ref: e4ef85082336a52c0c26fb7e16b86edc4006403c
dir: /vp9/encoder/vp9_segmentation.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 "limits.h"
#include "vpx_mem/vpx_mem.h"
#include "vp9/encoder/vp9_segmentation.h"
#include "vp9/common/vp9_pred_common.h"
void vp9_update_gf_useage_maps(VP9_COMP *cpi, VP9_COMMON *cm, MACROBLOCK *x) {
int mb_row, mb_col;
MODE_INFO *this_mb_mode_info = cm->mi;
x->gf_active_ptr = (signed char *)cpi->gf_active_flags;
if ((cm->frame_type == KEY_FRAME) || (cm->refresh_golden_frame)) {
// Reset Gf useage monitors
vpx_memset(cpi->gf_active_flags, 1, (cm->mb_rows * cm->mb_cols));
cpi->gf_active_count = cm->mb_rows * cm->mb_cols;
} else {
// for each macroblock row in image
for (mb_row = 0; mb_row < cm->mb_rows; mb_row++) {
// for each macroblock col in image
for (mb_col = 0; mb_col < cm->mb_cols; mb_col++) {
// If using golden then set GF active flag if not already set.
// If using last frame 0,0 mode then leave flag as it is
// else if using non 0,0 motion or intra modes then clear
// flag if it is currently set
if ((this_mb_mode_info->mbmi.ref_frame == GOLDEN_FRAME) ||
(this_mb_mode_info->mbmi.ref_frame == ALTREF_FRAME)) {
if (*(x->gf_active_ptr) == 0) {
*(x->gf_active_ptr) = 1;
cpi->gf_active_count++;
}
} else if ((this_mb_mode_info->mbmi.mode != ZEROMV) &&
*(x->gf_active_ptr)) {
*(x->gf_active_ptr) = 0;
cpi->gf_active_count--;
}
x->gf_active_ptr++; // Step onto next entry
this_mb_mode_info++; // skip to next mb
}
// this is to account for the border
this_mb_mode_info++;
}
}
}
void vp9_enable_segmentation(VP9_PTR ptr) {
VP9_COMP *cpi = (VP9_COMP *)(ptr);
// Set the appropriate feature bit
cpi->mb.e_mbd.segmentation_enabled = 1;
cpi->mb.e_mbd.update_mb_segmentation_map = 1;
cpi->mb.e_mbd.update_mb_segmentation_data = 1;
}
void vp9_disable_segmentation(VP9_PTR ptr) {
VP9_COMP *cpi = (VP9_COMP *)(ptr);
// Clear the appropriate feature bit
cpi->mb.e_mbd.segmentation_enabled = 0;
}
void vp9_set_segmentation_map(VP9_PTR ptr,
unsigned char *segmentation_map) {
VP9_COMP *cpi = (VP9_COMP *)(ptr);
// Copy in the new segmentation map
vpx_memcpy(cpi->segmentation_map, segmentation_map,
(cpi->common.mb_rows * cpi->common.mb_cols));
// Signal that the map should be updated.
