xref: /aosp_15_r20/external/webrtc/modules/audio_processing/aec3/decimator.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
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 
21 namespace webrtc {
22 
23 // Provides functionality for decimating a signal.
24 class Decimator {
25  public:
26   explicit Decimator(size_t down_sampling_factor);
27 
28   Decimator(const Decimator&) = delete;
29   Decimator& operator=(const Decimator&) = delete;
30 
31   // Downsamples the signal.
32   void Decimate(rtc::ArrayView<const float> in, rtc::ArrayView<float> out);
33 
34  private:
35   const size_t down_sampling_factor_;
36   CascadedBiQuadFilter anti_aliasing_filter_;
37   CascadedBiQuadFilter noise_reduction_filter_;
38 };
39 }  // namespace webrtc
40 
41 #endif  // MODULES_AUDIO_PROCESSING_AEC3_DECIMATOR_H_
42