libvpx: Pull from upstream

source/libvpx/vp8/encoder/denoising.c

Index: source/libvpx/vp8/encoder/denoising.c
===================================================================
--- source/libvpx/vp8/encoder/denoising.c	(revision 278778)
+++ source/libvpx/vp8/encoder/denoising.c	(working copy)
@@ -136,17 +136,67 @@
 
     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;
 }
 
-int vp8_denoiser_allocate(VP8_DENOISER *denoiser, int width, int height)
+int vp8_denoiser_allocate(VP8_DENOISER *denoiser, int width, int height,
+                          int num_mb_rows, int num_mb_cols)
 {
     int i;
     assert(denoiser);
+    denoiser->num_mb_cols = num_mb_cols;
 
     for (i = 0; i < MAX_REF_FRAMES; i++)
     {
@@ -174,6 +224,10 @@
 
     vpx_memset(denoiser->yv12_mc_running_avg.buffer_alloc, 0,
                denoiser->yv12_mc_running_avg.frame_size);
+
+    denoiser->denoise_state = vpx_calloc((num_mb_rows * num_mb_cols), 1);
+    vpx_memset(denoiser->denoise_state, 0, (num_mb_rows * num_mb_cols));
+
     return 0;
 }
 
@@ -195,12 +249,20 @@
                              unsigned int best_sse,
                              unsigned int zero_mv_sse,
                              int recon_yoffset,
-                             int recon_uvoffset)
+                             int recon_uvoffset,
+                             loop_filter_info_n *lfi_n,
+                             int mb_row,
+                             int mb_col,
+                             int block_index)
 {
     int mv_row;
     int mv_col;
     unsigned int motion_magnitude2;
     unsigned int sse_thresh;
+    int sse_diff_thresh = 0;
+    // Spatial loop filter: only applied selectively based on
+    // temporal filter state of block relative to top/left neighbors.
+    int apply_spatial_loop_filter = 1;
     MV_REFERENCE_FRAME frame = x->best_reference_frame;
     MV_REFERENCE_FRAME zero_frame = x->best_zeromv_reference_frame;
 
@@ -214,7 +276,11 @@
         MB_MODE_INFO saved_mbmi;
         MACROBLOCKD *filter_xd = &x->e_mbd;
         MB_MODE_INFO *mbmi = &filter_xd->mode_info_context->mbmi;
-        int sse_diff = zero_mv_sse - best_sse;
+        int sse_diff = 0;
+        // Bias on zero motion vector sse.
+        int zero_bias = 95;
+        zero_mv_sse = (unsigned int)((int64_t)zero_mv_sse * zero_bias / 100);
+        sse_diff = zero_mv_sse - best_sse;
 
         saved_mbmi = *mbmi;
 
@@ -225,11 +291,16 @@
         mbmi->need_to_clamp_mvs = x->need_to_clamp_best_mvs;
         mv_col = x->best_sse_mv.as_mv.col;
         mv_row = x->best_sse_mv.as_mv.row;
+        // Bias to zero_mv if small amount of motion.
+        // Note sse_diff_thresh is intialized to zero, so this ensures
+        // we will always choose zero_mv for denoising if
+        // zero_mv_see <= best_sse (i.e., sse_diff <= 0).
+        if ((unsigned int)(mv_row * mv_row + mv_col * mv_col)
+            <= NOISE_MOTION_THRESHOLD)
+            sse_diff_thresh = (int)SSE_DIFF_THRESHOLD;
 
         if (frame == INTRA_FRAME ||
-            ((unsigned int)(mv_row *mv_row + mv_col *mv_col)
-              <= NOISE_MOTION_THRESHOLD &&
-             sse_diff < (int)SSE_DIFF_THRESHOLD))
+            sse_diff <= sse_diff_thresh)
         {
             /*
              * Handle intra blocks as referring to last frame with zero motion
@@ -308,6 +379,8 @@
                                          running_avg_y, avg_y_stride,
                                          x->thismb, 16, motion_magnitude2,
                                          x->increase_denoising);
+        denoiser->denoise_state[block_index] = motion_magnitude2 > 0 ?
+            kFilterNonZeroMV : kFilterZeroMV;
     }
     if (decision == COPY_BLOCK)
     {
@@ -318,5 +391,59 @@
                 x->thismb, 16,
                 denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset,
                 denoiser->yv12_running_avg[INTRA_FRAME].y_stride);
+        denoiser->denoise_state[block_index] = kNoFilter;
     }
+    // Option to selectively deblock the denoised signal.
+    if (apply_spatial_loop_filter) {
+      loop_filter_info lfi;
+      int apply_filter_col = 0;
+      int apply_filter_row = 0;
+      int apply_filter = 0;
+      int y_stride = denoiser->yv12_running_avg[INTRA_FRAME].y_stride;
+      int uv_stride =denoiser->yv12_running_avg[INTRA_FRAME].uv_stride;
+
+      // Fix filter level to some nominal value for now.
+      int filter_level = 32;
+
+      int hev_index = lfi_n->hev_thr_lut[INTER_FRAME][filter_level];
+      lfi.mblim = lfi_n->mblim[filter_level];
+      lfi.blim = lfi_n->blim[filter_level];
+      lfi.lim = lfi_n->lim[filter_level];
+      lfi.hev_thr = lfi_n->hev_thr[hev_index];
+
+      // Apply filter if there is a difference in the denoiser filter state
+      // between the current and left/top block, or if non-zero motion vector
+      // is used for the motion-compensated filtering.
+      if (mb_col > 0) {
+        apply_filter_col = !((denoiser->denoise_state[block_index] ==
+            denoiser->denoise_state[block_index - 1]) &&
+            denoiser->denoise_state[block_index] != kFilterNonZeroMV);
+        if (apply_filter_col) {
+          // Filter left vertical edge.
+          apply_filter = 1;
+          vp8_loop_filter_mbv(
+              denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset,
+              NULL, NULL, y_stride, uv_stride, &lfi);
+        }
+      }
+      if (mb_row > 0) {
+        apply_filter_row = !((denoiser->denoise_state[block_index] ==
+            denoiser->denoise_state[block_index - denoiser->num_mb_cols]) &&
+            denoiser->denoise_state[block_index] != kFilterNonZeroMV);
+        if (apply_filter_row) {
+          // Filter top horizontal edge.
+          apply_filter = 1;
+          vp8_loop_filter_mbh(
+              denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset,
+              NULL, NULL, y_stride, uv_stride, &lfi);
+        }
+      }
+      if (apply_filter) {
+        // Update the signal block |x|. Pixel changes are only to top and/or
+        // left boundary pixels: can we avoid full block copy here.
+        vp8_copy_mem16x16(
+            denoiser->yv12_running_avg[INTRA_FRAME].y_buffer + recon_yoffset,
+            y_stride, x->thismb, 16);
+      }
+    }
 }