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Further formant experiments

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This commit is contained in:
Chris Cannam
2022-06-06 12:08:52 +01:00
parent c33582a8c4
commit baab6ae66e
2 changed files with 43 additions and 13 deletions
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41
src/finer/R3StretcherImpl.cpp
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@@ -682,6 +682,7 @@ R3StretcherImpl::analyseFormant()
if (f.envelope[i] > 1.0e10) f.envelope[i] = 1.0e10;
}
//!!!
double scale = m_pitchScale;
for (int target = 0; target < binCount; ++target) {
int source = int(round(target * scale));
@@ -717,13 +718,13 @@ R3StretcherImpl::synthesiseChannel(int c, int outhop)
scale->mag.data(),
bufSize);
if (m_formant->enabled) {
// if (m_formant->enabled) {
// formant shift only the middle register
if (it.first == m_guideConfiguration.classificationFftSize) {
v_divide(scale->mag.data(), m_formant->envelope.data(), bufSize);
v_multiply(scale->mag.data(), m_formant->shifted.data(), bufSize);
}
}
// if (it.first == m_guideConfiguration.classificationFftSize) {
// v_divide(scale->mag.data(), m_formant->envelope.data(), bufSize);
// v_multiply(scale->mag.data(), m_formant->shifted.data(), bufSize);
// }
// }
}
for (const auto &band : cd->guidance.fftBands) {
@@ -748,17 +749,35 @@ R3StretcherImpl::synthesiseChannel(int c, int outhop)
// domain. Aliasing is reduced by the shorter resynthesis
// window
//!!! I don't think we have binForFrequency etc available in
//!!! this class - really that's ridiculous
int lowBin = int(floor(fftSize * band.f0 / m_parameters.sampleRate));
int highBin = int(floor(fftSize * band.f1 / m_parameters.sampleRate));
if (highBin % 2 == 1) --highBin;
for (int i = 0; i < fftSize/2 + 1; ++i) {
if (i >= lowBin && i < highBin) {
scale->mag[i] *= winscale;
} else {
scale->mag[i] = 0.f;
int formantHigh = int(floor(fftSize * 7000.0 / m_parameters.sampleRate));
for (int i = 0; i < lowBin; ++i) {
scale->mag[i] = 0.0;
}
if (m_formant->enabled) {
double targetFactor = double(m_formant->fftSize) / double(fftSize);
double sourceFactor = targetFactor * m_pitchScale;
double scaleFactor = 1.0 / targetFactor;
for (int i = lowBin; i < highBin && i < formantHigh; ++i) {
double source = m_formant->envelopeAt(i * sourceFactor);
double target = m_formant->envelopeAt(i * targetFactor);
if (target > 0.0) {
scale->mag[i] *= (source * source) / (target * target);
}
}
}
for (int i = lowBin; i < highBin; ++i) {
scale->mag[i] *= winscale;
}
for (int i = highBin; i < fftSize/2 + 1; ++i) {
scale->mag[i] = 0.0;
}
}
// Resynthesise each FFT size (scale) individually, then sum. This

11
src/finer/R3StretcherImpl.h
View File

@@ -223,15 +223,26 @@ protected:
struct FormantData {
bool enabled;
int fftSize;
FixedVector<double> cepstra;
FixedVector<double> envelope;
FixedVector<double> shifted;
FormantData(int _fftSize) :
enabled(false),
fftSize(_fftSize),
cepstra(_fftSize, 0.0),
envelope(_fftSize, 0.0),
shifted(_fftSize, 0.0) { }
double envelopeAt(double bin) const {
int b0 = int(floor(bin)), b1 = int(ceil(bin));
if (b1 == b0) return envelope.at(b0);
else {
double diff = bin - double(b0);
return envelope.at(b0) * (1.0 - diff) + envelope.at(b1) * diff;
}
}
};
Parameters m_parameters;