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author | Kshitij Sisodia <kshitij.sisodia@arm.com> | 2022-05-06 09:13:03 +0100 |
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committer | Kshitij Sisodia <kshitij.sisodia@arm.com> | 2022-05-06 17:11:41 +0100 |
commit | aa4bcb14d0cbee910331545dd2fc086b58c37170 (patch) | |
tree | e67a43a43f61c6f8b6aad19018b0827baf7e31a6 /source/application/api/use_case/noise_reduction/src/RNNoiseFeatureProcessor.cc | |
parent | fcca863bafd5f33522bc14c23dde4540e264ec94 (diff) | |
download | ml-embedded-evaluation-kit-aa4bcb14d0cbee910331545dd2fc086b58c37170.tar.gz |
MLECO-3183: Refactoring application sources
Platform agnostic application sources are moved into application
api module with their own independent CMake projects.
Changes for MLECO-3080 also included - they create CMake projects
individial API's (again, platform agnostic) that dependent on the
common logic. The API for KWS_API "joint" API has been removed and
now the use case relies on individual KWS, and ASR API libraries.
Change-Id: I1f7748dc767abb3904634a04e0991b74ac7b756d
Signed-off-by: Kshitij Sisodia <kshitij.sisodia@arm.com>
Diffstat (limited to 'source/application/api/use_case/noise_reduction/src/RNNoiseFeatureProcessor.cc')
-rw-r--r-- | source/application/api/use_case/noise_reduction/src/RNNoiseFeatureProcessor.cc | 892 |
1 files changed, 892 insertions, 0 deletions
diff --git a/source/application/api/use_case/noise_reduction/src/RNNoiseFeatureProcessor.cc b/source/application/api/use_case/noise_reduction/src/RNNoiseFeatureProcessor.cc new file mode 100644 index 0000000..036894c --- /dev/null +++ b/source/application/api/use_case/noise_reduction/src/RNNoiseFeatureProcessor.cc @@ -0,0 +1,892 @@ +/* + * Copyright (c) 2021-2022 Arm Limited. All rights reserved. + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#include "RNNoiseFeatureProcessor.hpp" +#include "log_macros.h" + +#include <algorithm> +#include <cmath> +#include <cstring> + +namespace arm { +namespace app { +namespace rnn { + +#define VERIFY(x) \ +do { \ + if (!(x)) { \ + printf_err("Assert failed:" #x "\n"); \ + exit(1); \ + } \ +} while(0) + +RNNoiseFeatureProcessor::RNNoiseFeatureProcessor() : + m_halfWindow(FRAME_SIZE, 0), + m_dctTable(NB_BANDS * NB_BANDS), + m_analysisMem(FRAME_SIZE, 0), + m_cepstralMem(CEPS_MEM, vec1D32F(NB_BANDS, 0)), + m_memId{0}, + m_synthesisMem(FRAME_SIZE, 0), + m_pitchBuf(PITCH_BUF_SIZE, 0), + m_lastGain{0.0}, + m_lastPeriod{0}, + m_memHpX{}, + m_lastGVec(NB_BANDS, 0) +{ + constexpr uint32_t numFFt = 2 * FRAME_SIZE; + static_assert(numFFt != 0, "Num FFT can't be 0"); + + math::MathUtils::FftInitF32(numFFt, this->m_fftInstReal, FftType::real); + math::MathUtils::FftInitF32(numFFt, this->m_fftInstCmplx, FftType::complex); + this->InitTables(); +} + +void RNNoiseFeatureProcessor::PreprocessFrame(const float* audioData, + const size_t audioLen, + FrameFeatures& features) +{ + /* Note audioWindow is modified in place */ + const arrHp aHp {-1.99599, 0.99600 }; + const arrHp bHp {-2.00000, 1.00000 }; + + vec1D32F audioWindow{audioData, audioData + audioLen}; + + this->BiQuad(bHp, aHp, this->m_memHpX, audioWindow); + this->ComputeFrameFeatures(audioWindow, features); +} + +void RNNoiseFeatureProcessor::PostProcessFrame(vec1D32F& modelOutput, FrameFeatures& features, vec1D32F& outFrame) +{ + std::vector<float> outputBands = modelOutput; + std::vector<float> gain(FREQ_SIZE, 0); + + if (!features.m_silence) { + PitchFilter(features, outputBands); + for (size_t i = 0; i < NB_BANDS; i++) { + float alpha = .6f; + outputBands[i] = std::max(outputBands[i], alpha * m_lastGVec[i]); + m_lastGVec[i] = outputBands[i]; + } + InterpBandGain(gain, outputBands); + for (size_t i = 0; i < FREQ_SIZE; i++) { + features.m_fftX[2 * i] *= gain[i]; /* Real. */ + features.m_fftX[2 * i + 1] *= gain[i]; /*imaginary. */ + + } + + } + + FrameSynthesis(outFrame, features.m_fftX); +} + +void RNNoiseFeatureProcessor::InitTables() +{ + constexpr float pi = M_PI; + constexpr float halfPi = M_PI / 2; + constexpr float halfPiOverFrameSz = halfPi/FRAME_SIZE; + + for (uint32_t i = 0; i < FRAME_SIZE; i++) { + const float sinVal = math::MathUtils::SineF32(halfPiOverFrameSz * (i + 0.5f)); + m_halfWindow[i] = math::MathUtils::SineF32(halfPi * sinVal * sinVal); + } + + for (uint32_t i = 0; i < NB_BANDS; i++) { + for (uint32_t j = 0; j < NB_BANDS; j++) { + m_dctTable[i * NB_BANDS + j] = math::MathUtils::CosineF32((i + 0.5f) * j * pi / NB_BANDS); + } + m_dctTable[i * NB_BANDS] *= math::MathUtils::SqrtF32(0.5f); + } +} + +void RNNoiseFeatureProcessor::BiQuad( + const arrHp& bHp, + const arrHp& aHp, + arrHp& memHpX, + vec1D32F& audioWindow) +{ + for (float& audioElement : audioWindow) { + const auto xi = audioElement; + const auto yi = audioElement + memHpX[0]; + memHpX[0] = memHpX[1] + (bHp[0] * xi - aHp[0] * yi); + memHpX[1] = (bHp[1] * xi - aHp[1] * yi); + audioElement = yi; + } +} + +void RNNoiseFeatureProcessor::ComputeFrameFeatures(vec1D32F& audioWindow, + FrameFeatures& features) +{ + this->FrameAnalysis(audioWindow, + features.m_fftX, + features.m_Ex, + this->m_analysisMem); + + float energy = 0.0; + + vec1D32F Ly(NB_BANDS, 0); + vec1D32F p(WINDOW_SIZE, 0); + vec1D32F pitchBuf(PITCH_BUF_SIZE >> 1, 0); + + VERIFY(PITCH_BUF_SIZE >= this->m_pitchBuf.size()); + std::copy_n(this->m_pitchBuf.begin() + FRAME_SIZE, + PITCH_BUF_SIZE - FRAME_SIZE, + this->m_pitchBuf.begin()); + + VERIFY(FRAME_SIZE <= audioWindow.size() && PITCH_BUF_SIZE > FRAME_SIZE); + std::copy_n(audioWindow.begin(), + FRAME_SIZE, + this->m_pitchBuf.begin() + PITCH_BUF_SIZE - FRAME_SIZE); + + this->PitchDownsample(pitchBuf, PITCH_BUF_SIZE); + + VERIFY(pitchBuf.size() > PITCH_MAX_PERIOD/2); + vec1D32F xLp(pitchBuf.size() - PITCH_MAX_PERIOD/2, 0); + std::copy_n(pitchBuf.begin() + PITCH_MAX_PERIOD/2, xLp.size(), xLp.begin()); + + int pitchIdx = this->PitchSearch(xLp, pitchBuf, + PITCH_FRAME_SIZE, (PITCH_MAX_PERIOD - (3*PITCH_MIN_PERIOD))); + + pitchIdx = this->RemoveDoubling( + pitchBuf, + PITCH_MAX_PERIOD, + PITCH_MIN_PERIOD, + PITCH_FRAME_SIZE, + PITCH_MAX_PERIOD - pitchIdx); + + size_t stIdx = PITCH_BUF_SIZE - WINDOW_SIZE - pitchIdx; + VERIFY((static_cast<int>(PITCH_BUF_SIZE) - static_cast<int>(WINDOW_SIZE) - pitchIdx) >= 