void mgc2mgc(double *c1, const int m1, const double a1, const double g1,
double *c2, const int m2, const double a2, const double g2)
{
double a;
static double *ca = NULL;
static int size_a;
if (ca == NULL) {
ca = dgetmem(m1 + 1);
size_a = m1;
}
if (m1 > size_a) {
free(ca);
ca = dgetmem(m1 + 1);
size_a = m1;
}
a = (a2 - a1) / (1 - a1 * a2);
if (a == 0) {
movem(c1, ca, sizeof(*c1), m1 + 1);
gnorm(ca, ca, m1, g1);
gc2gc(ca, m1, g1, c2, m2, g2);
ignorm(c2, c2, m2, g2);
} else {
freqt(c1, m1, c2, m2, a);
gnorm(c2, c2, m2, g1);
gc2gc(c2, m2, g1, c2, m2, g2);
ignorm(c2, c2, m2, g2);
}
return;
}
int gcep(double *xw, const int flng, double *gc, const int m, const double g,
const int itr1, const int itr2, const double d, const double e,
const double f, const int itype)
{
int i, j, flag = 0;
double t, s, dd = 0.0;
static double *x = NULL, *y, *cr, *ci, *rr, *hr, *hi, *er, *ei;
static int size;
if (x == NULL) {
x = dgetmem(9 * flng);
size = flng;
y = x + flng;
cr = y + flng;
ci = cr + flng;
rr = ci + flng;
hr = rr + flng;
hi = hr + flng;
er = hi + flng;
ei = er + flng;
}
if (flng > size) {
free(x);
x = dgetmem(9 * flng);
size = flng;
y = x + flng;
cr = y + flng;
ci = cr + flng;
rr = ci + flng;
hr = rr + flng;
hi = hr + flng;
er = hi + flng;
ei = er + flng;
}
movem(xw, x, sizeof(*x), flng);
switch (itype) {
case 0: /* windowed data sequence */
fftr(x, y, flng);
for (i = 0; i < flng; i++) {
x[i] = x[i] * x[i] + y[i] * y[i] + e; /* periodegram */
}
break;
case 1: /* dB */
for (i = 0; i <= flng / 2; i++) {
x[i] /= 20.0 / log(10.0); /* dB -> amplitude spectrum */
x[i] = x[i] * x[i] + e; /* amplitude -> periodgram */
}
break;
case 2: /* log */
for (i = 0; i <= flng / 2; i++) {
x[i] = exp(x[i]); /* log -> amplitude spectrum */
x[i] = x[i] * x[i] + e; /* amplitude -> periodgram */
}
break;
case 3: /* amplitude */
for (i = 0; i <= flng / 2; i++) {
x[i] = x[i] * x[i] + e; /* amplitude -> periodgram */
}
break;
case 4: /* periodgram */
for (i = 0; i <= flng / 2; i++) {
x[i] = x[i] + e;
}
break;
default:
fprintf(stderr, "mgcep : Input type %d is not supported!\n", itype);
exit(1);
}
if (itype > 0) {
for (i = 1; i < flng / 2; i++)
x[flng - i] = x[i];
}
for (i = 0; i < flng; i++)
cr[i] = log(x[i]);
/* initial value of generalized cepstrum */
ifftr(cr, y, flng); /* x : IFFT[x] */
cr[0] = exp(cr[0] / 2);
gc2gc(cr, m, 0.0, gc, m, g); /* gc : generalized cepstrum */
/* Newton-Raphson method */
for (j = 1; j <= itr2; j++) {
fillz(cr, sizeof(*cr), flng);
movem(&gc[1], &cr[1], sizeof(*cr), m);
fftr(cr, ci, flng); /* cr+jci : FFT[gc] */
for (i = 0; i < flng; i++) {
t = x[i] / agexp(g, cr[i], ci[i]);
cr[i] = 1 + g * cr[i];
ci[i] = g * ci[i];
s = cr[i] * cr[i] + ci[i] * ci[i];
rr[i] = t / s;
hr[i] = (cr[i] * cr[i] - ci[i] * ci[i]) * t / (s * s);
hi[i] = 2 * cr[i] * ci[i] * t / (s * s);
er[i] = cr[i] * t / s;
ei[i] = ci[i] * t / s;
}
ifftr(rr, y, flng); /* rr : r(k) */
ifft(hr, hi, flng); /* hr : h(k) */
ifft(er, ei, flng); /* er : e(k) */
s = gc[0]; /* gc[0] : gain */
for (i = 1, t = 0.0; i <= m; i++)
t += er[i] * gc[i];
t = er[0] + g * t;
t = sqrt(fabs(t));
if (j >= itr1) {
if (fabs((t - dd) / t) < d) {
flag = 1;
break;
}
dd = t;
}
for (i = 2; i <= m + m; i++)
hr[i] *= 1 + g;
if (theq(rr, &hr[2], &y[1], &er[1], m, f)) {
fprintf(stderr, "gcep : Error in theq() at %dth iteration!\n", j);
exit(1);
}
gc[0] = t;
for (i = 1; i <= m; i++)
gc[i] += y[i];
}
if (flag)
return (0);
else
return (-1);
}
