_mgcep.c

Speech Signal Processing Toolkit 3.0

/*
  ----------------------------------------------------------------
	Speech Signal Processing Toolkit (SPTK): version 3.0
			 SPTK Working Group

		   Department of Computer Science
		   Nagoya Institute of Technology
				and
    Interdisciplinary Graduate School of Science and Engineering
		   Tokyo Institute of Technology
		      Copyright (c) 1984-2000
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 ----------------------------------------------------------------
*/

/****************************************************************

    $Id: _mgcep.c,v 1.2 2002/12/25 05:31:39 sako Exp $

    Mel-Generalized Cepstral Analysis

	int mgcep(xw, flng, b, m, a, g, itr1, itr2, dd, e);

	double   *xw  : input sequence
	int      flng : frame length
	double   *b   : coefficient b'(m)
	int      m    : order of mel cepstrum
	double   a    : alpha
	double   g    : gamma
	int      n    : order of recursions
	int      itr1 : minimum number of iteration
	int      itr2 : maximum number of iteration
	double   dd   : end condition
	double   e    : initial value for log-periodgram

	return value : 	0 -> completed by end condition
			-1-> completed by maximum iteration

*****************************************************************/

#include <stdio.h>
#include <SPTK.h>

double exp(), pow(), sqrt(), fabs();
double gain();

int mgcep(xw, flng, b, m, a, g, n, itr1, itr2, dd, e)
double *xw, *b, a, g, dd, e;
int flng, itr1, itr2, m, n;
{
    int    	  i, j, flag = 0;
    static double *x = NULL, *y, *d;
    static int    size_x, size_c;
    double 	  ep, epo, newton();
    
    if(x == NULL){
	x = dgetmem(flng+flng);
	y = x + flng;
	size_x = flng;
	
	d = dgetmem(m+1);
	size_c = m;
    }
    if(flng > size_x){
	free(x);
	x = dgetmem(flng+flng);
	y = x + flng;
	size_x = flng;
    }
    if(m > size_c){
	free(d);
	d = dgetmem(m+1);
	size_c = m;
    }
    
    movem(xw, x, sizeof(*x), flng);
    /*  periodegram  */
    fftr(x, y, flng);
    for(i=0; i<flng; i++)
	x[i] = x[i]*x[i] + y[i]*y[i] + e;

    /* initial value */    
    fillz(b, sizeof(*b), m+1);
    ep = newton(x, flng, b, m, a, -1.0, n, 0);

    if(g != -1.0){
	if (a != 0.0){
	    ignorm(b, b, m, -1.0);	/*  K, b'r(m)    -> br(m)         */
            b2mc(b, b, m, a);		/*  br(m)        -> c~r(m)        */
            gnorm(b, d, m, -1.0);	/*  c~r(m)       -> K~, c~'r(m)   */
	}
	else 
	    movem(b, d, sizeof(*b), m+1);

        gc2gc(d, m, -1.0, b, m, g);	/*  K~, c~'r(m)  -> K~, c~'r'(m)  */

	if (a != 0.0){
            ignorm(b, b, m, g);		/*  K~, c~'r'(m) -> c~r(m)        */
            mc2b(b, b, m, a);		/*  c~r(m)       -> br(m)         */
            gnorm(b, b, m, g);		/*  br(m)        -> K, b'r'(m)    */
	}
    }
    
    /*  Newton-Raphson method  */
    if(g != -1.0){
	for(j=1; j<=itr2; j++){
	    epo = ep;
	    ep = newton(x, flng, b, m, a, g, n, i);

	    if(j >= itr1)
		if (fabs((epo - ep)/ep) < dd){
		    flag = 1;
		    break;
		}
	}
    }

    if(flag) return(0);
    else     return(-1);
}

double newton(x, flng, c, m, a, g, n, j)
double *x, *c, a, g;
int flng, m, n, j;
{
    int		 i, m2;
    double 	 t, s, tr, ti, trr, tii, log();
    static double  *cr = NULL, *ci, *pr, *qr, *qi, *rr, *ri, *b;
    static int   size_cr, size_b;
    
    if(cr == NULL){
	cr = dgetmem(7*flng);
	ci = cr + flng;  pr = ci + flng;
	qr = pr + flng;  qi = qr + flng;
	rr = qi + flng;  ri = rr + flng;
	size_cr = flng;

	b = dgetmem(m+1);
	size_b = m;
    }
    if(flng > size_cr){
	free(cr);
	cr = dgetmem(7*flng);
	ci = cr + flng;  pr = ci + flng;
	qr = pr + flng;  qi = qr + flng;
	rr = qi + flng;  ri = rr + flng;
	size_cr = flng;
    }
    if(m > size_b){
	free(b);
	b = dgetmem(m+1);
	size_b = m;
    }

