difmag.c

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/*

$Log$
Revision 1.15 2004/06/26 03:50:14 markster
Merge source cleanups (bug #1911)

Revision 1.14 2003/02/12 13:59:14 matteo
mer feb 12 14:56:57 CET 2003

Revision 1.1.1.1 2003/02/12 13:59:14 matteo
mer feb 12 14:56:57 CET 2003

Revision 1.2 2000/01/05 08:20:39 markster
Some OSS fixes and a few lpc changes to make it actually work

 * 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"

#ifdef P_R_O_T_O_T_Y_P_E_S
extern int difmag_(real *speech, integer *lpita, integer *tau, integer *ltau, integer *maxlag, real *amdf, integer *minptr, integer *maxptr);
#endif

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

/* DIFMAG Version 49 */

/* $Log$
 * Revision 1.15 2004/06/26 03:50:14 markster
 * Merge source cleanups (bug #1911)
 *
 * Revision 1.14 2003/02/12 13:59:14 matteo
 * mer feb 12 14:56:57 CET 2003
 *
 * Revision 1.1.1.1 2003/02/12 13:59:14 matteo
 * mer feb 12 14:56:57 CET 2003
 *
 * Revision 1.2 2000/01/05 08:20:39 markster
 * Some OSS fixes and a few lpc changes to make it actually work
 *
 * 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_ */