Refactor probability savings search.
- Avoid excessive copying
- Don't bother searching if no update can possibly offer savings
- Simplify the interface
- Remove the confusing av1_cost_upd256 macro
(cherry picked from libvpx/master commit
19e0b406c9601ec79f96cba654347e48650929ed)
Change-Id: Id9d9676a361fd1203b27e930cd29c23b2813ce59
diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index a36f0c9..6829a80 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -2476,8 +2476,8 @@
int u = 0;
if (t == PIVOT_NODE)
s = av1_prob_diff_update_savings_search_model(
- frame_branch_ct[i][j][k][l][0],
- old_coef_probs[i][j][k][l], &newp, upd, stepsize, probwt);
+ frame_branch_ct[i][j][k][l][0], oldp, &newp, upd,
+ stepsize, probwt);
else
s = av1_prob_diff_update_savings_search(
frame_branch_ct[i][j][k][l][t], oldp, &newp, upd, probwt);
@@ -2512,8 +2512,8 @@
int u = 0;
if (t == PIVOT_NODE)
s = av1_prob_diff_update_savings_search_model(
- frame_branch_ct[i][j][k][l][0],
- old_coef_probs[i][j][k][l], &newp, upd, stepsize, probwt);
+ frame_branch_ct[i][j][k][l][0], *oldp, &newp, upd,
+ stepsize, probwt);
else
s = av1_prob_diff_update_savings_search(
frame_branch_ct[i][j][k][l][t], *oldp, &newp, upd,
@@ -2548,8 +2548,8 @@
int u = 0;
if (t == PIVOT_NODE) {
s = av1_prob_diff_update_savings_search_model(
- frame_branch_ct[i][j][k][l][0],
- old_coef_probs[i][j][k][l], &newp, upd, stepsize, probwt);
+ frame_branch_ct[i][j][k][l][0], *oldp, &newp, upd,
+ stepsize, probwt);
} else {
s = av1_prob_diff_update_savings_search(
frame_branch_ct[i][j][k][l][t], *oldp, &newp, upd,
diff --git a/av1/encoder/subexp.c b/av1/encoder/subexp.c
index 81bb56d..ff213c5 100644
--- a/av1/encoder/subexp.c
+++ b/av1/encoder/subexp.c
@@ -15,8 +15,6 @@
#include "av1/encoder/cost.h"
#include "av1/encoder/subexp.h"
-#define av1_cost_upd256 ((int)(av1_cost_one(upd) - av1_cost_zero(upd)))
-
static const uint8_t update_bits[255] = {
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 8, 8, 8, 8, 8,
@@ -33,6 +31,7 @@
11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
11, 11, 11, 11, 11, 11, 11, 0,
};
+#define MIN_DELP_BITS 5
static int recenter_nonneg(int v, int m) {
if (v > (m << 1))
@@ -122,15 +121,17 @@
int bestsavings = 0;
aom_prob newp, bestnewp = oldp;
const int step = *bestp > oldp ? -1 : 1;
+ const int upd_cost = av1_cost_one(upd) - av1_cost_zero(upd);
- for (newp = *bestp; newp != oldp; newp += step) {
- const uint32_t new_b = cost_branch256(ct, newp);
- const uint32_t update_b =
- prob_diff_update_cost(newp, oldp) + av1_cost_upd256;
- const int savings = (int)((int64_t)old_b - new_b - update_b * probwt);
- if (savings > bestsavings) {
- bestsavings = savings;
- bestnewp = newp;
+ if (old_b > (uint32_t)upd_cost + (MIN_DELP_BITS << AV1_PROB_COST_SHIFT)) {
+ for (newp = *bestp; newp != oldp; newp += step) {
+ const int new_b = cost_branch256(ct, newp);
+ const int update_b = prob_diff_update_cost(newp, oldp) + upd_cost;
