static LPC _Sound_to_LPC (Sound me, int predictionOrder, double analysisWidth, double dt,
double preEmphasisFrequency, int method, double tol1, double tol2) {
double t1, samplingFrequency = 1.0 / my dx;
double windowDuration = 2 * analysisWidth; /* gaussian window */
long nFrames, frameErrorCount = 0;
if (floor (windowDuration / my dx) < predictionOrder + 1) Melder_throw ("Analysis window duration too short.\n"
"For a prediction order of ", predictionOrder, " the analysis window duration has to be greater than ", my dx * (predictionOrder + 1),
"Please increase the analysis window duration or lower the prediction order.");
// Convenience: analyse the whole sound into one LPC_frame
if (windowDuration > my dx * my nx) {
windowDuration = my dx * my nx;
}
Sampled_shortTermAnalysis (me, windowDuration, dt, & nFrames, & t1);
autoSound sound = Data_copy (me);
autoSound sframe = Sound_createSimple (1, windowDuration, samplingFrequency);
autoSound window = Sound_createGaussian (windowDuration, samplingFrequency);
autoLPC thee = LPC_create (my xmin, my xmax, nFrames, dt, t1, predictionOrder, my dx);
autoMelderProgress progress (L"LPC analysis");
if (preEmphasisFrequency < samplingFrequency / 2) {
Sound_preEmphasis (sound.peek(), preEmphasisFrequency);
}
for (long i = 1; i <= nFrames; i++) {
LPC_Frame lpcframe = (LPC_Frame) & thy d_frames[i];
double t = Sampled_indexToX (thee.peek(), i);
LPC_Frame_init (lpcframe, predictionOrder);
Sound_into_Sound (sound.peek(), sframe.peek(), t - windowDuration / 2);
Vector_subtractMean (sframe.peek());
Sounds_multiply (sframe.peek(), window.peek());
if (method == LPC_METHOD_AUTO) {
if (! Sound_into_LPC_Frame_auto (sframe.peek(), lpcframe)) {
frameErrorCount++;
}
} else if (method == LPC_METHOD_COVAR) {
if (! Sound_into_LPC_Frame_covar (sframe.peek(), lpcframe)) {
frameErrorCount++;
}
} else if (method == LPC_METHOD_BURG) {
if (! Sound_into_LPC_Frame_burg (sframe.peek(), lpcframe)) {
frameErrorCount++;
}
} else if (method == LPC_METHOD_MARPLE) {
if (! Sound_into_LPC_Frame_marple (sframe.peek(), lpcframe, tol1, tol2)) {
frameErrorCount++;
}
}
if ( (i % 10) == 1) {
Melder_progress ( (double) i / nFrames, L"LPC analysis of frame ",
Melder_integer (i), L" out of ", Melder_integer (nFrames), L".");
}
}
return thee.transfer();
}
autoLPC Cepstrumc_to_LPC (Cepstrumc me) {
try {
autoLPC thee = LPC_create (my xmin, my xmax, my nx, my dx, my x1,
my maxnCoefficients, 1.0 / my samplingFrequency);
for (long i = 1; i <= my nx; i++) {
LPC_Frame_init (& thy d_frames[i], my frame[i].nCoefficients);
Cepstrumc_Frame_into_LPC_Frame (& my frame[i], & thy d_frames[i]);
}
return thee;
} catch (MelderError) {
Melder_throw (me, U":no LPC created.");
}
}
LPC Formant_to_LPC (Formant me, double samplingPeriod) {
try {
autoLPC thee = LPC_create (my xmin, my xmax, my nx, my dx, my x1, 2 * my maxnFormants, samplingPeriod);
for (long i = 1; i <= my nx; i++) {
Formant_Frame f = & my d_frames[i];
LPC_Frame lpc = & thy d_frames[i];
long m = 2 * f -> nFormants;
LPC_Frame_init (lpc, m);
Formant_Frame_into_LPC_Frame (f, lpc, samplingPeriod);
}
return thee.transfer();
} catch (MelderError) {
Melder_throw (me, ": no LPC created.");
}
}
LPC LFCC_to_LPC (LFCC me, long numberOfCoefficients) {
try {
if (numberOfCoefficients < 1) {
numberOfCoefficients = my maximumNumberOfCoefficients;
}
numberOfCoefficients = MIN (numberOfCoefficients, my maximumNumberOfCoefficients);
autoLPC thee = LPC_create (my xmin, my xmax, my nx, my dx, my x1, numberOfCoefficients, 0.5 / my fmax);
