vp8 denoiser: Some adjustments to usage of skin and motion.

Switch to use new skin model.

And fix condition for denoising skin block.
Previous condition did not denoise skin blocks if the selected
mode was non-zero motion in current frame. Modify condition to
also force no denoising if that mode was not selected as zero motion
now and for at least "x" past frames in a row (x = 2).

Change-Id: I00753e3fe45b9a308a7ef43c58f11868e3bfc6b0

vp8/encoder/denoising.c

diff --git a/vp8/encoder/denoising.c b/vp8/encoder/denoising.c
index 5ae44e8..c85251e 100644
--- a/vp8/encoder/denoising.c
+++ b/vp8/encoder/denoising.c
@@ -497,7 +497,8 @@
                              loop_filter_info_n *lfi_n,
                              int mb_row,
                              int mb_col,
-                             int block_index)
+                             int block_index,
+                             int consec_zero_last)
 
 {
     int mv_row;
@@ -608,11 +609,6 @@
     motion_threshold = denoiser->denoise_pars.scale_motion_thresh *
         NOISE_MOTION_THRESHOLD;
 
-    // If block is considered to be skin area, lower the motion threshold.
-    // In current version set threshold = 0, so only denoise zero mv on skin.
-    if (x->is_skin)
-        motion_threshold = 0;
-
     if (motion_magnitude2 <
         denoiser->denoise_pars.scale_increase_filter * NOISE_MOTION_THRESHOLD)
       x->increase_denoising = 1;
@@ -624,6 +620,15 @@
     if (best_sse > sse_thresh || motion_magnitude2 > motion_threshold)
       decision = COPY_BLOCK;
 
+    // If block is considered skin, don't denoise if the block
+    // (1) is selected as non-zero motion for current frame, or
+    // (2) has not been selected as ZERO_LAST mode at least x past frames
+    // in a row.
+    // TODO(marpan): Parameter "x" should be varied with framerate.
+    // In particualar, should be reduced for temporal layers (base layer/LAST).
+    if (x->is_skin && (consec_zero_last < 2 || motion_magnitude2 > 0))
+      decision = COPY_BLOCK;
+
     if (decision == FILTER_BLOCK)
     {
         unsigned char *mc_running_avg_y =

vp8/encoder/denoising.h

diff --git a/vp8/encoder/denoising.h b/vp8/encoder/denoising.h
index 148ccda..34c561d 100644
--- a/vp8/encoder/denoising.h
+++ b/vp8/encoder/denoising.h
@@ -108,7 +108,8 @@
                              loop_filter_info_n *lfi_n,
                              int mb_row,
                              int mb_col,
-                             int block_index);
+                             int block_index,
+                             int consec_zero_last);
 
 #ifdef __cplusplus
 }  // extern "C"

vp8/encoder/pickinter.c

diff --git a/vp8/encoder/pickinter.c b/vp8/encoder/pickinter.c
index 51fbe54..0708d65 100644
--- a/vp8/encoder/pickinter.c
+++ b/vp8/encoder/pickinter.c
@@ -36,7 +36,7 @@
 extern unsigned int cnt_pm;
 #endif
 
-#define MODEL_MODE 0
+#define MODEL_MODE 1
 
 extern const int vp8_ref_frame_order[MAX_MODES];
 extern const MB_PREDICTION_MODE vp8_mode_order[MAX_MODES];
@@ -1477,7 +1477,8 @@
         vp8_denoiser_denoise_mb(&cpi->denoiser, x, best_sse, zero_mv_sse,
                                 recon_yoffset, recon_uvoffset,
                                 &cpi->common.lf_info, mb_row, mb_col,
-                                block_index);
+                                block_index,
+                                cpi->consec_zero_last_mvbias[block_index]);
 
         // Reevaluate ZEROMV after denoising: for large noise content
         // (i.e., cpi->mse_source_denoised is above threshold), do this for all

vp8/encoder/rdopt.c

diff --git a/vp8/encoder/rdopt.c b/vp8/encoder/rdopt.c
index ab0ad15..9063cea 100644
--- a/vp8/encoder/rdopt.c
+++ b/vp8/encoder/rdopt.c
@@ -2530,7 +2530,7 @@
         vp8_denoiser_denoise_mb(&cpi->denoiser, x, best_sse, zero_mv_sse,
                                 recon_yoffset, recon_uvoffset,
                                 &cpi->common.lf_info, mb_row, mb_col,
-                                block_index);
+                                block_index, 0);
 
         /* Reevaluate ZEROMV after denoising. */
         if (best_mode.mbmode.ref_frame == INTRA_FRAME &&