The Tor Browser: comparison media/libvpx/vp9/common/vp9_mvref

--1:000000000000
+:70d3542f69b5
+/*
+*  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"
+#define MVREF_NEIGHBOURS 8
+typedef enum {
+BOTH_ZERO = 0,
+ZERO_PLUS_PREDICTED = 1,
+BOTH_PREDICTED = 2,
+NEW_PLUS_NON_INTRA = 3,
+BOTH_NEW = 4,
+INTRA_PLUS_NON_INTRA = 5,
+BOTH_INTRA = 6,
+INVALID_CASE = 9
+} motion_vector_context;
+// This is used to figure out a context for the ref blocks. The code flattens
+// an array that would have 3 possible counts (0, 1 & 2) for 3 choices by
+// adding 9 for each intra block, 3 for each zero mv and 1 for each new
+// motion vector. This single number is then converted into a context
+// with a single lookup ( counter_to_context ).
+static const int mode_2_counter[MB_MODE_COUNT] = {
+9,  // DC_PRED
+9,  // V_PRED
+9,  // H_PRED
+9,  // D45_PRED
+9,  // D135_PRED
+9,  // D117_PRED
+9,  // D153_PRED
+9,  // D207_PRED
+9,  // D63_PRED
+9,  // TM_PRED
+0,  // NEARESTMV
+0,  // NEARMV
+3,  // ZEROMV
+1,  // NEWMV
+};
+// There are 3^3 different combinations of 3 counts that can be either 0,1 or
+// 2. However the actual count can never be greater than 2 so the highest
+// counter we need is 18. 9 is an invalid counter that's never used.
+static const int counter_to_context[19] = {
+BOTH_PREDICTED,  // 0
+NEW_PLUS_NON_INTRA,  // 1
+BOTH_NEW,  // 2
+ZERO_PLUS_PREDICTED,  // 3
+NEW_PLUS_NON_INTRA,  // 4
+INVALID_CASE,  // 5
+BOTH_ZERO,  // 6
+INVALID_CASE,  // 7
+INVALID_CASE,  // 8
+INTRA_PLUS_NON_INTRA,  // 9
+INTRA_PLUS_NON_INTRA,  // 10
+INVALID_CASE,  // 11
+INTRA_PLUS_NON_INTRA,  // 12
+INVALID_CASE,  // 13
+INVALID_CASE,  // 14
+INVALID_CASE,  // 15
+INVALID_CASE,  // 16
+INVALID_CASE,  // 17
+BOTH_INTRA  // 18
+};
+static const MV mv_ref_blocks[BLOCK_SIZES][MVREF_NEIGHBOURS] = {
+// 4X4
+{{-1, 0}, {0, -1}, {-1, -1}, {-2, 0}, {0, -2}, {-2, -1}, {-1, -2}, {-2, -2}},
+// 4X8
+{{-1, 0}, {0, -1}, {-1, -1}, {-2, 0}, {0, -2}, {-2, -1}, {-1, -2}, {-2, -2}},
+// 8X4
+{{-1, 0}, {0, -1}, {-1, -1}, {-2, 0}, {0, -2}, {-2, -1}, {-1, -2}, {-2, -2}},
+// 8X8
+{{-1, 0}, {0, -1}, {-1, -1}, {-2, 0}, {0, -2}, {-2, -1}, {-1, -2}, {-2, -2}},
+// 8X16
+{{0, -1}, {-1, 0}, {1, -1}, {-1, -1}, {0, -2}, {-2, 0}, {-2, -1}, {-1, -2}},
+// 16X8
+{{-1, 0}, {0, -1}, {-1, 1}, {-1, -1}, {-2, 0}, {0, -2}, {-1, -2}, {-2, -1}},
+// 16X16
+{{-1, 0}, {0, -1}, {-1, 1}, {1, -1}, {-1, -1}, {-3, 0}, {0, -3}, {-3, -3}},
+// 16X32
+{{0, -1}, {-1, 0}, {2, -1}, {-1, -1}, {-1, 1}, {0, -3}, {-3, 0}, {-3, -3}},
+// 32X16
+{{-1, 0}, {0, -1}, {-1, 2}, {-1, -1}, {1, -1}, {-3, 0}, {0, -3}, {-3, -3}},
+// 32X32
