src/short_term.c - platform/external/libgsm - Git at Google

 /*
  * 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: /tmp_amd/presto/export/kbs/jutta/src/gsm/RCS/short_term.c,v 1.2 1994/05/10 20:18:47 jutta Exp $ */

 #include <stdio.h>
 #include <assert.h>

 #include "private.h"

 #include "gsm.h"
 #include "proto.h"

 /*
  *  SHORT TERM ANALYSIS FILTERING SECTION
  */

 /* 4.2.8 */

 static void Decoding_of_the_coded_Log_Area_Ratios P2((LARc,LARpp),
 	word 	* LARc,		/* coded log area ratio	[0..7] 	IN	*/
 	word	* LARpp)	/* out: decoded ..			*/
 {
 	register word	temp1 /* , temp2 */;
 	register long	ltmp;	/* for GSM_ADD */

 	/*  This procedure requires for efficient implementation
 	 *  two tables.
  	 *
 	 *  INVA[1..8] = integer( (32768 * 8) / real_A[1..8])
 	 *  MIC[1..8]  = minimum value of the LARc[1..8]
 	 */

 	/*  Compute the LARpp[1..8]
 	 */

 	/* 	for (i = 1; i <= 8; i++, B++, MIC++, INVA++, LARc++, LARpp++) {
 	 *
 	 *		temp1  = GSM_ADD( *LARc, *MIC ) << 10;
 	 *		temp2  = *B << 1;
 	 *		temp1  = GSM_SUB( temp1, temp2 );
 	 *
 	 *		assert(*INVA != MIN_WORD);
 	 *
 	 *		temp1  = GSM_MULT_R( *INVA, temp1 );
 	 *		*LARpp = GSM_ADD( temp1, temp1 );
 	 *	}
 	 */

 #undef	STEP
 #define	STEP( B_TIMES_TWO, MIC, INVA )	\
 		temp1    = GSM_ADD( *LARc++, MIC ) << 10;	\
 		temp1    = GSM_SUB( temp1, B_TIMES_TWO );	\
 		temp1    = GSM_MULT_R( INVA, temp1 );		\
 		*LARpp++ = GSM_ADD( temp1, temp1 );

 	STEP(      0,  -32,  13107 );
 	STEP(      0,  -32,  13107 );
 	STEP(   4096,  -16,  13107 );
 	STEP(  -5120,  -16,  13107 );

 	STEP(    188,   -8,  19223 );
 	STEP(  -3584,   -8,  17476 );
 	STEP(   -682,   -4,  31454 );
 	STEP(  -2288,   -4,  29708 );

 	/* NOTE: the addition of *MIC is used to restore
 	 * 	 the sign of *LARc.
 	 */
 }

 /* 4.2.9 */
 /* Computation of the quantized reflection coefficients
  */

 /* 4.2.9.1  Interpolation of the LARpp[1..8] to get the LARp[1..8]
  */

 /*
  *  Within each frame of 160 analyzed speech samples the short term
  *  analysis and synthesis filters operate with four different sets of
  *  coefficients, derived from the previous set of decoded LARs(LARpp(j-1))
  *  and the actual set of decoded LARs (LARpp(j))
  *
  * (Initial value: LARpp(j-1)[1..8] = 0.)
  */

 static void Coefficients_0_12 P3((LARpp_j_1, LARpp_j, LARp),
 	register word * LARpp_j_1,
 	register word * LARpp_j,
 	register word * LARp)
 {
 	register int 	i;
 	register longword ltmp;

 	for (i = 1; i <= 8; i++, LARp++, LARpp_j_1++, LARpp_j++) {
 		*LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 ));
 		*LARp = GSM_ADD( *LARp,  SASR( *LARpp_j_1, 1));
 	}
 }

 static void Coefficients_13_26 P3((LARpp_j_1, LARpp_j, LARp),
 	register word * LARpp_j_1,
 	register word * LARpp_j,
 	register word * LARp)
 {
 	register int i;
 	register longword ltmp;
 	for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) {
 		*LARp = GSM_ADD( SASR( *LARpp_j_1, 1), SASR( *LARpp_j, 1 ));
 	}
 }

 static void Coefficients_27_39 P3((LARpp_j_1, LARpp_j, LARp),
 	register word * LARpp_j_1,
 	register word * LARpp_j,
 	register word * LARp)
 {
 	register int i;
 	register longword ltmp;

 	for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) {
 		*LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 ));
 		*LARp = GSM_ADD( *LARp, SASR( *LARpp_j, 1 ));
 	}
 }


 static void Coefficients_40_159 P2((LARpp_j, LARp),
 	register word * LARpp_j,
 	register word * LARp)
 {
 	register int i;

