deemp.c

sloedgy open sip stack source code

/*

$Log: deemp.c,v $
Revision 1.1  2006/06/26 03:02:52  joegenbaclor
I have decided to include the latest development realease  of OPAL tagged Deimos Devel 1 (June 8 2006) as inegrated classes to opensipstack to avoid future version conflicts due to the fast pace in OPAL development.   This move is also aimed to reduce the size of projects using OPAL componets such as the soon to be relased OpenSIPPhone.

Revision 2.2  2005/08/08 03:28:41  dereksmithies
Eradicate all "/ * within comments" messages from GCC compilations.

Revision 2.1  2003/03/14 09:53:27  robertj
Updated to openH323 v1.11.7

Revision 1.1  2000/06/05 04:45:12  robertj
Added LPC-10 2400bps codec

 * Revision 1.2  1996/08/20  20:23:46  jaf
 * Removed all static local variables that were SAVE'd in the Fortran
 * code, and put them in struct lpc10_decoder_state that is passed as an
 * argument.
 *
 * Removed init function, since all initialization is now done in
 * init_lpc10_decoder_state().
 *
 * Revision 1.1  1996/08/19  22:32:34  jaf
 * Initial revision
 *

*/

#ifdef P_R_O_T_O_T_Y_P_E_S
extern int deemp_(real *x, integer *n, struct lpc10_decoder_state *st);
#endif

/*  -- translated by f2c (version 19951025).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

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

/* 	DEEMP Version 48 */

/*
 * $Log: deemp.c,v $
 * Revision 1.1  2006/06/26 03:02:52  joegenbaclor
 * I have decided to include the latest development realease  of OPAL tagged Deimos Devel 1 (June 8 2006) as inegrated classes to opensipstack to avoid future version conflicts due to the fast pace in OPAL development.   This move is also aimed to reduce the size of projects using OPAL componets such as the soon to be relased OpenSIPPhone.
 *
 * Revision 2.2  2005/08/08 03:28:41  dereksmithies
 * Eradicate all "/ * within comments" messages from GCC compilations.
 *
 * Revision 2.1  2003/03/14 09:53:27  robertj
 * Updated to openH323 v1.11.7
 *
 * Revision 1.1  2000/06/05 04:45:12  robertj
 * Added LPC-10 2400bps codec
 *
 * Revision 1.2  1996/08/20  20:23:46  jaf
 * Removed all static local variables that were SAVE'd in the Fortran
 * code, and put them in struct lpc10_decoder_state that is passed as an
 * argument.
 *
 * Removed init function, since all initialization is now done in
 * init_lpc10_decoder_state().
 *
 * Revision 1.1  1996/08/19  22:32:34  jaf
 * Initial revision
 * */
/* Revision 1.3  1996/03/20  15:54:37  jaf */
/* Added comments about which indices of array arguments are read or */
/* written. */

/* Added entry INITDEEMP to reinitialize the local state variables, if */
/* desired. */

/* Revision 1.2  1996/03/14  22:11:13  jaf */
/* Comments added explaining which of the local variables of this */
/* subroutine need to be saved from one invocation to the next, and which */
/* do not. */

/* Revision 1.1  1996/02/07 14:44:53  jaf */
/* Initial revision */


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

/*  De-Emphasize output speech with   1 / ( 1 - .75z**-1 ) */
/*    cascaded with 200 Hz high pass filter */
/*    ( 1 - 1.9998z**-1 + z**-2 ) / ( 1 - 1.75z**-1 + .78z**-2 ) */

/*  WARNING!  The coefficients above may be out of date with the code */
/*  below.  Either that, or some kind of transformation was performed */
/*  on the coefficients above to create the code below. */

/* Input: */
/*  N  - Number of samples */
/* Input/Output: */
/*  X  - Speech */
/*       Indices 1 through N are read before being written. */

/* This subroutine maintains local state from one call to the next.  If */
/* you want to switch to using a new audio stream for this filter, or */
/* reinitialize its state for any other reason, call the ENTRY */
/* INITDEEMP. */

/* Subroutine */ int deemp_(real *x, integer *n, struct lpc10_decoder_state *st)
{
    /* Initialized data */

    real *dei1;
    real *dei2;
    real *deo1;
    real *deo2;
    real *deo3;

    /* System generated locals */
    integer i__1;
    real r__1;

    /* Local variables */
    integer k;
    real dei0;

/*       Arguments */
/*       Local variables that need not be saved */
/*       Local state */
/*       All of the locals saved below were not given explicit initial */
/*       values in the original code.  I think 0 is a safe choice. */
    /* Parameter adjustments */
    if (x) {
	--x;
	}

    /* Function Body */

    dei1 = &(st->dei1);
    dei2 = &(st->dei2);
    deo1 = &(st->deo1);
    deo2 = &(st->deo2);
    deo3 = &(st->deo3);

    i__1 = *n;
    for (k = 1; k <= i__1; ++k) {
	dei0 = x[k];
	r__1 = x[k] - *dei1 * 1.9998f + *dei2;
	x[k] = r__1 + *deo1 * 2.5f - *deo2 * 2.0925f + *deo3 * .585f;
	*dei2 = *dei1;
	*dei1 = dei0;
	*deo3 = *deo2;
	*deo2 = *deo1;
	*deo1 = x[k];
    }
    return 0;
} /* deemp_ */