for (long i = 1; i <= my nx; i++) {
LPC_Frame_init (& thy d_frames[i], numberOfCoefficients);
CC_Frame_into_LPC_Frame (& my frame[i], & thy d_frames[i]);
}
return thee.transfer();
} catch (MelderError) {
Melder_throw (me, U": no LPC created.");
}
}
autoLPC VocalTractTier_to_LPC (VocalTractTier me, double timeStep) {
try {
if (my d_vocalTracts -> size == 0) {
Melder_throw (U"Empty VocalTractTier");
}
long numberOfFrames = (long) floor ((my xmax - my xmin) / timeStep);
VocalTractPoint vtp = (VocalTractPoint) my d_vocalTracts -> item[1];
long numberOfSections = vtp -> d_vocalTract -> nx;
double samplingPeriod = 1.0 / (1000.0 * numberOfSections);
autoNUMmatrix<double> area (1, numberOfFrames, 1, numberOfSections + 1);
autoNUMvector<double> areavec (1, numberOfSections + 1);
autoLPC thee = LPC_create (my xmin, my xmax, numberOfFrames, timeStep, timeStep / 2, numberOfSections, samplingPeriod);
// interpolate each section
for (long isection = 1; isection <= numberOfSections; isection++) {
autoRealTier sectioni = RealTier_create (my xmin, my xmax);
for (long i = 1; i <= my d_vocalTracts -> size; i++) {
VocalTractPoint vtpi = (VocalTractPoint) my d_vocalTracts -> item[i];
double areai = vtpi -> d_vocalTract -> z[1][isection];
RealTier_addPoint (sectioni.peek(), vtpi -> number, areai);
}
for (long iframe = 1; iframe <= numberOfFrames; iframe++) {
double time = thy x1 + (iframe - 1) * thy dx;
area[iframe][isection] = RealTier_getValueAtTime (sectioni.peek(), time);
area[iframe][numberOfSections + 1] = 0.0001; // normalisation is area[n+1] = 0.0001
}
}
for (long iframe = 1; iframe <= numberOfFrames; iframe++) {
LPC_Frame frame = &thy d_frames[iframe];
LPC_Frame_init (frame, numberOfSections);
for (long i = 1; i <= numberOfSections + 1; i++) {
areavec[i] = area[iframe][numberOfSections + 1 - i];
}
NUMlpc_area_to_lpc (areavec.peek(), numberOfSections + 1, frame -> a);
frame -> gain = 1e-6; // something
}
return thee;
} catch (MelderError) {
Melder_throw (U": not converted to LPC.");
}
}
double LPC_Frame_getVTL_wakita (LPC_Frame me, double samplingPeriod, double refLength) {
struct structLPC_Frame lpc_struct;
LPC_Frame lpc = & lpc_struct;
struct structFormant_Frame f_struct;
Formant_Frame f = & f_struct;
struct structTube_Frame rc_struct, af_struct;
Tube_Frame rc = & rc_struct, af = & af_struct;
try {
long m = my nCoefficients;
double length, dlength = 0.001, wakita_length = NUMundefined;
double varMin = 1e308;
memset (& lpc_struct, 0, sizeof (lpc_struct));
memset (& f_struct, 0, sizeof (f_struct));
memset (& rc_struct, 0, sizeof (rc_struct));
memset (& af_struct, 0, sizeof (af_struct));
LPC_Frame_init (lpc, m);
Tube_Frame_init (rc, m, refLength);
Tube_Frame_init (af, m, refLength);
// Step 2
LPC_Frame_into_Formant_Frame (me, f, samplingPeriod, 0);
// LPC_Frame_into_Formant_Frame performs the Formant_Frame_init !!
if (f -> nFormants < 1) {
Melder_throw (U"Not enough formants.");
}
double *area = af -> c;
double lmin = length = 0.10;
double plength = refLength;
while (length <= 0.25) {
// Step 3
double fscale = plength / length;
for (long i = 1; i <= f -> nFormants; i++) {
f -> formant[i].frequency *= fscale;
f -> formant[i].bandwidth *= fscale;
}
/*
20000125: Bovenstaande schaling van f1/b1 kan ook gedaan worden door
MGfb_to_a (f, b, nf, samplingFrequency*length/refLength, a1)
De berekening is extreem gevoelig voor de samplefrequentie: een zelfde
stel f,b waardes geven andere lengtes afhankelijk van Fs. Ook het
weglaten van een hogere formant heeft consekwenties.