 	for (i = 1; i <= 8; i++, LARp++, LARpp_j++)
 		*LARp = *LARpp_j;
 }

 /* 4.2.9.2 */

 static void LARp_to_rp P1((LARp),
 	register word * LARp)	/* [0..7] IN/OUT  */
 /*
  *  The input of this procedure is the interpolated LARp[0..7] array.
  *  The reflection coefficients, rp[i], are used in the analysis
  *  filter and in the synthesis filter.
  */
 {
 	register int 		i;
 	register word		temp;
 	register longword	ltmp;

 	for (i = 1; i <= 8; i++, LARp++) {

 		/* temp = GSM_ABS( *LARp );
 	         *
 		 * if (temp < 11059) temp <<= 1;
 		 * else if (temp < 20070) temp += 11059;
 		 * else temp = GSM_ADD( temp >> 2, 26112 );
 		 *
 		 * *LARp = *LARp < 0 ? -temp : temp;
 		 */

 		if (*LARp < 0) {
 			temp = *LARp == MIN_WORD ? MAX_WORD : -(*LARp);
 			*LARp = - ((temp < 11059) ? temp << 1
 				: ((temp < 20070) ? temp + 11059
 				:  GSM_ADD( temp >> 2, 26112 )));
 		} else {
 			temp  = *LARp;
 			*LARp =    (temp < 11059) ? temp << 1
 				: ((temp < 20070) ? temp + 11059
 				:  GSM_ADD( temp >> 2, 26112 ));
 		}
 	}
 }


 /* 4.2.10 */
 static void Short_term_analysis_filtering P4((S,rp,k_n,s),
 	struct gsm_state * S,
 	register word	* rp,	/* [0..7]	IN	*/
 	register int 	k_n, 	/*   k_end - k_start	*/
 	register word	* s	/* [0..n-1]	IN/OUT	*/
 )
 /*
  *  This procedure computes the short term residual signal d[..] to be fed
  *  to the RPE-LTP loop from the s[..] signal and from the local rp[..]
  *  array (quantized reflection coefficients).  As the call of this
  *  procedure can be done in many ways (see the interpolation of the LAR
  *  coefficient), it is assumed that the computation begins with index
  *  k_start (for arrays d[..] and s[..]) and stops with index k_end
  *  (k_start and k_end are defined in 4.2.9.1).  This procedure also
  *  needs to keep the array u[0..7] in memory for each call.
  */
 {
 	register word		* u = S->u;
 	register int		i;
 	register word		di, zzz, ui, sav, rpi;
 	register longword 	ltmp;

 	for (; k_n--; s++) {

 		di = sav = *s;

 		for (i = 0; i < 8; i++) {		/* YYY */

 			ui    = u[i];
 			rpi   = rp[i];
 			u[i]  = sav;

 			zzz   = GSM_MULT_R(rpi, di);
 			sav   = GSM_ADD(   ui,  zzz);

 			zzz   = GSM_MULT_R(rpi, ui);
 			di    = GSM_ADD(   di,  zzz );
 		}

 		*s = di;
 	}
 }

 #if defined(USE_FLOAT_MUL) && defined(FAST)

 static void Fast_Short_term_analysis_filtering P4((S,rp,k_n,s),
 	struct gsm_state * S,
 	register word	* rp,	/* [0..7]	IN	*/
 	register int 	k_n, 	/*   k_end - k_start	*/
 	register word	* s	/* [0..n-1]	IN/OUT	*/
 )
 {
 	register word		* u = S->u;
 	register int		i;

 	float 	  uf[8],
 		 rpf[8];

 	register float scalef = 3.0517578125e-5;
 	register float		sav, di, temp;

 	for (i = 0; i < 8; ++i) {
 		uf[i]  = u[i];
 		rpf[i] = rp[i] * scalef;
 	}
 	for (; k_n--; s++) {
 		sav = di = *s;
 		for (i = 0; i < 8; ++i) {
 			register float rpfi = rpf[i];
 			register float ufi  = uf[i];

 			uf[i] = sav;
 			temp  = rpfi * di + ufi;
 			di   += rpfi * ufi;
 			sav   = temp;
 		}
 		*s = di;
 	}
 	for (i = 0; i < 8; ++i) u[i] = uf[i];
 }
 #endif /* ! (defined (USE_FLOAT_MUL) && defined (FAST)) */

 static void Short_term_synthesis_filtering P5((S,rrp,k,wt,sr),
 	struct gsm_state * S,
 	register word	* rrp,	/* [0..7]	IN	*/
 	register int	k,	/* k_end - k_start	*/
 	register word	* wt,	/* [0..k-1]	IN	*/
 	register word	* sr	/* [0..k-1]	OUT	*/
 )
 {
 	register word		* v = S->v;
 	register int		i;
 	register word		sri, tmp1, tmp2;
 	register longword	ltmp;	/* for GSM_ADD  & GSM_SUB */

 	while (k--) {
 		sri = *wt++;
 		for (i = 8; i--;) {

 			/* sri = GSM_SUB( sri, gsm_mult_r( rrp[i], v[i] ) );
 			 */
 			tmp1 = rrp[i];
 			tmp2 = v[i];
 			tmp2 =  ( tmp1 == MIN_WORD && tmp2 == MIN_WORD
 				? MAX_WORD
 				: 0x0FFFF & (( (longword)tmp1 * (longword)tmp2
 					     + 16384) >> 15)) ;

 			sri  = GSM_SUB( sri, tmp2 );

