/* * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische * Universitaet Berlin.  See the accompanying file "COPYRIGHT" for * details.  THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. *//* $Header: /home/kbs/jutta/src/gsm/gsm-1.0/src/RCS/long_term.c,v 1.6 1996/07/02 12:33:19 jutta Exp $ */#include <stdio.h>#include <assert.h>#include "private.h"#include "gsm.h"#include "proto.h"/* *  4.2.11 .. 4.2.12 LONG TERM PREDICTOR (LTP) SECTION *//* * This module computes the LTP gain (bc) and the LTP lag (Nc) * for the long term analysis filter.   This is done by calculating a * maximum of the cross-correlation function between the current * sub-segment short term residual signal d[0..39] (output of * the short term analysis filter; for simplification the index * of this array begins at 0 and ends at 39 for each sub-segment of the * RPE-LTP analysis) and the previous reconstructed short term * residual signal dp[ -120 .. -1 ].  A dynamic scaling must be * performed to avoid overflow. */ /* The next procedure exists in six versions.  First two integer  * version (if USE_FLOAT_MUL is not defined); then four floating  * point versions, twice with proper scaling (USE_FLOAT_MUL defined),  * once without (USE_FLOAT_MUL and FAST defined, and fast run-time  * option used).  Every pair has first a Cut version (see the -C  * option to toast or the LTP_CUT option to gsm_option()), then the  * uncut one.  (For a detailed explanation of why this is altogether  * a bad idea, see Henry Spencer and Geoff Collyer, ``#ifdef Considered  * Harmful''.)  */#ifndef  USE_FLOAT_MUL#ifdef	LTP_CUTstatic void Cut_Calculation_of_the_LTP_parameters P5((st, d,dp,bc_out,Nc_out),	struct gsm_state * st,	register word	* d,		/* [0..39]	IN	*/	register word	* dp,		/* [-120..-1]	IN	*/	word		* bc_out,	/* 		OUT	*/	word		* Nc_out	/* 		OUT	*/){	register int  	k, lambda;	word		Nc, bc;	word		wt[40];	longword	L_result;	longword	L_max, L_power;	word		R, S, dmax, scal, best_k;	word		ltp_cut;	register word	temp, wt_k;	/*  Search of the optimum scaling of d[0..39].	 */	dmax = 0;	for (k = 0; k <= 39; k++) {		temp = d[k];		temp = GSM_ABS( temp );		if (temp > dmax) {			dmax = temp;			best_k = k;		}	}	temp = 0;	if (dmax == 0) scal = 0;	else {		assert(dmax > 0);		temp = gsm_norm( (longword)dmax << 16 );	}	if (temp > 6) scal = 0;	else scal = 6 - temp;	assert(scal >= 0);	/* Search for the maximum cross-correlation and coding of the LTP lag	 */	L_max = 0;	Nc    = 40;	/* index for the maximum cross-correlation */	wt_k  = SASR(d[best_k], scal);	for (lambda = 40; lambda <= 120; lambda++) {		L_result = (longword)wt_k * dp[best_k - lambda];		if (L_result > L_max) {			Nc    = lambda;			L_max = L_result;		}	}	*Nc_out = Nc;	L_max <<= 1;	/*  Rescaling of L_max	 */	assert(scal <= 100 && scal >= -100);	L_max = L_max >> (6 - scal);	/* sub(6, scal) */	assert( Nc <= 120 && Nc >= 40);	/*   Compute the power of the reconstructed short term residual	 *   signal dp[..]	 */	L_power = 0;	for (k = 0; k <= 39; k++) {		register longword L_temp;		L_temp   = SASR( dp[k - Nc], 3 );		L_power += L_temp * L_temp;	}	L_power <<= 1;	/* from L_MULT */	/*  Normalization of L_max and L_power	 */	if (L_max <= 0)  {		*bc_out = 0;		return;	}	if (L_max >= L_power) {		*bc_out = 3;		return;	}	temp = gsm_norm( L_power );	R = SASR( L_max   << temp, 16 );	S = SASR( L_power << temp, 16 );	/*  Coding of the LTP gain	 */	/*  Table 4.3a must be used to obtain the level DLB[i] for the	 *  quantization of the LTP gain b to get the coded version bc.	 */	for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break;	*bc_out = bc;}#endif 	/* LTP_CUT */static void Calculation_of_the_LTP_parameters P4((d,dp,bc_out,Nc_out),	register word	* d,		/* [0..39]	IN	*/	register word	* dp,		/* [-120..