0); + std::copy_n(this->m_pitchBuf.begin() + stIdx, WINDOW_SIZE, p.begin()); + + this->ApplyWindow(p); + this->ForwardTransform(p, features.m_fftP); + this->ComputeBandEnergy(features.m_fftP, features.m_Ep); + this->ComputeBandCorr(features.m_fftX, features.m_fftP, features.m_Exp); + + for (uint32_t i = 0 ; i < NB_BANDS; ++i) { + features.m_Exp[i] /= math::MathUtils::SqrtF32( + 0.001f + features.m_Ex[i] * features.m_Ep[i]); + } + + vec1D32F dctVec(NB_BANDS, 0); + this->DCT(features.m_Exp, dctVec); + + features.m_featuresVec = vec1D32F (NB_FEATURES, 0); + for (uint32_t i = 0; i < NB_DELTA_CEPS; ++i) { + features.m_featuresVec[NB_BANDS + 2*NB_DELTA_CEPS + i] = dctVec[i]; + } + + features.m_featuresVec[NB_BANDS + 2*NB_DELTA_CEPS] -= 1.3; + features.m_featuresVec[NB_BANDS + 2*NB_DELTA_CEPS + 1] -= 0.9; + features.m_featuresVec[NB_BANDS + 3*NB_DELTA_CEPS] = 0.01 * (static_cast<int>(pitchIdx) - 300); + + float logMax = -2.f; + float follow = -2.f; + for (uint32_t i = 0; i < NB_BANDS; ++i) { + Ly[i] = log10f(1e-2f + features.m_Ex[i]); + Ly[i] = std::max<float>(logMax - 7, std::max<float>(follow - 1.5, Ly[i])); + logMax = std::max<float>(logMax, Ly[i]); + follow = std::max<float>(follow - 1.5, Ly[i]); + energy += features.m_Ex[i]; + } + + /* If there's no audio avoid messing up the state. */ + features.m_silence = true; + if (energy < 0.04) { + return; + } else { + features.m_silence = false; + } + + this->DCT(Ly, features.m_featuresVec); + features.m_featuresVec[0] -= 12.0; + features.m_featuresVec[1] -= 4.0; + + VERIFY(CEPS_MEM > 2); + uint32_t stIdx1 = this->m_memId < 1 ? CEPS_MEM + this->m_memId - 1 : this->m_memId - 1; + uint32_t stIdx2 = this->m_memId < 2 ? CEPS_MEM + this->m_memId - 2 : this->m_memId - 2; + VERIFY(stIdx1 < this->m_cepstralMem.size()); + VERIFY(stIdx2 < this->m_cepstralMem.size()); + auto ceps1 = this->m_cepstralMem[stIdx1]; + auto ceps2 = this->m_cepstralMem[stIdx2]; + + /* Ceps 0 */ + for (uint32_t i = 0; i < NB_BANDS; ++i) { + this->m_cepstralMem[this->m_memId][i] = features.m_featuresVec[i]; + } + + for (uint32_t i = 0; i < NB_DELTA_CEPS; ++i) { + features.m_featuresVec[i] = this->m_cepstralMem[this->m_memId][i] + ceps1[i] + ceps2[i]; + features.m_featuresVec[NB_BANDS + i] = this->m_cepstralMem[this->m_memId][i] - ceps2[i]; + features.m_featuresVec[NB_BANDS + NB_DELTA_CEPS + i] = + this->m_cepstralMem[this->m_memId][i] - 2 * ceps1[i] + ceps2[i]; + } + + /* Spectral variability features. */ + this->m_memId += 1; + if (this->m_memId == CEPS_MEM) { + this->m_memId = 0; + } + + float specVariability = 0.f; + + VERIFY(this->m_cepstralMem.size() >= CEPS_MEM); + for (size_t i = 0; i < CEPS_MEM; ++i) { + float minDist = 1e15; + for (size_t j = 0; j < CEPS_MEM; ++j) { + float dist = 0.f; + for (size_t k = 0; k < NB_BANDS; ++k) { + VERIFY(this->m_cepstralMem[i].size() >= NB_BANDS); + auto tmp = this->m_cepstralMem[i][k] - this->m_cepstralMem[j][k]; + dist += tmp * tmp; + } + + if (j != i) { + minDist = std::min<float>(minDist, dist); + } + } + specVariability += minDist; + } + + VERIFY(features.m_featuresVec.size() >= NB_BANDS + 3 * NB_DELTA_CEPS + 1); + features.m_featuresVec[NB_BANDS + 3 * NB_DELTA_CEPS + 1] = specVariability / CEPS_MEM - 2.1; +} + +void