pitsyn.c

lpc10-15为美军2400bps语音压缩标准的C语音源代码。

/*

$Log: pitsyn.c,v $
 * Revision 1.2  1996/08/20  20:40:12  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  22:31:12  jaf
 * Initial revision
 *

*/

#ifdef P_R_O_T_O_T_Y_P_E_S
extern int pitsyn_(integer *order, integer *voice, integer *pitch, real *rms, real *rc, integer *lframe, integer *ivuv, integer *ipiti, real *rmsi, real *rci, integer *nout, real *ratio, 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"

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

/* 	PITSYN Version 53 */

/* $Log: pitsyn.c,v $
 * Revision 1.2  1996/08/20  20:40:12  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  22:31:12  jaf
 * Initial revision
 * */
/* Revision 1.2  1996/03/25  18:49:07  jaf */
/* Added commments about which indices of array arguments are read or */
/* written. */

/* Rearranged local variable declarations to indicate which need to be */
/* saved from one invocation to the next.  Added entry INITPITSYN to */
/* reinitialize local state variables, if desired. */

/* Added lots of comments about proving that the maximum number of pitch */
/* periods (NOUT) that can be returned is 16.  The call to STOP that */
/* could happen if NOUT got too large was removed as a result. */

/* Also proved that the total number of samples returned from N calls, */
/* each with identical values of LFRAME, will always be in the range */
/* N*LFRAME-MAXPIT+1 to N*LFRAME. */

/* Revision 1.1  1996/02/07 14:48:18  jaf */
/* Initial revision */


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

/*   Synthesize a single pitch epoch */

/* Input: */
/*  ORDER  - Synthesis order (number of RC's) */
/*  VOICE  - Half frame voicing decisions */
/*           Indices 1 through 2 read. */
/*  LFRAME - Length of speech buffer */
/* Input/Output: */
/*  PITCH  - Pitch */
/*           This value should be in the range MINPIT (20) to MAXPIT */
/*           (156), inclusive. */
/*           PITCH can be modified under some conditions. */
/*  RMS    - Energy  (can be modified) */
/*           RMS is changed to 1 if the value passed in is less than 1. */
/*  RC     - Reflection coefficients */
/*           Indices 1 through ORDER can be temporarily overwritten with */
/*           RCO, and then replaced with original values, under some */
/*           conditions. */
/* Output: */
/*  IVUV   - Pitch epoch voicing decisions */
/*           Indices (I) of IVUV, IPITI, and RMSI are written, */
/*           and indices (J,I) of RCI are written, */
/*           where I ranges from 1 to NOUT, and J ranges from 1 to ORDER. */
/*  IPITI  - Pitch epoch length */
/*  RMSI   - Pitch epoch energy */
/*  RCI    - Pitch epoch RC's */
/*  NOUT   - Number of pitch periods in this frame */
/*           This is at least 0, at least 1 if MAXPIT .LT. LFRAME (this */
/*           is currently true on every call), and can never be more than */
/*           (LFRAME+MAXPIT-1)/PITCH, which is currently 16 with */
/*           LFRAME=180, MAXPIT=156, and PITCH .GE. 20, as SYNTHS */
/*           guarantees when it calls this subroutine. */
/*  RATIO  - Previous to present energy ratio */
/*           Always assigned a value. */

/* Subroutine */ int pitsyn_(integer *order, integer *voice, 
	integer *pitch, real *rms, real *rc, integer *lframe, integer *ivuv, 
	integer *ipiti, real *rmsi, real *rci, integer *nout, real *ratio,
			       struct lpc10_decoder_state *st)
{
    /* Initialized data */

    real *rmso;
    logical *first;

    /* System generated locals */
    integer rci_dim1, rci_offset, i__1, i__2;
    real r__1;

    /* Builtin functions */
    double log(doublereal), exp(doublereal);

    /* Local variables */
    real alrn, alro, yarc[10], prop;
    integer i__, j, vflag, jused, lsamp;
    integer *jsamp;
    real slope;
    integer *ipito;
    real uvpit;
    integer ip, nl, ivoice;
    integer *ivoico;
    integer istart;
    real *rco;
    real xxy;

