RTL271_1/evrcc/code/fndppf.c

/**********************************************************************
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*******************************************************************/
 
/*======================================================================*/
/*     Enhanced Variable Rate Codec - Bit-Exact C Specification         */
/*     Copyright (C) 1997-1998 Telecommunications Industry Association. */
/*     All rights reserved.                                             */
/*----------------------------------------------------------------------*/
/* Note:  Reproduction and use of this software for the design and      */
/*     development of North American Wideband CDMA Digital              */
/*     Cellular Telephony Standards is authorized by the TIA.           */
/*     The TIA does not authorize the use of this software for any      */
/*     other purpose.                                                   */
/*                                                                      */
/*     The availability of this software does not provide any license   */
/*     by implication, estoppel, or otherwise under any patent rights   */
/*     of TIA member companies or others covering any use of the        */
/*     contents herein.                                                 */
/*                                                                      */
/*     Any copies of this software or derivative works must include     */
/*     this and all other proprietary notices.                          */
/*======================================================================*/
/*  Memory Usage:                           				*/
/*      ROM:                            				*/
/*      Static/Global RAM:                      			*/
/*      Stack/Local RAM:                    				*/
/*----------------------------------------------------------------------*/
/************************************************************************
* Routine name: fndppf                                                  *
* Function: forward pitch predictor.		                        *
* Inputs:   buf    - data buffer.                                       *
*           dmin   - minimum delay value.                               *
*           dmax   - maximum delay value.                               *
*           prevdelay - previous frame delay value.                     *
*           length - size of pitch window.                              *
* Outputs:  delay  - predicted delay.                                   *
*           beta   - gain value.                                        *
*                                                                       *
************************************************************************/
#include "e_globs.h"
#include "macro.h"

//#include "mathevrc.h"
#include "dsp_math.h"
#include "mathdp31.h"
#include "mathadv.h"

void fndppf(INT16 *delay, INT16 *beta, INT16 *buf, INT16 dmin, INT16 dmax, INT16 length)
{
	static INT16 b = -10224;	/* rom storage */

	static INT16 a[3] =
	{-18739, 16024, -4882};		/* a[] scaled down by 4 */

	INT16 dnew = 0;
	INT16 sum;
	INT32 Lsum;
	register INT16 m, i, n;
	static INT16 DECbuf[FrameSize / 4];
	INT32 Lcorrmax, Lcmax, Ltmp;
	INT16 tap1;
	INT16 M1, M2, dnewtmp = 0;
	static INT16 lastgoodpitch = 0;
	static INT16 lastbeta = 0;
	static INT16 memory[3];
	static int FirstTime = 1;
	INT16 Lsum_scale;
	INT16 shift, Lcorr_scale, Lcmax_scale;
	INT16 n1, n2, nq, nq1;
	INT32 Ltempf;
	/* init static variables (should be in init routine for implementation) */
	if (FirstTime)
	{
		FirstTime = 0;
		n1 = (shr(FrameSize, 2));
		for (i = 0; i < n1; i++)
			DECbuf[i] = 0;
		memory[0] = memory[1] = memory[2] = 0;
	}

	/* Shift  memory of DECbuf */
	for (i = 0; i < shr(length, 3); i++)
	{
		DECbuf[i] = DECbuf[i + shr(length, 3)];
	}
	/* filter signal and decimate */
	for (i = 0, n = shr(length, 3); i < shr(length, 1); i++)
	{
		Ltempf = L_shr(L_deposit_h(buf[i + shr(length, 1)]), 4);
		Ltempf = L_msu(Ltempf, memory[0], a[0]);
		Ltempf = L_msu(Ltempf, memory[1], a[1]);
		Ltempf = L_msu(Ltempf, memory[2], a[2]);
		Ltempf = L_shl(Ltempf, 2);

		shift = 0;
		if ((i + 1) % 4 == 0)
		{
			Lsum = L_add(Ltempf, L_deposit_h(memory[2]));
			Lsum = L_mac(Lsum, memory[0], b);
			Lsum = L_mac(Lsum, memory[1], b);

			DECbuf[n++] = round32(L_shl(Lsum, 1));
		}
		memory[2] = memory[1];
		memory[1] = memory[0];
		memory[0] = round32(Ltempf);
	}

	/* perform first search for best delay value in decimated domain */
	Lcorrmax = (LW_MIN);
        Lcorr_scale = 1;

	for (m = shr(dmin, 2); m <= shr(dmax, 2); m++)
	{
                n1 = 1;
		for (i = 0, Lsum = 0; i < sub(shr(length, 2), m); i++)
		{
			Ltempf = L_mult(DECbuf[i], DECbuf[i + m]);
			Ltempf = L_shr(Ltempf, n1);
			Lsum = L_add(Lsum, Ltempf);
			if (L_abs(Lsum) >= 0x40000000)
			{
				Lsum = L_shr(Lsum, 1);
				n1++;
			}
		}
		if (
		    ((Lcorr_scale >= n1) && (L_shr(Lsum, sub(Lcorr_scale, n1)) > Lcorrmax))
		 || ((Lcorr_scale < n1) && (Lsum > L_shr(Lcorrmax, sub(n1, Lcorr_scale))))
		 ) 
		{
			Lcorrmax = Lsum;
			Lcorr_scale = n1;
			dnew = m;
		}

