OLD | NEW |
| (Empty) |
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 #include "webrtc/modules/audio_processing/aec3/power_echo_model.h" | |
11 | |
12 #include <string.h> | |
13 #include <algorithm> | |
14 | |
15 #include "webrtc/base/optional.h" | |
16 | |
17 namespace webrtc { | |
18 namespace { | |
19 | |
20 // Computes the spectral power over that last 20 frames. | |
21 void RecentMaximum(const RenderBuffer& X_buffer, | |
22 std::array<float, kFftLengthBy2Plus1>* R2) { | |
23 R2->fill(0.f); | |
24 for (size_t j = 0; j < 20; ++j) { | |
25 std::transform(R2->begin(), R2->end(), X_buffer.Spectrum(j).begin(), | |
26 R2->begin(), | |
27 [](float a, float b) { return std::max(a, b); }); | |
28 } | |
29 } | |
30 | |
31 constexpr float kHInitial = 10.f; | |
32 constexpr int kUpdateCounterInitial = 300; | |
33 | |
34 } // namespace | |
35 | |
36 PowerEchoModel::PowerEchoModel() { | |
37 H2_.fill(CountedFloat(kHInitial, kUpdateCounterInitial)); | |
38 } | |
39 | |
40 PowerEchoModel::~PowerEchoModel() = default; | |
41 | |
42 void PowerEchoModel::HandleEchoPathChange( | |
43 const EchoPathVariability& variability) { | |
44 if (variability.gain_change) { | |
45 H2_.fill(CountedFloat(kHInitial, kUpdateCounterInitial)); | |
46 } | |
47 } | |
48 | |
49 void PowerEchoModel::EstimateEcho( | |
50 const RenderBuffer& render_buffer, | |
51 const std::array<float, kFftLengthBy2Plus1>& capture_spectrum, | |
52 const AecState& aec_state, | |
53 std::array<float, kFftLengthBy2Plus1>* echo_spectrum) { | |
54 RTC_DCHECK(echo_spectrum); | |
55 | |
56 const RenderBuffer& X_buffer = render_buffer; | |
57 const auto& Y2 = capture_spectrum; | |
58 std::array<float, kFftLengthBy2Plus1>* S2 = echo_spectrum; | |
59 | |
60 // Choose delay to use. | |
61 const rtc::Optional<size_t> delay = | |
62 aec_state.FilterDelay() | |
63 ? aec_state.FilterDelay() | |
64 : (aec_state.ExternalDelay() ? rtc::Optional<size_t>(std::min<size_t>( | |
65 *aec_state.ExternalDelay(), | |
66 X_buffer.Buffer().size() - 1)) | |
67 : rtc::Optional<size_t>()); | |
68 | |
69 // Compute R2. | |
70 std::array<float, kFftLengthBy2Plus1> render_max; | |
71 if (!delay) { | |
72 RecentMaximum(render_buffer, &render_max); | |
73 } | |
74 const std::array<float, kFftLengthBy2Plus1>& X2_active = | |
75 delay ? render_buffer.Spectrum(*delay) : render_max; | |
76 | |
77 if (!aec_state.SaturatedCapture()) { | |
78 // Corresponds of WGN of power -46dBFS. | |
79 constexpr float kX2Min = 44015068.0f; | |
80 const int max_update_counter_value = delay ? 300 : 500; | |
81 | |
82 std::array<float, kFftLengthBy2Plus1> new_H2; | |
83 | |
84 // new_H2 = Y2 / X2. | |
85 std::transform(X2_active.begin(), X2_active.end(), Y2.begin(), | |
86 new_H2.begin(), | |
87 [&](float a, float b) { return a > kX2Min ? b / a : -1.f; }); | |
88 | |
89 // Lambda for updating H2 in a maximum statistics manner. | |
90 auto H2_updater = [&](float a, CountedFloat b) { | |
91 if (a > 0) { | |
92 if (a > b.value) { | |
93 b.counter = max_update_counter_value; | |
94 b.value = a; | |
95 } else if (--b.counter <= 0) { | |
96 b.value = std::max(b.value * 0.9f, 1.f); | |
97 } | |
98 } | |
99 return b; | |
100 }; | |
101 | |
102 std::transform(new_H2.begin(), new_H2.end(), H2_.begin(), H2_.begin(), | |
103 H2_updater); | |
104 } | |
105 | |
106 // S2 = H2*X2_active. | |
107 std::transform(H2_.begin(), H2_.end(), X2_active.begin(), S2->begin(), | |
108 [](CountedFloat a, float b) { return a.value * b; }); | |
109 } | |
110 | |
111 } // namespace webrtc | |
OLD | NEW |