void aubio_pvoc_do(aubio_pvoc_t *pv, fvec_t * datanew, cvec_t *fftgrain) {
/* slide */
aubio_pvoc_swapbuffers(pv->data->data,pv->dataold->data,
datanew->data,pv->win_s,pv->hop_s);
/* windowing */
fvec_weight(pv->data, pv->w);
/* shift */
fvec_shift(pv->data);
/* calculate fft */
aubio_fft_do (pv->fft,pv->data,fftgrain);
}
void
aubio_beattracking_checkstate (aubio_beattracking_t * bt)
{
uint_t i, j, a, b;
uint_t flagconst = 0;
sint_t counter = bt->counter;
uint_t flagstep = bt->flagstep;
smpl_t gp = bt->gp;
smpl_t bp = bt->bp;
smpl_t rp = bt->rp;
smpl_t rp1 = bt->rp1;
smpl_t rp2 = bt->rp2;
uint_t laglen = bt->rwv->length;
uint_t acflen = bt->acf->length;
uint_t step = bt->step;
fvec_t *acf = bt->acf;
fvec_t *acfout = bt->acfout;
if (gp) {
// compute shift invariant comb filterbank
fvec_zeros (acfout);
for (i = 1; i < laglen - 1; i++) {
for (a = 1; a <= bt->timesig; a++) {
for (b = 1; b < 2 * a; b++) {
acfout->data[i] += acf->data[i * a + b - 1];
}
}
}
// since gp is set, gwv has been computed in previous checkstate
fvec_weight (acfout, bt->gwv);
gp = fvec_quadratic_peak_pos (acfout, fvec_max_elem (acfout));
} else {
//still only using general model
gp = 0;
}
//now look for step change - i.e. a difference between gp and rp that
// is greater than 2*constthresh - always true in first case, since gp = 0
if (counter == 0) {
if (ABS (gp - rp) > 2. * bt->g_var) {
flagstep = 1; // have observed step change.
counter = 3; // setup 3 frame counter
} else {
flagstep = 0;
}
}
//i.e. 3rd frame after flagstep initially set
if (counter == 1 && flagstep == 1) {
//check for consistency between previous beatperiod values
if (ABS (2 * rp - rp1 - rp2) < bt->g_var) {
//if true, can activate context dependent model
flagconst = 1;
counter = 0; // reset counter and flagstep
} else {
//if not consistent, then don't flag consistency!
flagconst = 0;
counter = 2; // let it look next time
}
} else if (counter > 0) {
//if counter doesn't = 1,
counter = counter - 1;
}
rp2 = rp1;
rp1 = rp;
if (flagconst) {
/* first run of new hypothesis */
gp = rp;
bt->timesig = fvec_gettimesig (acf, acflen, gp);
for (j = 0; j < laglen; j++)
bt->gwv->data[j] =
EXP (-.5 * SQR ((smpl_t) (j + 1. - gp)) / SQR (bt->g_var));
flagconst = 0;
bp = gp;
/* flat phase weighting */
fvec_ones (bt->phwv);
} else if (bt->timesig) {
/* context dependant model */
bp = gp;
/* gaussian phase weighting */
if (step > bt->lastbeat) {
for (j = 0; j < 2 * laglen; j++) {
bt->phwv->data[j] =
EXP (-.5 * SQR ((smpl_t) (1. + j - step +
bt->lastbeat)) / (bp / 8.));
}
} else {
//AUBIO_DBG("NOT using phase weighting as step is %d and lastbeat %d \n",
// step,bt->lastbeat);
fvec_ones (bt->phwv);
}
} else {
/* initial state */
bp = rp;
/* flat phase weighting */
fvec_ones (bt->phwv);
}
/* do some further checks on the final bp value */
/* if tempo is > 206 bpm, half it */
while (0 < bp && bp < 25) {
#if AUBIO_BEAT_WARNINGS
AUBIO_WRN ("doubling from %f (%f bpm) to %f (%f bpm)\n",
bp, 60.*44100./512./bp, bp/2., 60.*44100./512./bp/2. );
//AUBIO_DBG("warning, halving the tempo from %f\n", 60.*samplerate/hopsize/bp);
#endif /* AUBIO_BEAT_WARNINGS */
bp = bp * 2;
}
//AUBIO_DBG("tempo:\t%3.5f bpm | ", 5168./bp);
/* smoothing */
//bp = (uint_t) (0.8 * (smpl_t)bp + 0.2 * (smpl_t)bp2);
//AUBIO_DBG("tempo:\t%3.5f bpm smoothed | bp2 %d | bp %d | ", 5168./bp, bp2, bp);
//bp2 = bp;
//AUBIO_DBG("time signature: %d \n", bt->timesig);
