ref: 37cbdc63bc16efdd9075ab3ceb161d6cab7fc0bb
dir: /lpc10/difmag.c/
/*
* Revision 1.1 1996/08/19 22:32:31 jaf
* Initial revision
*
*/
/* -- translated by f2c (version 19951025).
You must link the resulting object file with the libraries:
-lf2c -lm (in that order)
*/
#include "f2c.h"
extern int difmag_(real *speech, integer *lpita, integer *tau, integer *ltau, integer *maxlag, real *amdf, integer *minptr, integer *maxptr);
/* ********************************************************************** */
/* DIFMAG Version 49 */
/*
* Revision 1.1 1996/08/19 22:32:31 jaf
* Initial revision
* */
/* Revision 1.3 1996/03/15 23:09:39 jaf */
/* Just added a few comments about which array indices of the arguments */
/* are used, and mentioning that this subroutine has no local state. */
/* Revision 1.2 1996/03/13 14:41:31 jaf */
/* Comments added explaining that none of the local variables of this */
/* subroutine need to be saved from one invocation to the next. */
/* Revision 1.1 1996/02/07 14:45:04 jaf */
/* Initial revision */
/* ********************************************************************* */
/* Compute Average Magnitude Difference Function */
/* Inputs: */
/* SPEECH - Low pass filtered speech */
/* Indices MIN_N1 through MAX_N1+LPITA-1 are read, where */
/* MIN_N1 = (MAXLAG - MAX_TAU)/2+1 MAX_TAU = max of TAU(I) for I=1,LTAU
*/
/* MAX_N1 = (MAXLAG - MIN_TAU)/2+1 MIN_TAU = min of TAU(I) for I=1,LTAU
*/
/* LPITA - Length of speech buffer */
/* TAU - Table of lags */
/* Indices 1 through LTAU read. */
/* LTAU - Number of lag values to compute */
/* MAXLAG - Maximum possible lag value */
/* Outputs: */
/* (All of these outputs are also read, but only after being written.) */
/* AMDF - Average Magnitude Difference for each lag in TAU */
/* Indices 1 through LTAU written */
/* MINPTR - Index of minimum AMDF value */
/* MAXPTR - Index of maximum AMDF value */
/* This subroutine has no local state. */
/* Subroutine */ int difmag_(real *speech, integer *lpita, integer *tau,
integer *ltau, integer *maxlag, real *amdf, integer *minptr, integer *
maxptr)
{
/* System generated locals */
integer i__1, i__2;
real r__1;
/* Local variables */
integer i__, j, n1, n2;
real sum;
/* Arguments */
/* Local variables that need not be saved */
/* Local state */
/* None */
/* Parameter adjustments */
--amdf;
--tau;
--speech;
/* Function Body */
*minptr = 1;
*maxptr = 1;
i__1 = *ltau;
for (i__ = 1; i__ <= i__1; ++i__) {
n1 = (*maxlag - tau[i__]) / 2 + 1;
n2 = n1 + *lpita - 1;
sum = 0.f;
i__2 = n2;
for (j = n1; j <= i__2; j += 4) {
sum += (r__1 = speech[j] - speech[j + tau[i__]], abs(r__1));
}
amdf[i__] = sum;
if (amdf[i__] < amdf[*minptr]) {
*minptr = i__;
}
if (amdf[i__] > amdf[*maxptr]) {
*maxptr = i__;
}
}
return 0;
} /* difmag_ */