+ const int savings = (int)((int64_t)old_b - new_b - update_b * probwt);
+ if (savings > bestsavings) {
+ bestsavings = savings;
+ bestnewp = newp;
+ }
}
}
*bestp = bestnewp;
@@ -138,37 +139,39 @@
}
int av1_prob_diff_update_savings_search_model(const unsigned int *ct,
- const aom_prob *oldp,
+ const aom_prob oldp,
aom_prob *bestp, aom_prob upd,
int stepsize, int probwt) {
int i, old_b, new_b, update_b, savings, bestsavings;
int newp;
- const int step_sign = *bestp > oldp[PIVOT_NODE] ? -1 : 1;
+ const int step_sign = *bestp > oldp ? -1 : 1;
const int step = stepsize * step_sign;
- aom_prob bestnewp, newplist[ENTROPY_NODES], oldplist[ENTROPY_NODES];
- av1_model_to_full_probs(oldp, oldplist);
- memcpy(newplist, oldp, sizeof(aom_prob) * UNCONSTRAINED_NODES);
- for (i = UNCONSTRAINED_NODES, old_b = 0; i < ENTROPY_NODES; ++i)
- old_b += cost_branch256(ct + 2 * i, oldplist[i]);
- old_b += cost_branch256(ct + 2 * PIVOT_NODE, oldplist[PIVOT_NODE]);
+ const int upd_cost = av1_cost_one(upd) - av1_cost_zero(upd);
+ const aom_prob *newplist, *oldplist;
+ aom_prob bestnewp;
+ oldplist = av1_pareto8_full[oldp - 1];
+ old_b = cost_branch256(ct + 2 * PIVOT_NODE, oldp);
+ for (i = UNCONSTRAINED_NODES; i < ENTROPY_NODES; ++i)
+ old_b += cost_branch256(ct + 2 * i, oldplist[i - UNCONSTRAINED_NODES]);
bestsavings = 0;
- bestnewp = oldp[PIVOT_NODE];
+ bestnewp = oldp;
assert(stepsize > 0);
- for (newp = *bestp; (newp - oldp[PIVOT_NODE]) * step_sign < 0; newp += step) {
- if (newp < 1 || newp > 255) continue;
- newplist[PIVOT_NODE] = newp;
- av1_model_to_full_probs(newplist, newplist);
- for (i = UNCONSTRAINED_NODES, new_b = 0; i < ENTROPY_NODES; ++i)
- new_b += cost_branch256(ct + 2 * i, newplist[i]);
- new_b += cost_branch256(ct + 2 * PIVOT_NODE, newplist[PIVOT_NODE]);
- update_b = prob_diff_update_cost(newp, oldp[PIVOT_NODE]) + av1_cost_upd256;
- savings = old_b - new_b - update_b * probwt;
- if (savings > bestsavings) {
- bestsavings = savings;
- bestnewp = newp;
+ if (old_b > upd_cost + (MIN_DELP_BITS << AV1_PROB_COST_SHIFT)) {
+ for (newp = *bestp; (newp - oldp) * step_sign < 0; newp += step) {
+ if (newp < 1 || newp > 255) continue;
+ newplist = av1_pareto8_full[newp - 1];
+ new_b = cost_branch256(ct + 2 * PIVOT_NODE, newp);
+ for (i = UNCONSTRAINED_NODES; i < ENTROPY_NODES; ++i)
+ new_b += cost_branch256(ct + 2 * i, newplist[i - UNCONSTRAINED_NODES]);
+ update_b = prob_diff_update_cost(newp, oldp) + upd_cost;
+ savings = old_b - new_b - update_b * probwt;
+ if (savings > bestsavings) {
+ bestsavings = savings;
+ bestnewp = newp;
+ }
}
}
diff --git a/av1/encoder/subexp.h b/av1/encoder/subexp.h
index d01dea9..9cd3c0b 100644
--- a/av1/encoder/subexp.h
+++ b/av1/encoder/subexp.h
@@ -29,7 +29,7 @@
int probwt);
int av1_prob_diff_update_savings_search_model(const unsigned int *ct,
- const aom_prob *oldp,
+ const aom_prob oldp,
aom_prob *bestp, aom_prob upd,
int stepsize, int probwt);
