External VNR speed improvement and more.

webrtc/modules/video_processing/video_denoiser.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
+
 #include "webrtc/common_video/libyuv/include/scaler.h"
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/modules/video_processing/video_denoiser.h"
 
+#if DISPLAY  // Rectangle diagnostics
+static void CopyMem8x8(const uint8_t* src,
+                       int src_stride,
+                       uint8_t* dst,
+                       int dst_stride) {
+  for (int i = 0; i < 8; i++) {
+    memcpy(dst, src, 8);
+    src += src_stride;
+    dst += dst_stride;
+  }
+}
+
+static void ShowRect(const std::unique_ptr<DenoiserFilter>& filter,
+                     const std::unique_ptr<uint8_t[]>& d_status,
+                     const std::unique_ptr<uint8_t[]>& d_status_red,
+                     const std::unique_ptr<uint8_t[]>& x_density,
+                     const std::unique_ptr<uint8_t[]>& y_density,
+                     const uint8_t* u_src,
+                     const uint8_t* v_src,
+                     uint8_t* u_dst,
+                     uint8_t* v_dst,
+                     int mb_rows_,
+                     int mb_cols_,
+                     int stride_u_,
+                     int stride_v_) {
+  for (int mb_row = 0; mb_row < mb_rows_; ++mb_row) {
+    for (int mb_col = 0; mb_col < mb_cols_; ++mb_col) {
+      int mb_index = mb_row * mb_cols_ + mb_col;
+      const uint8_t* mb_src_u =
+          u_src + (mb_row << 3) * stride_u_ + (mb_col << 3);
+      const uint8_t* mb_src_v =
+          v_src + (mb_row << 3) * stride_v_ + (mb_col << 3);
+      uint8_t* mb_dst_u = u_dst + (mb_row << 3) * stride_u_ + (mb_col << 3);
+      uint8_t* mb_dst_v = v_dst + (mb_row << 3) * stride_v_ + (mb_col << 3);
+      uint8_t uv_tmp[8 * 8];
+      memset(uv_tmp, 200, 8 * 8);
+      if (d_status[mb_index] == 1) {
+        // Paint to red.
+        CopyMem8x8(mb_src_u, stride_u_, mb_dst_u, stride_u_);
+        CopyMem8x8(uv_tmp, 8, mb_dst_v, stride_v_);
+      } else if (d_status_red[mb_row * mb_cols_ + mb_col] &&
+                 x_density[mb_col] * y_density[mb_row]) {
+        // Paint to blue.
+        CopyMem8x8(uv_tmp, 8, mb_dst_u, stride_u_);
+        CopyMem8x8(mb_src_v, stride_v_, mb_dst_v, stride_v_);
+      } else {
+        CopyMem8x8(mb_src_u, stride_u_, mb_dst_u, stride_u_);
+        CopyMem8x8(mb_src_v, stride_v_, mb_dst_v, stride_v_);
+      }
+    }
+  }
+}
+#endif
+
 namespace webrtc {
 
 VideoDenoiser::VideoDenoiser(bool runtime_cpu_detection)
     : width_(0),
       height_(0),
       filter_(DenoiserFilter::Create(runtime_cpu_detection, &cpu_type_)),
       ne_(new NoiseEstimation()) {}
 
-#if EXPERIMENTAL
-// Check the mb position(1: close to the center, 3: close to the border).
-static int PositionCheck(int mb_row, int mb_col, int mb_rows, int mb_cols) {
-  if ((mb_row >= (mb_rows >> 3)) && (mb_row <= (7 * mb_rows >> 3)) &&
-      (mb_col >= (mb_cols >> 3)) && (mb_col <= (7 * mb_cols >> 3)))
+// Check the mb position, return 1: close to the frame center, 3: close to the
+// border, 2: in between.
