75 lines
2.4 KiB
C
75 lines
2.4 KiB
C
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/*
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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_AEC3_FFT_H_
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#define MODULES_AUDIO_PROCESSING_AEC3_AEC3_FFT_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/fft_data.h"
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#include "modules/audio_processing/utility/ooura_fft.h"
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#include "rtc_base/checks.h"
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#include "rtc_base/constructormagic.h"
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namespace webrtc {
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// Wrapper class that provides 128 point real valued FFT functionality with the
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// FftData type.
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class Aec3Fft {
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public:
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enum class Window { kRectangular, kHanning, kSqrtHanning };
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Aec3Fft() = default;
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// Computes the FFT. Note that both the input and output are modified.
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void Fft(std::array<float, kFftLength>* x, FftData* X) const {
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RTC_DCHECK(x);
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RTC_DCHECK(X);
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ooura_fft_.Fft(x->data());
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X->CopyFromPackedArray(*x);
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}
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// Computes the inverse Fft.
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void Ifft(const FftData& X, std::array<float, kFftLength>* x) const {
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RTC_DCHECK(x);
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X.CopyToPackedArray(x);
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ooura_fft_.InverseFft(x->data());
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}
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// Windows the input using a Hanning window, and then adds padding of
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// kFftLengthBy2 initial zeros before computing the Fft.
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void ZeroPaddedFft(rtc::ArrayView<const float> x,
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Window window,
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FftData* X) const;
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// Concatenates the kFftLengthBy2 values long x and x_old before computing the
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// Fft. After that, x is copied to x_old.
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void PaddedFft(rtc::ArrayView<const float> x,
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rtc::ArrayView<const float> x_old,
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FftData* X) const {
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PaddedFft(x, x_old, Window::kRectangular, X);
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}
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// Padded Fft using a time-domain window.
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void PaddedFft(rtc::ArrayView<const float> x,
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rtc::ArrayView<const float> x_old,
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Window window,
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FftData* X) const;
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private:
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const OouraFft ooura_fft_;
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RTC_DISALLOW_COPY_AND_ASSIGN(Aec3Fft);
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};
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} // namespace webrtc
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#endif // MODULES_AUDIO_PROCESSING_AEC3_AEC3_FFT_H_
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