External VNR speed improvement and more.

webrtc/modules/video_processing/util/noise_estimation.cc

 /*
  *  Copyright (c) 2016 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/modules/video_processing/util/noise_estimation.h"
 
 namespace webrtc {
 
 void NoiseEstimation::Init(int width, int height, CpuType cpu_type) {
   int mb_cols = width >> 4;
   int mb_rows = height >> 4;
   consec_low_var_.reset(new uint32_t[mb_cols * mb_rows]());
   width_ = width;
   height_ = height;
   mb_cols_ = width_ >> 4;
   mb_rows_ = height_ >> 4;
   cpu_type_ = cpu_type;
 }
 
 void NoiseEstimation::GetNoise(int mb_index, uint32_t var, uint32_t luma) {
   consec_low_var_[mb_index]++;
   num_static_block_++;
   if (consec_low_var_[mb_index] >= kConsecLowVarFrame &&
-      (luma >> 8) < kAverageLumaMax && (luma >> 8) > kAverageLumaMin) {
+      (luma >> 6) < kAverageLumaMax && (luma >> 6) > kAverageLumaMin) {
     // Normalized var by the average luma value, this gives more weight to
     // darker blocks.
-    int nor_var = var / (luma >> 12);
+    int nor_var = var / (luma >> 10);
     noise_var_ +=
         nor_var > kBlockSelectionVarMax ? kBlockSelectionVarMax : nor_var;
     num_noisy_block_++;
   }
 }
 
 void NoiseEstimation::ResetConsecLowVar(int mb_index) {
   consec_low_var_[mb_index] = 0;
 }
 
 void NoiseEstimation::UpdateNoiseLevel() {
   // TODO(jackychen): Tune a threshold for numb_noisy_block > T to make the
   // condition more reasonable.
   // No enough samples implies the motion of the camera or too many moving
   // objects in the frame.
-  if (num_static_block_ < (0.65 * mb_cols_ * mb_rows_) || !num_noisy_block_) {
+  if (num_static_block_ <
+          (0.65 * mb_cols_ * mb_rows_ / NOISE_SUBSAMPLE_INTERVAL) ||
+      !num_noisy_block_) {
+#if DISPLAY
+    printf("Not enough samples. %d \n", num_static_block_);
+#endif
     noise_var_ = 0;
     noise_var_accum_ = 0;
+    num_noisy_block_ = 0;
     num_static_block_ = 0;
-    num_noisy_block_ = 0;
-#if DISPLAY
-    printf("Not enough samples.\n");
-#endif
     return;
   } else {
+#if DISPLAY
+    printf("%d %d fraction = %.3f\n", num_static_block_,
+           mb_cols_ * mb_rows_ / NOISE_SUBSAMPLE_INTERVAL,
+           percent_static_block_);
+#endif
     // Normalized by the number of noisy blocks.
     noise_var_ /= num_noisy_block_;
     // Get the percentage of static blocks.
-    percent_static_block_ =
-        static_cast<double>(num_static_block_) / (mb_cols_ * mb_rows_);
-#if DISPLAY
-    printf("%d %d fraction = %.3f\n", num_static_block_, mb_cols_ * mb_rows_,
-           percent_static_block_);
-#endif
+    percent_static_block_ = static_cast<double>(num_static_block_) /
+                            (mb_cols_ * mb_rows_ / NOISE_SUBSAMPLE_INTERVAL);
     num_noisy_block_ = 0;
     num_static_block_ = 0;
   }
   // For the first frame just update the value with current noise_var_,
   // otherwise, use the averaging window.
   if (noise_var_accum_ == 0) {
     noise_var_accum_ = noise_var_;
   } else {
     noise_var_accum_ = (noise_var_accum_ * 15 + noise_var_) / 16;
   }
-  // Reset noise_var_ for the next frame.
-  noise_var_ = 0;
 #if DISPLAY
   printf("noise_var_accum_ = %.1f, noise_var_ = %d.\n", noise_var_accum_,
          noise_var_);
 #endif
+  // Reset noise_var_ for the next frame.
+  noise_var_ = 0;
 }
 
 uint8_t NoiseEstimation::GetNoiseLevel() {
   int noise_thr = cpu_type_ ? kNoiseThreshold : kNoiseThresholdNeon;
   UpdateNoiseLevel();
   if (noise_var_accum_ > noise_thr) {
     return 1;
   }
   return 0;
 }
 
 }  // namespace webrtc