xref: /aosp_15_r20/external/webrtc/modules/audio_processing/aec3/fft_data.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1 /*
2  *  Copyright (c) 2017 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 #ifndef MODULES_AUDIO_PROCESSING_AEC3_FFT_DATA_H_
12 #define MODULES_AUDIO_PROCESSING_AEC3_FFT_DATA_H_
13 
14 // Defines WEBRTC_ARCH_X86_FAMILY, used below.
15 #include "rtc_base/system/arch.h"
16 
17 #if defined(WEBRTC_ARCH_X86_FAMILY)
18 #include <emmintrin.h>
19 #endif
20 #include <algorithm>
21 #include <array>
22 
23 #include "api/array_view.h"
24 #include "modules/audio_processing/aec3/aec3_common.h"
25 
26 namespace webrtc {
27 
28 // Struct that holds imaginary data produced from 128 point real-valued FFTs.
29 struct FftData {
30   // Copies the data in src.
AssignFftData31   void Assign(const FftData& src) {
32     std::copy(src.re.begin(), src.re.end(), re.begin());
33     std::copy(src.im.begin(), src.im.end(), im.begin());
34     im[0] = im[kFftLengthBy2] = 0;
35   }
36 
37   // Clears all the imaginary.
ClearFftData38   void Clear() {
39     re.fill(0.f);
40     im.fill(0.f);
41   }
42 
43   // Computes the power spectrum of the data.
44   void SpectrumAVX2(rtc::ArrayView<float> power_spectrum) const;
45 
46   // Computes the power spectrum of the data.
SpectrumFftData47   void Spectrum(Aec3Optimization optimization,
48                 rtc::ArrayView<float> power_spectrum) const {
49     RTC_DCHECK_EQ(kFftLengthBy2Plus1, power_spectrum.size());
50     switch (optimization) {
51 #if defined(WEBRTC_ARCH_X86_FAMILY)
52       case Aec3Optimization::kSse2: {
53         constexpr int kNumFourBinBands = kFftLengthBy2 / 4;
54         constexpr int kLimit = kNumFourBinBands * 4;
55         for (size_t k = 0; k < kLimit; k += 4) {
56           const __m128 r = _mm_loadu_ps(&re[k]);
57           const __m128 i = _mm_loadu_ps(&im[k]);
58           const __m128 ii = _mm_mul_ps(i, i);
59           const __m128 rr = _mm_mul_ps(r, r);
60           const __m128 rrii = _mm_add_ps(rr, ii);
61           _mm_storeu_ps(&power_spectrum[k], rrii);
62         }
63         power_spectrum[kFftLengthBy2] = re[kFftLengthBy2] * re[kFftLengthBy2] +
64                                         im[kFftLengthBy2] * im[kFftLengthBy2];
65       } break;
66       case Aec3Optimization::kAvx2:
67         SpectrumAVX2(power_spectrum);
68         break;
69 #endif
70       default:
71         std::transform(re.begin(), re.end(), im.begin(), power_spectrum.begin(),
72                        [](float a, float b) { return a * a + b * b; });
73     }
74   }
75 
76   // Copy the data from an interleaved array.
CopyFromPackedArrayFftData77   void CopyFromPackedArray(const std::array<float, kFftLength>& v) {
78     re[0] = v[0];
79     re[kFftLengthBy2] = v[1];
80     im[0] = im[kFftLengthBy2] = 0;
81     for (size_t k = 1, j = 2; k < kFftLengthBy2; ++k) {
82       re[k] = v[j++];
83       im[k] = v[j++];
84     }
85   }
86 
87   // Copies the data into an interleaved array.
CopyToPackedArrayFftData88   void CopyToPackedArray(std::array<float, kFftLength>* v) const {
89     RTC_DCHECK(v);
90     (*v)[0] = re[0];
91     (*v)[1] = re[kFftLengthBy2];
92     for (size_t k = 1, j = 2; k < kFftLengthBy2; ++k) {
93       (*v)[j++] = re[k];
94       (*v)[j++] = im[k];
95     }
96   }
97 
98   std::array<float, kFftLengthBy2Plus1> re;
99   std::array<float, kFftLengthBy2Plus1> im;
100 };
101 
102 }  // namespace webrtc
103 
104 #endif  // MODULES_AUDIO_PROCESSING_AEC3_FFT_DATA_H_
105