ref: 567746d3f0d39d7c44682df18f6617515540d522
parent: 1349e8634ca1be8a128501b74164ae0b523e0ee0
parent: 4e81ab82d55d44e2b125f00017d2026226c5483a
author: Marco Paniconi <marpan@google.com>
date: Tue May 27 11:32:16 EDT 2014
Merge "Fix to reduce block artifacts from vp8 temporal denoiser."
--- a/vp8/encoder/denoising.c
+++ b/vp8/encoder/denoising.c
@@ -136,8 +136,56 @@
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;
--- a/vp8/encoder/x86/denoising_sse2.c
+++ b/vp8/encoder/x86/denoising_sse2.c
@@ -112,9 +112,70 @@
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;
+ }
}
}
--
⑨