1 /*
2  *  Copyright (c) 2014 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 #include "common_audio/real_fourier.h"
12 
13 #include "common_audio/real_fourier_ooura.h"
14 #include "common_audio/signal_processing/include/signal_processing_library.h"
15 #include "rtc_base/checks.h"
16 
17 namespace webrtc {
18 
19 using std::complex;
20 
21 const size_t RealFourier::kFftBufferAlignment = 32;
22 
Create(int fft_order)23 std::unique_ptr<RealFourier> RealFourier::Create(int fft_order) {
24   return std::unique_ptr<RealFourier>(new RealFourierOoura(fft_order));
25 }
26 
FftOrder(size_t length)27 int RealFourier::FftOrder(size_t length) {
28   RTC_CHECK_GT(length, 0U);
29   return WebRtcSpl_GetSizeInBits(static_cast<uint32_t>(length - 1));
30 }
31 
FftLength(int order)32 size_t RealFourier::FftLength(int order) {
33   RTC_CHECK_GE(order, 0);
34   return size_t{1} << order;
35 }
36 
ComplexLength(int order)37 size_t RealFourier::ComplexLength(int order) {
38   return FftLength(order) / 2 + 1;
39 }
40 
AllocRealBuffer(int count)41 RealFourier::fft_real_scoper RealFourier::AllocRealBuffer(int count) {
42   return fft_real_scoper(static_cast<float*>(
43       AlignedMalloc(sizeof(float) * count, kFftBufferAlignment)));
44 }
45 
AllocCplxBuffer(int count)46 RealFourier::fft_cplx_scoper RealFourier::AllocCplxBuffer(int count) {
47   return fft_cplx_scoper(static_cast<complex<float>*>(
48       AlignedMalloc(sizeof(complex<float>) * count, kFftBufferAlignment)));
49 }
50 
51 }  // namespace webrtc
52