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 #include "modules/audio_processing/aec3/render_buffer.h"
12
13 #include <algorithm>
14
15 #include "modules/audio_processing/aec3/aec3_common.h"
16 #include "rtc_base/checks.h"
17
18 namespace webrtc {
19
RenderBuffer(Aec3Optimization optimization,size_t num_bands,size_t num_partitions,const std::vector<size_t> num_ffts_for_spectral_sums)20 RenderBuffer::RenderBuffer(Aec3Optimization optimization,
21 size_t num_bands,
22 size_t num_partitions,
23 const std::vector<size_t> num_ffts_for_spectral_sums)
24 : optimization_(optimization),
25 fft_buffer_(num_partitions),
26 spectrum_buffer_(num_partitions, std::array<float, kFftLengthBy2Plus1>()),
27 spectral_sums_(num_ffts_for_spectral_sums.size(),
28 std::array<float, kFftLengthBy2Plus1>()),
29 last_block_(num_bands, std::vector<float>(kBlockSize, 0.f)),
30 fft_() {
31 // Current implementation only allows a maximum of one spectral sum lengths.
32 RTC_DCHECK_EQ(1, num_ffts_for_spectral_sums.size());
33 spectral_sums_length_ = num_ffts_for_spectral_sums[0];
34 RTC_DCHECK_GE(fft_buffer_.size(), spectral_sums_length_);
35
36 Clear();
37 }
38
39 RenderBuffer::~RenderBuffer() = default;
40
Clear()41 void RenderBuffer::Clear() {
42 position_ = 0;
43 for (auto& sum : spectral_sums_) {
44 sum.fill(0.f);
45 }
46
47 for (auto& spectrum : spectrum_buffer_) {
48 spectrum.fill(0.f);
49 }
50
51 for (auto& fft : fft_buffer_) {
52 fft.Clear();
53 }
54
55 for (auto& b : last_block_) {
56 std::fill(b.begin(), b.end(), 0.f);
57 }
58 }
59
Insert(const std::vector<std::vector<float>> & block)60 void RenderBuffer::Insert(const std::vector<std::vector<float>>& block) {
61 // Compute the FFT of the data in the lowest band.
62 FftData X;
63 fft_.PaddedFft(block[0], last_block_[0], &X);
64
65 // Copy the last render frame.
66 RTC_DCHECK_EQ(last_block_.size(), block.size());
67 for (size_t k = 0; k < block.size(); ++k) {
68 RTC_DCHECK_EQ(last_block_[k].size(), block[k].size());
69 std::copy(block[k].begin(), block[k].end(), last_block_[k].begin());
70 }
71
72 // Insert X into the buffer.
73 position_ = position_ > 0 ? position_ - 1 : fft_buffer_.size() - 1;
74 fft_buffer_[position_].Assign(X);
75
76 // Compute and insert the spectrum for the FFT into the spectrum buffer.
77 X.Spectrum(optimization_, &spectrum_buffer_[position_]);
78
79 // Pre-compute and cache the spectral sums.
80 std::copy(spectrum_buffer_[position_].begin(),
81 spectrum_buffer_[position_].end(), spectral_sums_[0].begin());
82 size_t position = (position_ + 1) % fft_buffer_.size();
83 for (size_t j = 1; j < spectral_sums_length_; ++j) {
84 const std::array<float, kFftLengthBy2Plus1>& spectrum =
85 spectrum_buffer_[position];
86
87 for (size_t k = 0; k < spectral_sums_[0].size(); ++k) {
88 spectral_sums_[0][k] += spectrum[k];
89 }
90
91 position = position < (fft_buffer_.size() - 1) ? position + 1 : 0;
92 }
93 }
94
95 } // namespace webrtc
96