+int VideoDenoiser::PositionCheck(int mb_row, int mb_col, int noise_level) {
+  if (noise_level == 0)
     return 1;
-  else if ((mb_row >= (mb_rows >> 4)) && (mb_row <= (15 * mb_rows >> 4)) &&
-           (mb_col >= (mb_cols >> 4)) && (mb_col <= (15 * mb_cols >> 4)))
+  if ((mb_row <= (mb_rows_ >> 4)) || (mb_col <= (mb_cols_ >> 4)) ||
+      (mb_col >= (15 * mb_cols_ >> 4)))
+    return 3;
+  else if ((mb_row <= (mb_rows_ >> 3)) || (mb_col <= (mb_cols_ >> 3)) ||
+           (mb_col >= (7 * mb_cols_ >> 3)))
     return 2;
   else
-    return 3;
-}
-
-static void ReduceFalseDetection(const std::unique_ptr<uint8_t[]>& d_status,
-                                 std::unique_ptr<uint8_t[]>* d_status_tmp1,
-                                 std::unique_ptr<uint8_t[]>* d_status_tmp2,
-                                 int noise_level,
-                                 int mb_rows,
-                                 int mb_cols) {
-  // Draft. This can be optimized. This code block is to reduce false detection
-  // in moving object detection.
-  int mb_row_min = noise_level ? mb_rows >> 3 : 1;
-  int mb_col_min = noise_level ? mb_cols >> 3 : 1;
-  int mb_row_max = noise_level ? (7 * mb_rows >> 3) : mb_rows - 2;
-  int mb_col_max = noise_level ? (7 * mb_cols >> 3) : mb_cols - 2;
-  memcpy((*d_status_tmp1).get(), d_status.get(), mb_rows * mb_cols);
-  // Up left.
-  for (int mb_row = mb_row_min; mb_row <= mb_row_max; ++mb_row) {
-    for (int mb_col = mb_col_min; mb_col <= mb_col_max; ++mb_col) {
-      (*d_status_tmp1)[mb_row * mb_cols + mb_col] |=
-          ((*d_status_tmp1)[(mb_row - 1) * mb_cols + mb_col] |
-           (*d_status_tmp1)[mb_row * mb_cols + mb_col - 1]);
-    }
-  }
-  memcpy((*d_status_tmp2).get(), (*d_status_tmp1).get(), mb_rows * mb_cols);
-  memcpy((*d_status_tmp1).get(), d_status.get(), mb_rows * mb_cols);
-  // Bottom left.
-  for (int mb_row = mb_row_max; mb_row >= mb_row_min; --mb_row) {
-    for (int mb_col = mb_col_min; mb_col <= mb_col_max; ++mb_col) {
-      (*d_status_tmp1)[mb_row * mb_cols + mb_col] |=
-          ((*d_status_tmp1)[(mb_row + 1) * mb_cols + mb_col] |
-           (*d_status_tmp1)[mb_row * mb_cols + mb_col - 1]);
-      (*d_status_tmp2)[mb_row * mb_cols + mb_col] &=
-          (*d_status_tmp1)[mb_row * mb_cols + mb_col];
-    }
-  }
-  memcpy((*d_status_tmp1).get(), d_status.get(), mb_rows * mb_cols);
-  // Up right.
-  for (int mb_row = mb_row_min; mb_row <= mb_row_max; ++mb_row) {
-    for (int mb_col = mb_col_max; mb_col >= mb_col_min; --mb_col) {
-      (*d_status_tmp1)[mb_row * mb_cols + mb_col] |=
-          ((*d_status_tmp1)[(mb_row - 1) * mb_cols + mb_col] |
-           (*d_status_tmp1)[mb_row * mb_cols + mb_col + 1]);
-      (*d_status_tmp2)[mb_row * mb_cols + mb_col] &=
-          (*d_status_tmp1)[mb_row * mb_cols + mb_col];
-    }
-  }
-  memcpy((*d_status_tmp1).get(), d_status.get(), mb_rows * mb_cols);
-  // Bottom right.
