ref: 4b7baf805f1577daa47b874d291d5bc242a7d03c
dir: libvpx/vp8/decoder/decodemv.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 "decodemv.h"
#include "treereader.h"
#include "vp8/common/entropymv.h"
#include "vp8/common/entropymode.h"
#include "onyxd_int.h"
#include "vp8/common/findnearmv.h"
static B_PREDICTION_MODE read_bmode(vp8_reader *bc, const vp8_prob *p) {
const int i = vp8_treed_read(bc, vp8_bmode_tree, p);
return (B_PREDICTION_MODE)i;
}
static MB_PREDICTION_MODE read_ymode(vp8_reader *bc, const vp8_prob *p) {
const int i = vp8_treed_read(bc, vp8_ymode_tree, p);
return (MB_PREDICTION_MODE)i;
}
static MB_PREDICTION_MODE read_kf_ymode(vp8_reader *bc, const vp8_prob *p) {
const int i = vp8_treed_read(bc, vp8_kf_ymode_tree, p);
return (MB_PREDICTION_MODE)i;
}
static MB_PREDICTION_MODE read_uv_mode(vp8_reader *bc, const vp8_prob *p) {
const int i = vp8_treed_read(bc, vp8_uv_mode_tree, p);
return (MB_PREDICTION_MODE)i;
}
static void read_kf_modes(VP8D_COMP *pbi, MODE_INFO *mi) {
vp8_reader *const bc = &pbi->mbc[8];
const int mis = pbi->common.mode_info_stride;
mi->mbmi.ref_frame = INTRA_FRAME;
mi->mbmi.mode = read_kf_ymode(bc, vp8_kf_ymode_prob);
if (mi->mbmi.mode == B_PRED) {
int i = 0;
mi->mbmi.is_4x4 = 1;
do {
const B_PREDICTION_MODE A = above_block_mode(mi, i, mis);
const B_PREDICTION_MODE L = left_block_mode(mi, i);
mi->bmi[i].as_mode = read_bmode(bc, vp8_kf_bmode_prob[A][L]);
} while (++i < 16);
}
mi->mbmi.uv_mode = read_uv_mode(bc, vp8_kf_uv_mode_prob);
}
static int read_mvcomponent(vp8_reader *r, const MV_CONTEXT *mvc) {
const vp8_prob *const p = (const vp8_prob *)mvc;
int x = 0;
if (vp8_read(r, p[mvpis_short])) { /* Large */
int i = 0;
do {
x += vp8_read(r, p[MVPbits + i]) << i;
} while (++i < 3);
i = mvlong_width - 1; /* Skip bit 3, which is sometimes implicit */
do {
x += vp8_read(r, p[MVPbits + i]) << i;
} while (--i > 3);
if (!(x & 0xFFF0) || vp8_read(r, p[MVPbits + 3])) x += 8;
} else { /* small */
x = vp8_treed_read(r, vp8_small_mvtree, p + MVPshort);
}
if (x && vp8_read(r, p[MVPsign])) x = -x;
return x;
}
static void read_mv(vp8_reader *r, MV *mv, const MV_CONTEXT *mvc) {
mv->row = (short)(read_mvcomponent(r, mvc) * 2);
mv->col = (short)(read_mvcomponent(r, ++mvc) * 2);
}
static void read_mvcontexts(vp8_reader *bc, MV_CONTEXT *mvc) {
int i = 0;
do {
const vp8_prob *up = vp8_mv_update_probs[i].prob;
vp8_prob *p = (vp8_prob *)(mvc + i);
vp8_prob *const pstop = p + MVPcount;
do {
if (vp8_read(bc, *up++)) {
const vp8_prob x = (vp8_prob)vp8_read_literal(bc, 7);
*p = x ? x << 1 : 1;
}
} while (++p < pstop);
} while (++i < 2);
}
static const unsigned char mbsplit_fill_count[4] = { 8, 8, 4, 1 };
static const unsigned char mbsplit_fill_offset[4][16] = {
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
