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/*
* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef MODULES_AUDIO_PROCESSING_AEC3_FFT_DATA_H_
#define MODULES_AUDIO_PROCESSING_AEC3_FFT_DATA_H_
// Defines WEBRTC_ARCH_X86_FAMILY, used below.
#include "rtc_base/system/arch.h"
#if defined(WEBRTC_ARCH_X86_FAMILY)
#include <emmintrin.h>
#endif
#include <algorithm>
#include <array>
#include "api/array_view.h"
#include "modules/audio_processing/aec3/aec3_common.h"
namespace webrtc {
// Struct that holds imaginary data produced from 128 point real-valued FFTs.
struct FftData {
// Copies the data in src.
void Assign(const FftData& src) {
std::copy(src.re.begin(), src.re.end(), re.begin());
std::copy(src.im.begin(), src.im.end(), im.begin());
im[0] = im[kFftLengthBy2] = 0;
}
// Clears all the imaginary.
void Clear() {
re.fill(0.f);
im.fill(0.f);
}
// Computes the power spectrum of the data.
void SpectrumAVX2(rtc::ArrayView<float> power_spectrum) const;
// Computes the power spectrum of the data.
void Spectrum(Aec3Optimization optimization,
rtc::ArrayView<float> power_spectrum) const {
RTC_DCHECK_EQ(kFftLengthBy2Plus1, power_spectrum.size());
switch (optimization) {
#if defined(WEBRTC_ARCH_X86_FAMILY)
case Aec3Optimization::kSse2: {
constexpr int kNumFourBinBands = kFftLengthBy2 / 4;
constexpr int kLimit = kNumFourBinBands * 4;
for (size_t k = 0; k < kLimit; k += 4) {
const __m128 r = _mm_loadu_ps(&re[k]);
const __m128 i = _mm_loadu_ps(&im[k]);
const __m128 ii = _mm_mul_ps(i, i);
const __m128 rr = _mm_mul_ps(r, r);
const __m128 rrii = _mm_add_ps(rr, ii);
_mm_storeu_ps(&power_spectrum[k], rrii);
}
power_spectrum[kFftLengthBy2] = re[kFftLengthBy2] * re[kFftLengthBy2] +
im[kFftLengthBy2] * im[kFftLengthBy2];
} break;
case Aec3Optimization::kAvx2:
SpectrumAVX2(power_spectrum);
break;
#endif
default:
std::transform(re.begin(), re.end(), im.begin(), power_spectrum.begin(),
[](float a, float b) { return a * a + b * b; });
}
}
// Copy the data from an interleaved array.
void CopyFromPackedArray(const std::array<float, kFftLength>& v) {
re[0] = v[0];
re[kFftLengthBy2] = v[1];
im[0] = im[kFftLengthBy2] = 0;
for (size_t k = 1, j = 2; k < kFftLengthBy2; ++k) {
re[k] = v[j++];
im[k] = v[j++];
}
}
// Copies the data into an interleaved array.
void CopyToPackedArray(std::array<float, kFftLength>* v) const {
RTC_DCHECK(v);
(*v)[0] = re[0];
(*v)[1] = re[kFftLengthBy2];
for (size_t k = 1, j = 2; k < kFftLengthBy2; ++k) {
(*v)[j++] = re[k];
(*v)[j++] = im[k];
}
}
std::array<float, kFftLengthBy2Plus1> re;
std::array<float, kFftLengthBy2Plus1> im;
};
} // namespace webrtc
#endif // MODULES_AUDIO_PROCESSING_AEC3_FFT_DATA_H_