-  for (int mb_row = mb_row_max; mb_row >= mb_row_min; --mb_row) {
-    for (int mb_col = mb_col_max; mb_col >= mb_col_min; --mb_col) {
-      (*d_status_tmp1)[mb_row * mb_cols + mb_col] |=
-          ((*d_status_tmp1)[(mb_row + 1) * mb_cols + mb_col] |
-           (*d_status_tmp1)[mb_row * mb_cols + mb_col + 1]);
-      (*d_status_tmp2)[mb_row * mb_cols + mb_col] &=
-          (*d_status_tmp1)[mb_row * mb_cols + mb_col];
-    }
-  }
-}
-
-static bool TrailingBlock(const std::unique_ptr<uint8_t[]>& d_status,
-                          int mb_row,
-                          int mb_col,
-                          int mb_rows,
-                          int mb_cols) {
-  int mb_index = mb_row * mb_cols + mb_col;
-  if (!mb_row || !mb_col || mb_row == mb_rows - 1 || mb_col == mb_cols - 1)
-    return false;
-  return d_status[mb_index + 1] || d_status[mb_index - 1] ||
-         d_status[mb_index + mb_cols] || d_status[mb_index - mb_cols];
-}
-#endif
-
-#if DISPLAY
-void ShowRect(const std::unique_ptr<DenoiserFilter>& filter,
-              const std::unique_ptr<uint8_t[]>& d_status,
-              const std::unique_ptr<uint8_t[]>& d_status_tmp2,
-              const std::unique_ptr<uint8_t[]>& x_density,
-              const std::unique_ptr<uint8_t[]>& y_density,
-              const uint8_t* u_src,
-              const uint8_t* v_src,
-              uint8_t* u_dst,
-              uint8_t* v_dst,
-              int mb_rows,
-              int mb_cols,
-              int stride_u,
-              int stride_v) {
-  for (int mb_row = 0; mb_row < mb_rows; ++mb_row) {
-    for (int mb_col = 0; mb_col < mb_cols; ++mb_col) {
-      int mb_index = mb_row * mb_cols + mb_col;
-      const uint8_t* mb_src_u =
-          u_src + (mb_row << 3) * stride_u + (mb_col << 3);
-      const uint8_t* mb_src_v =
-          v_src + (mb_row << 3) * stride_v + (mb_col << 3);
-      uint8_t* mb_dst_u = u_dst + (mb_row << 3) * stride_u + (mb_col << 3);
-      uint8_t* mb_dst_v = v_dst + (mb_row << 3) * stride_v + (mb_col << 3);
-      uint8_t y_tmp_255[8 * 8];
-      memset(y_tmp_255, 200, 8 * 8);
-      // x_density_[mb_col] * y_density_[mb_row]
-      if (d_status[mb_index] == 1) {
-        // Paint to red.
-        filter->CopyMem8x8(mb_src_u, stride_u, mb_dst_u, stride_u);
-        filter->CopyMem8x8(y_tmp_255, 8, mb_dst_v, stride_v);
-#if EXPERIMENTAL
-      } else if (d_status_tmp2[mb_row * mb_cols + mb_col] &&
-                 x_density[mb_col] * y_density[mb_row]) {
-#else
-      } else if (x_density[mb_col] * y_density[mb_row]) {
-#endif
-        // Paint to blue.
-        filter->CopyMem8x8(y_tmp_255, 8, mb_dst_u, stride_u);
-        filter->CopyMem8x8(mb_src_v, stride_v, mb_dst_v, stride_v);
-      } else {
-        filter->CopyMem8x8(mb_src_u, stride_u, mb_dst_u, stride_u);
-        filter->CopyMem8x8(mb_src_v, stride_v, mb_dst_v, stride_v);
-      }
-    }
-  }
-}
-#endif
+    return 1;
+}
+
+// To reduce false detection in moving object detection (MOD).
