double Function_window (double tim, int windowType) {
static double one_by_bessi_0_12, one_by_bessi_0_20;
switch (windowType) {
case Function_RECTANGULAR:
if (tim < -0.5 || tim > 0.5) return 0.0;
return 1;
case Function_TRIANGULAR:
if (tim < -0.5 || tim > 0.5) return 0.0;
return 1 - tim - tim;
case Function_PARABOLIC:
if (tim < -0.5 || tim > 0.5) return 0.0;
return 1 - 4 * tim * tim;
case Function_HANNING:
if (tim < -0.5 || tim > 0.5) return 0.0;
return 0.5 + 0.5 * cos (2 * NUMpi * tim);
case Function_HAMMING:
if (tim < -0.5 || tim > 0.5) return 0.0;
return 0.54 + 0.46 * cos (2 * NUMpi * tim);
case Function_POTTER:
if (tim < -0.77 || tim > 0.77) return 0.0;
return 0.54 + 0.46 * cos (2 * NUMpi * tim);
case Function_KAISER12:
if (tim < -0.77 || tim > 0.77) return 0.0;
if (one_by_bessi_0_12 == 0.0) one_by_bessi_0_12 = 1.0 / NUMbessel_i0_f (12);
return NUMbessel_i0_f (12 * sqrt (1 - (1.0 / 0.77 / 0.77) * tim * tim)) * one_by_bessi_0_12;
case Function_KAISER20:
if (tim <= -1 || tim >= 1) return 0.0;
if (one_by_bessi_0_20 == 0.0) one_by_bessi_0_20 = 1.0 / NUMbessel_i0_f (20.24);
return NUMbessel_i0_f (20.24 * sqrt (1 - tim * tim)) * one_by_bessi_0_20;
case Function_GAUSSIAN:
return exp ((- NUMpi * NUMpi) * tim * tim);
default:
return 0.0;
}
}
static autoIntensity Sound_to_Intensity_ (Sound me, double minimumPitch, double timeStep, int subtractMeanPressure) {
try {
/*
* Preconditions.
*/
if (! NUMdefined (minimumPitch)) Melder_throw (U"(Sound-to-Intensity:) Minimum pitch undefined.");
if (! NUMdefined (timeStep)) Melder_throw (U"(Sound-to-Intensity:) Time step undefined.");
if (timeStep < 0.0) Melder_throw (U"(Sound-to-Intensity:) Time step should be zero or positive instead of ", timeStep, U".");
if (my dx <= 0.0) Melder_throw (U"(Sound-to-Intensity:) The Sound's time step should be positive.");
if (minimumPitch <= 0.0) Melder_throw (U"(Sound-to-Intensity:) Minimum pitch should be positive.");
/*
* Defaults.
*/
if (timeStep == 0.0) timeStep = 0.8 / minimumPitch; // default: four times oversampling Hanning-wise
double windowDuration = 6.4 / minimumPitch;
Melder_assert (windowDuration > 0.0);
double halfWindowDuration = 0.5 * windowDuration;
long halfWindowSamples = (long) floor (halfWindowDuration / my dx);
autoNUMvector <double> amplitude (- halfWindowSamples, halfWindowSamples);
autoNUMvector <double> window (- halfWindowSamples, halfWindowSamples);
for (long i = - halfWindowSamples; i <= halfWindowSamples; i ++) {
double x = i * my dx / halfWindowDuration, root = 1 - x * x;
window [i] = root <= 0.0 ? 0.0 : NUMbessel_i0_f ((2 * NUMpi * NUMpi + 0.5) * sqrt (root));
}
long numberOfFrames;
double thyFirstTime;
try {
Sampled_shortTermAnalysis (me, windowDuration, timeStep, & numberOfFrames, & thyFirstTime);
} catch (MelderError) {
Melder_throw (U"The duration of the sound in an intensity analysis should be at least 6.4 divided by the minimum pitch (", minimumPitch, U" Hz), "
U"i.e. at least ", 6.4 / minimumPitch, U" s, instead of ", my xmax - my xmin, U" s.");
}
autoIntensity thee = Intensity_create (my xmin, my xmax, numberOfFrames, timeStep, thyFirstTime);
for (long iframe = 1; iframe <= numberOfFrames; iframe ++) {
double midTime = Sampled_indexToX (thee.peek(), iframe);
long midSample = Sampled_xToNearestIndex (me, midTime);
long leftSample = midSample - halfWindowSamples, rightSample = midSample + halfWindowSamples;
double sumxw = 0.0, sumw = 0.0, intensity;
if (leftSample < 1) leftSample = 1;
if (rightSample > my nx) rightSample = my nx;
for (long channel = 1; channel <= my ny; channel ++) {
for (long i = leftSample; i <= rightSample; i ++) {