{ 0, 1, 4, 5, 8, 9, 12, 13, 2, 3, 6, 7, 10, 11, 14, 15 },
{ 0, 1, 4, 5, 2, 3, 6, 7, 8, 9, 12, 13, 10, 11, 14, 15 },
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 }
};
static void mb_mode_mv_init(VP8D_COMP *pbi) {
vp8_reader *const bc = &pbi->mbc[8];
MV_CONTEXT *const mvc = pbi->common.fc.mvc;
#if CONFIG_ERROR_CONCEALMENT
/* Default is that no macroblock is corrupt, therefore we initialize
* mvs_corrupt_from_mb to something very big, which we can be sure is
* outside the frame. */
pbi->mvs_corrupt_from_mb = UINT_MAX;
#endif
/* Read the mb_no_coeff_skip flag */
pbi->common.mb_no_coeff_skip = (int)vp8_read_bit(bc);
pbi->prob_skip_false = 0;
if (pbi->common.mb_no_coeff_skip) {
pbi->prob_skip_false = (vp8_prob)vp8_read_literal(bc, 8);
}
if (pbi->common.frame_type != KEY_FRAME) {
pbi->prob_intra = (vp8_prob)vp8_read_literal(bc, 8);
pbi->prob_last = (vp8_prob)vp8_read_literal(bc, 8);
pbi->prob_gf = (vp8_prob)vp8_read_literal(bc, 8);
if (vp8_read_bit(bc)) {
int i = 0;
do {
pbi->common.fc.ymode_prob[i] = (vp8_prob)vp8_read_literal(bc, 8);
} while (++i < 4);
}
if (vp8_read_bit(bc)) {
int i = 0;
do {
pbi->common.fc.uv_mode_prob[i] = (vp8_prob)vp8_read_literal(bc, 8);
} while (++i < 3);
}
read_mvcontexts(bc, mvc);
}
}
const vp8_prob vp8_sub_mv_ref_prob3[8][VP8_SUBMVREFS - 1] = {
{ 147, 136, 18 }, /* SUBMVREF_NORMAL */
{ 223, 1, 34 }, /* SUBMVREF_LEFT_ABOVE_SAME */
{ 106, 145, 1 }, /* SUBMVREF_LEFT_ZED */
{ 208, 1, 1 }, /* SUBMVREF_LEFT_ABOVE_ZED */
{ 179, 121, 1 }, /* SUBMVREF_ABOVE_ZED */
{ 223, 1, 34 }, /* SUBMVREF_LEFT_ABOVE_SAME */
{ 179, 121, 1 }, /* SUBMVREF_ABOVE_ZED */
{ 208, 1, 1 } /* SUBMVREF_LEFT_ABOVE_ZED */
};
static const vp8_prob *get_sub_mv_ref_prob(const int left, const int above) {
int lez = (left == 0);
int aez = (above == 0);
int lea = (left == above);
const vp8_prob *prob;
prob = vp8_sub_mv_ref_prob3[(aez << 2) | (lez << 1) | (lea)];
return prob;
}
static void decode_split_mv(vp8_reader *const bc, MODE_INFO *mi,
const MODE_INFO *left_mb, const MODE_INFO *above_mb,
MB_MODE_INFO *mbmi, int_mv best_mv,
MV_CONTEXT *const mvc, int mb_to_left_edge,
int mb_to_right_edge, int mb_to_top_edge,
int mb_to_bottom_edge) {
int s; /* split configuration (16x8, 8x16, 8x8, 4x4) */
/* number of partitions in the split configuration (see vp8_mbsplit_count) */
int num_p;
int j = 0;
s = 3;
num_p = 16;
if (vp8_read(bc, 110)) {
s = 2;
num_p = 4;
if (vp8_read(bc, 111)) {
s = vp8_read(bc, 150);
num_p = 2;
}
}
do /* for each subset j */
{
int_mv leftmv, abovemv;
int_mv blockmv;
int k; /* first block in subset j */
const vp8_prob *prob;
k = vp8_mbsplit_offset[s][j];
if (!(k & 3)) {
/* On L edge, get from MB to left of us */
if (left_mb->mbmi.mode != SPLITMV) {
leftmv.as_int = left_mb->mbmi.mv.as_int;
} else {
