RTL271_1/evrcc/code/c3_10pf.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:                    */
/*----------------------------------------------------------------------*/

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

#define L_SUBFR   54
#define NB_PULSE  3
#define NB_TRACK  3
#define STEP      7
#define NB_POS    8
#define MSIZE     64

#define Q15_1_7  4682

Longword Inv_sqrt(				/* (o) Q30 : output value   (range: 0<=val<1)           */
					 Longword L_x	/* (i) Q0  : input value    (range: 0<=val<=7fffffff)   */
);

/*-------------------------------------------------------------------*
 * Function  code_3i54_10bits()                                      *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                      *
 * Algebraic codebook; 10 bits: 3 pulses in a frame of 54 samples.   *
 *-------------------------------------------------------------------*
 * The code length is 54, containing 3 nonzero pulses: i0, i1 and i2.*
 * All pulses have a fixed amplitude: +1 for i0 and i2, -1 for i1.   *
 * 1 bit is used to change sign of all pulses.                       *
 * Each pulse can have 8 possible positions:                         *
 *                                                                   *
 * track0 (i0):  0,  7, 14, ... 49                                   *
 * track1 (i1):  2,  9, 16, ... 51                                   *
 * track2 (i2):  4, 11, 18, ... 53                                   *
 *-------------------------------------------------------------------*/

void code_3i54_10bits(
						 Shortword dn[],	/* (i) Q0 : dn[54] correlation between target and h[]     */
						 Shortword l_subfr,		/* (i)    : lenght of subframe (53 or 54)                 */
						 Shortword H[],		/* (i) Q12: impulse response of weighted synthesis filter */
						 Shortword code[],	/* (o) Q12: algebraic (fixed) codebook excitation         */
						 Shortword y[],		/* (o) Q10: filtered fixed codebook excitation            */
						 Shortword * indx	/* (o)    : index 1 words of 10 bits                      */
)
{
	Shortword i, k, i0, i1, i2, pos, index;
	Shortword psk, ps0, ps1, ps2, alpk, alp0, alp1, alp2;
	Longword s, cor;
	Shortword *p0, *p1, *p2, *p3, *p4, *p5;
	Shortword *h, *h_inv, *ptr_h1, *ptr_h2, *ptr_hf;

	/* these vectors are not static */

	Shortword codvec[NB_PULSE];
	Shortword cor_l2[NB_POS];
	Shortword h_buf[4 * L_SUBFR];
	Shortword rrixix[NB_PULSE][NB_POS], rrixiy[NB_PULSE][MSIZE];

	for (i=l_subfr; i<L_SUBFR; i++)
	{
		dn[i] = 0;
	}

 /*------------------------------------------------------------*
  * normalize h[] for maximum precision on correlation.        *
  *------------------------------------------------------------*/

	h = h_buf;
	h_inv = h_buf + (2 * L_SUBFR);
	for (i = 0; i < ((2 * L_SUBFR) - l_subfr); i++)
	{
		*h++ = 0;
		*h_inv++ = 0;
	}

	cor = 0;
	for (i = 0; i < l_subfr; i++)
		cor = L_mac(cor, H[i], H[i]);

	/* scale h[] with shift operation */

	k = norm_l(cor);
	k = shr(k, 1);

	for (i = 0; i < l_subfr; i++)
	{
		h[i] = shl(H[i], k);
	}
	cor = L_shl(cor, add(k, k));

 /*------------------------------------------------------------*
  * Scaling h[] with a factor (0.5 < fac < 0.25)               *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~               *
  * extract_h(cor) = 8192 .. 32768 --> we want 4096 (1/8 Q15)  *
  *                                                            *
  * 4096 (1/8) = fac^2 * extract_h(cor)                        *
  * fac = sqrt(4096/extract_h(cor))                            *
  *                                                            *
  * fac = 1/sqrt(cor/4096) * 256 = 0.125 to 0.5                *
  *------------------------------------------------------------*/

	cor = L_shr(cor, 12);
	k = extract_h(L_shl(Inv_sqrt(cor), 8));

	for (i = 0; i < l_subfr; i++)
	{
		h[i] = mult(h[i], k);
		h_inv[i] = negate(h[i]);
	}

	h -= (L_SUBFR - l_subfr);
	h_inv -= (L_SUBFR - l_subfr);

