ref: 16de4d7366f1f084eb969385016e1e950df9180f
dir: /vp9/common/vp9_mvref_common.c/
/* * Copyright (c) 2012 The WebM project authors. All Rights Reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #include "vp9/common/vp9_mvref_common.h" // This function searches the neighborhood of a given MB/SB // to try and find candidate reference vectors. static void find_mv_refs_idx(const VP9_COMMON *cm, const MACROBLOCKD *xd, MODE_INFO *mi, MV_REFERENCE_FRAME ref_frame, int_mv *mv_ref_list, int block, int mi_row, int mi_col, uint8_t *mode_context) { const int *ref_sign_bias = cm->ref_frame_sign_bias; int i, refmv_count = 0; const POSITION *const mv_ref_search = mv_ref_blocks[mi->sb_type]; int different_ref_found = 0; int context_counter = 0; const MV_REF *const prev_frame_mvs = cm->use_prev_frame_mvs ? cm->prev_frame->mvs + mi_row * cm->mi_cols + mi_col : NULL; const TileInfo *const tile = &xd->tile; // Blank the reference vector list memset(mv_ref_list, 0, sizeof(*mv_ref_list) * MAX_MV_REF_CANDIDATES); // The nearest 2 blocks are treated differently // if the size < 8x8 we get the mv from the bmi substructure, // and we also need to keep a mode count. for (i = 0; i < 2; ++i) { const POSITION *const mv_ref = &mv_ref_search[i]; if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) { const MODE_INFO *const candidate_mi = xd->mi[mv_ref->col + mv_ref->row * xd->mi_stride]; // Keep counts for entropy encoding. context_counter += mode_2_counter[candidate_mi->mode]; different_ref_found = 1; if (candidate_mi->ref_frame[0] == ref_frame) ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, 0, mv_ref->col, block), refmv_count, mv_ref_list, Done); else if (candidate_mi->ref_frame[1] == ref_frame) ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, 1, mv_ref->col, block), refmv_count, mv_ref_list, Done); } } // Check the rest of the neighbors in much the same way // as before except we don't need to keep track of sub blocks or // mode counts. for (; i < MVREF_NEIGHBOURS; ++i) { const POSITION *const mv_ref = &mv_ref_search[i]; if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) { const MODE_INFO *const candidate_mi = xd->mi[mv_ref->col + mv_ref->row * xd->mi_stride]; different_ref_found = 1; if (candidate_mi->ref_frame[0] == ref_frame) ADD_MV_REF_LIST(candidate_mi->mv[0], refmv_count, mv_ref_list, Done); else if (candidate_mi->ref_frame[1] == ref_frame) ADD_MV_REF_LIST(candidate_mi->mv[1], refmv_count, mv_ref_list, Done); } } // Check the last frame's mode and mv info. if (cm->use_prev_frame_mvs) { if (prev_frame_mvs->ref_frame[0] == ref_frame) { ADD_MV_REF_LIST(prev_frame_mvs->mv[0], refmv_count, mv_ref_list, Done); } else if (prev_frame_mvs->ref_frame[1] == ref_frame) { ADD_MV_REF_LIST(prev_frame_mvs->mv[1], refmv_count, mv_ref_list, Done); } } // Since we couldn't find 2 mvs from the same reference frame // go back through the neighbors and find motion vectors from // different reference frames. if (different_ref_found) { for (i = 0; i < MVREF_NEIGHBOURS; ++i) { const POSITION *mv_ref = &mv_ref_search[i]; if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) { const MODE_INFO *const candidate_mi = xd->mi[mv_ref->col + mv_ref->row * xd->mi_stride]; // If the candidate is INTRA we don't want to consider its mv. IF_DIFF_REF_FRAME_ADD_MV(candidate_mi, ref_frame, ref_sign_bias, refmv_count, mv_ref_list, Done); } } } // Since we still don't have a candidate we'll try the last frame. if (cm->use_prev_frame_mvs) { if (prev_frame_mvs->ref_frame[0] != ref_frame && prev_frame_mvs->ref_frame[0] > INTRA_FRAME) { int_mv mv = prev_frame_mvs->mv[0]; if (ref_sign_bias[prev_frame_mvs->ref_frame[0]] != ref_sign_bias[ref_frame]) { mv.as_mv.row *= -1; mv.as_mv.col *= -1; } ADD_MV_REF_LIST(mv, refmv_count, mv_ref_list, Done); } if (prev_frame_mvs->ref_frame[1] > INTRA_FRAME && prev_frame_mvs->ref_frame[1] != ref_frame && prev_frame_mvs->mv[1].as_int != prev_frame_mvs->mv[0].as_int) { int_mv mv = prev_frame_mvs->mv[1]; if (ref_sign_bias[prev_frame_mvs->ref_frame[1]] != ref_sign_bias[ref_frame]) { mv.as_mv.row *= -1; mv.as_mv.col *= -1; } ADD_MV_REF_LIST(mv, refmv_count, mv_ref_list, Done); } } Done: mode_context[ref_frame] = counter_to_context[context_counter]; // Clamp vectors for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i) clamp_mv_ref(&mv_ref_list[i].as_mv, xd); } void vp9_find_mv_refs(const VP9_COMMON *cm, const MACROBLOCKD *xd, MODE_INFO *mi, MV_REFERENCE_FRAME ref_frame, int_mv *mv_ref_list, int mi_row, int mi_col, uint8_t *mode_context) { find_mv_refs_idx(cm, xd, mi, ref_frame, mv_ref_list, -1, mi_row, mi_col, mode_context); } void vp9_find_best_ref_mvs(MACROBLOCKD *xd, int allow_hp, int_mv *mvlist, int_mv *nearest_mv, int_mv *near_mv) { int i; // Make sure all the candidates are properly clamped etc for (i = 0; i < MAX_MV_REF_CANDIDATES; ++i) { lower_mv_precision(&mvlist[i].as_mv, allow_hp); clamp_mv2(&mvlist[i].as_mv, xd); } *nearest_mv = mvlist[0]; *near_mv = mvlist[1]; } void vp9_append_sub8x8_mvs_for_idx(VP9_COMMON *cm, MACROBLOCKD *xd, int block, int ref, int mi_row, int mi_col, int_mv *nearest_mv, int_mv *near_mv, uint8_t *mode_context) { int_mv mv_list[MAX_MV_REF_CANDIDATES]; MODE_INFO *const mi = xd->mi[0]; b_mode_info *bmi = mi->bmi; int n; assert(MAX_MV_REF_CANDIDATES == 2); find_mv_refs_idx(cm, xd, mi, mi->ref_frame[ref], mv_list, block, mi_row, mi_col, mode_context); near_mv->as_int = 0; switch (block) { case 0: nearest_mv->as_int = mv_list[0].as_int; near_mv->as_int = mv_list[1].as_int; break; case 1: case 2: nearest_mv->as_int = bmi[0].as_mv[ref].as_int; for (n = 0; n < MAX_MV_REF_CANDIDATES; ++n) if (nearest_mv->as_int != mv_list[n].as_int) { near_mv->as_int = mv_list[n].as_int; break; } break; case 3: { int_mv candidates[2 + MAX_MV_REF_CANDIDATES]; candidates[0] = bmi[1].as_mv[ref]; candidates[1] = bmi[0].as_mv[ref]; candidates[2] = mv_list[0]; candidates[3] = mv_list[1]; nearest_mv->as_int = bmi[2].as_mv[ref].as_int; for (n = 0; n < 2 + MAX_MV_REF_CANDIDATES; ++n) if (nearest_mv->as_int != candidates[n].as_int) { near_mv->as_int = candidates[n].as_int; break; } break; } default: assert(0 && "Invalid block index."); } }