	}

	/* Compare against lastgoodpitch */
	if (lastgoodpitch != 0 && (abs_s(sub(lastgoodpitch, shl(dnew, 2))) > 2))
	{
		M1 = sub(shr(lastgoodpitch, 2), 2);
		if (M1 < shr(dmin, 2))
			M1 = shr(dmin, 2);
		M2 = add(M1, 4);
		if (M2 > shr(dmax, 2))
			M2 = shr(dmax, 2);

		Lcmax = LW_MIN;
                Lcmax_scale = 1;
		for (m = M1; m <= M2; m++)
		{
                        n1 = 1;
			for (i = 0, Lsum = 0; i < sub(shr(length, 2), m); i++)
			{
				Ltempf = L_mult(DECbuf[i], DECbuf[i + m]);
				Ltempf = L_shr(Ltempf, n1);
				Lsum = L_add(Lsum, Ltempf);
				if (L_abs(Lsum) >= 0x40000000)
				{
					Lsum = L_shr(Lsum, 1);
					n1++;
				}
			}

			if (
			    ((Lcmax_scale >= n1) && (L_shr(Lsum, sub(Lcmax_scale, n1)) > Lcmax))
			 || ((Lcmax_scale < n1) && (Lsum > L_shr(Lcmax, sub(n1, Lcmax_scale))))
			   ) 
			{					/* Gives some bias to low delays */
				Lcmax = Lsum;
				Lcmax_scale = n1;
				dnewtmp = m;
			}
		}
		Lsum = L_mpy_ls(Lcorrmax, 27361);
		if (
		    ((Lcmax_scale >= Lcorr_scale) && (L_shr(Lsum, sub(Lcmax_scale, Lcorr_scale)) < Lcmax))
		 || ((Lcmax_scale < Lcorr_scale) && (Lsum < L_shr(Lcmax, sub(Lcorr_scale, Lcmax_scale))))
		   ) 
		{
			dnew = dnewtmp;
		}
	}

	/* perform first search for best delay value in non-decimated buffer */
	M1 = Max(sub(shl(dnew, 2), 3), dmin);
	if (M1 < dmin)
		M1 = dmin;
	M2 = Min(add(shl(dnew, 2), 3), dmax);
	if (M2 > dmax)
		M2 = dmax;
	Lcorrmax = LW_MIN;
        Lcorr_scale = 1;
	for (m = M1; m <= M2; m++)
	{
                n1 = 1;
		for (i = 0, Lsum = 0; i < sub(length, m); i++)
		{
			Ltempf = L_mult(buf[i], buf[i + m]);

			Ltempf = L_shr(Ltempf, n1);
			Lsum = L_add(Lsum, Ltempf);
			if (L_abs(Lsum) >= 0x40000000)
			{
				Lsum = L_shr(Lsum, 1);
				n1++;
			}
		}

		if (
		    ((Lcorr_scale >= n1) && (L_shr(Lsum, sub(Lcorr_scale, n1)) > Lcorrmax))
		 || ((Lcorr_scale < n1) && (Lsum > L_shr(Lcorrmax, sub(n1, Lcorr_scale))))
		   ) 
		{
			Lcorrmax = Lsum;
			Lcorr_scale = n1;
			dnew = m;
		}
	}
        Lsum_scale = 1;
	for (i = 0, Lsum = 0; i < sub(length, dnew); i++)
	{
		Ltempf = L_mult(buf[i + dnew], buf[i + dnew]);
		Ltempf = L_shr(Ltempf, Lsum_scale);
		Lsum = L_add(Lsum, Ltempf);
		if (L_abs(Lsum) >= 0x40000000)
		{
			Lsum = L_shr(Lsum, 1);
			Lsum_scale++;
		}
	}

