MelFilter MFCC_to_MelFilter (MFCC me, long first, long last) {
try {
long nf = my maximumNumberOfCoefficients + 1;
autoNUMmatrix<double> cosinesTable (NUMcosinesTable (nf), 1, 1);
autoNUMvector<double> x (1, nf);
autoNUMvector<double> y (1, nf);
if (first >= last) {
first = 0; last = nf - 1;
}
if (first < 0 || last > nf - 1) {
Melder_throw ("MFCC_to_MelFilter: coefficients must be in interval [0,", my maximumNumberOfCoefficients, "].");
}
double df = (my fmax - my fmin) / (nf + 1);
autoMelFilter thee = MelFilter_create (my xmin, my xmax, my nx, my dx, my x1, my fmin, my fmax, nf, df, df);
for (long frame = 1; frame <= my nx; frame++) {
CC_Frame cf = (CC_Frame) & my frame[frame];
long iend = MIN (last, cf -> numberOfCoefficients);
x[1] = first == 0 ? cf -> c0 : 0;
for (long i = 1; i <= my maximumNumberOfCoefficients; i++) {
x[i + 1] = i < first || i > iend ? 0 : cf -> c[i];
}
NUMinverseCosineTransform (x.peek(), y.peek(), nf, cosinesTable.peek());
for (long i = 1; i <= nf; i++) {
thy z[i][frame] = y[i];
}
}
return thee.transfer();
} catch (MelderError) {
Melder_throw (me, ": no MelFilter created.");
}
}
MelFilter MFCC_to_MelFilter2 (MFCC me, long first_cc, long last_cc, double f1_mel, double df_mel) {
try {
int use_c0 = 0;
long nf = ((my fmax - my fmin) / df_mel + 0.5);
double fmin = MAX (f1_mel - df_mel, 0), fmax = f1_mel + (nf + 1) * df_mel;
if (nf < 1) {
Melder_throw ("MFCC_to_MelFilter: the position of the first filter, the distance between the filters, "
"and, the maximum do not result in a positive number of filters.");
}
// Default values
if (first_cc == 0) {
first_cc = 1;
use_c0 = 1;
}
if (last_cc == 0) {
last_cc = my maximumNumberOfCoefficients;
}
// Be strict
if (last_cc < first_cc || first_cc < 1 || last_cc > my maximumNumberOfCoefficients) {
Melder_throw ("MFCC_to_MelFilter: coefficients must be in interval [1,", my maximumNumberOfCoefficients, "].");
}
autoNUMmatrix<double> dct (NUMcosinesTable (first_cc, last_cc, nf), first_cc, 1); // TODO ??
//if ((dct = NUMcosinesTable (first_cc, last_cc, nf)) == NULL) return NULL;
autoMelFilter thee = MelFilter_create (my xmin, my xmax, my nx, my dx, my x1, fmin, fmax, nf, df_mel, f1_mel);
for (long frame = 1; frame <= my nx; frame++) {
CC_Frame cf = (CC_Frame) & my frame[frame];
long ie = MIN (last_cc, cf -> numberOfCoefficients);
for (long j = 1; j <= nf; j++) {
double t = 0;
for (long i = first_cc; i <= ie; i++) {
t += cf -> c[i] * dct[i][j];
}
// The inverse CT has a factor 1/N
t /= nf;
if (use_c0) {
t += cf -> c0;
}
thy z[j][frame] = t;
}
}
return thee.transfer();
} catch (MelderError) {
Melder_throw (me, ": no MelFilter created.");
}
}
MelFilter Matrix_to_MelFilter (I) {
iam (Matrix);
try {
autoMelFilter thee = MelFilter_create (my xmin, my xmax, my nx, my dx, my x1,
my ymin, my ymax, my ny, my dy, my y1);
NUMmatrix_copyElements (my z, thy z, 1, my ny, 1, my nx);
return thee.transfer();
} catch (MelderError) {
Melder_throw (me, U": not converted to MelFilter.");
}
}
MelFilter Sound_to_MelFilter (Sound me, double analysisWidth, double dt,
double f1_mel, double fmax_mel, double df_mel) {
try {
double t1, samplingFrequency = 1 / my dx, nyquist = 0.5 * samplingFrequency;
double windowDuration = 2 * analysisWidth; /* gaussian window */
double fmin_mel = 0;
double fbottom = HZTOMEL (100.0), fceiling = HZTOMEL (nyquist);
long nt, frameErrorCount = 0;
// Check defaults.
if (fmax_mel <= 0 || fmax_mel > fceiling) {
fmax_mel = fceiling;
}
if (fmax_mel <= f1_mel) {
f1_mel = fbottom; fmax_mel = fceiling;
}
if (f1_mel <= 0) {
f1_mel = fbottom;
}
if (df_mel <= 0) {
df_mel = 100.0;
}
// Determine the number of filters.
long nf = floor ( (fmax_mel - f1_mel) / df_mel + 0.5);
fmax_mel = f1_mel + nf * df_mel;
Sampled_shortTermAnalysis (me, windowDuration, dt, &nt, &t1);
autoSound sframe = Sound_createSimple (1, windowDuration, samplingFrequency);
autoSound window = Sound_createGaussian (windowDuration, samplingFrequency);
autoMelFilter thee = MelFilter_create (my xmin, my xmax, nt, dt, t1, fmin_mel,
fmax_mel, nf, df_mel, f1_mel);
autoMelderProgress progress (L"MelFilters analysis");
for (long i = 1; i <= nt; i++) {
double t = Sampled_indexToX (thee.peek(), i);
Sound_into_Sound (me, sframe.peek(), t - windowDuration / 2);
Sounds_multiply (sframe.peek(), window.peek());
if (! Sound_into_MelFilter_frame (sframe.peek(), thee.peek(), i)) {
frameErrorCount++;
}
if ( (i % 10) == 1) {
Melder_progress ( (double) i / nt, L"Frame ", Melder_integer (i), L" out of ",
Melder_integer (nt), L".");
}
}
if (frameErrorCount) Melder_warning (L"Analysis results of ", Melder_integer (frameErrorCount),
L" frame(s) out of ", Melder_integer (nt), L" will be suspect.");
// Window correction.
double ref = FilterBank_DBREF * gaussian_window_squared_correction (window -> nx);
NUMdmatrix_to_dBs (thy z, 1, thy ny, 1, thy nx, ref, FilterBank_DBFAC, FilterBank_DBFLOOR);
return thee.transfer();
} catch (MelderError) {
Melder_throw (me, ": no MelFilter created.");
}
}