cpi->mb.e_mbd.update_mb_segmentation_map = 1;
cpi->mb.e_mbd.update_mb_segmentation_data = 1;
}
void vp9_set_segment_data(VP9_PTR ptr,
signed char *feature_data,
unsigned char abs_delta) {
VP9_COMP *cpi = (VP9_COMP *)(ptr);
cpi->mb.e_mbd.mb_segment_abs_delta = abs_delta;
vpx_memcpy(cpi->mb.e_mbd.segment_feature_data, feature_data,
sizeof(cpi->mb.e_mbd.segment_feature_data));
// TBD ?? Set the feature mask
// vpx_memcpy(cpi->mb.e_mbd.segment_feature_mask, 0,
// sizeof(cpi->mb.e_mbd.segment_feature_mask));
}
// Based on set of segment counts calculate a probability tree
static void calc_segtree_probs(MACROBLOCKD *xd,
int *segcounts,
vp9_prob *segment_tree_probs) {
int count1, count2;
// Total count for all segments
count1 = segcounts[0] + segcounts[1];
count2 = segcounts[2] + segcounts[3];
// Work out probabilities of each segment
segment_tree_probs[0] = get_binary_prob(count1, count2);
segment_tree_probs[1] = get_prob(segcounts[0], count1);
segment_tree_probs[2] = get_prob(segcounts[2], count2);
}
// Based on set of segment counts and probabilities calculate a cost estimate
static int cost_segmap(MACROBLOCKD *xd,
int *segcounts,
vp9_prob *probs) {
int cost;
int count1, count2;
// Cost the top node of the tree
count1 = segcounts[0] + segcounts[1];
count2 = segcounts[2] + segcounts[3];
cost = count1 * vp9_cost_zero(probs[0]) +
count2 * vp9_cost_one(probs[0]);
// Now add the cost of each individual segment branch
if (count1 > 0)
cost += segcounts[0] * vp9_cost_zero(probs[1]) +
segcounts[1] * vp9_cost_one(probs[1]);
if (count2 > 0)
cost += segcounts[2] * vp9_cost_zero(probs[2]) +
segcounts[3] * vp9_cost_one(probs[2]);
return cost;
}
static void count_segs(VP9_COMP *cpi,
MODE_INFO *mi,
int *no_pred_segcounts,
int (*temporal_predictor_count)[2],
int *t_unpred_seg_counts,
int mb_size, int mb_row, int mb_col) {
VP9_COMMON *const cm = &cpi->common;
MACROBLOCKD *const xd = &cpi->mb.e_mbd;
const int segmap_index = mb_row * cm->mb_cols + mb_col;
const int segment_id = mi->mbmi.segment_id;
xd->mode_info_context = mi;
xd->mb_to_top_edge = -((mb_row * 16) << 3);
xd->mb_to_left_edge = -((mb_col * 16) << 3);
xd->mb_to_bottom_edge = ((cm->mb_rows - mb_size - mb_row) * 16) << 3;
xd->mb_to_right_edge = ((cm->mb_cols - mb_size - mb_col) * 16) << 3;
// Count the number of hits on each segment with no prediction
no_pred_segcounts[segment_id]++;
// Temporal prediction not allowed on key frames
if (cm->frame_type != KEY_FRAME) {
// Test to see if the segment id matches the predicted value.
const int seg_predicted =
(segment_id == vp9_get_pred_mb_segid(cm, xd, segmap_index));
// Get the segment id prediction context
const int pred_context = vp9_get_pred_context(cm, xd, PRED_SEG_ID);
// Store the prediction status for this mb and update counts
// as appropriate
vp9_set_pred_flag(xd, PRED_SEG_ID, seg_predicted);
temporal_predictor_count[pred_context][seg_predicted]++;
if (!seg_predicted)
// Update the "unpredicted" segment count
t_unpred_seg_counts[segment_id]++;
}
}
void vp9_choose_segmap_coding_method(VP9_COMP *cpi) {
VP9_COMMON *const cm = &cpi->common;
MACROBLOCKD *const xd = &cpi->mb.e_mbd;
int no_pred_cost;
int t_pred_cost = INT_MAX;
int i;
int mb_row, mb_col;
int temporal_predictor_count[PREDICTION_PROBS][2];
