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/vad_wrapper.h"
12
13 #include <array>
14 #include <utility>
15
16 #include "api/array_view.h"
17 #include "common_audio/resampler/include/push_resampler.h"
18 #include "modules/audio_processing/agc2/agc2_common.h"
19 #include "modules/audio_processing/agc2/rnn_vad/common.h"
20 #include "modules/audio_processing/agc2/rnn_vad/features_extraction.h"
21 #include "modules/audio_processing/agc2/rnn_vad/rnn.h"
22 #include "rtc_base/checks.h"
23
24 namespace webrtc {
25 namespace {
26
27 constexpr int kNumFramesPerSecond = 100;
28
29 class MonoVadImpl : public VoiceActivityDetectorWrapper::MonoVad {
30 public:
MonoVadImpl(const AvailableCpuFeatures & cpu_features)31 explicit MonoVadImpl(const AvailableCpuFeatures& cpu_features)
32 : features_extractor_(cpu_features), rnn_vad_(cpu_features) {}
33 MonoVadImpl(const MonoVadImpl&) = delete;
34 MonoVadImpl& operator=(const MonoVadImpl&) = delete;
35 ~MonoVadImpl() = default;
36
SampleRateHz() const37 int SampleRateHz() const override { return rnn_vad::kSampleRate24kHz; }
Reset()38 void Reset() override { rnn_vad_.Reset(); }
Analyze(rtc::ArrayView<const float> frame)39 float Analyze(rtc::ArrayView<const float> frame) override {
40 RTC_DCHECK_EQ(frame.size(), rnn_vad::kFrameSize10ms24kHz);
41 std::array<float, rnn_vad::kFeatureVectorSize> feature_vector;
42 const bool is_silence = features_extractor_.CheckSilenceComputeFeatures(
43 /*samples=*/{frame.data(), rnn_vad::kFrameSize10ms24kHz},
44 feature_vector);
45 return rnn_vad_.ComputeVadProbability(feature_vector, is_silence);
46 }
47
48 private:
49 rnn_vad::FeaturesExtractor features_extractor_;
50 rnn_vad::RnnVad rnn_vad_;
51 };
52
53 } // namespace
54
VoiceActivityDetectorWrapper(int vad_reset_period_ms,const AvailableCpuFeatures & cpu_features,int sample_rate_hz)55 VoiceActivityDetectorWrapper::VoiceActivityDetectorWrapper(
56 int vad_reset_period_ms,
57 const AvailableCpuFeatures& cpu_features,
58 int sample_rate_hz)
59 : VoiceActivityDetectorWrapper(vad_reset_period_ms,
60 std::make_unique<MonoVadImpl>(cpu_features),
61 sample_rate_hz) {}
62
VoiceActivityDetectorWrapper(int vad_reset_period_ms,std::unique_ptr<MonoVad> vad,int sample_rate_hz)63 VoiceActivityDetectorWrapper::VoiceActivityDetectorWrapper(
64 int vad_reset_period_ms,
65 std::unique_ptr<MonoVad> vad,
66 int sample_rate_hz)
67 : vad_reset_period_frames_(
68 rtc::CheckedDivExact(vad_reset_period_ms, kFrameDurationMs)),
69 time_to_vad_reset_(vad_reset_period_frames_),
70 vad_(std::move(vad)) {
71 RTC_DCHECK(vad_);
72 RTC_DCHECK_GT(vad_reset_period_frames_, 1);
73 resampled_buffer_.resize(
74 rtc::CheckedDivExact(vad_->SampleRateHz(), kNumFramesPerSecond));
75 Initialize(sample_rate_hz);
76 }
77
78 VoiceActivityDetectorWrapper::~VoiceActivityDetectorWrapper() = default;
79
Initialize(int sample_rate_hz)80 void VoiceActivityDetectorWrapper::Initialize(int sample_rate_hz) {
81 RTC_DCHECK_GT(sample_rate_hz, 0);
82 frame_size_ = rtc::CheckedDivExact(sample_rate_hz, kNumFramesPerSecond);
83 int status =
84 resampler_.InitializeIfNeeded(sample_rate_hz, vad_->SampleRateHz(),
85 /*num_channels=*/1);
86 constexpr int kStatusOk = 0;
87 RTC_DCHECK_EQ(status, kStatusOk);
88 vad_->Reset();
89 }
90
Analyze(AudioFrameView<const float> frame)91 float VoiceActivityDetectorWrapper::Analyze(AudioFrameView<const float> frame) {
92 // Periodically reset the VAD.
93 time_to_vad_reset_--;
94 if (time_to_vad_reset_ <= 0) {
95 vad_->Reset();
96 time_to_vad_reset_ = vad_reset_period_frames_;
97 }
98 // Resample the first channel of `frame`.
99 RTC_DCHECK_EQ(frame.samples_per_channel(), frame_size_);
100 resampler_.Resample(frame.channel(0).data(), frame_size_,
101 resampled_buffer_.data(), resampled_buffer_.size());
102
103 return vad_->Analyze(resampled_buffer_);
104 }
105
106 } // namespace webrtc
107