1 /* 2 * Copyright (c) 2016 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_RESIDUAL_ECHO_DETECTOR_H_ 12 #define MODULES_AUDIO_PROCESSING_RESIDUAL_ECHO_DETECTOR_H_ 13 14 #include <atomic> 15 #include <vector> 16 17 #include "api/array_view.h" 18 #include "modules/audio_processing/echo_detector/circular_buffer.h" 19 #include "modules/audio_processing/echo_detector/mean_variance_estimator.h" 20 #include "modules/audio_processing/echo_detector/moving_max.h" 21 #include "modules/audio_processing/echo_detector/normalized_covariance_estimator.h" 22 #include "modules/audio_processing/include/audio_processing.h" 23 24 namespace webrtc { 25 26 class ApmDataDumper; 27 class AudioBuffer; 28 29 class ResidualEchoDetector : public EchoDetector { 30 public: 31 ResidualEchoDetector(); 32 ~ResidualEchoDetector() override; 33 34 // This function should be called while holding the render lock. 35 void AnalyzeRenderAudio(rtc::ArrayView<const float> render_audio) override; 36 37 // This function should be called while holding the capture lock. 38 void AnalyzeCaptureAudio(rtc::ArrayView<const float> capture_audio) override; 39 40 // This function should be called while holding the capture lock. 41 void Initialize(int capture_sample_rate_hz, 42 int num_capture_channels, 43 int render_sample_rate_hz, 44 int num_render_channels) override; 45 46 // This function is for testing purposes only. SetReliabilityForTest(float value)47 void SetReliabilityForTest(float value) { reliability_ = value; } 48 49 // This function should be called while holding the capture lock. 50 EchoDetector::Metrics GetMetrics() const override; 51 52 private: 53 static std::atomic<int> instance_count_; 54 std::unique_ptr<ApmDataDumper> data_dumper_; 55 // Keep track if the `Process` function has been previously called. 56 bool first_process_call_ = true; 57 // Buffer for storing the power of incoming farend buffers. This is needed for 58 // cases where calls to BufferFarend and Process are jittery. 59 CircularBuffer render_buffer_; 60 // Count how long ago it was that the size of `render_buffer_` was zero. This 61 // value is also reset to zero when clock drift is detected and a value from 62 // the renderbuffer is discarded, even though the buffer is not actually zero 63 // at that point. This is done to avoid repeatedly removing elements in this 64 // situation. 65 size_t frames_since_zero_buffer_size_ = 0; 66 67 // Circular buffers containing delayed versions of the power, mean and 68 // standard deviation, for calculating the delayed covariance values. 69 std::vector<float> render_power_; 70 std::vector<float> render_power_mean_; 71 std::vector<float> render_power_std_dev_; 72 // Covariance estimates for different delay values. 73 std::vector<NormalizedCovarianceEstimator> covariances_; 74 // Index where next element should be inserted in all of the above circular 75 // buffers. 76 size_t next_insertion_index_ = 0; 77 78 MeanVarianceEstimator render_statistics_; 79 MeanVarianceEstimator capture_statistics_; 80 // Current echo likelihood. 81 float echo_likelihood_ = 0.f; 82 // Reliability of the current likelihood. 83 float reliability_ = 0.f; 84 MovingMax recent_likelihood_max_; 85 86 int log_counter_ = 0; 87 }; 88 89 } // namespace webrtc 90 91 #endif // MODULES_AUDIO_PROCESSING_RESIDUAL_ECHO_DETECTOR_H_ 92