+void VideoDenoiser::ReduceFalseDetection(
+    const std::unique_ptr<uint8_t[]>& d_status,
+    std::unique_ptr<uint8_t[]>* d_status_red,
+    int noise_level) {
+  // From up left corner.
+  int mb_col_stop = mb_cols_ - 1;
+  for (int mb_row = 0; mb_row <= mb_rows_ - 1; ++mb_row) {
+    for (int mb_col = 0; mb_col <= mb_col_stop; ++mb_col) {
+      if (d_status[mb_row * mb_cols_ + mb_col]) {
+        mb_col_stop = mb_col - 1;
+        break;
+      }
+      (*d_status_red)[mb_row * mb_cols_ + mb_col] = 0;
+    }
+  }
+  // From bottom left corner.
+  mb_col_stop = mb_cols_ - 1;
+  for (int mb_row = mb_rows_ - 1; mb_row >= 0; --mb_row) {
+    for (int mb_col = 0; mb_col <= mb_col_stop; ++mb_col) {
+      if (d_status[mb_row * mb_cols_ + mb_col]) {
+        mb_col_stop = mb_col - 1;
+        break;
+      }
+      (*d_status_red)[mb_row * mb_cols_ + mb_col] = 0;
+    }
+  }
+  // From up right corner.
+  mb_col_stop = 0;
+  for (int mb_row = 0; mb_row <= mb_rows_ - 1; ++mb_row) {
+    for (int mb_col = mb_cols_ - 1; mb_col >= mb_col_stop; --mb_col) {
+      if (d_status[mb_row * mb_cols_ + mb_col]) {
+        mb_col_stop = mb_col + 1;
+        break;
+      }
+      (*d_status_red)[mb_row * mb_cols_ + mb_col] = 0;
+    }
+  }
+  // From bottom right corner.
+  mb_col_stop = 0;
+  for (int mb_row = mb_rows_ - 1; mb_row >= 0; --mb_row) {
+    for (int mb_col = mb_cols_ - 1; mb_col >= mb_col_stop; --mb_col) {
+      if (d_status[mb_row * mb_cols_ + mb_col]) {
+        mb_col_stop = mb_col + 1;
+        break;
+      }
+      (*d_status_red)[mb_row * mb_cols_ + mb_col] = 0;
+    }
+  }
+}
+
+// Check if a neighbor block is a moving edge block.
+bool VideoDenoiser::IsTrailingBlock(const std::unique_ptr<uint8_t[]>& d_status,
+                                    int mb_row,
+                                    int mb_col) {
+  bool ret = false;
+  int mb_index = mb_row * mb_cols_ + mb_col;
+  if (!mb_row || !mb_col || mb_row == mb_rows_ - 1 || mb_col == mb_cols_ - 1)
+    ret = false;
+  else
+    ret = d_status[mb_index + 1] || d_status[mb_index - 1] ||
+          d_status[mb_index + mb_cols_] || d_status[mb_index - mb_cols_];
+  return ret;
+}
+
+void VideoDenoiser::DenoiserReset(const VideoFrame& frame,
+                                  VideoFrame* denoised_frame,
+                                  VideoFrame* denoised_frame_prev) {
+  width_ = frame.width();
+  height_ = frame.height();
+  mb_cols_ = width_ >> 4;
+  mb_rows_ = height_ >> 4;
+  stride_y_ = frame.stride(kYPlane);
+  stride_u_ = frame.stride(kUPlane);
+  stride_v_ = frame.stride(kVPlane);
+
+  // Allocate an empty buffer for denoised_frame_prev.
+  denoised_frame_prev->CreateEmptyFrame(width_, height_, stride_y_, stride_u_,
+                                        stride_v_);
+  // Allocate and initialize denoised_frame with key frame.
+  denoised_frame->CreateFrame(frame.buffer(kYPlane), frame.buffer(kUPlane),
+                              frame.buffer(kVPlane), width_, height_, stride_y_,
+                              stride_u_, stride_v_, kVideoRotation_0);
+  // Set time parameters to the output frame.
