Moving src/webrtc into src/.

In order to eliminate the WebRTC Subtree mirror in Chromium, 
WebRTC is moving the content of the src/webrtc directory up
to the src/ directory.

NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
TBR=tommi@webrtc.org

Bug: chromium:611808
Change-Id: Iac59c5b51b950f174119565bac87955a7994bc38
Reviewed-on: https://webrtc-review.googlesource.com/1560
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#19845}

modules/video_processing/util/noise_estimation.h

@@ -0,0 +1,63 @@
+/*
+ *  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.
+ */
+
+#ifndef WEBRTC_MODULES_VIDEO_PROCESSING_UTIL_NOISE_ESTIMATION_H_
+#define WEBRTC_MODULES_VIDEO_PROCESSING_UTIL_NOISE_ESTIMATION_H_
+
+#include <memory>
+
+#include "webrtc/modules/include/module_common_types.h"
+#include "webrtc/modules/video_processing/util/denoiser_filter.h"
+
+namespace webrtc {
+
+#define DISPLAY 0      // Rectangle diagnostics
+#define DISPLAYNEON 0  // Rectangle diagnostics on NEON
+
+const int kNoiseThreshold = 150;
+const int kNoiseThresholdNeon = 70;
+const int kConsecLowVarFrame = 6;
+const int kAverageLumaMin = 20;
+const int kAverageLumaMax = 220;
+const int kBlockSelectionVarMax = kNoiseThreshold << 1;
+
+// TODO(jackychen): To test different sampling strategy.
+// Collect noise data every NOISE_SUBSAMPLE_INTERVAL blocks.
+#define NOISE_SUBSAMPLE_INTERVAL 41
+
+class NoiseEstimation {
+ public:
+  void Init(int width, int height, CpuType cpu_type);
+  // Collect noise data from one qualified block.
+  void GetNoise(int mb_index, uint32_t var, uint32_t luma);
+  // Reset the counter for consecutive low-var blocks.
+  void ResetConsecLowVar(int mb_index);
+  // Update noise level for current frame.
+  void UpdateNoiseLevel();
+  // 0: low noise, 1: high noise
+  uint8_t GetNoiseLevel();
+
+ private:
+  int width_;
+  int height_;
+  int mb_rows_;
+  int mb_cols_;
+  int num_noisy_block_;
+  int num_static_block_;
+  CpuType cpu_type_;
+  uint32_t noise_var_;
+  double noise_var_accum_;
+  double percent_static_block_;
+  std::unique_ptr<uint32_t[]> consec_low_var_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_VIDEO_PROCESSING_UTIL_NOISE_ESTIMATION_H_