RNNoiseFeatureProcessor::FrameAnalysis( + const vec1D32F& audioWindow, + vec1D32F& fft, + vec1D32F& energy, + vec1D32F& analysisMem) +{ + vec1D32F x(WINDOW_SIZE, 0); + + /* Move old audio down and populate end with latest audio window. */ + VERIFY(x.size() >= FRAME_SIZE && analysisMem.size() >= FRAME_SIZE); + VERIFY(audioWindow.size() >= FRAME_SIZE); + + std::copy_n(analysisMem.begin(), FRAME_SIZE, x.begin()); + std::copy_n(audioWindow.begin(), x.size() - FRAME_SIZE, x.begin() + FRAME_SIZE); + std::copy_n(audioWindow.begin(), FRAME_SIZE, analysisMem.begin()); + + this->ApplyWindow(x); + + /* Calculate FFT. */ + ForwardTransform(x, fft); + + /* Compute band energy. */ + ComputeBandEnergy(fft, energy); +} + +void RNNoiseFeatureProcessor::ApplyWindow(vec1D32F& x) +{ + if (WINDOW_SIZE != x.size()) { + printf_err("Invalid size for vector to be windowed\n"); + return; + } + + VERIFY(this->m_halfWindow.size() >= FRAME_SIZE); + + /* Multiply input by sinusoidal function. */ + for (size_t i = 0; i < FRAME_SIZE; i++) { + x[i] *= this->m_halfWindow[i]; + x[WINDOW_SIZE - 1 - i] *= this->m_halfWindow[i]; + } +} + +void RNNoiseFeatureProcessor::ForwardTransform( + vec1D32F& x, + vec1D32F& fft) +{ + /* The input vector can be modified by the fft function. */ + fft.reserve(x.size() + 2); + fft.resize(x.size() + 2, 0); + math::MathUtils::FftF32(x, fft, this->m_fftInstReal); + + /* Normalise. */ + for (auto& f : fft) { + f /= this->m_fftInstReal.m_fftLen; + } + + /* Place the last freq element correctly */ + fft[fft.size()-2] = fft[1]; + fft[1] = 0; + + /* NOTE: We don't truncate out FFT vector as it already contains only the + * first half of the FFT's. The conjugates are not present. */ +} + +void RNNoiseFeatureProcessor::ComputeBandEnergy(const vec1D32F& fftX, vec1D32F& bandE) +{ + bandE = vec1D32F(NB_BANDS, 0); + + VERIFY(this->m_eband5ms.size() >= NB_BANDS); + for (uint32_t i = 0; i < NB_BANDS - 1; i++) { + const auto bandSize = (this->m_eband5ms[i + 1] - this->m_eband5ms[i]) + << FRAME_SIZE_SHIFT; + + for (uint32_t j = 0; j < bandSize; j++) { + const auto frac = static_cast<float>(j) / bandSize; + const auto idx = (this->m_eband5ms[i] << FRAME_SIZE_SHIFT) + j; + + auto tmp = fftX[2 * idx] * fftX[2 * idx]; /* Real part */ + tmp += fftX[2 * idx + 1] * fftX[2 * idx + 1]; /* Imaginary part */ + + bandE[i] += (1 - frac) * tmp; + bandE[i + 1] += frac * tmp; + } + } + bandE[0] *= 2; + bandE[NB_BANDS - 1] *= 2; +} + +void RNNoiseFeatureProcessor::ComputeBandCorr(const vec1D32F& X, const vec1D32F& P, vec1D32F& bandC) +{ + bandC = vec1D32F(NB_BANDS, 0); + VERIFY(this->m_eband5ms.size() >= NB_BANDS); + + for (uint32_t i = 0; i < NB_BANDS - 1; i++) { + const auto bandSize = (this->m_eband5ms[i + 1] - this->m_eband5ms[i]) << FRAME_SIZE_SHIFT; + + for (uint32_t j = 0; j < bandSize; j++) { + const auto frac = static_cast<float>(j) / bandSize; + const auto idx = (this->m_eband5ms[i] << FRAME_SIZE_SHIFT) + j; + + auto tmp = X[2 * idx] * P[2 * idx]; /* Real part */ + tmp += X[2 * idx + 1] * P[2 * idx + 1]; /* Imaginary part */ + + bandC[i] += (1 - frac) * tmp; + bandC[i + 1] += frac * tmp; + } + } + bandC[0] *= 2; + bandC[NB_BANDS - 1] *= 