        Lcmax_scale = 1;
	for (i = 0, Lcmax = 0; i < length - dnew; i++)
	{
		Ltempf = L_mult(buf[i], buf[i]);
		Ltempf = L_shr(Ltempf, Lcmax_scale);
		Lcmax = L_add(Lcmax, Ltempf);
		if (L_abs(Lcmax) >= 0x40000000)
		{
			Lcmax = L_shr(Lcmax, 1);
			Lcmax_scale++;
		}
	}
	nq = norm_l(Lsum);
	Lsum = L_shl(Lsum, nq);
	nq1 = norm_l(Lcmax);
	Lcmax = L_shl(Lcmax, nq1);
	Lsum = L_mpy_ll(Lsum, Lcmax);
	n1 = norm_l(Lsum);
	Lsum = L_shl(Lsum, n1);
	sum = sqroot(Lsum);
	n1 = add(add(n1, nq), nq1);
	n1 = sub(sub(n1, Lcmax_scale), Lsum_scale);
	n2 = shr(n1, 1);

	if (n1 & 1)
		Lsum = L_mult(sum, 23170);
	else
		Lsum = L_deposit_h(sum);

	n2 = add(n2, Lcorr_scale);
	Lcorrmax = L_shl(Lcorrmax, n2);

	if ((Lsum == 0) || (Lcorrmax <= 0))
		*beta = 0;
	else if (Lcorrmax > Lsum)
		*beta = 0x7fff;
	else
		*beta = round32(L_divide(Lcorrmax, Lsum));

	/* perform search for best delay value in around old pitch delay */
	if (lastgoodpitch != 0)
	{
		M1 = lastgoodpitch - 6;
		M2 = lastgoodpitch + 6;

		if (M1 < dmin)
			M1 = dmin;
		if (M2 > dmax)
			M2 = dmax;

		if (dnew > M2 || dnew < M1)
		{
			Lcmax = LW_MIN;
                        Lcmax_scale = 1;
			for (m = M1; m <= M2; m++)
			{
                                n1 = 1;
				for (i = 0, Lsum = 0; i < length - m; i++)
				{
					Ltempf = L_mult(buf[i], buf[i + m]);
					Ltempf = L_shr(Ltempf, n1);
					Lsum = L_add(Lsum, Ltempf);
					if (L_abs(Lsum) >= 0x40000000)
					{
						Lsum = L_shr(Lsum, 1);
						n1++;
					}
				}

				if (
				    ((Lcmax_scale >= n1) && (L_shr(Lsum, sub(Lcmax_scale, n1)) > Lcmax))
				 || ((Lcmax_scale < n1) && (Lsum > L_shr(Lcmax, sub(n1, Lcmax_scale))))
				   ) 
				{
					Lcmax = Lsum;
					dnewtmp = m;
					Lcmax_scale = n1;
				}
			}
                        Lcorr_scale = 1;
			for (i = 0, Ltmp = 0; i < length - dnewtmp; i++)
			{
				Ltempf = L_mult(buf[i + dnewtmp], buf[i + dnewtmp]);
				Ltempf = L_shr(Ltempf, Lcorr_scale);
				Ltmp = L_add(Ltmp, Ltempf);
				if (L_abs(Ltmp) >= 0x40000000)
				{
					Ltmp = L_shr(Ltmp, 1);
					Lcorr_scale++;
				}

			}
                        Lsum_scale = 1;
			for (i = 0, Lsum = 0; i < length - dnewtmp; i++)
			{

				Ltempf = L_mult(buf[i], buf[i]);
				Ltempf = L_shr(Ltempf, Lsum_scale);
				Lsum = L_add(Lsum, Ltempf);
				if (L_abs(Lsum) >= 0x40000000)
				{
					Lsum = L_shr(Lsum, 1);
					Lsum_scale++;
				}
			}

			nq = norm_l(Ltmp);
			Ltmp = L_shl(Ltmp, nq);
			nq1 = norm_l(Lsum);
			Lsum = L_shl(Lsum, nq1);
			Ltmp = L_mpy_ll(Ltmp, Lsum);
			n1 = norm_l(Ltmp);
			Ltmp = L_shl(Ltmp, n1);
			sum = sqroot(Ltmp);

			n1 = add(add(n1, nq), nq1);
			n1 = sub(sub(n1, Lsum_scale), Lcorr_scale);
			n2 = shr(n1, 1);

			if (n1 & 1)
				Ltmp = L_mult(sum, 23170);
			else
				Ltmp = L_deposit_h(sum);

			n2 = add(n2, Lcmax_scale);
			Lcmax = L_shl(Lcmax, n2);

			if ((Ltmp == 0) || (Lcmax <= 0))
				tap1 = 0;
			else if (Lcmax >= Ltmp)
				tap1 = 0x7fff;
			else
				tap1 = round32(L_divide(Lcmax, Ltmp));

			/* Replace dnew with dnewtmp if tap1 is large enough */
			if ((dnew > M2 && (shr(tap1, 1) > mult_r(9830, *beta))) ||
				(dnew < M1 && (shr(tap1, 1) > mult_r(19661, *beta))))
			{
				dnew = dnewtmp;
				*beta = (tap1);
			}
		}
	}

	*delay = dnew;
	if (*beta > 13107)
	{
		lastgoodpitch = dnew;
		lastbeta = *beta;
	}
	else
	{
		lastbeta = mult_r(24576, lastbeta);
		if (lastbeta < 9830)
			lastgoodpitch = 0;
	}
}