Commit 1c724d01 authored by Marco's avatar Marco

vp9: Updates to noise estimation.

Add threshold/condition on spatial_variance and brightness level.
Modification to normalization of block variance.
Change resolution limit below which we disable noise estimation.

Change-Id: If5be08a26ceda351242d8a58d2f0bc88c0a918f0
parent 57cae22c
......@@ -28,11 +28,11 @@ void vp9_noise_estimate_init(NOISE_ESTIMATE *const ne,
ne->level = kLow;
ne->value = 0;
ne->count = 0;
ne->thresh = 20;
ne->thresh = 90;
if (width * height >= 1920 * 1080) {
ne->thresh = 70;
ne->thresh = 200;
} else if (width * height >= 1280 * 720) {
ne->thresh = 40;
ne->thresh = 130;
}
}
......@@ -55,8 +55,8 @@ int enable_noise_estimation(VP9_COMP *const cpi) {
cpi->resize_state == ORIG &&
!cpi->use_svc &&
cpi->oxcf.content != VP9E_CONTENT_SCREEN &&
cpi->common.width > 352 &&
cpi->common.height > 288)
cpi->common.width >= 640 &&
cpi->common.height >= 480)
return 1;
else
return 0;
......@@ -86,6 +86,8 @@ void vp9_update_noise_estimate(VP9_COMP *const cpi) {
int frame_period = 10;
int thresh_consec_zeromv = 8;
unsigned int thresh_sum_diff = 128;
unsigned int thresh_sum_spatial = (200 * 200) << 8;
unsigned int thresh_spatial_var = (32 * 32) << 8;
int num_frames_estimate = 20;
int min_blocks_estimate = cm->mi_rows * cm->mi_cols >> 7;
// Estimate is between current source and last source.
......@@ -108,8 +110,7 @@ void vp9_update_noise_estimate(VP9_COMP *const cpi) {
uint64_t avg_est = 0;
int bsize = BLOCK_16X16;
static const unsigned char const_source[16] = {
128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
128, 128};
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
// Loop over sub-sample of 16x16 blocks of frame, and for blocks that have
// been encoded as zero/small mv at least x consecutive frames, compute
// the variance to update estimate of noise in the source.
......@@ -164,8 +165,12 @@ void vp9_update_noise_estimate(VP9_COMP *const cpi) {
const unsigned int spatial_variance =
cpi->fn_ptr[bsize].vf(src_y, src_ystride, const_source,
0, &sse2);
avg_est += variance / (10 + spatial_variance);
num_samples++;
// Avoid blocks with high brightness and high spatial variance.
if ((sse2 - spatial_variance) < thresh_sum_spatial &&
spatial_variance < thresh_spatial_var) {
avg_est += variance / ((spatial_variance >> 9) + 1);
num_samples++;
}
}
}
}
......@@ -184,7 +189,7 @@ void vp9_update_noise_estimate(VP9_COMP *const cpi) {
// duplicate frames).
if (num_samples > min_blocks_estimate && avg_est > 0) {
// Normalize.
avg_est = (avg_est << 8) / num_samples;
avg_est = avg_est / num_samples;
// Update noise estimate.
ne->value = (int)((3 * ne->value + avg_est) >> 2);
ne->count++;
......
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