leftmv.as_int = (left_mb->bmi + k + 4 - 1)->mv.as_int;
}
} else {
leftmv.as_int = (mi->bmi + k - 1)->mv.as_int;
}
if (!(k >> 2)) {
/* On top edge, get from MB above us */
if (above_mb->mbmi.mode != SPLITMV) {
abovemv.as_int = above_mb->mbmi.mv.as_int;
} else {
abovemv.as_int = (above_mb->bmi + k + 16 - 4)->mv.as_int;
}
} else {
abovemv.as_int = (mi->bmi + k - 4)->mv.as_int;
}
prob = get_sub_mv_ref_prob(leftmv.as_int, abovemv.as_int);
if (vp8_read(bc, prob[0])) {
if (vp8_read(bc, prob[1])) {
blockmv.as_int = 0;
if (vp8_read(bc, prob[2])) {
blockmv.as_mv.row = read_mvcomponent(bc, &mvc[0]) * 2;
blockmv.as_mv.row += best_mv.as_mv.row;
blockmv.as_mv.col = read_mvcomponent(bc, &mvc[1]) * 2;
blockmv.as_mv.col += best_mv.as_mv.col;
}
} else {
blockmv.as_int = abovemv.as_int;
}
} else {
blockmv.as_int = leftmv.as_int;
}
mbmi->need_to_clamp_mvs |=
vp8_check_mv_bounds(&blockmv, mb_to_left_edge, mb_to_right_edge,
mb_to_top_edge, mb_to_bottom_edge);
{
/* Fill (uniform) modes, mvs of jth subset.
Must do it here because ensuing subsets can
refer back to us via "left" or "above". */
const unsigned char *fill_offset;
unsigned int fill_count = mbsplit_fill_count[s];
fill_offset =
&mbsplit_fill_offset[s][(unsigned char)j * mbsplit_fill_count[s]];
do {
mi->bmi[*fill_offset].mv.as_int = blockmv.as_int;
fill_offset++;
} while (--fill_count);
}
} while (++j < num_p);
mbmi->partitioning = s;
}
static void read_mb_modes_mv(VP8D_COMP *pbi, MODE_INFO *mi,
MB_MODE_INFO *mbmi) {
vp8_reader *const bc = &pbi->mbc[8];
mbmi->ref_frame = (MV_REFERENCE_FRAME)vp8_read(bc, pbi->prob_intra);
if (mbmi->ref_frame) { /* inter MB */
enum { CNT_INTRA, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV };
int cnt[4];
int *cntx = cnt;
int_mv near_mvs[4];
int_mv *nmv = near_mvs;
const int mis = pbi->mb.mode_info_stride;
const MODE_INFO *above = mi - mis;
const MODE_INFO *left = mi - 1;
const MODE_INFO *aboveleft = above - 1;
int *ref_frame_sign_bias = pbi->common.ref_frame_sign_bias;
mbmi->need_to_clamp_mvs = 0;
if (vp8_read(bc, pbi->prob_last)) {
mbmi->ref_frame =
(MV_REFERENCE_FRAME)((int)(2 + vp8_read(bc, pbi->prob_gf)));
}
/* Zero accumulators */
nmv[0].as_int = nmv[1].as_int = nmv[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) {
(++nmv)->as_int = above->mbmi.mv.as_int;
mv_bias(ref_frame_sign_bias[above->mbmi.ref_frame], mbmi->ref_frame,
nmv, 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], mbmi->ref_frame,
&this_mv, ref_frame_sign_bias);
if (this_mv.as_int != nmv->as_int) {
(++nmv)->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], mbmi->ref_frame,
&this_mv, ref_frame_sign_bias);
if (this_mv.as_int != nmv->as_int) {
(++nmv)->as_int = this_mv.as_int;
++cntx;
}
*cntx += 1;
} else {
cnt[CNT_INTRA] += 1;
}
}