+  denoised_frame->set_timestamp(frame.timestamp());
+  denoised_frame->set_render_time_ms(frame.render_time_ms());
+
+  // Init noise estimator and allocate buffers.
+  ne_->Init(width_, height_, cpu_type_);
+  d_status_.reset(new uint8_t[mb_cols_ * mb_rows_]);
+  mb_filter_decision_.reset(new DenoiserDecision[mb_cols_ * mb_rows_]);
+  x_density_.reset(new uint8_t[mb_cols_]);
+  y_density_.reset(new uint8_t[mb_rows_]);
+  mod_.reset(new uint8_t[mb_cols_ * mb_rows_]);
+}
+
+void VideoDenoiser::CopySrcOnMOB(const uint8_t* y_src, uint8_t* y_dst) {
+  // Loop over to copy src block if the block is marked as moving object block
+  // or if the block may cause trailing artifacts.
+  for (int mb_row = 0; mb_row < mb_rows_; ++mb_row) {
+    const int mb_index_base = mb_row * mb_cols_;
+    const int offset_base = (mb_row << 4) * stride_y_;
+    const uint8_t* mb_src_base = y_src + offset_base;
+    uint8_t* mb_dst_base = y_dst + offset_base;
+    for (int mb_col = 0; mb_col < mb_cols_; ++mb_col) {
+      const int mb_index = mb_index_base + mb_col;
+      const uint32_t offset_col = mb_col << 4;
+      const uint8_t* mb_src = mb_src_base + offset_col;
+      uint8_t* mb_dst = mb_dst_base + offset_col;
+      // Check if the block is a moving object block or may cause a trailing
+      // artifacts.
+      if (mb_filter_decision_[mb_index] != FILTER_BLOCK ||
+          IsTrailingBlock(d_status_, mb_row, mb_col) ||
+          (x_density_[mb_col] * y_density_[mb_row] &&
+           mod_[mb_row * mb_cols_ + mb_col])) {
+        // Copy y source.
+        filter_->CopyMem16x16(mb_src, stride_y_, mb_dst, stride_y_);
+      }
+    }
+  }
+}
 
 void VideoDenoiser::DenoiseFrame(const VideoFrame& frame,
                                  VideoFrame* denoised_frame,
                                  VideoFrame* denoised_frame_prev,
-                                 int noise_level_prev) {
-  int stride_y = frame.stride(kYPlane);
-  int stride_u = frame.stride(kUPlane);
-  int stride_v = frame.stride(kVPlane);
-  // If previous width and height are different from current frame's, then no
-  // denoising for the current frame.
+                                 bool noise_estimation_enabled) {
+  // If previous width and height are different from current frame's, need to
+  // reallocate the buffers and no denoising for the current frame.
   if (width_ != frame.width() || height_ != frame.height()) {
-    width_ = frame.width();
-    height_ = frame.height();
-    denoised_frame->CreateFrame(frame.buffer(kYPlane), frame.buffer(kUPlane),
-                                frame.buffer(kVPlane), width_, height_,
-                                stride_y, stride_u, stride_v, kVideoRotation_0);
-    denoised_frame_prev->CreateFrame(
-        frame.buffer(kYPlane), frame.buffer(kUPlane), frame.buffer(kVPlane),
-        width_, height_, stride_y, stride_u, stride_v, kVideoRotation_0);
-    // Setting time parameters to the output frame.
-    denoised_frame->set_timestamp(frame.timestamp());
-    denoised_frame->set_render_time_ms(frame.render_time_ms());
-    ne_->Init(width_, height_, cpu_type_);
+    DenoiserReset(frame, denoised_frame, denoised_frame_prev);
     return;
   }
-  // For 16x16 block.
