void Leq::compute() {
const std::vector<Real>& signal = _signal.get();
Real& leq = _leq.get();
if (signal.empty()) {
throw EssentiaException("Leq: input signal is empty");
}
leq = pow2db(instantPower(signal));
}
void ReplayGain::compute() {
const vector<Real>& signal = _signal.get();
Real& gain = _gain.get();
// we do not have enough input data to construct a single frame...
// return the same value as if it was silence
if ((int)signal.size() < _rmsWindowSize) {
throw EssentiaException("ReplayGain: The input size must not be less than 0.05ms");
}
// 1. Equal loudness filter
vector<Real> eqloudSignal;
_eqloudFilter->input("signal").set(signal);
_eqloudFilter->output("signal").set(eqloudSignal);
_eqloudFilter->compute();
// 2. RMS Energy calculation
int nFrames = (int)eqloudSignal.size() / _rmsWindowSize;
vector<Real> rms(nFrames, 0.0);
for (int i = 0; i < nFrames; i++) {
Real vrms = 0.0;
for (int j = i*_rmsWindowSize; j < (i+1)*_rmsWindowSize; j++) {
vrms += eqloudSignal[j] * eqloudSignal[j];
}
vrms /= _rmsWindowSize;
// Convert value to db
// Note that vrms is energy and not an amplitude as sqrt is not applied
rms[i] = pow2db(vrms);
}
// 3. Statistical processing, as described in the algorithm, the 5% point is taken to
// represent the overall loudness of the input audio signal
sort(rms.begin(), rms.end());
Real loudness = rms[(int)(0.95*rms.size())];
// 4. Calibration with reference level
// file is ref_pink.wav, downloaded on reference site (www.replaygain.org)
Real ref_loudness = -31.492595672607422;
// 5. Replay gain
gain = ref_loudness - loudness;
}
void Leq::finalProduce() {
if (_size == 0) throw EssentiaException("Leq: signal is empty");
_leq.push(pow2db(_energy/_size));
}