/*       Arguments */
/* $Log: pitsyn.c,v $
 * Revision 1.2  1996/08/20  20:40:12  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  22:31:12  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 */
/*       LSAMP is initialized in the IF (FIRST) THEN clause, but it is */
/*       not used the first time through, and it is given a value before 
*/
/*       use whenever FIRST is .FALSE., so it appears unnecessary to */
/*       assign it a value when FIRST is .TRUE. */
/*       Local state */
/* FIRST  - .TRUE. only on first call to PITSYN. */
/* IVOICO - Previous VOICE(2) value. */
/* IPITO  - Previous PITCH value. */
/* RMSO   - Previous RMS value. */
/* RCO    - Previous RC values. */

/* JSAMP  - If this routine is called N times with identical values of */
/*          LFRAME, then the total length of all pitch periods returned */
/*          is always N*LFRAME-JSAMP, and JSAMP is always in the range 0 
*/
/*          to MAXPIT-1 (see below for why this is so).  Thus JSAMP is */
/*          the number of samples "left over" from the previous call to */
/*          PITSYN, that haven't been "used" in a pitch period returned */
/*          from this subroutine.  Every time this subroutine is called, 
*/
/*          it returns pitch periods with a total length of at most */
/*          LFRAME+JSAMP. */

/* IVOICO, IPITO, RCO, and JSAMP need not be assigned an initial value */
/* with a DATA statement, because they are always initialized on the */
/* first call to PITSYN. */

/* FIRST and RMSO should be initialized with DATA statements, because */
/* even on the first call, they are used before being initialized. */
    /* Parameter adjustments */
    if (rc) {
	--rc;
	}
    if (rci) {
	rci_dim1 = *order;
	rci_offset = rci_dim1 + 1;
	rci -= rci_offset;
	}
    if (voice) {
	--voice;
	}
    if (ivuv) {
	--ivuv;
	}
    if (ipiti) {
	--ipiti;
	}
    if (rmsi) {
	--rmsi;
	}

    /* Function Body */
    ivoico = &(st->ivoico);
    ipito = &(st->ipito);
    rmso = &(st->rmso);
    rco = &(st->rco[0]);
    jsamp = &(st->jsamp);
    first = &(st->first_pitsyn);

    if (*rms < 1.f) {
	*rms = 1.f;
    }
    if (*rmso < 1.f) {
	*rmso = 1.f;
    }
    uvpit = 0.f;
    *ratio = *rms / (*rmso + 8.f);
    if (*first) {
	lsamp = 0;
	ivoice = voice[2];
	if (ivoice == 0) {
	    *pitch = *lframe / 4;
	}
	*nout = *lframe / *pitch;
	*jsamp = *lframe - *nout * *pitch;

/*          SYNTHS only calls this subroutine with PITCH in the range 
20 */
/*          to 156.  LFRAME = MAXFRM = 180, so NOUT is somewhere in th
e */
/*          range 1 to 9. */

/*          JSAMP is "LFRAME mod PITCH", so it is in the range 0 to */
/*          (PITCH-1), or 0 to MAXPIT-1=155, after the first call. */

	i__1 = *nout;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    i__2 = *order;
	    for (j = 1; j <= i__2; ++j) {
		rci[j + i__ * rci_dim1] = rc[j];
	    }
	    ivuv[i__] = ivoice;
	    ipiti[i__] = *pitch;
	    rmsi[i__] = *rms;
	}
	*first = FALSE_;
    } else {
	vflag = 0;
	lsamp = *lframe + *jsamp;
	slope = (*pitch - *ipito) / (real) lsamp;
	*nout = 0;
	jused = 0;
	istart = 1;
	if (voice[1] == *ivoico && voice[2] == voice[1]) {
	    if (voice[2] == 0) {
/* SSUV - -   0  ,  0  ,  0 */
		*pitch = *lframe / 4;
		*ipito = *pitch;
		if (*ratio > 8.f) {
		    *rmso = *rms;
		}
	    }