New module for the adaptive level controlling functionality in the audio processing module

webrtc/modules/audio_processing/level_controller/noise_spectrum_estimator.h

Index: webrtc/modules/audio_processing/level_controller/noise_spectrum_estimator.h
diff --git a/webrtc/modules/audio_processing/level_controller/noise_spectrum_estimator.h b/webrtc/modules/audio_processing/level_controller/noise_spectrum_estimator.h
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index 0000000000000000000000000000000000000000..4bf81e39fe9ef44bd1199e929648fb8906fb4fec
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+/*
+ *  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_AUDIO_PROCESSING_LEVEL_CONTROLLER_NOISE_SPECTRUM_ESTIMATOR_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_LEVEL_CONTROLLER_NOISE_SPECTRUM_ESTIMATOR_H_
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/base/constructormagic.h"
+
+namespace webrtc {
+
+class ApmDataDumper;
+
+class NoiseSpectrumEstimator {
+ public:
+  explicit NoiseSpectrumEstimator(ApmDataDumper* data_dumper);
+  void Initialize();
+  void Update(rtc::ArrayView<const float> spectrum, bool first_update);
+
+  rtc::ArrayView<const float> GetNoiseSpectrum() const {
+    return rtc::ArrayView<const float>(noise_spectrum_);
+  }
+
+ private:
+  ApmDataDumper* data_dumper_;
+  float noise_spectrum_[65];
+
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(NoiseSpectrumEstimator);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_LEVEL_CONTROLLER_NOISE_SPECTRUM_ESTIMATOR_H_