ref: 3156a28f6120f7fd79079a9525a54c758d4f7f77
dir: /vp8/common/findnearmv.c/
/*
* Copyright (c) 2010 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 "findnearmv.h"
const unsigned char vp8_mbsplit_offset[4][16] = {
{ 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 2, 8, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 }
};
/* Predict motion vectors using those from already-decoded nearby blocks.
Note that we only consider one 4x4 subblock from each candidate 16x16
macroblock. */
void vp8_find_near_mvs(MACROBLOCKD *xd, const MODE_INFO *here, int_mv *nearest,
int_mv *nearby, int_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(ref_frame_sign_bias[above->mbmi.ref_frame], 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(ref_frame_sign_bias[left->mbmi.ref_frame], 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(ref_frame_sign_bias[aboveleft->mbmi.ref_frame], 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->as_int = near_mvs[0].as_int;
nearest->as_int = near_mvs[CNT_NEAREST].as_int;
nearby->as_int = near_mvs[CNT_NEAR].as_int;
}
static void invert_and_clamp_mvs(int_mv *inv, int_mv *src, MACROBLOCKD *xd) {
inv->as_mv.row = src->as_mv.row * -1;
inv->as_mv.col = src->as_mv.col * -1;
vp8_clamp_mv2(inv, xd);
vp8_clamp_mv2(src, xd);
}
int vp8_find_near_mvs_bias(MACROBLOCKD *xd, const MODE_INFO *here,
int_mv mode_mv_sb[2][MB_MODE_COUNT],
int_mv best_mv_sb[2], int cnt[4], int refframe,
int *ref_frame_sign_bias) {
int sign_bias = ref_frame_sign_bias[refframe];
vp8_find_near_mvs(xd, here, &mode_mv_sb[sign_bias][NEARESTMV],
&mode_mv_sb[sign_bias][NEARMV], &best_mv_sb[sign_bias], cnt,
refframe, ref_frame_sign_bias);
invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARESTMV],
&mode_mv_sb[sign_bias][NEARESTMV], xd);
invert_and_clamp_mvs(&mode_mv_sb[!sign_bias][NEARMV],
&mode_mv_sb[sign_bias][NEARMV], xd);
invert_and_clamp_mvs(&best_mv_sb[!sign_bias], &best_mv_sb[sign_bias], xd);
return sign_bias;
}
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;
}