random_.c

sloedgy open sip stack source code

/*

$Log: random_.c,v $
Revision 1.1  2006/08/04 07:25:25  joegenbaclor
*** empty log message ***

Revision 1.1  2006/06/26 03:02:54  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 03:28:42  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  20:41:32  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  22:30:49  jaf
 * Initial revision
 *

*/

#ifdef P_R_O_T_O_T_Y_P_E_S
extern integer random_(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"

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

/* 	RANDOM Version 49 

 * $Log: random_.c,v $
 * Revision 1.1  2006/08/04 07:25:25  joegenbaclor
 * *** empty log message ***
 *
 * Revision 1.1  2006/06/26 03:02:54  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 03:28:42  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  20:41:32  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  22:30:49  jaf
 * Initial revision
 * */
/* Revision 1.3  1996/03/20  16:13:54  jaf */
/* Rearranged comments a little bit, and added comments explaining that */
/* even though there is local state here, there is no need to create an */
/* ENTRY for reinitializing it. */

/* Revision 1.2  1996/03/14  22:25:29  jaf */
/* Just rearranged the comments and local variable declarations a bit. */

/* Revision 1.1  1996/02/07 14:49:01  jaf */
/* Initial revision */


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

/*  Pseudo random number generator based on Knuth, Vol 2, p. 27. */

/* Function Return: */
/*  RANDOM - Integer variable, uniformly distributed over -32768 to 32767 */

/* This subroutine maintains local state from one call to the next. */
/* In the context of the LPC10 coder, there is no reason to reinitialize */
/* this local state when switching between audio streams, because its */
/* results are only used to generate noise for unvoiced frames. */

integer random_(struct lpc10_decoder_state *st)
{
    /* Initialized data */

    integer *j;
    integer *k;
    shortint *y;

    /* System generated locals */
    integer ret_val;

/* 	Parameters/constants */
/*       Local state */
/*   The following is a 16 bit 2's complement addition, */
/*   with overflow checking disabled */

    j = &(st->j);
    k = &(st->k);
    y = &(st->y[0]);

    y[*k - 1] += y[*j - 1];
    ret_val = y[*k - 1];
    --(*k);
    if (*k <= 0) {
	*k = 5;
    }
    --(*j);
    if (*j <= 0) {
	*j = 5;
    }
    return ret_val;
} /* random_ */