webrtc/modules/audio_processing/ns/ns_fft.cc
Mirko Bonadei f0d64a5f9b Reland "Unify OOURA implementations in one directory."
This is a reland of 09b439c6f7

Original change's description:
> Unify OOURA implementations in one directory.
>
> This CL moves the two OOURA implementations present in the WebRTC tree
> in one place.
>
> No functional change is expected.
>
> TBR=kwiberg@webrtc.org
>
> No-Try: True
> Bug: webrtc:11509
> Change-Id: I330a9ec57e3dc65c9c8b43edd4bb295c55920efa
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/173682
> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
> Reviewed-by: Per Åhgren <peah@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#31106}

TBR=kwiberg@webrtc.org, peah@webrtc.org

No-Tree-Checks: True
No-Try: True
Bug: webrtc:11509
Change-Id: Ifc28b0380062ab5aad5c498700aa3cc7f9c7802c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/173720
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31111}
2020-04-20 16:08:19 +00:00

64 lines
2 KiB
C++

/*
* Copyright (c) 2019 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.
*/
#include "modules/audio_processing/ns/ns_fft.h"
#include "common_audio/third_party/ooura/fft_size_256/fft4g.h"
namespace webrtc {
NrFft::NrFft() : bit_reversal_state_(kFftSize / 2), tables_(kFftSize / 2) {
// Initialize WebRtc_rdt (setting (bit_reversal_state_[0] to 0 triggers
// initialization)
bit_reversal_state_[0] = 0.f;
std::array<float, kFftSize> tmp_buffer;
tmp_buffer.fill(0.f);
WebRtc_rdft(kFftSize, 1, tmp_buffer.data(), bit_reversal_state_.data(),
tables_.data());
}
void NrFft::Fft(rtc::ArrayView<float, kFftSize> time_data,
rtc::ArrayView<float, kFftSize> real,
rtc::ArrayView<float, kFftSize> imag) {
WebRtc_rdft(kFftSize, 1, time_data.data(), bit_reversal_state_.data(),
tables_.data());
imag[0] = 0;
real[0] = time_data[0];
imag[kFftSizeBy2Plus1 - 1] = 0;
real[kFftSizeBy2Plus1 - 1] = time_data[1];
for (size_t i = 1; i < kFftSizeBy2Plus1 - 1; ++i) {
real[i] = time_data[2 * i];
imag[i] = time_data[2 * i + 1];
}
}
void NrFft::Ifft(rtc::ArrayView<const float> real,
rtc::ArrayView<const float> imag,
rtc::ArrayView<float> time_data) {
time_data[0] = real[0];
time_data[1] = real[kFftSizeBy2Plus1 - 1];
for (size_t i = 1; i < kFftSizeBy2Plus1 - 1; ++i) {
time_data[2 * i] = real[i];
time_data[2 * i + 1] = imag[i];
}
WebRtc_rdft(kFftSize, -1, time_data.data(), bit_reversal_state_.data(),
tables_.data());
// Scale the output
constexpr float kScaling = 2.f / kFftSize;
for (float& d : time_data) {
d *= kScaling;
}
}
} // namespace webrtc