-1]	IN	*/	word		* bc_out,	/* 		OUT	*/	word		* Nc_out	/* 		OUT	*/){	register int  	k, lambda;	word		Nc, bc;	word		wt[40];	longword	L_max, L_power;	word		R, S, dmax, scal;	register word	temp;	/*  Search of the optimum scaling of d[0..39].	 */	dmax = 0;	for (k = 0; k <= 39; k++) {		temp = d[k];		temp = GSM_ABS( temp );		if (temp > dmax) dmax = temp;	}	temp = 0;	if (dmax == 0) scal = 0;	else {		assert(dmax > 0);		temp = gsm_norm( (longword)dmax << 16 );	}	if (temp > 6) scal = 0;	else scal = 6 - temp;	assert(scal >= 0);	/*  Initialization of a working array wt	 */	for (k = 0; k <= 39; k++) wt[k] = SASR( d[k], scal );	/* Search for the maximum cross-correlation and coding of the LTP lag	 */	L_max = 0;	Nc    = 40;	/* index for the maximum cross-correlation */	for (lambda = 40; lambda <= 120; lambda++) {# undef STEP#		define STEP(k) 	(longword)wt[k] * dp[k - lambda]		register longword L_result;		L_result  = STEP(0)  ; L_result += STEP(1) ;		L_result += STEP(2)  ; L_result += STEP(3) ;		L_result += STEP(4)  ; L_result += STEP(5)  ;		L_result += STEP(6)  ; L_result += STEP(7)  ;		L_result += STEP(8)  ; L_result += STEP(9)  ;		L_result += STEP(10) ; L_result += STEP(11) ;		L_result += STEP(12) ; L_result += STEP(13) ;		L_result += STEP(14) ; L_result += STEP(15) ;		L_result += STEP(16) ; L_result += STEP(17) ;		L_result += STEP(18) ; L_result += STEP(19) ;		L_result += STEP(20) ; L_result += STEP(21) ;		L_result += STEP(22) ; L_result += STEP(23) ;		L_result += STEP(24) ; L_result += STEP(25) ;		L_result += STEP(26) ; L_result += STEP(27) ;		L_result += STEP(28) ; L_result += STEP(29) ;		L_result += STEP(30) ; L_result += STEP(31) ;		L_result += STEP(32) ; L_result += STEP(33) ;		L_result += STEP(34) ; L_result += STEP(35) ;		L_result += STEP(36) ; L_result += STEP(37) ;		L_result += STEP(38) ; L_result += STEP(39) ;		if (L_result > L_max) {			Nc    = lambda;			L_max = L_result;		}	}	*Nc_out = Nc;	L_max <<= 1;	/*  Rescaling of L_max	 */	assert(scal <= 100 && scal >=  -100);	L_max = L_max >> (6 - scal);	/* sub(6, scal) */	assert( Nc <= 120 && Nc >= 40);	/*   Compute the power of the reconstructed short term residual	 *   signal dp[..]	 */	L_power = 0;	for (k = 0; k <= 39; k++) {		register longword L_temp;		L_temp   = SASR( dp[k - Nc], 3 );		L_power += L_temp * L_temp;	}	L_power <<= 1;	/* from L_MULT */	/*  Normalization of L_max and L_power	 */	if (L_max <= 0)  {		*bc_out = 0;		return;	}	if (L_max >= L_power) {		*bc_out = 3;		return;	}	temp = gsm_norm( L_power );	R = SASR( L_max   << temp, 16 );	S = SASR( L_power << temp, 16 );	/*  Coding of the LTP gain	 */	/*  Table 4.3a must be used to obtain the level DLB[i] for the	 *  quantization of the LTP gain b to get the coded version bc.	 */	for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break;	*bc_out = bc;}#else	/* USE_FLOAT_MUL */#ifdef	LTP_CUTstatic void Cut_Calculation_of_the_LTP_parameters P5((st, d,dp,bc_out,Nc_out),	struct gsm_state * st,		/*              IN 	*/	register word	* d,		/* [0..39]	IN	*/	register word	* dp,		/* [-120..-1]	IN	*/	word		* bc_out,	/* 		OUT	*/	word		* Nc_out	/* 		OUT	*/){	register int  	k, lambda;	word		Nc, bc;	word		ltp_cut;	float		wt_float[40];	float		dp_float_base[120], * dp_float = dp_float_base + 120;	longword	L_max, L_power;	word		R, S, dmax, scal;	register word	temp;	/*  Search of the optimum scaling of d[0..39].	 */	dmax = 0;	for (k = 0; k <= 39; k++) {		temp = d[k];		temp = GSM_ABS( temp );		if (temp > dmax) dmax = temp;	}	temp = 0;	if (dmax == 0) scal = 0;	else {		assert(dmax > 0);		temp = gsm_norm( (longword)dmax << 16 );	}	if (temp > 6) scal = 0;	else scal = 6 - temp;	assert(scal >= 0);	ltp_cut = (longword)SASR(dmax, scal) * st->ltp_cut / 100; 	/*  Initialization of a working array wt	 */	for (k = 0; k < 40; k++) {		register word w = SASR( d[k], scal );		if (w < 0 ? w > -ltp_cut : w < ltp_cut) {			wt_float[k] = 0.0;		}		else {			wt_float[k] =  w;		}	}	for (k = -120; k <  0; k++) dp_float[k] =  dp[k];	/* Search for the maximum cross-correlation and coding of the LTP lag	 */	L_max = 0;	Nc    = 40;	/* index for the maximum cross-correlation */	for (lambda = 40; lambda <= 120; lambda += 9) {		/*  Calculate L_result for l = lambda .. lambda + 9.		 */		register float *lp = dp_float - lambda;		register float	W;		register float	a = lp[-8], b = lp[-7], c = lp[-6],				d = lp[-5], e = lp[-4], f = lp[-3],				g = lp[-2], h = lp[-1];		register float  E; 		register float  S0 = 0, S1 = 0, S2 = 0, S3 = 0, S4 = 0,				S5 = 0, S6 = 0, S7 = 0, S8 = 0;#		undef STEP#		define	STEP(K, a, b, c, d, e, f, g, h) \			if ((W = wt_float[K]) != 0.0) {	\			E = W * a; S8 += E;		\			E = W * b; S7 += E;		\			E = W * c; S6 += E;		\			E = W * d; S5 += E;		\			E = W * e; S4 += E;		\			E = W * f; S3 += E;		\			E = W * g; S2 += E;		\			E = W * h; S1 += E;		\			a  = lp[K];			\			E = W * a; S0 += E; } else (a = lp[K])#		define	STEP_A(K)	STEP(K, a, b, c, d, e, f, g, h)#		define	STEP_B(K)	STEP(K, b, c, d, e, f, g, h, a)#		define	STEP_C(K)	STEP(K, c, d, e, f, g, h, a, b)#		define	STEP_D(K)	STEP(K, d, e, f, g, h, a, b, c)#		define	STEP_E(K)	STEP(K, e, f, g, h, a, b, c, d)#		define	STEP_F(K)	STEP(K, f, g, h, a, b, c, d, e)#		define	STEP_G(K)	STEP(K, g, h, a, b, c, d, e, f)#		define	STEP_H(K)	STEP(K, h, a, b, c, d, e, f, g)		STEP_A( 0); STEP_B( 1); STEP_C( 2); STEP_D( 3);		STEP_E( 4); STEP_F( 5); STEP_G( 6); STEP_H( 7);		STEP_A( 8); STEP_B( 9); STEP_C(10); STEP_D(11);		STEP_E(12); STEP_F(13); STEP_G(14); STEP_H(15);		STEP_A(16); STEP_B(17); STEP_C(18); STEP_D(19);		STEP_E(20); STEP_F(21); STEP_G(22); STEP_H(23);		STEP_A(24); STEP_B(25); STEP_C(26); STEP_D(27);		STEP_E(28); STEP_F(29); STEP_G(30); STEP_H(31);		STEP_A(32); STEP_B(33); STEP_C(34); STEP_D(35);		STEP_E(36); STEP_F(37); STEP_G(38); STEP_H(39);		if (S0 > L_max) { L_max = S0; Nc = lambda;     }		if (S1 > L_max) { L_max = S1; Nc = lambda + 1; }		if (S2 > L_max) { L_max = S2; Nc = lambda + 2; }		if (S3 > L_max) { L_max = S3; Nc = lambda + 3; }		if (S4 > L_max) { L_max = S4; Nc = lambda + 4; }		if (S5 > L_max) { L_max = S5; Nc = lambda + 5; }		if (S6 > L_max) { L_max = S6; Nc = lambda + 6; }		if (S7 > L_max) { L_max = S7; Nc = lambda + 7; }		if (S8 > L_max) { L_max = S8; Nc = lambda + 8; }	}	*Nc_out = Nc;	L_max <<= 1;	/*  Rescaling of L_max	 */	assert(scal <= 100 && scal >=  -100);	L_max = L_max >> (6 - scal);	/* sub(6, scal) */	assert( Nc <= 120 && Nc >= 40);	/*   Compute the power of the reconstructed short term residual	 *   signal dp[..]	 */	L_power = 0;	for (k = 0; k <= 39; k++) {		register longword L_temp;		L_temp   = SASR( dp[k - Nc], 3 );		L_power += L_temp * L_temp;	}	L_power <<= 1;	/* from L_MULT */	/*  Normalization of L_max and L_power	 */	if (L_max <= 0)  {		*bc_out = 0;		return;	}	if (L_max >= L_power) {		*bc_out = 3;		return;	}	temp = gsm_norm( L_power );	R = SASR( L_max   << temp, 16 );	S = SASR( L_power << temp, 16 );	/*  Coding of the LTP gain	 */	/*  Table 4.3a must be used to obtain the level DLB[i] for the	 *  quantization of the LTP gain b to get the coded version bc.	 */	for (bc = 0; bc <= 2; bc++) if (R <= gsm_mult(S, gsm_DLB[bc])) break;	*bc_out = bc;}#endif /* LTP_CUT */static void Calculation_of_the_LTP_parameters P4((d,dp,bc_out,Nc_out),	register word	* d,		/* [0..39]	IN	*/	register word	* dp,		/* [-120..-1]	IN	*/	word		* bc_out,	/* 		OUT	*/	word		* Nc_out	/* 		OUT	*/