ref: 11e3ac62a5ebb99321119c51fc20a62c88d73cce
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"
#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, // D27_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 check_sub_blocks, int which_mv,
int search_col, int block_idx) {
return (check_sub_blocks && 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) \
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); \
}
// 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) \
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 && \
(CANDIDATE)->ref_frame[1] > INTRA_FRAME && \
(CANDIDATE)->mv[1].as_int != (CANDIDATE)->mv[0].as_int) { \
ADD_MV_REF_LIST(scale_mv((CANDIDATE), 1, ref_frame, ref_sign_bias)); \
}
// Checks that the given mi_row, mi_col and search point
// are inside the borders of the tile.
static INLINE int is_inside(int mi_col, int mi_row,
int cur_tile_mi_col_start,
int cur_tile_mi_col_end,
int mi_rows,
const MV *mv_ref) {
return !(mi_row + mv_ref->row < 0 ||
mi_col + mv_ref->col < cur_tile_mi_col_start ||
mi_row + mv_ref->row >= mi_rows ||
mi_col + mv_ref->col >= cur_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(VP9_COMMON *cm, MACROBLOCKD *xd, MODE_INFO *here,
const MODE_INFO *lf_here,
const MV_REFERENCE_FRAME ref_frame,
int_mv *mv_ref_list, const int *ref_sign_bias,
const int block_idx,
const int mi_row, const int mi_col) {
int idx;
MB_MODE_INFO *mbmi = &xd->mode_info_context->mbmi;
int refmv_count = 0;
const MV *mv_ref_search = mv_ref_blocks[mbmi->sb_type];
const MODE_INFO *candidate;
const int check_sub_blocks = block_idx >= 0;
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 (idx = 0; idx < 2; ++idx) {
const MV *mv_ref = &mv_ref_search[idx];
if (!is_inside(mi_col, mi_row, cm->cur_tile_mi_col_start,
cm->cur_tile_mi_col_end, cm->mi_rows, mv_ref))
continue;
candidate = here + mv_ref->col + mv_ref->row * xd->mode_info_stride;
// Keep counts for entropy encoding.
context_counter += mode_2_counter[candidate->mbmi.mode];
// Check if the candidate comes from the same reference frame.
if (candidate->mbmi.ref_frame[0] == ref_frame) {
ADD_MV_REF_LIST(get_sub_block_mv(candidate, check_sub_blocks, 0,
mv_ref->col, block_idx));
different_ref_found = candidate->mbmi.ref_frame[1] != ref_frame;
} else {
different_ref_found = 1;
if (candidate->mbmi.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, check_sub_blocks, 1,
mv_ref->col, block_idx));
}
}
}
// 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 (; idx < MVREF_NEIGHBOURS; ++idx) {
const MV *mv_ref = &mv_ref_search[idx];
if (!is_inside(mi_col, mi_row, cm->cur_tile_mi_col_start,
cm->cur_tile_mi_col_end, cm->mi_rows, mv_ref))
continue;
candidate = here + mv_ref->col + mv_ref->row * xd->mode_info_stride;
if (candidate->mbmi.ref_frame[0] == ref_frame) {
ADD_MV_REF_LIST(candidate->mbmi.mv[0]);
different_ref_found = candidate->mbmi.ref_frame[1] != ref_frame;
} else {
different_ref_found = 1;
if (candidate->mbmi.ref_frame[1] == ref_frame) {
ADD_MV_REF_LIST(candidate->mbmi.mv[1]);
}
}
}
// Check the last frame's mode and mv info.
if (lf_here != NULL) {
if (lf_here->mbmi.ref_frame[0] == ref_frame) {
ADD_MV_REF_LIST(lf_here->mbmi.mv[0]);
} else if (lf_here->mbmi.ref_frame[1] == ref_frame) {
ADD_MV_REF_LIST(lf_here->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 (idx = 0; idx < MVREF_NEIGHBOURS; ++idx) {
const MV *mv_ref = &mv_ref_search[idx];
if (!is_inside(mi_col, mi_row, cm->cur_tile_mi_col_start,
cm->cur_tile_mi_col_end, cm->mi_rows, mv_ref))
continue;
candidate = here + mv_ref->col + mv_ref->row * xd->mode_info_stride;
// If the candidate is INTRA we don't want to consider its mv.
if (!is_inter_block(&candidate->mbmi))
continue;
IF_DIFF_REF_FRAME_ADD_MV(&candidate->mbmi);
}
}
// Since we still don't have a candidate we'll try the last frame.
if (lf_here != NULL && is_inter_block(&lf_here->mbmi)) {
IF_DIFF_REF_FRAME_ADD_MV(&lf_here->mbmi);
}
Done:
mbmi->mode_context[ref_frame] = counter_to_context[context_counter];
// Clamp vectors
for (idx = 0; idx < MAX_MV_REF_CANDIDATES; ++idx)
clamp_mv_ref(&mv_ref_list[idx].as_mv, xd);
}