Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/comfort_noise_generator.h

+/*
+ *  Copyright (c) 2017 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_AEC3_COMFORT_NOISE_GENERATOR_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_
+
+#include <array>
+#include <memory>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_processing/aec3/aec_state.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_common.h"
+#include "webrtc/modules/audio_processing/aec3/fft_data.h"
+
+namespace webrtc {
+namespace aec3 {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+
+void EstimateComfortNoise_SSE2(const std::array<float, kFftLengthBy2Plus1>& N2,
+                               uint32_t* seed,
+                               FftData* lower_band_noise,
+                               FftData* upper_band_noise);
+#endif
+void EstimateComfortNoise(const std::array<float, kFftLengthBy2Plus1>& N2,
+                          uint32_t* seed,
+                          FftData* lower_band_noise,
+                          FftData* upper_band_noise);
+
+}  // namespace aec3
+
+// Generates the comfort noise.
+class ComfortNoiseGenerator {
+ public:
+  explicit ComfortNoiseGenerator(Aec3Optimization optimization);
+  ~ComfortNoiseGenerator();
+
+  // Computes the comfort noise.
+  void Compute(const AecState& aec_state,
+               const std::array<float, kFftLengthBy2Plus1>& capture_spectrum,
+               FftData* lower_band_noise,
+               FftData* upper_band_noise);
+
+  // Returns the estimate of the background noise spectrum.
+  const std::array<float, kFftLengthBy2Plus1>& NoiseSpectrum() const {
+    return N2_;
+  }
+
+ private:
+  const Aec3Optimization optimization_;
+  uint32_t seed_;
+  std::unique_ptr<std::array<float, kFftLengthBy2Plus1>> N2_initial_;
+  std::array<float, kFftLengthBy2Plus1> Y2_smoothed_;
+  std::array<float, kFftLengthBy2Plus1> N2_;
+  int N2_counter_ = 0;
+
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(ComfortNoiseGenerator);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_