1 /*
2 * Copyright (c) 2018 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/agc2/saturation_protector.h"
12
13 #include <algorithm>
14 #include <iterator>
15
16 #include "modules/audio_processing/logging/apm_data_dumper.h"
17 #include "rtc_base/numerics/safe_minmax.h"
18
19 namespace webrtc {
20
21 namespace {
ShiftBuffer(std::array<float,kPeakEnveloperBufferSize> * buffer_)22 void ShiftBuffer(std::array<float, kPeakEnveloperBufferSize>* buffer_) {
23 // Move everything one element back.
24 std::copy(buffer_->begin() + 1, buffer_->end(), buffer_->begin());
25 }
26 } // namespace
27
28 SaturationProtector::PeakEnveloper::PeakEnveloper() = default;
29
Process(float frame_peak_dbfs)30 void SaturationProtector::PeakEnveloper::Process(float frame_peak_dbfs) {
31 // Update the delayed buffer and the current superframe peak.
32 current_superframe_peak_dbfs_ =
33 std::max(current_superframe_peak_dbfs_, frame_peak_dbfs);
34 speech_time_in_estimate_ms_ += kFrameDurationMs;
35 if (speech_time_in_estimate_ms_ > kPeakEnveloperSuperFrameLengthMs) {
36 speech_time_in_estimate_ms_ = 0;
37 const bool buffer_full = elements_in_buffer_ == kPeakEnveloperBufferSize;
38 if (buffer_full) {
39 ShiftBuffer(&peak_delay_buffer_);
40 *peak_delay_buffer_.rbegin() = current_superframe_peak_dbfs_;
41 } else {
42 peak_delay_buffer_[elements_in_buffer_] = current_superframe_peak_dbfs_;
43 elements_in_buffer_++;
44 }
45 current_superframe_peak_dbfs_ = -90.f;
46 }
47 }
48
Query() const49 float SaturationProtector::PeakEnveloper::Query() const {
50 float result;
51 if (elements_in_buffer_ > 0) {
52 result = peak_delay_buffer_[0];
53 } else {
54 result = current_superframe_peak_dbfs_;
55 }
56 return result;
57 }
58
SaturationProtector(ApmDataDumper * apm_data_dumper)59 SaturationProtector::SaturationProtector(ApmDataDumper* apm_data_dumper)
60 : SaturationProtector(apm_data_dumper, GetExtraSaturationMarginOffsetDb()) {
61 }
62
SaturationProtector(ApmDataDumper * apm_data_dumper,float extra_saturation_margin_db)63 SaturationProtector::SaturationProtector(ApmDataDumper* apm_data_dumper,
64 float extra_saturation_margin_db)
65 : apm_data_dumper_(apm_data_dumper),
66 last_margin_(GetInitialSaturationMarginDb()),
67 extra_saturation_margin_db_(extra_saturation_margin_db) {}
68
UpdateMargin(const VadWithLevel::LevelAndProbability & vad_data,float last_speech_level_estimate)69 void SaturationProtector::UpdateMargin(
70 const VadWithLevel::LevelAndProbability& vad_data,
71 float last_speech_level_estimate) {
72 peak_enveloper_.Process(vad_data.speech_peak_dbfs);
73 const float delayed_peak_dbfs = peak_enveloper_.Query();
74 const float difference_db = delayed_peak_dbfs - last_speech_level_estimate;
75
76 if (last_margin_ < difference_db) {
77 last_margin_ = last_margin_ * kSaturationProtectorAttackConstant +
78 difference_db * (1.f - kSaturationProtectorAttackConstant);
79 } else {
80 last_margin_ = last_margin_ * kSaturationProtectorDecayConstant +
81 difference_db * (1.f - kSaturationProtectorDecayConstant);
82 }
83
84 last_margin_ = rtc::SafeClamp<float>(last_margin_, 12.f, 25.f);
85 }
86
LastMargin() const87 float SaturationProtector::LastMargin() const {
88 return last_margin_ + extra_saturation_margin_db_;
89 }
90
Reset()91 void SaturationProtector::Reset() {
92 peak_enveloper_ = PeakEnveloper();
93 }
94
DebugDumpEstimate() const95 void SaturationProtector::DebugDumpEstimate() const {
96 if (apm_data_dumper_) {
97 apm_data_dumper_->DumpRaw(
98 "agc2_adaptive_saturation_protector_delayed_peak_dbfs",
99 peak_enveloper_.Query());
100 apm_data_dumper_->DumpRaw("agc2_adaptive_saturation_margin_db",
101 last_margin_);
102 }
103 }
104
105 } // namespace webrtc
106