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 "modules/audio_processing/splitting_filter.h"
12
13 #include "common_audio/channel_buffer.h"
14 #include "common_audio/signal_processing/include/signal_processing_library.h"
15 #include "rtc_base/checks.h"
16
17 namespace webrtc {
18
SplittingFilter(size_t num_channels,size_t num_bands,size_t num_frames)19 SplittingFilter::SplittingFilter(size_t num_channels,
20 size_t num_bands,
21 size_t num_frames)
22 : num_bands_(num_bands) {
23 RTC_CHECK(num_bands_ == 2 || num_bands_ == 3);
24 if (num_bands_ == 2) {
25 two_bands_states_.resize(num_channels);
26 } else if (num_bands_ == 3) {
27 for (size_t i = 0; i < num_channels; ++i) {
28 three_band_filter_banks_.push_back(std::unique_ptr<ThreeBandFilterBank>(
29 new ThreeBandFilterBank(num_frames)));
30 }
31 }
32 }
33
34 SplittingFilter::~SplittingFilter() = default;
35
Analysis(const IFChannelBuffer * data,IFChannelBuffer * bands)36 void SplittingFilter::Analysis(const IFChannelBuffer* data,
37 IFChannelBuffer* bands) {
38 RTC_DCHECK_EQ(num_bands_, bands->num_bands());
39 RTC_DCHECK_EQ(data->num_channels(), bands->num_channels());
40 RTC_DCHECK_EQ(data->num_frames(),
41 bands->num_frames_per_band() * bands->num_bands());
42 if (bands->num_bands() == 2) {
43 TwoBandsAnalysis(data, bands);
44 } else if (bands->num_bands() == 3) {
45 ThreeBandsAnalysis(data, bands);
46 }
47 }
48
Synthesis(const IFChannelBuffer * bands,IFChannelBuffer * data)49 void SplittingFilter::Synthesis(const IFChannelBuffer* bands,
50 IFChannelBuffer* data) {
51 RTC_DCHECK_EQ(num_bands_, bands->num_bands());
52 RTC_DCHECK_EQ(data->num_channels(), bands->num_channels());
53 RTC_DCHECK_EQ(data->num_frames(),
54 bands->num_frames_per_band() * bands->num_bands());
55 if (bands->num_bands() == 2) {
56 TwoBandsSynthesis(bands, data);
57 } else if (bands->num_bands() == 3) {
58 ThreeBandsSynthesis(bands, data);
59 }
60 }
61
TwoBandsAnalysis(const IFChannelBuffer * data,IFChannelBuffer * bands)62 void SplittingFilter::TwoBandsAnalysis(const IFChannelBuffer* data,
63 IFChannelBuffer* bands) {
64 RTC_DCHECK_EQ(two_bands_states_.size(), data->num_channels());
65 for (size_t i = 0; i < two_bands_states_.size(); ++i) {
66 WebRtcSpl_AnalysisQMF(data->ibuf_const()->channels()[i],
67 data->num_frames(),
68 bands->ibuf()->channels(0)[i],
69 bands->ibuf()->channels(1)[i],
70 two_bands_states_[i].analysis_state1,
71 two_bands_states_[i].analysis_state2);
72 }
73 }
74
TwoBandsSynthesis(const IFChannelBuffer * bands,IFChannelBuffer * data)75 void SplittingFilter::TwoBandsSynthesis(const IFChannelBuffer* bands,
76 IFChannelBuffer* data) {
77 RTC_DCHECK_LE(data->num_channels(), two_bands_states_.size());
78 for (size_t i = 0; i < data->num_channels(); ++i) {
79 WebRtcSpl_SynthesisQMF(bands->ibuf_const()->channels(0)[i],
80 bands->ibuf_const()->channels(1)[i],
81 bands->num_frames_per_band(),
82 data->ibuf()->channels()[i],
83 two_bands_states_[i].synthesis_state1,
84 two_bands_states_[i].synthesis_state2);
85 }
86 }
87
ThreeBandsAnalysis(const IFChannelBuffer * data,IFChannelBuffer * bands)88 void SplittingFilter::ThreeBandsAnalysis(const IFChannelBuffer* data,
89 IFChannelBuffer* bands) {
90 RTC_DCHECK_EQ(three_band_filter_banks_.size(), data->num_channels());
91 for (size_t i = 0; i < three_band_filter_banks_.size(); ++i) {
92 three_band_filter_banks_[i]->Analysis(data->fbuf_const()->channels()[i],
93 data->num_frames(),
94 bands->fbuf()->bands(i));
95 }
96 }
97
ThreeBandsSynthesis(const IFChannelBuffer * bands,IFChannelBuffer * data)98 void SplittingFilter::ThreeBandsSynthesis(const IFChannelBuffer* bands,
99 IFChannelBuffer* data) {
100 RTC_DCHECK_LE(data->num_channels(), three_band_filter_banks_.size());
101 for (size_t i = 0; i < data->num_channels(); ++i) {
102 three_band_filter_banks_[i]->Synthesis(bands->fbuf_const()->bands(i),
103 bands->num_frames_per_band(),
104 data->fbuf()->channels()[i]);
105 }
106 }
107
108 } // namespace webrtc
109