+{{-1, 1}, {1, -1}, {-1, 2}, {2, -1}, {-1, -1}, {-3, 0}, {0, -3}, {-3, -3}},
+// 32X64
+{{0, -1}, {-1, 0}, {4, -1}, {-1, 2}, {-1, -1}, {0, -3}, {-3, 0}, {2, -1}},
+// 64X32
+{{-1, 0}, {0, -1}, {-1, 4}, {2, -1}, {-1, -1}, {-3, 0}, {0, -3}, {-1, 2}},
+// 64X64
+{{-1, 3}, {3, -1}, {-1, 4}, {4, -1}, {-1, -1}, {-1, 0}, {0, -1}, {-1, 6}}
+};
+static const int idx_n_column_to_subblock[4][2] = {
+{1, 2},
+{1, 3},
+{3, 2},
+{3, 3}
+};
+// clamp_mv_ref
+#define MV_BORDER (16 << 3)  // Allow 16 pels in 1/8th pel units
+static void clamp_mv_ref(MV *mv, const MACROBLOCKD *xd) {
+clamp_mv(mv, xd->mb_to_left_edge - MV_BORDER,
+xd->mb_to_right_edge + MV_BORDER,
+xd->mb_to_top_edge - MV_BORDER,
+xd->mb_to_bottom_edge + MV_BORDER);
+}
+// This function returns either the appropriate sub block or block's mv
+// on whether the block_size < 8x8 and we have check_sub_blocks set.
+static INLINE int_mv get_sub_block_mv(const MODE_INFO *candidate, int which_mv,
+int search_col, int block_idx) {
+return block_idx >= 0 && candidate->mbmi.sb_type < BLOCK_8X8
+? candidate->bmi[idx_n_column_to_subblock[block_idx][search_col == 0]]
+.as_mv[which_mv]
+: candidate->mbmi.mv[which_mv];
+}
+// Performs mv sign inversion if indicated by the reference frame combination.
+static INLINE int_mv scale_mv(const MB_MODE_INFO *mbmi, int ref,
+const MV_REFERENCE_FRAME this_ref_frame,
+const int *ref_sign_bias) {
+int_mv mv = mbmi->mv[ref];
+if (ref_sign_bias[mbmi->ref_frame[ref]] != ref_sign_bias[this_ref_frame]) {
+mv.as_mv.row *= -1;
+mv.as_mv.col *= -1;
+}
+return mv;
+}
+// This macro is used to add a motion vector mv_ref list if it isn't
+// already in the list.  If it's the second motion vector it will also
+// skip all additional processing and jump to done!
+#define ADD_MV_REF_LIST(MV) \
+do { \
+if (refmv_count) { \
+if ((MV).as_int != mv_ref_list[0].as_int) { \
+mv_ref_list[refmv_count] = (MV); \
+goto Done; \
+} \
+} else { \
+mv_ref_list[refmv_count++] = (MV); \
+} \
+} while (0)
+// If either reference frame is different, not INTRA, and they
+// are different from each other scale and add the mv to our list.
+#define IF_DIFF_REF_FRAME_ADD_MV(CANDIDATE) \
+do { \
+if ((CANDIDATE)->ref_frame[0] != ref_frame) \
+ADD_MV_REF_LIST(scale_mv((CANDIDATE), 0, ref_frame, ref_sign_bias)); \
+if ((CANDIDATE)->ref_frame[1] != ref_frame && \
+has_second_ref(CANDIDATE) && \
+(CANDIDATE)->mv[1].as_int != (CANDIDATE)->mv[0].as_int) \
+ADD_MV_REF_LIST(scale_mv((CANDIDATE), 1, ref_frame, ref_sign_bias)); \
+} while (0)
+// Checks that the given mi_row, mi_col and search point
+// are inside the borders of the tile.
