irc2pc.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 13:59:15 matteo
mer feb 12 14:56:57 CET 2003

Revision 1.1.1.1 2003/02/12 13:59:15 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 22:31:56 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 irc2pc_(real *rc, real *pc, integer *order, real *gprime, real *g2pass);
#endif

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

/* IRC2PC Version 48 */

/* $Log$
 * Revision 1.15 2004/06/26 03:50:14 markster
 * Merge source cleanups (bug #1911)
 *
 * Revision 1.14 2003/02/12 13:59:15 matteo
 * mer feb 12 14:56:57 CET 2003
 *
 * Revision 1.1.1.1 2003/02/12 13:59:15 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 22:31:56 jaf
 * Initial revision
 * */
/* Revision 1.3 1996/03/20 15:47:19 jaf */
/* Added comments about which indices of array arguments are read or */
/* written. */

/* Revision 1.2 1996/03/14 16:59:04 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 14:47:27 jaf */
/* Initial revision */


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

/* Convert Reflection Coefficients to Predictor Coeficients */

/* Inputs: */
/* RC - Reflection coefficients */
/* Indices 1 through ORDER read. */
/* ORDER - Number of RC's */
/* GPRIME - Excitation modification gain */
/* Outputs: */
/* PC - Predictor coefficients */
/* Indices 1 through ORDER written. */
/* Indices 1 through ORDER-1 are read after being written. */
/* G2PASS - Excitation modification sharpening factor */

/* This subroutine has no local state. */

/* Subroutine */ int irc2pc_(real *rc, real *pc, integer *order, real *gprime,
 real *g2pass)
{
 /* System generated locals */
 integer i__1, i__2;

 /* Builtin functions */
 double sqrt(doublereal);

 /* Local variables */
 real temp[10];
 integer i__, j;

/* Arguments */
/* $Log$
 * Revision 1.15 2004/06/26 03:50:14 markster
 * Merge source cleanups (bug #1911)
 *
 * Revision 1.14 2003/02/12 13:59:15 matteo
 * mer feb 12 14:56:57 CET 2003
 *
 * Revision 1.1.1.1 2003/02/12 13:59:15 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 22:31:56 jaf
 * Initial revision
 * */
/* Revision 1.3 1996/03/29 22:03:47 jaf */
/* Removed definitions for any constants that were no longer used. */

/* Revision 1.2 1996/03/26 19:34:33 jaf */
/* Added comments indicating which constants are not needed in an */
/* application that uses the LPC-10 coder. */

/* Revision 1.1 1996/02/07 14:43:51 jaf */
/* Initial revision */

/* LPC Configuration parameters: */
/* Frame size, Prediction order, Pitch period */
/* Local variables that need not be saved */
 /* Parameter adjustments */
 --pc;
 --rc;

 /* Function Body */
 *g2pass = 1.f;
 i__1 = *order;
 for (i__ = 1; i__ <= i__1; ++i__) {
 *g2pass *= 1.f - rc[i__] * rc[i__];
 }
 *g2pass = *gprime * (real)sqrt(*g2pass);
 pc[1] = rc[1];
 i__1 = *order;
 for (i__ = 2; i__ <= i__1; ++i__) {
 i__2 = i__ - 1;
 for (j = 1; j <= i__2; ++j) {
 temp[j - 1] = pc[j] - rc[i__] * pc[i__ - j];
 }
 i__2 = i__ - 1;
 for (j = 1; j <= i__2; ++j) {
 pc[j] = temp[j - 1];
 }
 pc[i__] = rc[i__];
 }
 return 0;
} /* irc2pc_ */