Revert "Pull the Voice Activity Detector out from the AGC"

webrtc/modules/audio_processing/vad/voice_activity_detector.cc

-/*
- *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#include "webrtc/modules/audio_processing/vad/voice_activity_detector.h"
-
-#include <algorithm>
-
-#include "webrtc/base/checks.h"
-
-namespace webrtc {
-namespace {
-
-const int kMaxLength = 320;
-const int kNumChannels = 1;
-
-const double kDefaultVoiceValue = 1.0;
-const double kNeutralProbability = 0.5;
-const double kLowProbability = 0.01;
-
-}  // namespace
-
-VoiceActivityDetector::VoiceActivityDetector()
-    : last_voice_probability_(kDefaultVoiceValue),
-      // Initialize to the most common resampling situation.
-      resampler_(kMaxLength, kLength10Ms, kNumChannels),
-      standalone_vad_(StandaloneVad::Create()) {
-}
-
-// Because ISAC has a different chunk length, it updates
-// |chunkwise_voice_probabilities_| and |chunkwise_rms_| when there is new data.
-// Otherwise it clears them.
-void VoiceActivityDetector::ProcessChunk(const int16_t* audio,
-                                         int length,
-                                         int sample_rate_hz) {
-  DCHECK_EQ(length, sample_rate_hz / 100);
-  DCHECK_LE(length, kMaxLength);
-  // Resample to the required rate.
-  const int16_t* resampled_ptr = audio;
-  if (sample_rate_hz != kSampleRateHz) {
-    CHECK_EQ(
-        resampler_.ResetIfNeeded(sample_rate_hz, kSampleRateHz, kNumChannels),
-        0);
-    resampler_.Push(audio, length, resampled_, kLength10Ms, length);
-    resampled_ptr = resampled_;
-  }
-  DCHECK_EQ(length, kLength10Ms);
-
-  // Each chunk needs to be passed into |standalone_vad_|, because internally it
-  // buffers the audio and processes it all at once when GetActivity() is
-  // called.
-  CHECK_EQ(standalone_vad_->AddAudio(audio, length), 0);
-
-  audio_processing_.ExtractFeatures(resampled_ptr, length, &features_);
-
-  chunkwise_voice_probabilities_.resize(features_.num_frames);
-  chunkwise_rms_.resize(features_.num_frames);
-  std::copy(features_.rms, features_.rms + chunkwise_rms_.size(),
-            chunkwise_rms_.begin());
-  if (features_.num_frames > 0) {
-    if (features_.silence) {
-      // The other features are invalid, so set the voice probabilities to an
-      // arbitrary low value.
-      std::fill(chunkwise_voice_probabilities_.begin(),
-                chunkwise_voice_probabilities_.end(), kLowProbability);
-    } else {
-      std::fill(chunkwise_voice_probabilities_.begin(),
-                chunkwise_voice_probabilities_.end(), kNeutralProbability);
-      CHECK_GE(
-          standalone_vad_->GetActivity(&chunkwise_voice_probabilities_[0],
-                                       chunkwise_voice_probabilities_.size()),
-          0);
-      CHECK_GE(pitch_based_vad_.VoicingProbability(
-                   features_, &chunkwise_voice_probabilities_[0]),
-               0);
-    }
-    last_voice_probability_ = chunkwise_voice_probabilities_.back();
-  }
-}
-
-}  // namespace webrtc