-  int mb_cols = width_ >> 4;
-  int mb_rows = height_ >> 4;
-  if (metrics_.get() == nullptr)
-    metrics_.reset(new DenoiseMetrics[mb_cols * mb_rows]());
-  if (d_status_.get() == nullptr) {
-    d_status_.reset(new uint8_t[mb_cols * mb_rows]());
-#if EXPERIMENTAL
-    d_status_tmp1_.reset(new uint8_t[mb_cols * mb_rows]());
-    d_status_tmp2_.reset(new uint8_t[mb_cols * mb_rows]());
-#endif
-    x_density_.reset(new uint8_t[mb_cols]());
-    y_density_.reset(new uint8_t[mb_rows]());
-  }
-
-  // Denoise on Y plane.
+
+  // Set buffer pointers.
+  const uint8_t* y_src = frame.buffer(kYPlane);
+  const uint8_t* u_src = frame.buffer(kUPlane);
+  const uint8_t* v_src = frame.buffer(kVPlane);
   uint8_t* y_dst = denoised_frame->buffer(kYPlane);
   uint8_t* u_dst = denoised_frame->buffer(kUPlane);
   uint8_t* v_dst = denoised_frame->buffer(kVPlane);
   uint8_t* y_dst_prev = denoised_frame_prev->buffer(kYPlane);
-  const uint8_t* y_src = frame.buffer(kYPlane);
-  const uint8_t* u_src = frame.buffer(kUPlane);
-  const uint8_t* v_src = frame.buffer(kVPlane);
-  uint8_t noise_level = noise_level_prev == -1 ? 0 : ne_->GetNoiseLevel();
-  // Temporary buffer to store denoising result.
-  uint8_t y_tmp[16 * 16] = {0};
-  memset(x_density_.get(), 0, mb_cols);
-  memset(y_density_.get(), 0, mb_rows);
-
+  memset(x_density_.get(), 0, mb_cols_);
+  memset(y_density_.get(), 0, mb_rows_);
+  memset(mod_.get(), 1, mb_cols_ * mb_rows_);
+
+  uint8_t noise_level = noise_estimation_enabled ? ne_->GetNoiseLevel() : 0;
+  int thr_var_base = 16 * 16 * 5;
   // Loop over blocks to accumulate/extract noise level and update x/y_density
   // factors for moving object detection.
-  for (int mb_row = 0; mb_row < mb_rows; ++mb_row) {
-    for (int mb_col = 0; mb_col < mb_cols; ++mb_col) {
-      const uint8_t* mb_src = y_src + (mb_row << 4) * stride_y + (mb_col << 4);
-      uint8_t* mb_dst_prev =
-          y_dst_prev + (mb_row << 4) * stride_y + (mb_col << 4);
-      int mb_index = mb_row * mb_cols + mb_col;
-#if EXPERIMENTAL
-      int pos_factor = PositionCheck(mb_row, mb_col, mb_rows, mb_cols);
-      uint32_t thr_var_adp = 16 * 16 * 5 * (noise_level ? pos_factor : 1);
-#else
-      uint32_t thr_var_adp = 16 * 16 * 5;
-#endif
-      int brightness = 0;
-      for (int i = 0; i < 16; ++i) {
-        for (int j = 0; j < 16; ++j) {
-          brightness += mb_src[i * stride_y + j];
+  for (int mb_row = 0; mb_row < mb_rows_; ++mb_row) {
+    const int mb_index_base = mb_row * mb_cols_;
+    const int offset_base = (mb_row << 4) * stride_y_;
+    const uint8_t* mb_src_base = y_src + offset_base;
+    uint8_t* mb_dst_base = y_dst + offset_base;
+    uint8_t* mb_dst_prev_base = y_dst_prev + offset_base;
+    for (int mb_col = 0; mb_col < mb_cols_; ++mb_col) {
+      const int mb_index = mb_index_base + mb_col;
+      const bool ne_enable = (mb_index % NOISE_SUBSAMPLE_INTERVAL == 0);
+      const int pos_factor = PositionCheck(mb_row, mb_col, noise_level);
+      const uint32_t thr_var_adp = thr_var_base * pos_factor;
+      const uint32_t offset_col = mb_col << 4;
+      const uint8_t* mb_src = mb_src_base + offset_col;
+      uint8_t* mb_dst = mb_dst_base + offset_col;
+      uint8_t* mb_dst_prev = mb_dst_prev_base + offset_col;
+
+      // TODO(jackychen): Need SSE2/NEON opt.
