bc0b37c08a
This CL defines SpectralFeaturesExtractor which is responsible for computing the spectral features used as input for the RNN. Bug: webrtc:9076 Change-Id: I5e1396b89eca9c13bb268e8419a16436a9c3450f Reviewed-on: https://webrtc-review.googlesource.com/73760 Commit-Queue: Alessio Bazzica <alessiob@webrtc.org> Reviewed-by: Alex Loiko <aleloi@webrtc.org> Reviewed-by: Ivo Creusen <ivoc@webrtc.org> Cr-Commit-Position: refs/heads/master@{#23206}
56 lines
2.4 KiB
C++
56 lines
2.4 KiB
C++
/*
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* Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "modules/audio_processing/agc2/rnn_vad/pitch_search.h"
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#include "modules/audio_processing/agc2/rnn_vad/pitch_search_internal.h"
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namespace webrtc {
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namespace rnn_vad {
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// TODO(bugs.webrtc.org/9076): To decrease the stack size, add a class that uses
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// std::vector instances instead of the local arrays used in PitchSearch(). It
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// is also useful once https://webrtc-review.googlesource.com/c/src/+/73366
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// lands.
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PitchInfo PitchSearch(rtc::ArrayView<const float, kBufSize24kHz> pitch_buf,
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PitchInfo prev_pitch_48kHz,
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RealFourier* fft) {
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// Perform the initial pitch search at 12 kHz.
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std::array<float, kBufSize12kHz> pitch_buf_decimated;
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Decimate2x(pitch_buf,
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{pitch_buf_decimated.data(), pitch_buf_decimated.size()});
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// Compute auto-correlation terms.
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std::array<float, kNumInvertedLags12kHz> auto_corr;
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ComputePitchAutoCorrelation(
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{pitch_buf_decimated.data(), pitch_buf_decimated.size()}, kMaxPitch12kHz,
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{auto_corr.data(), auto_corr.size()}, fft);
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// Search for pitch at 12 kHz.
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std::array<size_t, 2> pitch_candidates_inv_lags = FindBestPitchPeriods(
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{auto_corr.data(), auto_corr.size()},
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{pitch_buf_decimated.data(), pitch_buf_decimated.size()}, kMaxPitch12kHz);
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// Refine the pitch period estimation.
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// The refinement is done using the pitch buffer that contains 24 kHz samples.
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// Therefore, adapt the inverted lags in |pitch_candidates_inv_lags| from 12
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// to 24 kHz.
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for (size_t i = 0; i < pitch_candidates_inv_lags.size(); ++i)
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pitch_candidates_inv_lags[i] *= 2;
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size_t pitch_inv_lag_48kHz = RefinePitchPeriod48kHz(
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pitch_buf,
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{pitch_candidates_inv_lags.data(), pitch_candidates_inv_lags.size()});
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// Look for stronger harmonics to find the final pitch period and its gain.
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RTC_DCHECK_LT(pitch_inv_lag_48kHz, kMaxPitch48kHz);
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return CheckLowerPitchPeriodsAndComputePitchGain(
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pitch_buf, kMaxPitch48kHz - pitch_inv_lag_48kHz, prev_pitch_48kHz);
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}
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} // namespace rnn_vad
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} // namespace webrtc
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