bt->counter = counter;
bt->flagstep = flagstep;
bt->gp = gp;
bt->bp = bp;
bt->rp1 = rp1;
bt->rp2 = rp2;
}
void
aubio_beattracking_do (aubio_beattracking_t * bt, const fvec_t * dfframe,
fvec_t * output)
{
uint_t i, k;
uint_t step = bt->step;
uint_t laglen = bt->rwv->length;
uint_t winlen = bt->dfwv->length;
uint_t maxindex = 0;
//number of harmonics in shift invariant comb filterbank
uint_t numelem = 4;
smpl_t phase; // beat alignment (step - lastbeat)
smpl_t beat; // beat position
smpl_t bp; // beat period
uint_t a, b; // used to build shift invariant comb filterbank
uint_t kmax; // number of elements used to find beat phase
/* copy dfframe, apply detection function weighting, and revert */
fvec_copy (dfframe, bt->dfrev);
fvec_weight (bt->dfrev, bt->dfwv);
fvec_rev (bt->dfrev);
/* compute autocorrelation function */
aubio_autocorr (dfframe, bt->acf);
/* if timesig is unknown, use metrically unbiased version of filterbank */
if (!bt->timesig) {
numelem = 4;
} else {
numelem = bt->timesig;
}
/* first and last output values are left intentionally as zero */
fvec_zeros (bt->acfout);
/* compute shift invariant comb filterbank */
for (i = 1; i < laglen - 1; i++) {
for (a = 1; a <= numelem; a++) {
for (b = 1; b < 2 * a; b++) {
bt->acfout->data[i] += bt->acf->data[i * a + b - 1]
* 1. / (2. * a - 1.);
}
}
}
/* apply Rayleigh weight */
fvec_weight (bt->acfout, bt->rwv);
/* find non-zero Rayleigh period */
maxindex = fvec_max_elem (bt->acfout);
if (maxindex > 0 && maxindex < bt->acfout->length - 1) {
bt->rp = fvec_quadratic_peak_pos (bt->acfout, maxindex);
} else {
bt->rp = bt->rayparam;
}
/* activate biased filterbank */
aubio_beattracking_checkstate (bt);
#if 0 // debug metronome mode
bt->bp = 36.9142;
#endif
bp = bt->bp;
/* end of biased filterbank */
if (bp == 0) {
fvec_zeros(output);
return;
}
/* deliberate integer operation, could be set to 3 max eventually */
kmax = FLOOR (winlen / bp);
/* initialize output */
fvec_zeros (bt->phout);
for (i = 0; i < bp; i++) {
for (k = 0; k < kmax; k++) {
bt->phout->data[i] += bt->dfrev->data[i + (uint_t) ROUND (bp * k)];
}
}
fvec_weight (bt->phout, bt->phwv);
/* find Rayleigh period */
maxindex = fvec_max_elem (bt->phout);
if (maxindex >= winlen - 1) {
#if AUBIO_BEAT_WARNINGS
AUBIO_WRN ("no idea what this groove's phase is\n");
#endif /* AUBIO_BEAT_WARNINGS */
phase = step - bt->lastbeat;
} else {
phase = fvec_quadratic_peak_pos (bt->phout, maxindex);
}
/* take back one frame delay */
phase += 1.;
#if 0 // debug metronome mode
phase = step - bt->lastbeat;
#endif
/* reset output */
fvec_zeros (output);
i = 1;
beat = bp - phase;
// AUBIO_DBG ("bp: %f, phase: %f, lastbeat: %f, step: %d, winlen: %d\n",
// bp, phase, bt->lastbeat, step, winlen);
/* the next beat will be earlier than 60% of the tempo period
skip this one */
if ( ( step - bt->lastbeat - phase ) < -0.40 * bp ) {
#if AUBIO_BEAT_WARNINGS
AUBIO_WRN ("back off-beat error, skipping this beat\n");
#endif /* AUBIO_BEAT_WARNINGS */
beat += bp;
}
/* start counting the beats */
while (beat + bp < 0) {
beat += bp;
}
if (beat >= 0) {
//AUBIO_DBG ("beat: %d, %f, %f\n", i, bp, beat);
output->data[i] = beat;
i++;
}
while (beat + bp <= step) {
beat += bp;
//AUBIO_DBG ("beat: %d, %f, %f\n", i, bp, beat);
output->data[i] = beat;
i++;
}
bt->lastbeat = beat;
/* store the number of beats in this frame as the first element */
output->data[0] = i;
}