2; +} + +void RNNoiseFeatureProcessor::DCT(vec1D32F& input, vec1D32F& output) +{ + VERIFY(this->m_dctTable.size() >= NB_BANDS * NB_BANDS); + for (uint32_t i = 0; i < NB_BANDS; ++i) { + float sum = 0; + + for (uint32_t j = 0, k = 0; j < NB_BANDS; ++j, k += NB_BANDS) { + sum += input[j] * this->m_dctTable[k + i]; + } + output[i] = sum * math::MathUtils::SqrtF32(2.0/22); + } +} + +void RNNoiseFeatureProcessor::PitchDownsample(vec1D32F& pitchBuf, size_t pitchBufSz) { + for (size_t i = 1; i < (pitchBufSz >> 1); ++i) { + pitchBuf[i] = 0.5 * ( + 0.5 * (this->m_pitchBuf[2 * i - 1] + this->m_pitchBuf[2 * i + 1]) + + this->m_pitchBuf[2 * i]); + } + + pitchBuf[0] = 0.5*(0.5*(this->m_pitchBuf[1]) + this->m_pitchBuf[0]); + + vec1D32F ac(5, 0); + size_t numLags = 4; + + this->AutoCorr(pitchBuf, ac, numLags, pitchBufSz >> 1); + + /* Noise floor -40db */ + ac[0] *= 1.0001; + + /* Lag windowing. */ + for (size_t i = 1; i < numLags + 1; ++i) { + ac[i] -= ac[i] * (0.008 * i) * (0.008 * i); + } + + vec1D32F lpc(numLags, 0); + this->LPC(ac, numLags, lpc); + + float tmp = 1.0; + for (size_t i = 0; i < numLags; ++i) { + tmp = 0.9f * tmp; + lpc[i] = lpc[i] * tmp; + } + + vec1D32F lpc2(numLags + 1, 0); + float c1 = 0.8; + + /* Add a zero. */ + lpc2[0] = lpc[0] + 0.8; + lpc2[1] = lpc[1] + (c1 * lpc[0]); + lpc2[2] = lpc[2] + (c1 * lpc[1]); + lpc2[3] = lpc[3] + (c1 * lpc[2]); + lpc2[4] = (c1 * lpc[3]); + + this->Fir5(lpc2, pitchBufSz >> 1, pitchBuf); +} + +int RNNoiseFeatureProcessor::PitchSearch(vec1D32F& xLp, vec1D32F& y, uint32_t len, uint32_t maxPitch) { + uint32_t lag = len + maxPitch; + vec1D32F xLp4(len >> 2, 0); + vec1D32F yLp4(lag >> 2, 0); + vec1D32F xCorr(maxPitch >> 1, 0); + + /* Downsample by 2 again. */ + for (size_t j = 0; j < (len >> 2); ++j) { + xLp4[j] = xLp[2*j]; + } + for (size_t j = 0; j < (lag >> 2); ++j) { + yLp4[j] = y[2*j]; + } + + this->PitchXCorr(xLp4, yLp4, xCorr, len >> 2, maxPitch >> 2); + + /* Coarse search with 4x decimation. */ + arrHp bestPitch = this->FindBestPitch(xCorr, yLp4, len >> 2, maxPitch >> 2); + + /* Finer search with 2x decimation. */ + const int maxIdx = (maxPitch >> 1); + for (int i = 0; i < maxIdx; ++i) { + xCorr[i] = 0; + if (std::abs(i - 2*bestPitch[0]) > 2 and std::abs(i - 2*bestPitch[1]) > 2) { + continue; + } + float sum = 0; + for (size_t j = 0; j < len >> 1; ++j) { + sum += xLp[j] * y[i+j]; + } + + xCorr[i] = std::max(-1.0f, sum); + } + + bestPitch = this->FindBestPitch(xCorr, y, len >> 1, maxPitch >> 1); + + int offset; + /* Refine by pseudo-interpolation. */ + if ( 0 < bestPitch[0] && bestPitch[0] < ((maxPitch >> 1) - 1)) { + float a = xCorr[bestPitch[0] - 1]; + float b = xCorr[bestPitch[0]]; + float c = xCorr[bestPitch[0] + 1]; + + if ( (c-a) > 0.7*(b-a) ) { + offset = 1; + } else if ( (a-c) > 0.7*(b-c) ) { + offset = -1; + } else { + offset = 0; + } + } else { + offset = 0; + } + + return 2*bestPitch[0] - offset; +} + +arrHp RNNoiseFeatureProcessor::FindBestPitch(vec1D32F& xCorr, vec1D32F& y, uint32_t len, uint32_t maxPitch) +{ + float Syy = 1; + arrHp bestNum {-1, -1}; + arrHp bestDen {0, 0}; + arrHp bestPitch {0, 1}; + + for (size_t j = 0; j < len; ++j) { + Syy += (y[j] * y[j]); + } + + for (size_t i = 0; i < maxPitch; ++i ) { + if (xCorr[i] > 0) { + float xCorr16 = xCorr[i] * 1e-12f; /* Avoid problems when squaring. */ + + float num = xCorr16 * xCorr16; + if (num*bestDen[1] > bestNum[1]*Syy) { + if (num*bestDen[0] > bestNum[0]*Syy) { + bestNum[1] = bestNum[0]; + bestDen[1] = bestDen[0]; + bestPitch[1] = bestPitch[0]; + bestNum[0] = num; + bestDen[0] = Syy; + bestPitch[0] = i; + } else { + bestNum[1] = num; + bestDen[1] = Syy; + bestPitch[1] = i; + } + } + } + + Syy += (y[i+len]*y[i+len]) - (y[i]*y[i]); + Syy = std::max(1.0f, Syy); + } + + return bestPitch; +} + +int RNNoiseFeatureProcessor::RemoveDoubling( + vec1D32F& pitchBuf, + uint32_t maxPeriod, + uint32_t minPeriod, + uint32_t frameSize, + size_t pitchIdx0_) +{ + constexpr std::array<size_t, 16> secondCheck {0, 0, 3, 2, 3, 2, 5, 2, 3, 2, 3, 2, 5, 2, 3, 2}; + uint32_t minPeriod0 = minPeriod; + float lastPeriod = static_cast<float>(this->m_lastPeriod)/2; + float lastGain = static_cast<float>(this->m_lastGain); + + maxPeriod /= 2; + minPeriod /= 2; + pitchIdx0_ /= 2; + frameSize /= 2; + uint32_t xStart = maxPeriod; + + if (pitchIdx0_ >= maxPeriod) { + pitchIdx0_ = maxPeriod - 1; + } + + size_t pitchIdx = pitchIdx0_; + const size_t pitchIdx0 = pitchIdx0_; + + float xx = 0; + for ( size_t i = xStart; i < xStart+frameSize; ++i) { + xx += (pitchBuf[i] * pitchBuf[i]); + } + + float xy = 0; + for ( size_t i = xStart; i < xStart+frameSize; ++i) { + xy += (pitchBuf[i] * pitchBuf[i-pitchIdx0]); + } + + vec1D32F yyLookup (maxPeriod+1, 0); + yyLookup[0] = xx; + float yy = xx; + + for ( size_t i = 1; i < yyLookup.size(); ++i) { + yy = yy + (pitchBuf[xStart-i] * pitchBuf[xStart-i]) - + (pitchBuf[xStart+frameSize-i] * pitchBuf[xStart+frameSize-i]); + yyLookup[i] = std::max(0.0f, yy); + } + + yy = yyLookup[pitchIdx0]; + float bestXy = xy; + float bestYy = yy; + + float g = this->ComputePitchGain(xy, xx, yy); + float g0 = g; + + /* Look for any pitch at pitchIndex/k. */ + for ( size_t k = 2; k < 16; ++k) { + size_t pitchIdx1 = (2*pitchIdx0+k) / (2*k); + if (pitchIdx1 < minPeriod) { + break; + } + + size_t pitchIdx1b; + /* Look for another strong correlation at T1b. */ + if (k == 2) { + if ((pitchIdx1 + pitchIdx0) > maxPeriod) { + pitchIdx1b = pitchIdx0; + } else { + pitchIdx1b = pitchIdx0 + pitchIdx1; + } + } else { + pitchIdx1b = (2*(secondCheck[k])*pitchIdx0 + k) / (2*k); + } + + xy = 0; + for ( size_t i = xStart; i < xStart+frameSize; ++i) { + xy += (pitchBuf[i] * pitchBuf[i-pitchIdx1]); + } + + float xy2 = 0; + for ( size_t i = xStart; i < xStart+frameSize; ++i) { + xy2 += (pitchBuf[i] * pitchBuf[i-pitchIdx1b]); + } + xy = 0.5f * (xy + xy2); + VERIFY(pitchIdx1b < maxPeriod+1); + yy = 0.5f * (yyLookup[pitchIdx1] + yyLookup[pitchIdx1b]); + + float g1 = this->ComputePitchGain(xy, xx, yy); + + float cont; + if (std::abs(pitchIdx1-lastPeriod) <= 1) { + cont = lastGain; + } else if (std::abs(pitchIdx1-lastPeriod) <= 2 and 5*k*k < pitchIdx0) { + cont = 0.5f*lastGain; + } else { + cont = 0.0f; + } + + float thresh = std::max(0.3, 0.7*g0-cont); + + /* Bias against very high pitch (very short period) to avoid false-positives + * due to