xref: /aosp_15_r20/external/webrtc/modules/audio_processing/aec3/fullband_erle_estimator.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1 /*
2  *  Copyright (c) 2018 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_FULLBAND_ERLE_ESTIMATOR_H_
12 #define MODULES_AUDIO_PROCESSING_AEC3_FULLBAND_ERLE_ESTIMATOR_H_
13 
14 #include <memory>
15 #include <vector>
16 
17 #include "absl/types/optional.h"
18 #include "api/array_view.h"
19 #include "api/audio/echo_canceller3_config.h"
20 #include "modules/audio_processing/aec3/aec3_common.h"
21 #include "modules/audio_processing/logging/apm_data_dumper.h"
22 
23 namespace webrtc {
24 
25 // Estimates the echo return loss enhancement using the energy of all the
26 // freuquency bands.
27 class FullBandErleEstimator {
28  public:
29   FullBandErleEstimator(const EchoCanceller3Config::Erle& config,
30                         size_t num_capture_channels);
31   ~FullBandErleEstimator();
32   // Resets the ERLE estimator.
33   void Reset();
34 
35   // Updates the ERLE estimator.
36   void Update(rtc::ArrayView<const float> X2,
37               rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> Y2,
38               rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> E2,
39               const std::vector<bool>& converged_filters);
40 
41   // Returns the fullband ERLE estimates in log2 units.
FullbandErleLog2()42   float FullbandErleLog2() const {
43     float min_erle = erle_time_domain_log2_[0];
44     for (size_t ch = 1; ch < erle_time_domain_log2_.size(); ++ch) {
45       min_erle = std::min(min_erle, erle_time_domain_log2_[ch]);
46     }
47     return min_erle;
48   }
49 
50   // Returns an estimation of the current linear filter quality. It returns a
51   // float number between 0 and 1 mapping 1 to the highest possible quality.
GetInstLinearQualityEstimates()52   rtc::ArrayView<const absl::optional<float>> GetInstLinearQualityEstimates()
53       const {
54     return linear_filters_qualities_;
55   }
56 
57   void Dump(const std::unique_ptr<ApmDataDumper>& data_dumper) const;
58 
59  private:
60   void UpdateQualityEstimates();
61 
62   class ErleInstantaneous {
63    public:
64     explicit ErleInstantaneous(const EchoCanceller3Config::Erle& config);
65     ~ErleInstantaneous();
66 
67     // Updates the estimator with a new point, returns true
68     // if the instantaneous ERLE was updated due to having enough
69     // points for performing the estimate.
70     bool Update(float Y2_sum, float E2_sum);
71     // Resets the instantaneous ERLE estimator to its initial state.
72     void Reset();
73     // Resets the members related with an instantaneous estimate.
74     void ResetAccumulators();
75     // Returns the instantaneous ERLE in log2 units.
GetInstErleLog2()76     absl::optional<float> GetInstErleLog2() const { return erle_log2_; }
77     // Gets an indication between 0 and 1 of the performance of the linear
78     // filter for the current time instant.
GetQualityEstimate()79     absl::optional<float> GetQualityEstimate() const {
80       if (erle_log2_) {
81         float value = inst_quality_estimate_;
82         if (clamp_inst_quality_to_zero_) {
83           value = std::max(0.f, value);
84         }
85         if (clamp_inst_quality_to_one_) {
86           value = std::min(1.f, value);
87         }
88         return absl::optional<float>(value);
89       }
90       return absl::nullopt;
91     }
92     void Dump(const std::unique_ptr<ApmDataDumper>& data_dumper) const;
93 
94    private:
95     void UpdateMaxMin();
96     void UpdateQualityEstimate();
97     const bool clamp_inst_quality_to_zero_;
98     const bool clamp_inst_quality_to_one_;
99     absl::optional<float> erle_log2_;
100     float inst_quality_estimate_;
101     float max_erle_log2_;
102     float min_erle_log2_;
103     float Y2_acum_;
104     float E2_acum_;
105     int num_points_;
106   };
107 
108   const float min_erle_log2_;
109   const float max_erle_lf_log2_;
110   std::vector<int> hold_counters_instantaneous_erle_;
111   std::vector<float> erle_time_domain_log2_;
112   std::vector<ErleInstantaneous> instantaneous_erle_;
113   std::vector<absl::optional<float>> linear_filters_qualities_;
114 };
115 
116 }  // namespace webrtc
117 
118 #endif  // MODULES_AUDIO_PROCESSING_AEC3_FULLBAND_ERLE_ESTIMATOR_H_
119