if (vp8_read(bc, vp8_mode_contexts[cnt[CNT_INTRA]][0])) {
/* If we have three distinct MV's ... */
/* See if above-left MV can be merged with NEAREST */
cnt[CNT_NEAREST] += ((cnt[CNT_SPLITMV] > 0) &
(nmv->as_int == near_mvs[CNT_NEAREST].as_int));
/* 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;
}
if (vp8_read(bc, vp8_mode_contexts[cnt[CNT_NEAREST]][1])) {
if (vp8_read(bc, vp8_mode_contexts[cnt[CNT_NEAR]][2])) {
int mb_to_top_edge;
int mb_to_bottom_edge;
int mb_to_left_edge;
int mb_to_right_edge;
MV_CONTEXT *const mvc = pbi->common.fc.mvc;
int near_index;
mb_to_top_edge = pbi->mb.mb_to_top_edge;
mb_to_bottom_edge = pbi->mb.mb_to_bottom_edge;
mb_to_top_edge -= LEFT_TOP_MARGIN;
mb_to_bottom_edge += RIGHT_BOTTOM_MARGIN;
mb_to_right_edge = pbi->mb.mb_to_right_edge;
mb_to_right_edge += RIGHT_BOTTOM_MARGIN;
mb_to_left_edge = pbi->mb.mb_to_left_edge;
mb_to_left_edge -= LEFT_TOP_MARGIN;
/* Use near_mvs[0] to store the "best" MV */
near_index = CNT_INTRA + (cnt[CNT_NEAREST] >= cnt[CNT_INTRA]);
vp8_clamp_mv2(&near_mvs[near_index], &pbi->mb);
cnt[CNT_SPLITMV] =
((above->mbmi.mode == SPLITMV) + (left->mbmi.mode == SPLITMV)) *
2 +
(aboveleft->mbmi.mode == SPLITMV);
if (vp8_read(bc, vp8_mode_contexts[cnt[CNT_SPLITMV]][3])) {
decode_split_mv(bc, mi, left, above, mbmi, near_mvs[near_index],
mvc, mb_to_left_edge, mb_to_right_edge,
mb_to_top_edge, mb_to_bottom_edge);
mbmi->mv.as_int = mi->bmi[15].mv.as_int;
mbmi->mode = SPLITMV;
mbmi->is_4x4 = 1;
} else {
int_mv *const mbmi_mv = &mbmi->mv;
read_mv(bc, &mbmi_mv->as_mv, (const MV_CONTEXT *)mvc);
mbmi_mv->as_mv.row += near_mvs[near_index].as_mv.row;
mbmi_mv->as_mv.col += near_mvs[near_index].as_mv.col;
/* Don't need to check this on NEARMV and NEARESTMV
* modes since those modes clamp the MV. The NEWMV mode
* does not, so signal to the prediction stage whether
* special handling may be required.
*/
mbmi->need_to_clamp_mvs =
vp8_check_mv_bounds(mbmi_mv, mb_to_left_edge, mb_to_right_edge,
mb_to_top_edge, mb_to_bottom_edge);
mbmi->mode = NEWMV;
}
} else {
mbmi->mode = NEARMV;
mbmi->mv.as_int = near_mvs[CNT_NEAR].as_int;
vp8_clamp_mv2(&mbmi->mv, &pbi->mb);
}
} else {
mbmi->mode = NEARESTMV;
mbmi->mv.as_int = near_mvs[CNT_NEAREST].as_int;
vp8_clamp_mv2(&mbmi->mv, &pbi->mb);
}
} else {
mbmi->mode = ZEROMV;
mbmi->mv.as_int = 0;
}
#if CONFIG_ERROR_CONCEALMENT
if (pbi->ec_enabled && (mbmi->mode != SPLITMV)) {
mi->bmi[0].mv.as_int = mi->bmi[1].mv.as_int = mi->bmi[2].mv.as_int =
mi->bmi[3].mv.as_int = mi->bmi[4].mv.as_int = mi->bmi[5].mv.as_int =
mi->bmi[6].mv.as_int = mi->bmi[7].mv.as_int =
mi->bmi[8].mv.as_int = mi->bmi[9].mv.as_int =
mi->bmi[10].mv.as_int = mi->bmi[11].mv.as_int =
mi->bmi[12].mv.as_int = mi->bmi[13].mv.as_int =
mi->bmi[14].mv.as_int = mi->bmi[15].mv.as_int =
mbmi->mv.as_int;
}