short-term correlation */ + if (pitchIdx1 < 3*minPeriod) { + thresh = std::max(0.4, 0.85*g0-cont); + } else if (pitchIdx1 < 2*minPeriod) { + thresh = std::max(0.5, 0.9*g0-cont); + } + if (g1 > thresh) { + bestXy = xy; + bestYy = yy; + pitchIdx = pitchIdx1; + g = g1; + } + } + + bestXy = std::max(0.0f, bestXy); + float pg; + if (bestYy <= bestXy) { + pg = 1.0; + } else { + pg = bestXy/(bestYy+1); + } + + std::array<float, 3> xCorr {0}; + for ( size_t k = 0; k < 3; ++k ) { + for ( size_t i = xStart; i < xStart+frameSize; ++i) { + xCorr[k] += (pitchBuf[i] * pitchBuf[i-(pitchIdx+k-1)]); + } + } + + size_t offset; + if ((xCorr[2]-xCorr[0]) > 0.7*(xCorr[1]-xCorr[0])) { + offset = 1; + } else if ((xCorr[0]-xCorr[2]) > 0.7*(xCorr[1]-xCorr[2])) { + offset = -1; + } else { + offset = 0; + } + + if (pg > g) { + pg = g; + } + + pitchIdx0_ = 2*pitchIdx + offset; + + if (pitchIdx0_ < minPeriod0) { + pitchIdx0_ = minPeriod0; + } + + this->m_lastPeriod = pitchIdx0_; + this->m_lastGain = pg; + + return this->m_lastPeriod; +} + +float RNNoiseFeatureProcessor::ComputePitchGain(float xy, float xx, float yy) +{ + return xy / math::MathUtils::SqrtF32(1+xx*yy); +} + +void RNNoiseFeatureProcessor::AutoCorr( + const vec1D32F& x, + vec1D32F& ac, + size_t lag, + size_t n) +{ + if (n < lag) { + printf_err("Invalid parameters for AutoCorr\n"); + return; + } + + auto fastN = n - lag; + + /* Auto-correlation - can be done by PlatformMath functions */ + this->PitchXCorr(x, x, ac, fastN, lag + 1); + + /* Modify auto-correlation by summing with auto-correlation for different lags. */ + for (size_t k = 0; k < lag + 1; k++) { + float d = 0; + for (size_t i = k + fastN; i < n; i++) { + d += x[i] * x[i - k]; + } + ac[k] += d; + } +} + + +void RNNoiseFeatureProcessor::PitchXCorr( + const vec1D32F& x, + const vec1D32F& y, + vec1D32F& xCorr, + size_t len, + size_t maxPitch) +{ + for (size_t i = 0; i < maxPitch; i++) { + float sum = 0; + for (size_t j = 0; j < len; j++) { + sum += x[j] * y[i + j]; + } + xCorr[i] = sum; + } +} + +/* Linear predictor coefficients */ +void RNNoiseFeatureProcessor::LPC( + const vec1D32F& correlation, + int32_t p, + vec1D32F& lpc) +{ + auto error = correlation[0]; + + if (error != 0) { + for (int i = 0; i < p; i++) { + + /* Sum up this iteration's reflection coefficient */ + float rr = 0; + for (int j = 0; j < i; j++) { + rr += lpc[j] * correlation[i - j]; + } + + rr += correlation[i + 1]; + auto r = -rr / error; + + /* Update LP coefficients and total error */ + lpc[i] = r; + for (int j = 0; j < ((i + 1) >> 1); j++) { + auto tmp1 = lpc[j]; + auto tmp2 = lpc[i - 1 - j]; + lpc[j] = tmp1 + (r * tmp2); + lpc[i - 1 - j] = tmp2 + (r * tmp1); + } + + error = error - (r * r * error); + + /* Bail out once we get 30dB gain */ + if (error < (0.001 * correlation[0])) { + break; + } + } + } +} + +void RNNoiseFeatureProcessor::Fir5( + const vec1D32F &num, + uint32_t N, + vec1D32F &x) +{ + auto num0 = num[0]; + auto num1 = num[1]; + auto num2 = num[2]; + auto num3 = num[3]; + auto num4 = num[4]; + auto mem0 = 0; + auto mem1 = 0; + auto mem2 = 0; + auto mem3 = 0; + auto mem4 = 0; + for (uint32_t i = 0; i < N; i++) + { + auto sum_ = x[i] + (num0 * mem0) + (num1 * mem1) + + (num2 * mem2) + (num3 * mem3) + (num4 * mem4); + mem4 = mem3; + mem3 = mem2; + mem2 = mem1; + mem1 = mem0; + mem0 = x[i]; + x[i] = sum_; + } +} + +void RNNoiseFeatureProcessor::PitchFilter(FrameFeatures &features, vec1D32F &gain) { + std::vector<float> r(NB_BANDS, 0); + std::vector<float> rf(FREQ_SIZE, 0); + std::vector<float> newE(NB_BANDS); + + for (size_t i = 0; i < NB_BANDS; i++) { + if (features.m_Exp[i] > gain[i]) { + r[i] = 1; + } else { + + + r[i] = std::pow(features.m_Exp[i], 2) * (1 - std::pow(gain[i], 2)) / + (.001 + std::pow(gain[i], 2) * (1 - std::pow(features.m_Exp[i], 2))); + } + + + r[i] = math::MathUtils::SqrtF32(std::min(1.0f, std::max(0.0f, r[i]))); + r[i] *= math::MathUtils::SqrtF32(features.m_Ex[i] / (1e-8f + features.m_Ep[i])); + } + + InterpBandGain(rf, r); + for (size_t i = 0; i < FREQ_SIZE - 1; i++) { + features.m_fftX[2 * i] += rf[i] * features.m_fftP[2 * i]; /* Real. */ + features.m_fftX[2 * i + 1] += rf[i] * features.m_fftP[2 * i + 1]; /* Imaginary. */ + + } + ComputeBandEnergy(features.m_fftX, newE); + std::vector<float> norm(NB_BANDS); + std::vector<float> normf(FRAME_SIZE, 0); + for (size_t i = 0; i < NB_BANDS; i++) { + norm[i] = math::MathUtils::SqrtF32(features.m_Ex[i] / (1e-8f + newE[i])); + } + + InterpBandGain(normf, norm); + for (size_t i = 0; i < FREQ_SIZE - 1; i++) { + features.m_fftX[2 * i] *= normf[i]; /* Real. */ + features.m_fftX[2 * i + 1] *= normf[i]; /* Imaginary. */ + + } +} + +void RNNoiseFeatureProcessor::FrameSynthesis(vec1D32F& outFrame, vec1D32F& fftY) { + std::vector<float> x(WINDOW_SIZE, 0); + InverseTransform(x, fftY); + ApplyWindow(x); + for (size_t i = 0; i < FRAME_SIZE; i++) { + outFrame[i] = x[i] + m_synthesisMem[i]; + } + memcpy((m_synthesisMem.data()), &x[FRAME_SIZE], FRAME_SIZE*sizeof(float)); +} + +void RNNoiseFeatureProcessor::InterpBandGain(vec1D32F& g, vec1D32F& bandE) { + for (size_t i = 0; i < NB_BANDS - 1; i++) { + int bandSize = (m_eband5ms[i + 1] - m_eband5ms[i]) << FRAME_SIZE_SHIFT; + for (int j = 0; j < bandSize; j++) { + float frac = static_cast<float>(j) / bandSize; + g[(m_eband5ms[i] << FRAME_SIZE_SHIFT) + j] = (1 - frac) * bandE[i] + frac * bandE[i + 1]; + } + } +} + +void RNNoiseFeatureProcessor::InverseTransform(vec1D32F& out, vec1D32F& fftXIn) { + + std::vector<float> x(WINDOW_SIZE * 2); /* This is complex. */ + vec1D32F newFFT; /* This is complex. */ + + size_t i; + for (i = 0; i < FREQ_SIZE * 2; i++) { + x[i] = fftXIn[i]; + } + for (i = FREQ_SIZE; i < WINDOW_SIZE; i++) { + x[2 * i] = x[2 * (WINDOW_SIZE - i)]; /* Real. */ + x[2 * i + 1] = -x[2 * (WINDOW_SIZE - i) + 1]; /* Imaginary. */ + } + + constexpr uint32_t numFFt = 2 * FRAME_SIZE; + static_assert(numFFt != 0, "numFFt cannot be 0!"); + + vec1D32F fftOut = vec1D32F(x.size(), 0); + math::MathUtils::FftF32(x,fftOut, m_fftInstCmplx); + + /* Normalize. */ + for (auto &f: fftOut) { + f /= numFFt; + } + + out[0] = WINDOW_SIZE * fftOut[0]; /* Real. */ + for (i = 1; i < WINDOW_SIZE; i++) { + out[i] = WINDOW_SIZE * fftOut[(WINDOW_SIZE * 2) - (2 * i)]; /* Real. */ + } +} + + +} /* namespace rnn */ +} /* namespace app */ +} /* namspace arm */ |