 /*------------------------------------------------------------*
  * Compute rrixix[][] needed for the codebook search.         *
  * This algorithm compute impulse response energy of all      *
  * positions (8) in each track (5).         Total = 5x8 = 40. *
  *------------------------------------------------------------*/

	/* storage order --> i2i2, i1i1, i0i0 */

	/* Init pointers to last position of rrixix[] */
	p0 = &rrixix[0][NB_POS - 1];
	p1 = &rrixix[1][NB_POS - 1];
	p2 = &rrixix[2][NB_POS - 1];

	ptr_h1 = h;
	cor = 0x00010000L;			/* 1.0 (for rounding) */
	for (i = 0; i < NB_POS; i++)
	{
		cor = L_mac(cor, *ptr_h1, *ptr_h1);
		ptr_h1++;
		*p2-- = extract_h(cor);
		cor = L_mac(cor, *ptr_h1, *ptr_h1);
		ptr_h1++;
		cor = L_mac(cor, *ptr_h1, *ptr_h1);
		ptr_h1++;
		*p1-- = extract_h(cor);
		cor = L_mac(cor, *ptr_h1, *ptr_h1);
		ptr_h1++;
		cor = L_mac(cor, *ptr_h1, *ptr_h1);
		ptr_h1++;
		*p0-- = extract_h(cor);
		cor = L_mac(cor, *ptr_h1, *ptr_h1);
		ptr_h1++;
		cor = L_mac(cor, *ptr_h1, *ptr_h1);
		ptr_h1++;
	}

	/* Divide all elements of rrixix[][] by 2. */

	p0 = &rrixix[0][0];
        for (i = 0; i < NB_PULSE*NB_POS ; i++)
		*p0++ = shr(*p0, 1);

 /*------------------------------------------------------------*
  * Compute rrixiy[][] needed for the codebook search.         *
  * This algorithm compute correlation between 2 pulses.       *
  *------------------------------------------------------------*/

	/* storage order --> i1i2, i0i1 */

	pos = MSIZE - 1;
	ptr_hf = h + 2;

	for (k = 0; k < NB_POS; k++)
	{
		p1 = &rrixiy[1][pos];
		p0 = &rrixiy[0][pos];

		cor = 0x00008000L;		/* 0.5 (for rounding) */
		ptr_h1 = h;
		ptr_h2 = ptr_hf;

		for (i = k + (Shortword) 1; i < NB_POS; i++)
		{
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			*p1 = extract_h(cor);
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			*p0 = extract_h(cor);
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;

			p1 -= (NB_POS + 1);
			p0 -= (NB_POS + 1);
		}
		cor = L_mac(cor, *ptr_h1, *ptr_h2);
		ptr_h1++;
		ptr_h2++;
		*p1 = extract_h(cor);
		cor = L_mac(cor, *ptr_h1, *ptr_h2);
		ptr_h1++;
		ptr_h2++;
		cor = L_mac(cor, *ptr_h1, *ptr_h2);
		ptr_h1++;
		ptr_h2++;
		*p0 = extract_h(cor);

		pos -= NB_POS;
		ptr_hf += STEP;
	}

	/* storage order --> i1i2, i0i1 */

	pos = MSIZE - 1;
	ptr_hf = h + 5;

	for (k = 0; k < NB_POS; k++)
	{
		p1 = &rrixiy[1][pos - 1];
		p0 = &rrixiy[0][pos - 1];

		cor = 0x00008000L;		/* 0.5 (for rounding) */
		ptr_h1 = h;
		ptr_h2 = ptr_hf;

		for (i = k + (Shortword) 1; i < NB_POS; i++)
		{
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			*p1 = extract_h(cor);
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			*p0 = extract_h(cor);
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;

			p1 -= (NB_POS + 1);
			p0 -= (NB_POS + 1);
		}

		pos--;
		ptr_hf += STEP;
	}

	/* storage order --> i0i2 */

	pos = MSIZE - 1;
	ptr_hf = h + 4;

	for (k = 0; k < NB_POS; k++)
	{
		p0 = &rrixiy[2][pos];

		cor = 0x00008000L;		/* 0.5 (for rounding) */
		ptr_h1 = h;
		ptr_h2 = ptr_hf;

		for (i = k + (Shortword) 1; i < NB_POS; i++)
		{
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			*p0 = extract_h(cor);
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;

