Commit d4440614 authored by Marco's avatar Marco

Non-rd variance partition: Adjustments to reduce dragging artifact.

For non-rd variannce partition, speed >= 5:
Adjustments to reduce dragging artifcat of background area near
slow moving boundary.

-Decrease base threshold under low source noise conditions.
-Add condition to split 64x64/32x32 based on average variances
of lower level blocks.

PSNR/SSIM metrics go down ~0.7/0.9% on average on RTC set.
Visually helps to reduce dragging artifact on some rtc clips.

Change-Id: If1f0a1aef1ddacd67464520ca070e167abf82fac
parent 74c67e3d
......@@ -496,6 +496,8 @@ static void set_vbp_thresholds(VP9_COMP *cpi, int64_t thresholds[], int q) {
threshold_base = 3 * threshold_base;
else if (noise_level == kMedium)
threshold_base = threshold_base << 1;
else if (noise_level < kLow)
threshold_base = (7 * threshold_base) >> 3;
}
if (cm->width <= 352 && cm->height <= 288) {
thresholds[0] = threshold_base >> 3;
......@@ -668,6 +670,8 @@ static int choose_partitioning(VP9_COMP *cpi,
v64x64 vt;
v16x16 vt2[16];
int force_split[21];
int avg_32x32;
int avg_16x16[4];
uint8_t *s;
const uint8_t *d;
int sp;
......@@ -819,6 +823,7 @@ static int choose_partitioning(VP9_COMP *cpi,
const int y32_idx = ((i >> 1) << 5);
const int i2 = i << 2;
force_split[i + 1] = 0;
avg_16x16[i] = 0;
for (j = 0; j < 4; j++) {
const int x16_idx = x32_idx + ((j & 1) << 4);
const int y16_idx = y32_idx + ((j >> 1) << 4);
......@@ -836,6 +841,7 @@ static int choose_partitioning(VP9_COMP *cpi,
is_key_frame);
fill_variance_tree(&vt.split[i].split[j], BLOCK_16X16);
get_variance(&vt.split[i].split[j].part_variances.none);
avg_16x16[i] += vt.split[i].split[j].part_variances.none.variance;
if (vt.split[i].split[j].part_variances.none.variance >
thresholds[2]) {
// 16X16 variance is above threshold for split, so force split to 8x8
......@@ -888,6 +894,7 @@ static int choose_partitioning(VP9_COMP *cpi,
}
// Fill the rest of the variance tree by summing split partition values.
avg_32x32 = 0;
for (i = 0; i < 4; i++) {
const int i2 = i << 2;
for (j = 0; j < 4; j++) {
......@@ -908,19 +915,29 @@ static int choose_partitioning(VP9_COMP *cpi,
}
}
fill_variance_tree(&vt.split[i], BLOCK_32X32);
// If variance of this 32x32 block is above the threshold, force the block
// to split. This also forces a split on the upper (64x64) level.
// If variance of this 32x32 block is above the threshold, or if its above
// (some threshold of) the average variance over the sub-16x16 blocks, then
// force this block to split. This also forces a split on the upper
// (64x64) level.
if (!force_split[i + 1]) {
get_variance(&vt.split[i].part_variances.none);
if (vt.split[i].part_variances.none.variance > thresholds[1]) {
if (vt.split[i].part_variances.none.variance > thresholds[1] ||
(!is_key_frame &&
vt.split[i].part_variances.none.variance > (3 * avg_16x16[i]) >> 2)) {
force_split[i + 1] = 1;
force_split[0] = 1;
}
avg_32x32 += vt.split[i].part_variances.none.variance;
}
}
if (!force_split[0]) {
fill_variance_tree(&vt, BLOCK_64X64);
get_variance(&vt.part_variances.none);
// If variance of this 64x64 block is above (some threshold of) the average
// variance over the sub-32x32 blocks, then force this block to split.
if (!is_key_frame &&
vt.part_variances.none.variance > (3 * avg_32x32) >> 3)
force_split[0] = 1;
}
// Now go through the entire structure, splitting every block size until
......
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