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| 1 /* |
| 2 * Copyright (c) 2015 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 "webrtc/modules/audio_processing/vad/voice_activity_detector.h" |
| 12 |
| 13 #include <algorithm> |
| 14 |
| 15 #include "webrtc/base/checks.h" |
| 16 |
| 17 namespace webrtc { |
| 18 namespace { |
| 19 |
| 20 const int kMaxLength = 320; |
| 21 const int kNumChannels = 1; |
| 22 |
| 23 const double kDefaultVoiceValue = 1.0; |
| 24 const double kNeutralProbability = 0.5; |
| 25 const double kLowProbability = 0.01; |
| 26 |
| 27 } // namespace |
| 28 |
| 29 VoiceActivityDetector::VoiceActivityDetector() |
| 30 : last_voice_probability_(kDefaultVoiceValue), |
| 31 // Initialize to the most common resampling situation. |
| 32 resampler_(kMaxLength, kLength10Ms, kNumChannels), |
| 33 standalone_vad_(StandaloneVad::Create()) { |
| 34 } |
| 35 |
| 36 // Because ISAC has a different chunk length, it updates |
| 37 // |chunkwise_voice_probabilities_| and |chunkwise_rms_| when there is new data. |
| 38 // Otherwise it clears them. |
| 39 void VoiceActivityDetector::ProcessChunk(const int16_t* audio, |
| 40 int length, |
| 41 int sample_rate_hz) { |
| 42 DCHECK_EQ(length, sample_rate_hz / 100); |
| 43 DCHECK_LE(length, kMaxLength); |
| 44 // Resample to the required rate. |
| 45 const int16_t* resampled_ptr = audio; |
| 46 if (sample_rate_hz != kSampleRateHz) { |
| 47 CHECK_EQ( |
| 48 resampler_.ResetIfNeeded(sample_rate_hz, kSampleRateHz, kNumChannels), |
| 49 0); |
| 50 resampler_.Push(audio, length, resampled_, kLength10Ms, length); |
| 51 resampled_ptr = resampled_; |
| 52 } |
| 53 DCHECK_EQ(length, kLength10Ms); |
| 54 |
| 55 // Each chunk needs to be passed into |standalone_vad_|, because internally it |
| 56 // buffers the audio and processes it all at once when GetActivity() is |
| 57 // called. |
| 58 CHECK_EQ(standalone_vad_->AddAudio(audio, length), 0); |
| 59 |
| 60 audio_processing_.ExtractFeatures(resampled_ptr, length, &features_); |
| 61 |
| 62 chunkwise_voice_probabilities_.resize(features_.num_frames); |
| 63 chunkwise_rms_.resize(features_.num_frames); |
| 64 std::copy(features_.rms, features_.rms + chunkwise_rms_.size(), |
| 65 chunkwise_rms_.begin()); |
| 66 if (features_.num_frames > 0) { |
| 67 if (features_.silence) { |
| 68 // The other features are invalid, so set the voice probabilities to an |
| 69 // arbitrary low value. |
| 70 std::fill(chunkwise_voice_probabilities_.begin(), |
| 71 chunkwise_voice_probabilities_.end(), kLowProbability); |
| 72 } else { |
| 73 std::fill(chunkwise_voice_probabilities_.begin(), |
| 74 chunkwise_voice_probabilities_.end(), kNeutralProbability); |
| 75 CHECK_GE( |
| 76 standalone_vad_->GetActivity(&chunkwise_voice_probabilities_[0], |
| 77 chunkwise_voice_probabilities_.size()), |
| 78 0); |
| 79 CHECK_GE(pitch_based_vad_.VoicingProbability( |
| 80 features_, &chunkwise_voice_probabilities_[0]), |
| 81 0); |
| 82 } |
| 83 last_voice_probability_ = chunkwise_voice_probabilities_.back(); |
| 84 } |
| 85 } |
| 86 |
| 87 } // namespace webrtc |
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