ref: 397aad3ec28020a9b766e362e061701783c9633e
dir: /vp8/common/findnearmv.c/
/*
* Copyright (c) 2010 The VP8 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 "findnearmv.h"
#define FINDNEAR_SEARCH_SITES 3
/* Predict motion vectors using those from already-decoded nearby blocks.
Note that we only consider one 4x4 subblock from each candidate 16x16
macroblock. */
typedef union
{
unsigned int as_int;
MV as_mv;
} int_mv; /* facilitates rapid equality tests */
static void mv_bias(const MODE_INFO *x, int refframe, int_mv *mvp, const int *ref_frame_sign_bias)
{
MV xmv;
xmv = x->mbmi.mv.as_mv;
if (ref_frame_sign_bias[x->mbmi.ref_frame] != ref_frame_sign_bias[refframe])
{
xmv.row *= -1;
xmv.col *= -1;
}
mvp->as_mv = xmv;
}
void vp8_clamp_mv(MV *mv, const MACROBLOCKD *xd)
{
if (mv->col < (xd->mb_to_left_edge - LEFT_TOP_MARGIN))
mv->col = xd->mb_to_left_edge - LEFT_TOP_MARGIN;
else if (mv->col > xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN)
mv->col = xd->mb_to_right_edge + RIGHT_BOTTOM_MARGIN;
if (mv->row < (xd->mb_to_top_edge - LEFT_TOP_MARGIN))
mv->row = xd->mb_to_top_edge - LEFT_TOP_MARGIN;
else if (mv->row > xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN)
mv->row = xd->mb_to_bottom_edge + RIGHT_BOTTOM_MARGIN;
}
void vp8_find_near_mvs
(
MACROBLOCKD *xd,
const MODE_INFO *here,
MV *nearest,
MV *nearby,
MV *best_mv,
int cnt[4],
int refframe,
int *ref_frame_sign_bias
)
{
const MODE_INFO *above = here - xd->mode_info_stride;
const MODE_INFO *left = here - 1;
const MODE_INFO *aboveleft = above - 1;
int_mv near_mvs[4];
int_mv *mv = near_mvs;
int *cntx = cnt;
enum {CNT_INTRA, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV};
/* Zero accumulators */
mv[0].as_int = mv[1].as_int = mv[2].as_int = 0;
cnt[0] = cnt[1] = cnt[2] = cnt[3] = 0;
/* Process above */
if (above->mbmi.ref_frame != INTRA_FRAME)
{
if (above->mbmi.mv.as_int)
{
(++mv)->as_int = above->mbmi.mv.as_int;
mv_bias(above, refframe, mv, ref_frame_sign_bias);
++cntx;
}
*cntx += 2;
}
/* Process left */
if (left->mbmi.ref_frame != INTRA_FRAME)
{
if (left->mbmi.mv.as_int)
{
int_mv this_mv;
this_mv.as_int = left->mbmi.mv.as_int;
mv_bias(left, refframe, &this_mv, ref_frame_sign_bias);
if (this_mv.as_int != mv->as_int)
{
(++mv)->as_int = this_mv.as_int;
++cntx;
}
*cntx += 2;
}
else
cnt[CNT_INTRA] += 2;
}
/* Process above left */
if (aboveleft->mbmi.ref_frame != INTRA_FRAME)
{
if (aboveleft->mbmi.mv.as_int)
{
int_mv this_mv;
this_mv.as_int = aboveleft->mbmi.mv.as_int;
mv_bias(aboveleft, refframe, &this_mv, ref_frame_sign_bias);
if (this_mv.as_int != mv->as_int)
{
(++mv)->as_int = this_mv.as_int;
++cntx;
}
*cntx += 1;
}
else
cnt[CNT_INTRA] += 1;
}
/* If we have three distinct MV's ... */
if (cnt[CNT_SPLITMV])
{
/* See if above-left MV can be merged with NEAREST */
if (mv->as_int == near_mvs[CNT_NEAREST].as_int)
cnt[CNT_NEAREST] += 1;
}
cnt[CNT_SPLITMV] = ((above->mbmi.mode == SPLITMV)
+ (left->mbmi.mode == SPLITMV)) * 2
+ (aboveleft->mbmi.mode == SPLITMV);
/* Swap near and nearest if necessary */
if (cnt[CNT_NEAR] > cnt[CNT_NEAREST])
{
int tmp;
tmp = cnt[CNT_NEAREST];
cnt[CNT_NEAREST] = cnt[CNT_NEAR];
cnt[CNT_NEAR] = tmp;
tmp = near_mvs[CNT_NEAREST].as_int;
near_mvs[CNT_NEAREST].as_int = near_mvs[CNT_NEAR].as_int;
near_mvs[CNT_NEAR].as_int = tmp;
}
/* Use near_mvs[0] to store the "best" MV */
if (cnt[CNT_NEAREST] >= cnt[CNT_INTRA])
near_mvs[CNT_INTRA] = near_mvs[CNT_NEAREST];
/* Set up return values */
*best_mv = near_mvs[0].as_mv;
*nearest = near_mvs[CNT_NEAREST].as_mv;
*nearby = near_mvs[CNT_NEAR].as_mv;
vp8_clamp_mv(nearest, xd);
vp8_clamp_mv(nearby, xd);
vp8_clamp_mv(best_mv, xd); //TODO: move this up before the copy
}
vp8_prob *vp8_mv_ref_probs(
vp8_prob p[VP8_MVREFS-1], const int near_mv_ref_ct[4]
)
{
p[0] = vp8_mode_contexts [near_mv_ref_ct[0]] [0];
p[1] = vp8_mode_contexts [near_mv_ref_ct[1]] [1];
p[2] = vp8_mode_contexts [near_mv_ref_ct[2]] [2];
p[3] = vp8_mode_contexts [near_mv_ref_ct[3]] [3];
//p[3] = vp8_mode_contexts [near_mv_ref_ct[1] + near_mv_ref_ct[2] + near_mv_ref_ct[3]] [3];
return p;
}
const B_MODE_INFO *vp8_left_bmi(const MODE_INFO *cur_mb, int b)
{
if (!(b & 3))
{
/* On L edge, get from MB to left of us */
--cur_mb;
b += 4;
}
return cur_mb->bmi + b - 1;
}
const B_MODE_INFO *vp8_above_bmi(const MODE_INFO *cur_mb, int b, int mi_stride)
{
if (!(b >> 2))
{
/* On top edge, get from MB above us */
cur_mb -= mi_stride;
b += 16;
}
return cur_mb->bmi + b - 4;
}