amplitude [i - midSample] = my z [channel] [i];
}
if (subtractMeanPressure) {
double sum = 0.0;
for (long i = leftSample; i <= rightSample; i ++) {
sum += amplitude [i - midSample];
}
double mean = sum / (rightSample - leftSample + 1);
for (long i = leftSample; i <= rightSample; i ++) {
amplitude [i - midSample] -= mean;
}
}
for (long i = leftSample; i <= rightSample; i ++) {
sumxw += amplitude [i - midSample] * amplitude [i - midSample] * window [i - midSample];
sumw += window [i - midSample];
}
}
intensity = sumxw / sumw;
intensity /= 4e-10;
thy z [1] [iframe] = intensity < 1e-30 ? -300 : 10 * log10 (intensity);
}
return thee;
} catch (MelderError) {
Melder_throw (me, U": intensity analysis not performed.");
}
}
void Sound_multiplyByWindow (Sound me, enum kSound_windowShape windowShape) {
for (long channel = 1; channel <= my ny; channel ++) {
long i, n = my nx;
double *amp = my z [channel];
double imid, edge, onebyedge1, factor;
switch (windowShape) {
case kSound_windowShape_RECTANGULAR:
;
break;
case kSound_windowShape_TRIANGULAR: /* "Bartlett" */
for (i = 1; i <= n; i ++) { double phase = (double) i / n; /* 0..1 */
amp [i] *= 1.0 - fabs ((2.0 * phase - 1.0)); }
break;
case kSound_windowShape_PARABOLIC: /* "Welch" */
for (i = 1; i <= n; i ++) { double phase = (double) i / n;
amp [i] *= 1.0 - (2.0 * phase - 1.0) * (2.0 * phase - 1.0); }
break;
case kSound_windowShape_HANNING:
for (i = 1; i <= n; i ++) { double phase = (double) i / n;
amp [i] *= 0.5 * (1.0 - cos (2.0 * NUMpi * phase)); }
break;
case kSound_windowShape_HAMMING:
for (i = 1; i <= n; i ++) { double phase = (double) i / n;
amp [i] *= 0.54 - 0.46 * cos (2.0 * NUMpi * phase); }
break;
case kSound_windowShape_GAUSSIAN_1:
imid = 0.5 * (n + 1), edge = exp (-3.0), onebyedge1 = 1 / (1.0 - edge); /* -0.5..+0.5 */
for (i = 1; i <= n; i ++) { double phase = ((double) i - imid) / n;
amp [i] *= (exp (-12.0 * phase * phase) - edge) * onebyedge1; }
break;
case kSound_windowShape_GAUSSIAN_2:
imid = 0.5 * (double) (n + 1), edge = exp (-12.0), onebyedge1 = 1 / (1.0 - edge);
for (i = 1; i <= n; i ++) { double phase = ((double) i - imid) / n;
amp [i] *= (exp (-48.0 * phase * phase) - edge) * onebyedge1; }
break;
case kSound_windowShape_GAUSSIAN_3:
imid = 0.5 * (double) (n + 1), edge = exp (-27.0), onebyedge1 = 1 / (1.0 - edge);
for (i = 1; i <= n; i ++) { double phase = ((double) i - imid) / n;
amp [i] *= (exp (-108.0 * phase * phase) - edge) * onebyedge1; }
break;
case kSound_windowShape_GAUSSIAN_4:
imid = 0.5 * (double) (n + 1), edge = exp (-48.0), onebyedge1 = 1 / (1.0 - edge);
for (i = 1; i <= n; i ++) { double phase = ((double) i - imid) / n;
amp [i] *= (exp (-192.0 * phase * phase) - edge) * onebyedge1; }
break;
case kSound_windowShape_GAUSSIAN_5:
imid = 0.5 * (double) (n + 1), edge = exp (-75.0), onebyedge1 = 1 / (1.0 - edge);
for (i = 1; i <= n; i ++) { double phase = ((double) i - imid) / n;
amp [i] *= (exp (-300.0 * phase * phase) - edge) * onebyedge1; }
break;
case kSound_windowShape_KAISER_1:
imid = 0.5 * (double) (n + 1);
factor = 1 / NUMbessel_i0_f (2 * NUMpi);
for (i = 1; i <= n; i ++) { double phase = 2 * ((double) i - imid) / n; /* -1..+1 */
double root = 1 - phase * phase;
amp [i] *= root <= 0.0 ? 0.0 : factor * NUMbessel_i0_f (2 * NUMpi * sqrt (root)); }
break;
case kSound_windowShape_KAISER_2:
imid = 0.5 * (double) (n + 1);
factor = 1 / NUMbessel_i0_f (2 * NUMpi * NUMpi + 0.5);
for (i = 1; i <= n; i ++) { double phase = 2 * ((double) i - imid) / n; /* -1..+1 */
double root = 1 - phase * phase;
amp [i] *= root <= 0.0 ? 0.0 : factor * NUMbessel_i0_f ((2 * NUMpi * NUMpi + 0.5) * sqrt (root)); }
break;
default:
break;
}
}
}