+      int luma = 0;
+      if (ne_enable) {
+        for (int i = 4; i < 12; ++i) {
+          for (int j = 4; j < 12; ++j) {
+            luma += mb_src[i * stride_y_ + j];
+          }
         }
       }
 
-      // Get the denoised block.
-      filter_->MbDenoise(mb_dst_prev, stride_y, y_tmp, 16, mb_src, stride_y, 0,
-                         1, true);
-      // The variance is based on the denoised blocks in time T and T-1.
-      metrics_[mb_index].var = filter_->Variance16x8(
-          mb_dst_prev, stride_y, y_tmp, 16, &metrics_[mb_index].sad);
-
-      if (metrics_[mb_index].var > thr_var_adp) {
-        ne_->ResetConsecLowVar(mb_index);
-        d_status_[mb_index] = 1;
-#if EXPERIMENTAL
-        if (noise_level == 0 || pos_factor < 3) {
-          x_density_[mb_col] += 1;
-          y_density_[mb_row] += 1;
+      // Get the filtered block and filter_decision.
+      mb_filter_decision_[mb_index] =
+          filter_->MbDenoise(mb_dst_prev, stride_y_, mb_dst, stride_y_, mb_src,
+                             stride_y_, 0, noise_level);
+
+      // If filter decision is FILTER_BLOCK, no need to check moving edge.
+      // It is unlikely for a moving edge block to be filtered in current
+      // setting.
+      if (mb_filter_decision_[mb_index] == FILTER_BLOCK) {
+        uint32_t sse_t = 0;
+        if (ne_enable) {
+          // The variance used in noise estimation is based on the src block in
+          // time t (mb_src) and filtered block in time t-1 (mb_dist_prev).
+          uint32_t noise_var = filter_->Variance16x8(mb_dst_prev, stride_y_,
+                                                     mb_src, stride_y_, &sse_t);
+          ne_->GetNoise(mb_index, noise_var, luma);
         }
-#else
-        x_density_[mb_col] += 1;
-        y_density_[mb_row] += 1;
-#endif
+        d_status_[mb_index] = 0;  // Not a moving edge block.
       } else {
         uint32_t sse_t = 0;
-        // The variance is based on the src blocks in time T and denoised block
-        // in time T-1.
-        uint32_t noise_var = filter_->Variance16x8(mb_dst_prev, stride_y,
-                                                   mb_src, stride_y, &sse_t);
-        ne_->GetNoise(mb_index, noise_var, brightness);
-        d_status_[mb_index] = 0;
-      }
-      // Track denoised frame.
-      filter_->CopyMem16x16(y_tmp, 16, mb_dst_prev, stride_y);
-    }
-  }
-
-#if EXPERIMENTAL
-  ReduceFalseDetection(d_status_, &d_status_tmp1_, &d_status_tmp2_, noise_level,
-                       mb_rows, mb_cols);
-#endif
-
-  // Denoise each MB based on the results of moving objects detection.