#endif
} else {
/* required for left and above block mv */
mbmi->mv.as_int = 0;
/* MB is intra coded */
if ((mbmi->mode = read_ymode(bc, pbi->common.fc.ymode_prob)) == B_PRED) {
int j = 0;
mbmi->is_4x4 = 1;
do {
mi->bmi[j].as_mode = read_bmode(bc, pbi->common.fc.bmode_prob);
} while (++j < 16);
}
mbmi->uv_mode = read_uv_mode(bc, pbi->common.fc.uv_mode_prob);
}
}
static void read_mb_features(vp8_reader *r, MB_MODE_INFO *mi, MACROBLOCKD *x) {
/* Is segmentation enabled */
if (x->segmentation_enabled && x->update_mb_segmentation_map) {
/* If so then read the segment id. */
if (vp8_read(r, x->mb_segment_tree_probs[0])) {
mi->segment_id =
(unsigned char)(2 + vp8_read(r, x->mb_segment_tree_probs[2]));
} else {
mi->segment_id =
(unsigned char)(vp8_read(r, x->mb_segment_tree_probs[1]));
}
}
}
static void decode_mb_mode_mvs(VP8D_COMP *pbi, MODE_INFO *mi) {
/* Read the Macroblock segmentation map if it is being updated explicitly
* this frame (reset to 0 above by default)
* By default on a key frame reset all MBs to segment 0
*/
if (pbi->mb.update_mb_segmentation_map) {
read_mb_features(&pbi->mbc[8], &mi->mbmi, &pbi->mb);
} else if (pbi->common.frame_type == KEY_FRAME) {
mi->mbmi.segment_id = 0;
}
/* Read the macroblock coeff skip flag if this feature is in use,
* else default to 0 */
if (pbi->common.mb_no_coeff_skip) {
mi->mbmi.mb_skip_coeff = vp8_read(&pbi->mbc[8], pbi->prob_skip_false);
} else {
mi->mbmi.mb_skip_coeff = 0;
}
mi->mbmi.is_4x4 = 0;
if (pbi->common.frame_type == KEY_FRAME) {
read_kf_modes(pbi, mi);
} else {
read_mb_modes_mv(pbi, mi, &mi->mbmi);
}
}
void vp8_decode_mode_mvs(VP8D_COMP *pbi) {
MODE_INFO *mi = pbi->common.mi;
int mb_row = -1;
int mb_to_right_edge_start;
mb_mode_mv_init(pbi);
pbi->mb.mb_to_top_edge = 0;
pbi->mb.mb_to_bottom_edge = ((pbi->common.mb_rows - 1) * 16) << 3;
mb_to_right_edge_start = ((pbi->common.mb_cols - 1) * 16) << 3;
while (++mb_row < pbi->common.mb_rows) {
int mb_col = -1;
pbi->mb.mb_to_left_edge = 0;
pbi->mb.mb_to_right_edge = mb_to_right_edge_start;
while (++mb_col < pbi->common.mb_cols) {
#if CONFIG_ERROR_CONCEALMENT
int mb_num = mb_row * pbi->common.mb_cols + mb_col;
#endif
decode_mb_mode_mvs(pbi, mi);
#if CONFIG_ERROR_CONCEALMENT
/* look for corruption. set mvs_corrupt_from_mb to the current
* mb_num if the frame is corrupt from this macroblock. */
if (vp8dx_bool_error(&pbi->mbc[8]) &&
mb_num < (int)pbi->mvs_corrupt_from_mb) {
pbi->mvs_corrupt_from_mb = mb_num;
/* no need to continue since the partition is corrupt from
* here on.
*/
return;
}
#endif
pbi->mb.mb_to_left_edge -= (16 << 3);
pbi->mb.mb_to_right_edge -= (16 << 3);
mi++; /* next macroblock */
}
pbi->mb.mb_to_top_edge -= (16 << 3);
pbi->mb.mb_to_bottom_edge -= (16 << 3);
mi++; /* skip left predictor each row */
}
}