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