-  for (int mb_row = 0; mb_row < mb_rows; ++mb_row) {
-    for (int mb_col = 0; mb_col < mb_cols; ++mb_col) {
-      const uint8_t* mb_src = y_src + (mb_row << 4) * stride_y + (mb_col << 4);
-      uint8_t* mb_dst = y_dst + (mb_row << 4) * stride_y + (mb_col << 4);
-      const uint8_t* mb_src_u =
-          u_src + (mb_row << 3) * stride_u + (mb_col << 3);
-      const uint8_t* mb_src_v =
-          v_src + (mb_row << 3) * stride_v + (mb_col << 3);
-      uint8_t* mb_dst_u = u_dst + (mb_row << 3) * stride_u + (mb_col << 3);
-      uint8_t* mb_dst_v = v_dst + (mb_row << 3) * stride_v + (mb_col << 3);
-#if EXPERIMENTAL
-      if ((!d_status_tmp2_[mb_row * mb_cols + mb_col] ||
-           x_density_[mb_col] * y_density_[mb_row] == 0) &&
-          !TrailingBlock(d_status_, mb_row, mb_col, mb_rows, mb_cols)) {
-#else
-      if (x_density_[mb_col] * y_density_[mb_row] == 0) {
-#endif
-        if (filter_->MbDenoise(mb_dst, stride_y, y_tmp, 16, mb_src, stride_y, 0,
-                               noise_level, false) == FILTER_BLOCK) {
-          filter_->CopyMem16x16(y_tmp, 16, mb_dst, stride_y);
+        // The variance used in MOD is based on the filtered blocks in time
+        // T (mb_dst) and T-1 (mb_dst_prev).
+        uint32_t noise_var = filter_->Variance16x8(mb_dst_prev, stride_y_,
+                                                   mb_dst, stride_y_, &sse_t);
+        if (noise_var > thr_var_adp) {  // Moving edge checking.
+          if (ne_enable) {
+            ne_->ResetConsecLowVar(mb_index);
+          }
+          d_status_[mb_index] = 1;  // Mark as moving edge block.
+          x_density_[mb_col] += (pos_factor < 3);
+          y_density_[mb_row] += (pos_factor < 3);
         } else {
-          // Copy y source.
-          filter_->CopyMem16x16(mb_src, stride_y, mb_dst, stride_y);
+          d_status_[mb_index] = 0;
+          if (ne_enable) {
+            // The variance used in noise estimation is based on the src block
+            // in time t (mb_src) and filtered block in time t-1 (mb_dist_prev).
+            uint32_t noise_var = filter_->Variance16x8(
+                mb_dst_prev, stride_y_, mb_src, stride_y_, &sse_t);
+            ne_->GetNoise(mb_index, noise_var, luma);
+          }
         }
-      } else {
-        // Copy y source.
-        filter_->CopyMem16x16(mb_src, stride_y, mb_dst, stride_y);
-      }
-      filter_->CopyMem8x8(mb_src_u, stride_u, mb_dst_u, stride_u);
-      filter_->CopyMem8x8(mb_src_v, stride_v, mb_dst_v, stride_v);
-    }
-  }
+      }
+    }  // End of for loop
+  }    // End of for loop
+
+  ReduceFalseDetection(d_status_, &mod_, noise_level);
+
+  CopySrcOnMOB(y_src, y_dst);
+
+  // TODO(jackychen): Need SSE2/NEON opt.
+  // Copy u/v planes.
+  memcpy(u_dst, u_src, (height_ >> 1) * stride_u_);
+  memcpy(v_dst, v_src, (height_ >> 1) * stride_v_);
+
+  // Set time parameters to the output frame.
+  denoised_frame->set_timestamp(frame.timestamp());
+  denoised_frame->set_render_time_ms(frame.render_time_ms());
 
 #if DISPLAY  // Rectangle diagnostics
   // Show rectangular region
-  ShowRect(filter_, d_status_, d_status_tmp2_, x_density_, y_density_, u_src,
-           v_src, u_dst, v_dst, mb_rows, mb_cols, stride_u, stride_v);
+  ShowRect(filter_, d_status_, mod_, x_density_, y_density_, u_src, v_src,
+           u_dst, v_dst, mb_rows_, mb_cols_, stride_u_, stride_v_);
 #endif
-
-  // Setting time parameters to the output frame.
-  denoised_frame->set_timestamp(frame.timestamp());
-  denoised_frame->set_render_time_ms(frame.render_time_ms());
-  return;
 }
 
 }  // namespace webrtc