De refLength zou eigenlijk vast moeten liggen op
refLength=c*aantalFormanten/Fs waarbij c=340 m/s (geluidssnelheid).
Bij Fs=10000 zou aantalFormanten=5 zijn en refLength -> 0.17 m
*/
// step 4
Formant_Frame_into_LPC_Frame (f, lpc, samplingPeriod);
// step 5
rc -> length = length;
LPC_Frame_into_Tube_Frame_rc (lpc, rc);
// step 6.1
Tube_Frames_rc_into_area (rc, af);
// step 6.2 Log(areas)
double logSum = 0.0;
for (long i = 1; i <= af -> nSegments; i++) {
area[i] = log (area[i]);
logSum += area[i];
}
// step 6.3 and 7
double var = 0.0;
for (long i = 1; i <= af -> nSegments; i++) {
double delta = area[i] - logSum / af -> nSegments;
var += delta * delta;
}
if (var < varMin) {
lmin = length; varMin = var;
}
plength = length;
length += dlength;
}
wakita_length = lmin;
f -> destroy ();
lpc -> destroy ();
rc -> destroy ();
af -> destroy ();
return wakita_length;
} catch (MelderError) {
f -> destroy ();
lpc -> destroy ();
rc -> destroy ();
af -> destroy ();
return NUMundefined;
}
}
double LPC_Frame_getVTL_wakita (LPC_Frame me, double samplingPeriod, double refLength)
{
struct structLPC_Frame lpc_struct;
LPC_Frame lpc = & lpc_struct;
struct structFormant_Frame f_struct;
Formant_Frame f = & f_struct;
struct structTube_Frame rc_struct, af_struct;
Tube_Frame rc = & rc_struct, af = & af_struct;
long i, m = my nCoefficients;
double lmin, length, dlength = 0.001, plength, wakita_length = NUMundefined;
double *area, var, varMin = 1e38, logSum;
double fscale = 1;
memset(& lpc_struct, 0, sizeof(lpc_struct));
memset(& f_struct, 0, sizeof(f_struct));
memset(& rc_struct, 0, sizeof(rc_struct));
memset(& af_struct, 0, sizeof(af_struct));
if (! LPC_Frame_init (lpc, m) ||
! Tube_Frame_init (rc, m, refLength) ||
! Tube_Frame_init (af, m, refLength) ||
/*
Step 2
*/
! LPC_Frame_into_Formant_Frame (me, f, samplingPeriod, 0) ||
/*
LPC_Frame_into_Formant_Frame performs the Formant_Frame_init !!
*/
f -> nFormants < 1) goto end;
area = af -> c;
lmin = length = 0.10;
plength = refLength;
while (length <= 0.25)
{
/* Step 3 */
fscale = plength / length;
for (i = 1; i <= f -> nFormants; i++)
{
f -> formant[i].frequency *= fscale;
f -> formant[i].bandwidth *= fscale;
}
/*
20000125: Bovenstaande schaling van f1/b1 kan ook gedaan worden door
MGfb_to_a (f, b, nf, samplingFrequency*length/refLength, a1)
De berekening is extreem gevoelig voor de samplefrequentie: een zelfde
stel f,b waardes geven andere lengtes afhankelijk van Fs. Ook het
weglaten van een hogere formant heeft consekwenties.
De refLength zou eigenlijk vast moeten liggen op
refLength=c*aantalFormanten/Fs waarbij c=340 m/s (geluidssnelheid).
Bij Fs=10000 zou aantalFormanten=5 zijn en refLength -> 0.17 m
*/
/* step 4 */
if (! Formant_Frame_into_LPC_Frame (f, lpc, samplingPeriod)) goto end;
/* step 5 */
rc -> length = length;
if (! LPC_Frame_into_Tube_Frame_rc (lpc, rc)) goto end;
/* step 6.1 */
if (! Tube_Frames_rc_into_area (rc, af)) goto end;
/* step 6.2 Log(areas) */
for (logSum = 0, i = 1; i <= af -> nSegments; i++)
{
area[i] = log (area[i]);
logSum += area[i];
}
/* step 6.3 and 7*/
for (var = 0, i = 1; i <= af -> nSegments; i++)
{
double delta = area[i] - logSum / af -> nSegments;
var += delta * delta;
}
if (var < varMin)
{
lmin = length; varMin = var;
}
plength = length;
length += dlength;
}
wakita_length = lmin;
end:
Formant_Frame_destroy (f);
LPC_Frame_destroy (lpc);
Tube_Frame_destroy (rc);
Tube_Frame_destroy (af);
return wakita_length;
}