tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

vad_wrapper.cc (3948B)

      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 <memory>
     15 #include <utility>
     16 
     17 #include "api/audio/audio_view.h"
     18 #include "common_audio/resampler/include/push_resampler.h"
     19 #include "modules/audio_processing/agc2/agc2_common.h"
     20 #include "modules/audio_processing/agc2/cpu_features.h"
     21 #include "modules/audio_processing/agc2/rnn_vad/common.h"
     22 #include "modules/audio_processing/agc2/rnn_vad/features_extraction.h"
     23 #include "modules/audio_processing/agc2/rnn_vad/rnn.h"
     24 #include "rtc_base/checks.h"
     25 
     26 namespace webrtc {
     27 namespace {
     28 
     29 constexpr int kNumFramesPerSecond = 100;
     30 
     31 class MonoVadImpl : public VoiceActivityDetectorWrapper::MonoVad {
     32 public:
     33  explicit MonoVadImpl(const AvailableCpuFeatures& cpu_features)
     34      : features_extractor_(cpu_features), rnn_vad_(cpu_features) {}
     35  MonoVadImpl(const MonoVadImpl&) = delete;
     36  MonoVadImpl& operator=(const MonoVadImpl&) = delete;
     37  ~MonoVadImpl() override = default;
     38 
     39  int SampleRateHz() const override { return rnn_vad::kSampleRate24kHz; }
     40  void Reset() override { rnn_vad_.Reset(); }
     41  float Analyze(MonoView<const float> frame) override {
     42    RTC_DCHECK_EQ(frame.size(), rnn_vad::kFrameSize10ms24kHz);
     43    std::array<float, rnn_vad::kFeatureVectorSize> feature_vector;
     44    const bool is_silence = features_extractor_.CheckSilenceComputeFeatures(
     45        /*samples=*/{frame.data(), rnn_vad::kFrameSize10ms24kHz},
     46        feature_vector);
     47    return rnn_vad_.ComputeVadProbability(feature_vector, is_silence);
     48  }
     49 
     50 private:
     51  rnn_vad::FeaturesExtractor features_extractor_;
     52  rnn_vad::RnnVad rnn_vad_;
     53 };
     54 
     55 }  // namespace
     56 
     57 VoiceActivityDetectorWrapper::VoiceActivityDetectorWrapper(
     58    const AvailableCpuFeatures& cpu_features,
     59    int sample_rate_hz)
     60    : VoiceActivityDetectorWrapper(kVadResetPeriodMs,
     61                                   cpu_features,
     62                                   sample_rate_hz) {}
     63 
     64 VoiceActivityDetectorWrapper::VoiceActivityDetectorWrapper(
     65    int vad_reset_period_ms,
     66    const AvailableCpuFeatures& cpu_features,
     67    int sample_rate_hz)
     68    : VoiceActivityDetectorWrapper(vad_reset_period_ms,
     69                                   std::make_unique<MonoVadImpl>(cpu_features),
     70                                   sample_rate_hz) {}
     71 
     72 VoiceActivityDetectorWrapper::VoiceActivityDetectorWrapper(
     73    int vad_reset_period_ms,
     74    std::unique_ptr<MonoVad> vad,
     75    int sample_rate_hz)
     76    : vad_reset_period_frames_(
     77          CheckedDivExact(vad_reset_period_ms, kFrameDurationMs)),
     78      frame_size_(CheckedDivExact(sample_rate_hz, kNumFramesPerSecond)),
     79      time_to_vad_reset_(vad_reset_period_frames_),
     80      vad_(std::move(vad)),
     81      resampled_buffer_(
     82          CheckedDivExact(vad_->SampleRateHz(), kNumFramesPerSecond)),
     83      resampler_(frame_size_,
     84                 resampled_buffer_.size(),
     85                 /*num_channels=*/1) {
     86  RTC_DCHECK_GT(vad_reset_period_frames_, 1);
     87  vad_->Reset();
     88 }
     89 
     90 VoiceActivityDetectorWrapper::~VoiceActivityDetectorWrapper() = default;
     91 
     92 float VoiceActivityDetectorWrapper::Analyze(
     93    DeinterleavedView<const float> frame) {
     94  // Periodically reset the VAD.
     95  time_to_vad_reset_--;
     96  if (time_to_vad_reset_ <= 0) {
     97    vad_->Reset();
     98    time_to_vad_reset_ = vad_reset_period_frames_;
     99  }
    100 
    101  // Resample the first channel of `frame`.
    102  RTC_DCHECK_EQ(frame.samples_per_channel(), frame_size_);
    103  MonoView<float> dst(resampled_buffer_.data(), resampled_buffer_.size());
    104  resampler_.Resample(frame[0], dst);
    105 
    106  return vad_->Analyze(resampled_buffer_);
    107 }
    108 
    109 }  // namespace webrtc