ref: c77aff1286df07fb9f3b49feaacf384703813eca
parent: 27bb4777cd8ecf0a0fa2599a25c84a13c6789d9b
author: Paul Wilkins <[email protected]>
date: Wed Apr 24 06:20:52 EDT 2013
Simplify Segment Coding Remove top node optimization. The improvement this gives is not sufficient to justify the extra complexity. Change-Id: I2bb4a12a50ffd52cacfa4a3e8acbb2e522066905
--- a/vp9/common/vp9_blockd.h
+++ b/vp9/common/vp9_blockd.h
@@ -399,7 +399,6 @@
// Probability Tree used to code Segment number
vp9_prob mb_segment_tree_probs[MB_FEATURE_TREE_PROBS];
- vp9_prob mb_segment_mispred_tree_probs[MAX_MB_SEGMENTS];
// Segment features
signed char segment_feature_data[MAX_MB_SEGMENTS][SEG_LVL_MAX];
--- a/vp9/decoder/vp9_decodemv.c
+++ b/vp9/decoder/vp9_decodemv.c
@@ -79,21 +79,6 @@
: vp9_read(r, p[1]);
}
-// This function reads the current macro block's segnent id from the bitstream
-// It should only be called if a segment map update is indicated.
-static int read_mb_segid_except(vp9_reader *r,
- VP9_COMMON *cm, MACROBLOCKD *xd,
- int mb_row, int mb_col) {
- const BLOCK_SIZE_TYPE sb_type = xd->mode_info_context->mbmi.sb_type;
- const int pred_seg_id = vp9_get_pred_mb_segid(cm, sb_type, mb_row, mb_col);
- const vp9_prob *const p = xd->mb_segment_tree_probs;
- const vp9_prob prob = xd->mb_segment_mispred_tree_probs[pred_seg_id];
-
- return vp9_read(r, prob)
- ? 2 + (pred_seg_id < 2 ? vp9_read(r, p[2]) : (pred_seg_id == 2))
- : (pred_seg_id >= 2 ? vp9_read(r, p[1]) : (pred_seg_id == 0));
-}
-
static void set_segment_id(VP9_COMMON *cm, MB_MODE_INFO *mbmi,
int mb_row, int mb_col, int segment_id) {
const int mb_index = mb_row * cm->mb_cols + mb_col;
@@ -551,7 +536,7 @@
// then use the predicted value, otherwise decode it explicitly
segment_id = pred_flag ? vp9_get_pred_mb_segid(cm, mbmi->sb_type,
mb_row, mb_col)
- : read_mb_segid_except(r, cm, xd, mb_row, mb_col);
+ : read_mb_segid(r, xd);
} else {
segment_id = read_mb_segid(r, xd); // Normal unpredicted coding mode
}
--- a/vp9/decoder/vp9_decodframe.c
+++ b/vp9/decoder/vp9_decodframe.c
@@ -1113,19 +1113,6 @@
pc->temporal_update = vp9_read_bit(r);
if (pc->temporal_update) {
- const vp9_prob *p = xd->mb_segment_tree_probs;
- vp9_prob *mispred_p = xd->mb_segment_mispred_tree_probs;
-
- const int c0 = p[0] * p[1];
- const int c1 = p[0] * (256 - p[1]);
- const int c2 = (256 - p[0]) * p[2];
- const int c3 = (256 - p[0]) * (256 - p[2]);
-
- mispred_p[0] = get_binary_prob(c1, c2 + c3);
- mispred_p[1] = get_binary_prob(c0, c2 + c3);
- mispred_p[2] = get_binary_prob(c0 + c1, c3);
- mispred_p[3] = get_binary_prob(c0 + c1, c2);
-
for (i = 0; i < PREDICTION_PROBS; i++)
pc->segment_pred_probs[i] = vp9_read_bit(r) ? vp9_read_prob(r)
: MAX_PROB;
--- a/vp9/encoder/vp9_bitstream.c
+++ b/vp9/encoder/vp9_bitstream.c
@@ -560,28 +560,6 @@
}
}
-static void write_mb_segid_except(VP9_COMMON *cm,
- vp9_writer *bc,
- const MB_MODE_INFO *mi,
- const MACROBLOCKD *xd,
- int mb_row, int mb_col) {
- // Encode the MB segment id.
