_gc2gc.c

语音信号处理工具包,里面提供了很多有用的操作。这是最新版本

/*
  ----------------------------------------------------------------
	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
			All Rights Reserved.

  Permission is hereby granted, free of charge, to use and
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  work is furnished to do so, subject to the following conditions:

    1. The code must retain the above copyright notice, this list
       of conditions and the following disclaimer.

    2. Any modifications must be clearly marked as such.

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  SPTK WORKING GROUP, AND THE CONTRIBUTORS TO THIS WORK DISCLAIM
  ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
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  SHALL NAGOYA INSTITUTE OF TECHNOLOGY, TOKYO INSITITUTE OF
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 ----------------------------------------------------------------
*/

/***************************************************************
    $Id: _gc2gc.c,v 1.2 2002/12/25 05:29:59 sako Exp $

    Generalized Cepstral Transformation	

	void gc2gc(c1, m1, g1, c2, m2, g2)

	double	*c1	: normalized generalized cepstrum (input)
	int	m1	: order of gc1
	double	g1	: gamma of gc1
	double	*c2	: normalized generalized cepstrum (output)
	int	m2	: order of gc2
	double	g2	: gamma of gc2

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

void gc2gc(c1, m1, g1, c2, m2, g2)
double 	*c1, *c2, g1, g2;
int 	m1, m2;
{
    int 	  i, min, k, mk;
    double 	  ss1, ss2, cc;
    static double *ca = NULL;
    static int    size;

    if(ca == NULL){
        ca = dgetmem(m1+1);
	size = m1;
    }
    if(m1 > size){
        free(ca);
        ca = dgetmem(m1+1);
	size = m1;
    }

    movem(c1, ca, sizeof(*c1), m1+1);

    c2[0] = ca[0];
    for (i = 1; i <= m2; i++){
	ss1 = ss2 = 0.0;
	min = m1 < i ? m1 : i - 1;
	for (k = 1; k <= min; k++){
	    mk = i - k;
	    cc = ca[k] * c2[mk];
	    ss2 += k * cc;
	    ss1 += mk * cc;
	}

	if (i <= m1)
	    c2[i] = ca[i] + (g2*ss2 - g1*ss1)/i;
	else
	    c2[i] = (g2*ss2 - g1*ss1)/i;
    }
}