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_DECIMATOR_H_ 12 #define MODULES_AUDIO_PROCESSING_AEC3_DECIMATOR_H_ 13 14 #include <array> 15 #include <vector> 16 17 #include "api/array_view.h" 18 #include "modules/audio_processing/aec3/aec3_common.h" 19 #include "modules/audio_processing/utility/cascaded_biquad_filter.h" 20 #include "rtc_base/constructor_magic.h" 21 22 namespace webrtc { 23 24 // Provides functionality for decimating a signal. 25 class Decimator { 26 public: 27 explicit Decimator(size_t down_sampling_factor); 28 29 // Downsamples the signal. 30 void Decimate(rtc::ArrayView<const float> in, rtc::ArrayView<float> out); 31 32 private: 33 const size_t down_sampling_factor_; 34 CascadedBiQuadFilter anti_aliasing_filter_; 35 CascadedBiQuadFilter noise_reduction_filter_; 36 37 RTC_DISALLOW_COPY_AND_ASSIGN(Decimator); 38 }; 39 } // namespace webrtc 40 41 #endif // MODULES_AUDIO_PROCESSING_AEC3_DECIMATOR_H_ 42