1 /*
2  *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_
12 #define MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_
13 
14 #include <array>
15 #include <memory>
16 
17 #include "modules/audio_processing/aec3/aec3_common.h"
18 #include "modules/audio_processing/aec3/aec_state.h"
19 #include "modules/audio_processing/aec3/fft_data.h"
20 #include "rtc_base/constructormagic.h"
21 
22 namespace webrtc {
23 namespace aec3 {
24 #if defined(WEBRTC_ARCH_X86_FAMILY)
25 
26 void EstimateComfortNoise_SSE2(const std::array<float, kFftLengthBy2Plus1>& N2,
27                                uint32_t* seed,
28                                FftData* lower_band_noise,
29                                FftData* upper_band_noise);
30 #endif
31 void EstimateComfortNoise(const std::array<float, kFftLengthBy2Plus1>& N2,
32                           uint32_t* seed,
33                           FftData* lower_band_noise,
34                           FftData* upper_band_noise);
35 
36 }  // namespace aec3
37 
38 // Generates the comfort noise.
39 class ComfortNoiseGenerator {
40  public:
41   explicit ComfortNoiseGenerator(Aec3Optimization optimization);
42   ~ComfortNoiseGenerator();
43 
44   // Computes the comfort noise.
45   void Compute(const AecState& aec_state,
46                const std::array<float, kFftLengthBy2Plus1>& capture_spectrum,
47                FftData* lower_band_noise,
48                FftData* upper_band_noise);
49 
50   // Returns the estimate of the background noise spectrum.
NoiseSpectrum()51   const std::array<float, kFftLengthBy2Plus1>& NoiseSpectrum() const {
52     return N2_;
53   }
54 
55  private:
56   const Aec3Optimization optimization_;
57   uint32_t seed_;
58   std::unique_ptr<std::array<float, kFftLengthBy2Plus1>> N2_initial_;
59   std::array<float, kFftLengthBy2Plus1> Y2_smoothed_;
60   std::array<float, kFftLengthBy2Plus1> N2_;
61   int N2_counter_ = 0;
62 
63   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(ComfortNoiseGenerator);
64 };
65 
66 }  // namespace webrtc
67 
68 #endif  // MODULES_AUDIO_PROCESSING_AEC3_COMFORT_NOISE_GENERATOR_H_
69