ 152 goto Done; \ 153 } \ 154 } else { \ 155 mv_ref_list[refmv_count++] = (MV); \ 156 } \ 157 } while (0) 158 159 // If either reference frame is different, not INTRA, and they 160 // are different from each other scale and add the mv to our list. 161 #define IF_DIFF_REF_FRAME_ADD_MV(CANDIDATE) \ 162 do { \ 163 if ((CANDIDATE)->ref_frame[0] != ref_frame) \ 164 ADD_MV_REF_LIST(scale_mv((CANDIDATE), 0, ref_frame, ref_sign_bias)); \ 165 if ((CANDIDATE)->ref_frame[1] != ref_frame && \ 166 has_second_ref(CANDIDATE) && \ 167 (CANDIDATE)->mv[1].as_int != (CANDIDATE)->mv[0].as_int) \ 168 ADD_MV_REF_LIST(scale_mv((CANDIDATE), 1, ref_frame, ref_sign_bias)); \ 169 } while (0) 170 171 172 // Checks that the given mi_row, mi_col and search point 173 // are inside the borders of the tile. 174 static INLINE int is_inside(const VP9_COMMON *cm, int mi_col, int mi_row, 175 const MV *mv) { 176 return !(mi_row + mv->row < 0 || 177 mi_col + mv->col < cm->cur_tile_mi_col_start || 178 mi_row + mv->row >= cm->mi_rows || 179 mi_col + mv->col >= cm->cur_tile_mi_col_end); 180 } 181 182 // This function searches the neighbourhood of a given MB/SB 183 // to try and find candidate reference vectors. 184 void vp9_find_mv_refs_idx(const VP9_COMMON *cm, const MACROBLOCKD *xd, 185 MODE_INFO *mi, const MODE_INFO *prev_mi, 186 MV_REFERENCE_FRAME ref_frame, 187 int_mv *mv_ref_list, 188 int block_idx, 189 int mi_row, int mi_col) { 190 const int *ref_sign_bias = cm->ref_frame_sign_bias; 191 int i, refmv_count = 0; 192 const MV *const mv_ref_search = mv_ref_blocks[mi->mbmi.sb_type]; 193 const MB_MODE_INFO *const prev_mbmi = prev_mi ? &prev_mi->mbmi : NULL; 194 int different_ref_found = 0; 195 int context_counter = 0; 196 197 // Blank the reference vector list 198 vpx_memset(mv_ref_list, 0, sizeof(*mv_ref_list) * MAX_MV_REF_CANDIDATES); 199 200 // The nearest 2 blocks are treated differently 201 // if the size < 8x8 we get the mv from the bmi substructure, 202 // and we also need to keep a mode count. 203 for (i = 0; i < 2; ++i) { 204 const MV *const mv_ref = &mv_ref_search[i]; 205 if (is_inside(cm, mi_col, mi_row, mv_ref)) { 206 const int check_sub_blocks = block_idx >= 0; 207 const MODE_INFO *const candidate_mi = xd->mi_8x8[mv_ref->col + mv_ref->row 208 * xd->mode_info_stride]; 209 const MB_MODE_INFO *const candidate = &candidate_mi->mbmi; 210 // Keep counts for entropy encoding. 211 context_counter += mode_2_counter[candidate->mode]; 212 213 // Check if the candidate comes from the same reference frame. 214 if (candidate->ref_frame[0] == ref_frame) { 215 ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, check_sub_blocks, 0, 216 mv_ref->col, block_idx)); 217 different_ref_found = candidate->ref_frame[1] != ref_frame; 218 } else { 219 if (candidate->ref_frame[1] == ref_frame) 220 // Add second motion vector if it has the same ref_frame. 221 ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, check_sub_blocks, 1, 222 mv_ref->col, block_idx)); 223 different_ref_found = 1; 224 } 225 } 226 } 227 228 // Check the rest of the neighbors in much the same way 229 // as before except we don't need to keep track of sub blocks or 230 // mode counts. 231 for (; i < MVREF_NEIGHBOURS; ++i) { 232 const MV *const mv_ref = &mv_ref_search[i]; 233 if (is_inside(cm, mi_col, mi_row, mv_ref)) { 234 const MB_MODE_INFO *const candidate = &xd->mi_8x8[mv_ref->col + 235 mv_ref->row 236 * xd->mode_info_stride]->mbmi; 237 238 if (candidate->ref_frame[0] == ref_frame) { 239 ADD_MV_REF_LIST(candidate->mv[0]); 240 different_ref_found = candidate->ref_frame[1] != ref_frame; 241 } else { 242 if (candidate->ref_frame[1] == ref_frame) 243 ADD_MV_REF_LIST(candidate->mv[1]); 244 different_ref_found = 1; 245 } 246 } 247 } 248 249 // Check the last frame's mode and mv info. 250 if (prev_mbmi) { 251 if (prev_mbmi->ref_frame[0] == ref_frame) 252 ADD_MV_REF_LIST(prev_mbmi->mv[0]); 253 else if (prev_mbmi->ref_frame[1] == ref_frame) 254 ADD_MV_REF_LIST(prev_mbmi->mv[1]); 255 } 256 257 // Since we couldn't find 2 mvs from the same reference frame 258 // go back through the neighbors and find motion vectors from 259 // different reference frames. 260 if (different_ref_found) { 261 for (i = 0; i < MVREF_NEIGHBOURS; ++i) { 262 const MV *mv_ref = &mv_ref_search[i]; 263 if (is_inside(cm, mi_col, mi_row, mv_ref)) { 264 const MB_MODE_INFO *const candidate = &xd->mi_8x8[mv_ref->col + 265 mv_ref->row 266 * xd->mode_info_stride]->mbmi; 267 268 // If the candidate is INTRA we don't want to consider its mv. 269 if (is_inter_block(candidate)) 270 IF_DIFF_REF_FRAME_ADD_MV(candidate); 271 } 272 } 273 } 274 275 // Since we still don't have a candidate we'll try the last frame. 276 if (prev_mbmi && is_inter_block(prev_mbmi)) 277 IF_DIFF_REF_FRAME_ADD_MV(prev_mbmi); 278 279 Done: 280 281 mi->mbmi.mode_context[ref_frame] = counter_to_context[context_counter]; 282 283 // Clamp vectors 284 for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i) 285 clamp_mv_ref(&mv_ref_list[i].as_mv, xd); 286 } 287