			p0 -= (NB_POS + 1);
		}
		cor = L_mac(cor, *ptr_h1, *ptr_h2);
		ptr_h1++;
		ptr_h2++;
		*p0 = extract_h(cor);

		pos -= NB_POS;
		ptr_hf += STEP;
	}

	/* storage order --> i0i2 */

	pos = MSIZE - 1;
	ptr_hf = h + 3;

	for (k = 0; k < NB_POS; k++)
	{
		p0 = &rrixiy[2][pos - 1];

		cor = 0x00008000L;		/* 0.5 (for rounding) */
		ptr_h1 = h;
		ptr_h2 = ptr_hf;

		for (i = k + (Shortword) 1; i < NB_POS; i++)
		{
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			*p0 = extract_h(cor);
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;
			cor = L_mac(cor, *ptr_h1, *ptr_h2);
			ptr_h1++;
			ptr_h2++;

			p0 -= (NB_POS + 1);
		}

		pos--;
		ptr_hf += STEP;
	}

 /*-------------------------------------------------------------------*
  *                 SEARCH THE BEST CODEVECTOR.                       *
  *                                                                   *
  * complexity: 8x8x8 = 512 tests                                     *
  *-------------------------------------------------------------------*/

	/* default value */
	psk = -1;
	alpk = 1;
	codvec[0] = 0;
	codvec[1] = 2;
	codvec[2] = 4;

	p0 = rrixix[0];
	p2 = rrixiy[0];
	p4 = rrixiy[2];

	for (i0 = 0; i0 < L_SUBFR; i0 += STEP)
	{
		ps0 = dn[i0];
		alp0 = *p0++;

		p1 = rrixix[1];
		p5 = rrixiy[1];

		for (i = 0; i < NB_POS; i++)
			cor_l2[i] = add(rrixix[2][i], *p4++);

		for (i1 = 2; i1 < L_SUBFR; i1 += STEP)
		{
			ps1 = sub(ps0, dn[i1]);
			/* alp1 = alp0 + rr[i1][i1] - 2.0 * rr[i0][i1]; */
			alp1 = add(alp0, sub(*p1++, *p2++));

			p3 = cor_l2;

			for (i2 = 4; i2 < L_SUBFR; i2 += STEP)
			{
				ps2 = add(ps1, dn[i2]);
				/* alp2 = alp1 + rr[i2][i2] + 2.0 * (rr[i0][i2] - rr[i1][i2]); */
				alp2 = add(alp1, sub(*p3++, *p5++));

				ps2 = mult(ps2, ps2);
				s = L_msu(L_mult(alpk, ps2), psk, alp2);

				if (s > 0)
				{
					psk = ps2;
					alpk = alp2;
					codvec[0] = i0;
					codvec[1] = i1;
					codvec[2] = i2;
				}
			}
		}
	}

 /*-------------------------------------------------------------------*
  * Build the codeword, the filtered codeword and index of codevector.*
  *-------------------------------------------------------------------*/

	ps2 = sub(add(dn[codvec[0]], dn[codvec[2]]), dn[codvec[1]]);

	for (i = 0; i < l_subfr; i++)
	{
		code[i] = 0;
	}

	if (ps2 < 0)
		index = 1;				/* global sign */
	else
		index = 0;

	for (k = 0; k < NB_PULSE; k++)
	{
		i = codvec[k];			/* read pulse position */

		pos = mult(i, Q15_1_7);	/* pos = position/7 */
		index = add(shl(index, 3), pos);

		if (((k != 1) && (ps2 >= 0)) || ((k == 1) && (ps2 < 0)))
		{
			if (i < l_subfr)
				code[i] = 4096;	/* codeword in Q12  format */
			codvec[k] += (2 * L_SUBFR);
		}
		else
		{
			if (i < l_subfr)
				code[i] = -4096;	/* codeword in Q12  format */
		}
	}

	for (i = 0; i < l_subfr; i++)
	{
		h[i] = H[i];
		h_inv[i] = negate(h[i]);
	}

	p0 = h_inv - codvec[0];
	p1 = h_inv - codvec[1];
	p2 = h_inv - codvec[2];

	for (i = 0; i < l_subfr; i++)
	{
		s = L_mult(*p0++, 8192);	/* Q12 --> Q10 */
		s = L_mac(s, *p1++, 8192);
		s = L_mac(s, *p2++, 8192);
		y[i] = round32(s);
	}

	*indx = index;

	return;
}