smartana.c

speech signal process tools

/*---------------------------------------------------------------------------+
|									     |
| This material contains proprietary software of Entropic Processing, Inc.   |
| Any reproduction, distribution, or publication without the the prior	     |
| written permission of Entropic Processing, Inc. is strictly prohibited.    |
| Any public distribution of copies of this work authorized in writing by    |
| Entropic Processing, Inc. must bear the notice			     |
|									     |
|              "Copyright 1986 Entropic Processing, Inc."		     |
----------------------------------------------------------------------------*/
#ifdef SCCS
static char *sccs_id = "@(#)smartana.c	1.2 9/8/86 EPI";
#endif

#include <stdio.h>
#define voiced 1
#define unvoiced 0
#define UU 0
#define UV 1
#define VU 2			/* 10 binary */
#define VV 3			/* 11 binary */

extern float num[];
smartana(locn, lpcfilter, order, inpbuf, blksze, correct_flag, sig_energy)
int     locn, *correct_flag, order, blksze;
float lpcfilter[], inpbuf[], sig_energy;
    {
	float   peak = 0;
	int     n, wt, i, j;
	float   tmp[100], c2[100], k1, k2, comp_gain, t2;

	*correct_flag = 0;

/* Compute gain and rc's of actual speech from that of pre-emphasized signal */
	n = order + 1;
	/* Compute composite filter coefficients */
	lpcfilter[0] = -1.0;
	lpcfilter[n] = 0.0;

	for (i = 1; i <= n; i++)
	    c2[i] = lpcfilter[i] + lpcfilter[i - 1] * num[1];
	/* Compute gain of composite filter */
	comp_gain = 1.0;
	k1 = 0.0;
	for (i = n; i > 0; i--)
	{
	    k2 = k1;
	    k1 = c2[i];
	    t2 = 1.0 - k1 * k1;
	    comp_gain *= t2;
	    for (j = 1; j <= i - 1; j++)
		tmp[j] = (c2[j] + k1 * c2[i - j]) / t2;
	    for (j = 1; j <= i - 1; j++)
		c2[j] = tmp[j];
	}
	comp_gain = 1.0 / comp_gain;
/* Obtain peak/rmsval of pre-emphasized signal */

	for (i = 0; i < blksze; i++)
	{
	    float   t = inpbuf[i];
	    t = t * t;
	    if (t > peak)
		peak = t;
	}
	peak = peak / sig_energy;

	wt = 0;
	if (peak < 8)
	{

	    if (lpcfilter[1] < -1.0)
		wt++;
	    if (comp_gain < 8)
		wt++;
	    if (k1 < 0.5)
		wt++;
	    if (wt > 1)
		*correct_flag = 1;
	    else
		*correct_flag = 0;
	}
    }