vpx/vp9/encoder/vp9_segmentation.c
Ronald S. Bultje 8bbcbdedcb Use recursive function in choosing segmentation map coding method.
This is shorter than fully writing out all cases (55 vs. 84 LOC), and
is easier to extend.

Change-Id: Ibad1bf6463198cad9188c5507181d4b03d393e6d
2013-04-29 12:04:51 -07:00

306 lines
11 KiB
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"
#include "vp9/common/vp9_tile_common.h"
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.mi_rows * cpi->common.mi_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) {
// Work out probabilities of each segment
segment_tree_probs[0] =
get_binary_prob(segcounts[0] + segcounts[1] + segcounts[2] + segcounts[3],
segcounts[4] + segcounts[5] + segcounts[6] + segcounts[7]);
segment_tree_probs[1] =
get_binary_prob(segcounts[0] + segcounts[1], segcounts[2] + segcounts[3]);
segment_tree_probs[2] = get_binary_prob(segcounts[0], segcounts[1]);
segment_tree_probs[3] = get_binary_prob(segcounts[2], segcounts[3]);
segment_tree_probs[4] =
get_binary_prob(segcounts[4] + segcounts[5], segcounts[6] + segcounts[7]);
segment_tree_probs[5] = get_binary_prob(segcounts[4], segcounts[5]);
segment_tree_probs[6] = get_binary_prob(segcounts[6], segcounts[7]);
}
// 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] + segcounts[2] + segcounts[3];
count2 = segcounts[3] + segcounts[4] + segcounts[5] + segcounts[6];
cost = count1 * vp9_cost_zero(probs[0]) +
count2 * vp9_cost_one(probs[0]);
// Cost subsequent levels
if (count1 > 0) {
count1 = segcounts[0] + segcounts[1];
count2 = segcounts[2] + segcounts[3];
cost += count1 * vp9_cost_zero(probs[1]) +
count2 * vp9_cost_one(probs[1]);
if (count1 > 0)
cost += segcounts[0] * vp9_cost_zero(probs[2]) +
segcounts[1] * vp9_cost_one(probs[2]);
if (count2 > 0)
cost += segcounts[2] * vp9_cost_zero(probs[3]) +
segcounts[3] * vp9_cost_one(probs[3]);
}
if (count2 > 0) {
count1 = segcounts[4] + segcounts[5];
count2 = segcounts[6] + segcounts[7];
cost += count1 * vp9_cost_zero(probs[4]) +
count2 * vp9_cost_one(probs[4]);
if (count1 > 0)
cost += segcounts[4] * vp9_cost_zero(probs[5]) +
segcounts[5] * vp9_cost_one(probs[5]);
if (count2 > 0)
cost += segcounts[6] * vp9_cost_zero(probs[6]) +
segcounts[7] * vp9_cost_one(probs[6]);
}
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 bw, int bh, int mi_row, int mi_col) {
VP9_COMMON *const cm = &cpi->common;
MACROBLOCKD *const xd = &cpi->mb.e_mbd;
const int segment_id = mi->mbmi.segment_id;
if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols)
return;
xd->mode_info_context = mi;
set_mi_row_col(cm, xd, mi_row, bh, mi_col, bw);
// 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 pred_seg_id = vp9_get_pred_mi_segid(cm, mi->mbmi.sb_type,
mi_row, mi_col);
const int seg_predicted = (segment_id == pred_seg_id);
// 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]++;
}
}
static void count_segs_sb(VP9_COMP *cpi, MODE_INFO *mi,
int *no_pred_segcounts,
int (*temporal_predictor_count)[2],
int *t_unpred_seg_counts,
int mi_row, int mi_col,
BLOCK_SIZE_TYPE bsize) {
VP9_COMMON *const cm = &cpi->common;
const int mis = cm->mode_info_stride;
int bwl, bhl;
const int bsl = mi_width_log2(bsize), bs = 1 << (bsl - 1);
if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols)
return;
bwl = mi_width_log2(mi->mbmi.sb_type);
bhl = mi_height_log2(mi->mbmi.sb_type);
if (bwl == bsl && bhl == bsl) {
count_segs(cpi, mi, no_pred_segcounts, temporal_predictor_count,
t_unpred_seg_counts, 1 << bsl, 1 << bsl, mi_row, mi_col);
} else if (bwl == bsl && bhl < bsl) {
count_segs(cpi, mi, no_pred_segcounts, temporal_predictor_count,
t_unpred_seg_counts, 1 << bsl, bs, mi_row, mi_col);
count_segs(cpi, mi + bs * mis, no_pred_segcounts, temporal_predictor_count,
t_unpred_seg_counts, 1 << bsl, bs, mi_row + bs, mi_col);
} else if (bwl < bsl && bhl == bsl) {
count_segs(cpi, mi, no_pred_segcounts, temporal_predictor_count,
t_unpred_seg_counts, bs, 1 << bsl, mi_row, mi_col);
count_segs(cpi, mi + bs, no_pred_segcounts, temporal_predictor_count,
t_unpred_seg_counts, bs, 1 << bsl, mi_row, mi_col + bs);
} else {
BLOCK_SIZE_TYPE subsize;
int n;
assert(bwl < bsl && bhl < bsl);
if (bsize == BLOCK_SIZE_SB64X64) {
subsize = BLOCK_SIZE_SB32X32;
} else {
assert(bsize == BLOCK_SIZE_SB32X32);
subsize = BLOCK_SIZE_MB16X16;
}
for (n = 0; n < 4; n++) {
const int y_idx = n >> 1, x_idx = n & 0x01;
count_segs_sb(cpi, mi + y_idx * bs * mis + x_idx * bs,
no_pred_segcounts, temporal_predictor_count,
t_unpred_seg_counts,
mi_row + y_idx * bs, mi_col + x_idx * bs, subsize);
}
}
}
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 tile_col, mi_row, mi_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_SEG_TREE_PROBS];
vp9_prob t_pred_tree[MB_SEG_TREE_PROBS];
vp9_prob t_nopred_prob[PREDICTION_PROBS];
const int mis = cm->mode_info_stride;
MODE_INFO *mi_ptr, *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 (tile_col = 0; tile_col < cm->tile_columns; tile_col++) {
vp9_get_tile_col_offsets(cm, tile_col);
mi_ptr = cm->mi + cm->cur_tile_mi_col_start;
for (mi_row = 0; mi_row < cm->mi_rows;
mi_row += (4 << CONFIG_SB8X8), mi_ptr += (4 << CONFIG_SB8X8) * mis) {
mi = mi_ptr;
for (mi_col = cm->cur_tile_mi_col_start;
mi_col < cm->cur_tile_mi_col_end;
mi_col += (4 << CONFIG_SB8X8), mi += (4 << CONFIG_SB8X8)) {
count_segs_sb(cpi, mi, no_pred_segcounts, temporal_predictor_count,
t_unpred_seg_counts, mi_row, mi_col, BLOCK_SIZE_SB64X64);
}
}
}
// 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));
}
}