+static INLINE int is_inside(const TileInfo *const tile,
+int mi_col, int mi_row, int mi_rows,
+const MV *mv) {
+return !(mi_row + mv->row < 0 ||
+mi_col + mv->col < tile->mi_col_start ||
+mi_row + mv->row >= mi_rows ||
+mi_col + mv->col >= tile->mi_col_end);
+}
+// This function searches the neighbourhood of a given MB/SB
+// to try and find candidate reference vectors.
+void vp9_find_mv_refs_idx(const VP9_COMMON *cm, const MACROBLOCKD *xd,
+const TileInfo *const tile,
+MODE_INFO *mi, const MODE_INFO *prev_mi,
+MV_REFERENCE_FRAME ref_frame,
+int_mv *mv_ref_list,
+int block_idx,
+int mi_row, int mi_col) {
+const int *ref_sign_bias = cm->ref_frame_sign_bias;
+int i, refmv_count = 0;
+const MV *const mv_ref_search = mv_ref_blocks[mi->mbmi.sb_type];
+const MB_MODE_INFO *const prev_mbmi = prev_mi ? &prev_mi->mbmi : NULL;
+int different_ref_found = 0;
+int context_counter = 0;
+// Blank the reference vector list
+vpx_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 MV *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_8x8[mv_ref->col + mv_ref->row
+* xd->mode_info_stride];
+const MB_MODE_INFO *const candidate = &candidate_mi->mbmi;
+// Keep counts for entropy encoding.
+context_counter += mode_2_counter[candidate->mode];
+// Check if the candidate comes from the same reference frame.
+if (candidate->ref_frame[0] == ref_frame) {
+ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, 0,
+mv_ref->col, block_idx));
+different_ref_found = candidate->ref_frame[1] != ref_frame;
+} else {
+if (candidate->ref_frame[1] == ref_frame)
+// Add second motion vector if it has the same ref_frame.
+ADD_MV_REF_LIST(get_sub_block_mv(candidate_mi, 1,
+mv_ref->col, block_idx));
+different_ref_found = 1;
+}
+}
+}
+// 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 MV *const mv_ref = &mv_ref_search[i];
+if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) {
+const MB_MODE_INFO *const candidate = &xd->mi_8x8[mv_ref->col +
+mv_ref->row
+* xd->mode_info_stride]->mbmi;
+if (candidate->ref_frame[0] == ref_frame) {
+ADD_MV_REF_LIST(candidate->mv[0]);
+different_ref_found = candidate->ref_frame[1] != ref_frame;
+} else {
+if (candidate->ref_frame[1] == ref_frame)
+ADD_MV_REF_LIST(candidate->mv[1]);
+different_ref_found = 1;
+}
+}
+}
+// Check the last frame's mode and mv info.
+if (prev_mbmi) {
+if (prev_mbmi->ref_frame[0] == ref_frame)
+ADD_MV_REF_LIST(prev_mbmi->mv[0]);
+else if (prev_mbmi->ref_frame[1] == ref_frame)
+ADD_MV_REF_LIST(prev_mbmi->mv[1]);
+}
+// 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 MV *mv_ref = &mv_ref_search[i];
+if (is_inside(tile, mi_col, mi_row, cm->mi_rows, mv_ref)) {
+const MB_MODE_INFO *const candidate = &xd->mi_8x8[mv_ref->col +
+mv_ref->row
+* xd->mode_info_stride]->mbmi;
+// If the candidate is INTRA we don't want to consider its mv.
+if (is_inter_block(candidate))
+IF_DIFF_REF_FRAME_ADD_MV(candidate);
+}
+}
+}
+// Since we still don't have a candidate we'll try the last frame.
+if (prev_mbmi && is_inter_block(prev_mbmi))
+IF_DIFF_REF_FRAME_ADD_MV(prev_mbmi);
+Done:
+mi->mbmi.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);
+}

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comparison: media/libvpx/vp9/common/vp9_mvref_common.c

media/libvpx/vp9/common/vp9_mvref_common.c