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Letting the delay estimator operate at a sampling frequency of 2 kHz with audio between 0 and 1 kHz makes it sensitive to noisy environments. This CL bandpass filters the 16 kHz signal before downsampling to 2 kHz in a way that the downsampled 2 kHz signal contains audio between 1 and 2 kHz. It also sets downsampling factor 8 as default which significantly reduces computational complexity. Bug: webrtc:9288,chromium:846615 Change-Id: Iaf67898a1a14326cd61bb7f81c14d3c12a697c8d Reviewed-on: https://webrtc-review.googlesource.com/78703 Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org> Reviewed-by: Per Åhgren <peah@webrtc.org> Cr-Commit-Position: refs/heads/master@{#23395}
40 lines
1.2 KiB
C++
40 lines
1.2 KiB
C++
/*
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* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef MODULES_AUDIO_PROCESSING_AEC3_DECIMATOR_H_
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#define MODULES_AUDIO_PROCESSING_AEC3_DECIMATOR_H_
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#include <array>
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#include "api/array_view.h"
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#include "modules/audio_processing/aec3/aec3_common.h"
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#include "modules/audio_processing/aec3/cascaded_biquad_filter.h"
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#include "rtc_base/constructormagic.h"
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namespace webrtc {
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// Provides functionality for decimating a signal.
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class Decimator {
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public:
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explicit Decimator(size_t down_sampling_factor);
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// Downsamples the signal.
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void Decimate(rtc::ArrayView<const float> in, rtc::ArrayView<float> out);
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private:
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const size_t down_sampling_factor_;
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CascadedBiQuadFilter anti_aliasing_filter_;
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CascadedBiQuadFilter noise_reduction_filter_;
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RTC_DISALLOW_COPY_AND_ASSIGN(Decimator);
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};
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} // namespace webrtc
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#endif // MODULES_AUDIO_PROCESSING_AEC3_DECIMATOR_H_
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