Commit 567746d3 authored by Marco Paniconi's avatar Marco Paniconi Committed by Gerrit Code Review
Browse files

Merge "Fix to reduce block artifacts from vp8 temporal denoiser."

parents 1349e863 4e81ab82
......@@ -136,8 +136,56 @@ int vp8_denoiser_filter_c(unsigned char *mc_running_avg_y, int mc_avg_y_stride,
sum_diff_thresh= SUM_DIFF_THRESHOLD;
if (increase_denoising) sum_diff_thresh = SUM_DIFF_THRESHOLD_HIGH;
if (abs(sum_diff) > sum_diff_thresh)
if (abs(sum_diff) > sum_diff_thresh) {
// Before returning to copy the block (i.e., apply no denoising), check
// if we can still apply some (weaker) temporal filtering to this block,
// that would otherwise not be denoised at all. Simplest is to apply
// an additional adjustment to running_avg_y to bring it closer to sig.
// The adjustment is capped by a maximum delta, and chosen such that
// in most cases the resulting sum_diff will be within the
// accceptable range given by sum_diff_thresh.
// The delta is set by the excess of absolute pixel diff over threshold.
int delta = ((abs(sum_diff) - sum_diff_thresh) >> 8) + 1;
// Only apply the adjustment for max delta up to 3.
if (delta < 4) {
sig -= sig_stride * 16;
mc_running_avg_y -= mc_avg_y_stride * 16;
running_avg_y -= avg_y_stride * 16;
for (r = 0; r < 16; ++r) {
for (c = 0; c < 16; ++c) {
int diff = mc_running_avg_y[c] - sig[c];
int adjustment = abs(diff);
if (adjustment > delta)
adjustment = delta;
if (diff > 0) {
// Bring denoised signal down.
if (running_avg_y[c] - adjustment < 0)
running_avg_y[c] = 0;
else
running_avg_y[c] = running_avg_y[c] - adjustment;
sum_diff -= adjustment;
} else if (diff < 0) {
// Bring denoised signal up.
if (running_avg_y[c] + adjustment > 255)
running_avg_y[c] = 255;
else
running_avg_y[c] = running_avg_y[c] + adjustment;
sum_diff += adjustment;
}
}
// TODO(marpan): Check here if abs(sum_diff) has gone below the
// threshold sum_diff_thresh, and if so, we can exit the row loop.
sig += sig_stride;
mc_running_avg_y += mc_avg_y_stride;
running_avg_y += avg_y_stride;
}
if (abs(sum_diff) > sum_diff_thresh)
return COPY_BLOCK;
} else {
return COPY_BLOCK;
}
}
vp8_copy_mem16x16(running_avg_y_start, avg_y_stride, sig_start, sig_stride);
return FILTER_BLOCK;
......
......@@ -112,9 +112,70 @@ int vp8_denoiser_filter_sse2(unsigned char *mc_running_avg_y,
sum_diff_thresh = SUM_DIFF_THRESHOLD;
if (increase_denoising) sum_diff_thresh = SUM_DIFF_THRESHOLD_HIGH;
if (abs(sum_diff) > sum_diff_thresh)
{
if (abs(sum_diff) > sum_diff_thresh) {
// Before returning to copy the block (i.e., apply no denoising),
// checK if we can still apply some (weaker) temporal filtering to
// this block, that would otherwise not be denoised at all. Simplest
// is to apply an additional adjustment to running_avg_y to bring it
// closer to sig. The adjustment is capped by a maximum delta, and
// chosen such that in most cases the resulting sum_diff will be
// within the accceptable range given by sum_diff_thresh.
// The delta is set by the excess of absolute pixel diff over the
// threshold.
int delta = ((abs(sum_diff) - sum_diff_thresh) >> 8) + 1;
// Only apply the adjustment for max delta up to 3.
if (delta < 4) {
const __m128i k_delta = _mm_set1_epi8(delta);
sig -= sig_stride * 16;
mc_running_avg_y -= mc_avg_y_stride * 16;
running_avg_y -= avg_y_stride * 16;
for (r = 0; r < 16; ++r) {
__m128i v_running_avg_y =
_mm_loadu_si128((__m128i *)(&running_avg_y[0]));
// Calculate differences.
const __m128i v_sig = _mm_loadu_si128((__m128i *)(&sig[0]));
const __m128i v_mc_running_avg_y =
_mm_loadu_si128((__m128i *)(&mc_running_avg_y[0]));
const __m128i pdiff = _mm_subs_epu8(v_mc_running_avg_y, v_sig);
const __m128i ndiff = _mm_subs_epu8(v_sig, v_mc_running_avg_y);
// Obtain the sign. FF if diff is negative.
const __m128i diff_sign = _mm_cmpeq_epi8(pdiff, k_0);
// Clamp absolute difference to delta to get the adjustment.
const __m128i adj =
_mm_min_epu8(_mm_or_si128(pdiff, ndiff), k_delta);
// Restore the sign and get positive and negative adjustments.
__m128i padj, nadj;
padj = _mm_andnot_si128(diff_sign, adj);
nadj = _mm_and_si128(diff_sign, adj);
// Calculate filtered value.
v_running_avg_y = _mm_subs_epu8(v_running_avg_y, padj);
v_running_avg_y = _mm_adds_epu8(v_running_avg_y, nadj);
_mm_storeu_si128((__m128i *)running_avg_y, v_running_avg_y);
// Accumulate the adjustments.
acc_diff = _mm_subs_epi8(acc_diff, padj);
acc_diff = _mm_adds_epi8(acc_diff, nadj);
// Update pointers for next iteration.
sig += sig_stride;
mc_running_avg_y += mc_avg_y_stride;
running_avg_y += avg_y_stride;
}
{
// Update the sum of all pixel differences of this MB.
union sum_union s;
s.v = acc_diff;
sum_diff = s.e[0] + s.e[1] + s.e[2] + s.e[3] + s.e[4] + s.e[5]
+ s.e[6] + s.e[7] + s.e[8] + s.e[9] + s.e[10] + s.e[11]
+ s.e[12] + s.e[13] + s.e[14] + s.e[15];
if (abs(sum_diff) > sum_diff_thresh) {
return COPY_BLOCK;
}
}
} else {
return COPY_BLOCK;
}
}
}
......
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