rcsynew.c

speech signal process tools

/*
 * This material contains unpublished, proprietary software of 
 * Entropic Research Laboratory, Inc. Any reproduction, distribution, 
 * or publication of this work must be authorized in writing by Entropic 
 * Research Laboratory, Inc., and must bear the notice: 
 *
 *    "Copyright (c) 1990-1993 Entropic Research Laboratory, Inc. 
 *                   All rights reserved"
 *
 * The copyright notice above does not evidence any actual or intended 
 * publication of this source code.     
 *
 * Written by:  David Talkin
 * Checked by:
 * Revised by:
 *
 * Brief description: rcsyn.c
 *
 */

static char *sccs_id = "%W%	%G%	ERL";

#include <math.h>
#include <stdio.h>
#include <esps/lpsyn.h>

double rc_gain(rc,n)
     register double *rc;
     register int n;
{
  register double sum, dif, *dp=rc;
  int i=n;
  for(sum = 1.0; n--;) {
    dif = *rc++;
    sum *= (1.0 - dif*dif);
  }
  if(sum < 0.0){
    for(n=0;n<i;n++) printf("%f ",dp[n]);
    printf("\n");
    return(0.0);
  }
  return(sqrt(sum));
}

double   lattice(rc, order, lsstate, input, usr)
register double   *rc, *lsstate;
register double input;
register int     order, usr;
{
  register int     i, j;
  register double   output, ki;

  output = input;

  for (i = order*usr, rc += order; i > 0; ) {
    ki = - *--rc;
    output += ki * lsstate[i];
    lsstate[i+1] = lsstate[i] - ki * output;
    for(j=usr,i--;--j; i--)
      lsstate[i+1] = lsstate[i];
  }
  lsstate[1] = output;
  return (output);
}

/* This one implements a Rosenberg polynomial source; open-phase
damping; adjustable open quotient; and period error diffusion. */
rcsyn(pb,init,op, damp, intcc, usr)
     register short *op;
     register int init, usr;
     register double damp, intcc;
     Pblock *pb;
{
  register int k,j, ord, nper, pcnt, count, nopen, orat;
  register double out, ransize, g, input, input2, decay, *mp1, *cp,
                  uc, ud, ue, uf, isq, pval, flow;
  double oq = 0.5, c;
  int decay_cnt=1;
  register short *ep;
  register LP_frame *rcf;
  double residp, residf, fnper, fk, ofreq, ginc, gold;
  static double lpm[MAX_ORD*10], rcold[MAX_ORD], drc[MAX_ORD], *mp2;

  ofreq = usr * pb->freq;		/* output frequency */
  ransize = 2 << 30;
  ransize *= 4;
  rcf = pb->head;
  ord = pb->head->order;
/*  if(intcc > .001) intcc = exp(log(intcc)/usr); */
  if(init)
    for(decay_cnt=usr, k=MAX_ORD, out = 0.0, residf = residp = 0.0, gold=0.0,
	count = 0,
	pcnt = 10000, nper = 0, mp1=lpm, mp2 = rcold; k--; ) {
      *mp1++ = 0.0;
      *mp2++ = 0.0;
    }
  while(rcf) {
    if(rcf->next)
      fk = residp + ofreq*(rcf->next->time - rcf->time);
    else
      if(rcf->prev)
	fk = residp + ofreq*(rcf->time - rcf->prev->time);
      else
	fk = .01*ofreq;	/* just force a 10ms frame */
    if(fk < 0.0) fk = 0.0;
    k = fk;		/* integerize samples generated by this frame */
    residp = fk - k;
    /* compute deltas for interpolated RC's and level */
    for(j=0, mp1 = rcold, mp2 = rcf->coef, cp = drc; j++ < ord;)
      *cp++ = (*mp2++ - *mp1++)/k;
    ginc = ((8.0*rcf->rms) - gold)/k;
    if(rcf->fr_type == VOICED) {
      fnper = residf + (ofreq * rcf->period);
      residf = fnper-((int)fnper); 
      for( ; k--; count++,pcnt++) {
	g = (gold += ginc);
	if(pcnt >= nper) {	/* reset the function generator */
	  nper = fnper;
	  oq = .6 + .0017*((1.0/rcf->period) - 160.0);
	  if(oq > .9) oq = .9;
	  nopen = 0.5 + oq*fnper;
	  uc = 2.0/(double)nopen;
	  ud = 3.0/(2.0*nopen);
	  c = .66667*nopen;	/* time of peak flow */
	  ue = uc/2.0;
	  uf = uc*ud/3.0;
	  isq = c*c;
	  pval = (ue*isq) - (uf*isq*c); /* value of peak flow */
	  pcnt = 1;
	}
	
	if(pcnt <= nopen) {	/* output open-phase signal */
	  isq = pcnt*pcnt;
	  input = uc*(pcnt - isq*ud);
	  flow = (ue*isq) - (uf*isq*pcnt);
	  decay = 1.0 - (damp*flow/pval);
	  out = g*lattice(rcold, ord, lpm, rc_gain(rcold,ord)*input,usr);
	} else {		/* output closed-phase signal */
	 input = 0.0;
	 out = g*lattice(rcold, ord, lpm, input, usr);
	}
	for(j=ord, mp1 = rcold, cp = drc; j--; )
	  *mp1++ += *cp++;
	*op++ = (out > 0.0)? out + .5 : out - .5;
	if(--decay_cnt <= 0) {
	  for(j=ord*usr, mp1=lpm; j--;) *mp1++ *= decay;
	  decay_cnt = usr;
	}
      }
    } else {			/* it is an unvoiced frame */
      input = 0.0;
      for(nper=0, pcnt=10000 ; k--; count++) {
	g = 1.0/ransize;
#ifdef OS5
	input =  g*(rand() - rand()) + intcc*input;
#else
	input =  g*(random() - random()) + intcc*input;
#endif
	input2 = input * rc_gain(rcold, ord);
	out = (gold += ginc)*lattice(rcold, ord, lpm, input2, usr);
	for(j=ord, mp1 = rcold, cp = drc; j--; )
	  *mp1++ += *cp++;
	*op++ = (out > 0.0)? out + .5 : out - .5;
      }
    }
    rcf = rcf->next;
  }
  return(count);
}