int no_pred_segcounts[MAX_MB_SEGMENTS];
int t_unpred_seg_counts[MAX_MB_SEGMENTS];
vp9_prob no_pred_tree[MB_FEATURE_TREE_PROBS];
vp9_prob t_pred_tree[MB_FEATURE_TREE_PROBS];
vp9_prob t_nopred_prob[PREDICTION_PROBS];
const int mis = cm->mode_info_stride;
MODE_INFO *mi_ptr = cm->mi, *mi;
// Set default state for the segment tree probabilities and the
// temporal coding probabilities
vpx_memset(xd->mb_segment_tree_probs, 255,
sizeof(xd->mb_segment_tree_probs));
vpx_memset(cm->segment_pred_probs, 255,
sizeof(cm->segment_pred_probs));
vpx_memset(no_pred_segcounts, 0, sizeof(no_pred_segcounts));
vpx_memset(t_unpred_seg_counts, 0, sizeof(t_unpred_seg_counts));
vpx_memset(temporal_predictor_count, 0, sizeof(temporal_predictor_count));
// First of all generate stats regarding how well the last segment map
// predicts this one
for (mb_row = 0; mb_row < cm->mb_rows; mb_row += 4, mi_ptr += 4 * mis) {
mi = mi_ptr;
for (mb_col = 0; mb_col < cm->mb_cols; mb_col += 4, mi += 4) {
if (mi->mbmi.sb_type == BLOCK_SIZE_SB64X64) {
count_segs(cpi, mi, no_pred_segcounts, temporal_predictor_count,
t_unpred_seg_counts, 4, mb_row, mb_col);
} else {
for (i = 0; i < 4; i++) {
int x_idx = (i & 1) << 1, y_idx = i & 2;
MODE_INFO *sb_mi = mi + y_idx * mis + x_idx;
if (mb_col + x_idx >= cm->mb_cols ||
mb_row + y_idx >= cm->mb_rows) {
continue;
}
if (sb_mi->mbmi.sb_type) {
assert(sb_mi->mbmi.sb_type == BLOCK_SIZE_SB32X32);
count_segs(cpi, sb_mi, no_pred_segcounts, temporal_predictor_count,
t_unpred_seg_counts, 2, mb_row + y_idx, mb_col + x_idx);
} else {
int j;
for (j = 0; j < 4; j++) {
const int x_idx_mb = x_idx + (j & 1), y_idx_mb = y_idx + (j >> 1);
MODE_INFO *mb_mi = mi + x_idx_mb + y_idx_mb * mis;
if (mb_col + x_idx_mb >= cm->mb_cols ||
mb_row + y_idx_mb >= cm->mb_rows) {
continue;
}
assert(mb_mi->mbmi.sb_type == BLOCK_SIZE_MB16X16);
count_segs(cpi, mb_mi, no_pred_segcounts,
temporal_predictor_count, t_unpred_seg_counts,
1, mb_row + y_idx_mb, mb_col + x_idx_mb);
}
}
}
}
}
}
// Work out probability tree for coding segments without prediction
// and the cost.
calc_segtree_probs(xd, no_pred_segcounts, no_pred_tree);
no_pred_cost = cost_segmap(xd, no_pred_segcounts, no_pred_tree);
// Key frames cannot use temporal prediction
if (cm->frame_type != KEY_FRAME) {
// Work out probability tree for coding those segments not
// predicted using the temporal method and the cost.
calc_segtree_probs(xd, t_unpred_seg_counts, t_pred_tree);
t_pred_cost = cost_segmap(xd, t_unpred_seg_counts, t_pred_tree);
// Add in the cost of the signalling for each prediction context
for (i = 0; i < PREDICTION_PROBS; i++) {
t_nopred_prob[i] = get_binary_prob(temporal_predictor_count[i][0],
temporal_predictor_count[i][1]);
// Add in the predictor signaling cost
t_pred_cost += (temporal_predictor_count[i][0] *
vp9_cost_zero(t_nopred_prob[i])) +
(temporal_predictor_count[i][1] *
vp9_cost_one(t_nopred_prob[i]));
}
}
// Now choose which coding method to use.
if (t_pred_cost < no_pred_cost) {
cm->temporal_update = 1;
vpx_memcpy(xd->mb_segment_tree_probs,
t_pred_tree, sizeof(t_pred_tree));
vpx_memcpy(&cm->segment_pred_probs,
t_nopred_prob, sizeof(t_nopred_prob));
} else {
cm->temporal_update = 0;
vpx_memcpy(xd->mb_segment_tree_probs,
no_pred_tree, sizeof(no_pred_tree));
}
}