- const int seg_id = mi->segment_id;
- const BLOCK_SIZE_TYPE sb_type = xd->mode_info_context->mbmi.sb_type;
- const int pred_seg_id = vp9_get_pred_mb_segid(cm, sb_type, mb_row, mb_col);
- const vp9_prob *p = xd->mb_segment_tree_probs;
- const vp9_prob p1 = xd->mb_segment_mispred_tree_probs[pred_seg_id];
-
- if (xd->segmentation_enabled && xd->update_mb_segmentation_map) {
- vp9_write(bc, seg_id >= 2, p1);
- if (pred_seg_id >= 2 && seg_id < 2) {
- vp9_write(bc, seg_id == 1, p[1]);
- } else if (pred_seg_id < 2 && seg_id >= 2) {
- vp9_write(bc, seg_id == 3, p[2]);
- }
- }
-}
-
// This function encodes the reference frame
static void encode_ref_frame(vp9_writer *const bc,
VP9_COMMON *const cm,
@@ -725,7 +703,7 @@
// If the mb segment id wasn't predicted code explicitly
if (!prediction_flag)
- write_mb_segid_except(pc, bc, mi, &cpi->mb.e_mbd, mb_row, mb_col);
+ write_mb_segid(bc, mi, &cpi->mb.e_mbd);
} else {
// Normal unpredicted coding
write_mb_segid(bc, mi, &cpi->mb.e_mbd);
--- a/vp9/encoder/vp9_segmentation.c
+++ b/vp9/encoder/vp9_segmentation.c
@@ -103,8 +103,7 @@
// Based on set of segment counts calculate a probability tree
static void calc_segtree_probs_pred(MACROBLOCKD *xd,
int (*segcounts)[MAX_MB_SEGMENTS],
- vp9_prob *segment_tree_probs,
- vp9_prob *mod_probs) {
+ vp9_prob *segment_tree_probs) {
int count[4];
assert(!segcounts[0][0] && !segcounts[1][1] &&
@@ -121,24 +120,12 @@
count[2] + count[3]);
segment_tree_probs[1] = get_binary_prob(count[0], count[1]);
segment_tree_probs[2] = get_binary_prob(count[2], count[3]);
-
- // now work out modified counts that the decoder would have
- count[0] = segment_tree_probs[0] * segment_tree_probs[1];
- count[1] = segment_tree_probs[0] * (256 - segment_tree_probs[1]);
- count[2] = (256 - segment_tree_probs[0]) * segment_tree_probs[2];
- count[3] = (256 - segment_tree_probs[0]) * (256 - segment_tree_probs[2]);
-
- // Work out modified probabilties depending on what segment was predicted
- mod_probs[0] = get_binary_prob(count[1], count[2] + count[3]);
- mod_probs[1] = get_binary_prob(count[0], count[2] + count[3]);
- mod_probs[2] = get_binary_prob(count[0] + count[1], count[3]);
- mod_probs[3] = get_binary_prob(count[0] + count[1], count[2]);
}
// Based on set of segment counts and probabilities calculate a cost estimate
static int cost_segmap_pred(MACROBLOCKD *xd,
int (*segcounts)[MAX_MB_SEGMENTS],
- vp9_prob *probs, vp9_prob *mod_probs) {
+ vp9_prob *probs) {
int pred_seg, cost = 0;
for (pred_seg = 0; pred_seg < MAX_MB_SEGMENTS; pred_seg++) {
@@ -147,8 +134,8 @@
// Cost the top node of the tree
count1 = segcounts[pred_seg][0] + segcounts[pred_seg][1];
count2 = segcounts[pred_seg][2] + segcounts[pred_seg][3];
- cost += count1 * vp9_cost_zero(mod_probs[pred_seg]) +
- count2 * vp9_cost_one(mod_probs[pred_seg]);
+ cost += count1 * vp9_cost_zero(probs[0]) +
+ count2 * vp9_cost_one(probs[0]);
// Now add the cost of each individual segment branch
if (pred_seg >= 2 && count1) {
@@ -217,7 +204,6 @@
vp9_prob no_pred_tree[MB_FEATURE_TREE_PROBS];
vp9_prob t_pred_tree[MB_FEATURE_TREE_PROBS];
- vp9_prob t_pred_tree_mod[MAX_MB_SEGMENTS];
vp9_prob t_nopred_prob[PREDICTION_PROBS];
const int mis = cm->mode_info_stride;
@@ -332,10 +318,8 @@
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_pred(xd, t_unpred_seg_counts, t_pred_tree,
- t_pred_tree_mod);
- t_pred_cost = cost_segmap_pred(xd, t_unpred_seg_counts, t_pred_tree,
- t_pred_tree_mod);
+ calc_segtree_probs_pred(xd, t_unpred_seg_counts, t_pred_tree);
+ t_pred_cost = cost_segmap_pred(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++) {
@@ -355,8 +339,6 @@
cm->temporal_update = 1;
vpx_memcpy(xd->mb_segment_tree_probs,
t_pred_tree, sizeof(t_pred_tree));
- vpx_memcpy(xd->mb_segment_mispred_tree_probs,
- t_pred_tree_mod, sizeof(t_pred_tree_mod));
vpx_memcpy(&cm->segment_pred_probs,
t_nopred_prob, sizeof(t_nopred_prob));
} else {