void
aubio_pitchspecacf_do (aubio_pitchspecacf_t * p, const fvec_t * input, fvec_t * output)
{
uint_t l, tau;
fvec_t *fftout = p->fftout;
// window the input
for (l = 0; l < input->length; l++) {
p->winput->data[l] = p->win->data[l] * input->data[l];
}
// get the real / imag parts of its fft
aubio_fft_do_complex (p->fft, p->winput, fftout);
for (l = 0; l < input->length / 2 + 1; l++) {
p->sqrmag->data[l] = SQR(fftout->data[l]);
}
// get the real / imag parts of the fft of the squared magnitude
aubio_fft_do_complex (p->fft, p->sqrmag, fftout);
// copy real part to acf
for (l = 0; l < fftout->length / 2 + 1; l++) {
p->acf->data[l] = fftout->data[l];
}
// get the minimum
tau = fvec_min_elem (p->acf);
// get the interpolated minimum
output->data[0] = fvec_quadratic_peak_pos (p->acf, tau) * 2.;
}
void
aubio_pitchyinfft_do (aubio_pitchyinfft_t * p, fvec_t * input, fvec_t * output)
{
uint_t tau, l;
uint_t length = p->fftout->length;
uint_t halfperiod;
fvec_t *fftout = p->fftout;
fvec_t *yin = p->yinfft;
smpl_t tmp = 0., sum = 0.;
// window the input
for (l = 0; l < input->length; l++) {
p->winput->data[l] = p->win->data[l] * input->data[l];
}
// get the real / imag parts of its fft
aubio_fft_do_complex (p->fft, p->winput, fftout);
// get the squared magnitude spectrum, applying some weight
p->sqrmag->data[0] = SQR(fftout->data[0]);
p->sqrmag->data[0] *= p->weight->data[0];
for (l = 1; l < length / 2; l++) {
p->sqrmag->data[l] = SQR(fftout->data[l]) + SQR(fftout->data[length - l]);
p->sqrmag->data[l] *= p->weight->data[l];
p->sqrmag->data[length - l] = p->sqrmag->data[l];
}
p->sqrmag->data[length / 2] = SQR(fftout->data[length / 2]);
p->sqrmag->data[length / 2] *= p->weight->data[length / 2];
// get sum of weighted squared mags
for (l = 0; l < length / 2 + 1; l++) {
sum += p->sqrmag->data[l];
}
sum *= 2.;
// get the real / imag parts of the fft of the squared magnitude
aubio_fft_do_complex (p->fft, p->sqrmag, fftout);
yin->data[0] = 1.;
for (tau = 1; tau < yin->length; tau++) {
// compute the square differences
yin->data[tau] = sum - fftout->data[tau];
// and the cumulative mean normalized difference function
tmp += yin->data[tau];
if (tmp != 0) {
yin->data[tau] *= tau / tmp;
} else {
yin->data[tau] = 1.;
}
}
// find best candidates
tau = fvec_min_elem (yin);
if (yin->data[tau] < p->tol) {
// no interpolation, directly return the period as an integer
//output->data[0] = tau;
//return;
// 3 point quadratic interpolation
//return fvec_quadratic_peak_pos (yin,tau,1);
/* additional check for (unlikely) octave doubling in higher frequencies */
if (tau > p->short_period) {
output->data[0] = fvec_quadratic_peak_pos (yin, tau);
} else {
/* should compare the minimum value of each interpolated peaks */
halfperiod = FLOOR (tau / 2 + .5);
if (yin->data[halfperiod] < p->tol)
output->data[0] = fvec_quadratic_peak_pos (yin, halfperiod);
else
output->data[0] = fvec_quadratic_peak_pos (yin, tau);
}
} else {
output->data[0] = 0.;
}
}
void aubio_fft_do(aubio_fft_t * s, fvec_t * input, cvec_t * spectrum) {
aubio_fft_do_complex(s, input, s->compspec);
aubio_fft_get_spectrum(s->compspec, spectrum);
}