    m2 = m + m;
    
    fillz(cr, sizeof(*cr), flng);
    movem(&c[1], &cr[1], sizeof(*c), m);
    
    if (a != 0.0) 
	b2c(cr, m, cr, n, -a);
    
    fftr(cr, ci, flng);			/* cr +j ci : FFT[c]  */

    if (g == -1.0) 
	movem(x, pr, sizeof(*x), flng);
    else if (g == 0.0)
        for (i=0; i<flng; i++) 
	    pr[i] = x[i] / exp(cr[i] + cr[i]);
    else
        for (i=0; i<flng; i++){
            tr = 1 + g * cr[i]; ti = g * ci[i];
            s = (trr = tr * tr) + (tii = ti * ti);
            t = x[i] * pow(s, -1.0/g);
            pr[i] = (t /= s);
            rr[i] = tr * t; ri[i] = ti * t;
            t /= s; qr[i] = (trr - tii) * t;
	    s = tr * ti * t; qi[i] = s + s;
        }

    ifftr(pr, ci, flng);

    if (a != 0.0) 
	b2c(pr, n, pr, m2, a);
    
    if (g == 0.0 || g == -1.0){
        movem(pr, qr, sizeof(*pr), m2+1);
        movem(pr, rr, sizeof(*pr), m+1);
    }
    else{
       ifft(qr, qi, flng);
       ifft(rr, ri, flng);
       
       if (a != 0.0){
	   b2c(qr, n, qr, n, a);
	   b2c(rr, n, rr, m, a);
       }
   }

    if (a != 0.0){
	ptrans(pr, m, a);
	qtrans(qr, m, a);
    }

    /*  c[0] : gain, t : epsilon  */
    if (g != -1.0) 
	c[0] = sqrt(t = gain(rr, c, m, g));
    
    if (g == -1.0)
	fillz(qr, sizeof(*qr), m2+1);
    else if (g != 0.0) 
	for (i=2; i<=m2; i++) 
	    qr[i] *= 1.0 + g;
    
    if (theq(pr, &qr[2], &b[1], &rr[1], m, -1.)){
        fprintf(stderr, "mgcep : Error in theq() at %dth iteration !\n",j);
        exit(1);
    }

    for (i=1; i<=m; i++) c[i] += b[i];

    /*  c[0] : gain, t : epsilon  */
    if (g == -1.0) 
	c[0] = sqrt(t = gain(rr, c, m, g));
    
    return(log(t));
}

/*  gain(epsilon) calculation  */
double gain(er, c, m, g)
double *er, *c, g;
int m;
{
    register int i;
    double t;

    if (g != 0.0){
        for (t=0.0,i=1; i<=m; i++) t += er[i] * c[i];
        return(er[0] + g*t);
    }
    else return(er[0]);
    
}

/*  b'(m) to c(m)  */
b2c(b, m1, c, m2, a)
double *b, *c, a;
int m1, m2;
{
    register int        i, j;
    static double       *d = NULL, *g;
    static int          size;
    double 		k;
    
    if(d == NULL){
        size = m2;
        d = dgetmem(size+size+2);
        g = d + size + 1;
    }
    if(m2 > size){
        free(d);
        size = m2;
        d = dgetmem(size+size+2);
        g = d + size + 1;
    }

    k = 1 - a * a;

    fillz(g, sizeof(*g), m2 + 1);
    
    for (i = -m1; i <= 0; i++){
        d[0] = g[0];
	g[0] = b[-i];

        if (1 <= m2) 
	    g[1] = k * d[0] + a * (d[1] = g[1]);

        for (j = 2; j <= m2; j++)
            g[j] = d[j - 1] + a * ((d[j] = g[j]) - g[j - 1]);
    }
    movem(g, c, sizeof(*g), m2 + 1);
}

/*  recursion for p(m)  */
ptrans(p, m, a)
double *p, a;
register int m;
{
    double d, o;

    d = p[m];
    for (m--; m > 0; m--){ 
	o = p[m] + a * d;
	d = p[m]; p[m] = o;
    }
    o =  a * d; 
    p[m] = (1. - a * a) * p[m] + o + o;
}

/*  recursion for q(m)  */
qtrans(q, m, a)
double *q, a;
register int m;
{
    register int i;
    double d, o;

    m += m;
    i = 1; d = q[i];
    for (i++; i <= m; i++){ 
	o = q[i] + a * d;
	d = q[i]; q[i] = o;
    }
}