 			/* v[i+1] = GSM_ADD( v[i], gsm_mult_r( rrp[i], sri ) );
 			 */
 			tmp1  = ( tmp1 == MIN_WORD && sri == MIN_WORD
 				? MAX_WORD
 				: 0x0FFFF & (( (longword)tmp1 * (longword)sri
 					     + 16384) >> 15)) ;

 			v[i+1] = GSM_ADD( v[i], tmp1);
 		}
 		*sr++ = v[0] = sri;
 	}
 }


 #if defined(FAST) && defined(USE_FLOAT_MUL)

 static void Fast_Short_term_synthesis_filtering P5((S,rrp,k,wt,sr),
 	struct gsm_state * S,
 	register word	* rrp,	/* [0..7]	IN	*/
 	register int	k,	/* k_end - k_start	*/
 	register word	* wt,	/* [0..k-1]	IN	*/
 	register word	* sr	/* [0..k-1]	OUT	*/
 )
 {
 	register word		* v = S->v;
 	register int		i;

 	float va[9], rrpa[8];
 	register float scalef = 3.0517578125e-5, temp;

 	for (i = 0; i < 8; ++i) {
 		va[i]   = v[i];
 		rrpa[i] = (float)rrp[i] * scalef;
 	}
 	while (k--) {
 		register float sri = *wt++;
 		for (i = 8; i--;) {
 			sri -= rrpa[i] * va[i];
 			if     (sri < -32768.) sri = -32768.;
 			else if (sri > 32767.) sri =  32767.;

 			temp = va[i] + rrpa[i] * sri;
 			if     (temp < -32768.) temp = -32768.;
 			else if (temp > 32767.) temp =  32767.;
 			va[i+1] = temp;
 		}
 		*sr++ = va[0] = sri;
 	}
 	for (i = 0; i < 9; ++i) v[i] = va[i];
 }

 #endif /* defined(FAST) && defined(USE_FLOAT_MUL) */

 void Gsm_Short_Term_Analysis_Filter P3((S,LARc,s),

 	struct gsm_state * S,

 	word	* LARc,		/* coded log area ratio [0..7]  IN	*/
 	word	* s		/* signal [0..159]		IN/OUT	*/
 )
 {
 	word		* LARpp_j	= S->LARpp[ S->j      ];
 	word		* LARpp_j_1	= S->LARpp[ S->j ^= 1 ];

 	word		LARp[8];

 #undef	FILTER
 #if 	defined(FAST) && defined(USE_FLOAT_MUL)
 # 	define	FILTER 	(* (S->fast			\
 			   ? Fast_Short_term_analysis_filtering	\
 		    	   : Short_term_analysis_filtering	))

 #else
 # 	define	FILTER	Short_term_analysis_filtering
 #endif

 	Decoding_of_the_coded_Log_Area_Ratios( LARc, LARpp_j );

 	Coefficients_0_12(  LARpp_j_1, LARpp_j, LARp );
 	LARp_to_rp( LARp );
 	FILTER( S, LARp, 13, s);

 	Coefficients_13_26( LARpp_j_1, LARpp_j, LARp);
 	LARp_to_rp( LARp );
 	FILTER( S, LARp, 14, s + 13);

 	Coefficients_27_39( LARpp_j_1, LARpp_j, LARp);
 	LARp_to_rp( LARp );
 	FILTER( S, LARp, 13, s + 27);

 	Coefficients_40_159( LARpp_j, LARp);
 	LARp_to_rp( LARp );
 	FILTER( S, LARp, 120, s + 40);
 }

 void Gsm_Short_Term_Synthesis_Filter P4((S, LARcr, wt, s),
 	struct gsm_state * S,

 	word	* LARcr,	/* received log area ratios [0..7] IN  */
 	word	* wt,		/* received d [0..159]		   IN  */

 	word	* s		/* signal   s [0..159]		  OUT  */
 )
 {
 	word		* LARpp_j	= S->LARpp[ S->j     ];
 	word		* LARpp_j_1	= S->LARpp[ S->j ^=1 ];

 	word		LARp[8];

 #undef	FILTER
 #if 	defined(FAST) && defined(USE_FLOAT_MUL)

 # 	define	FILTER 	(* (S->fast			\
 			   ? Fast_Short_term_synthesis_filtering	\
 		    	   : Short_term_synthesis_filtering	))
 #else
 #	define	FILTER	Short_term_synthesis_filtering
 #endif

 	Decoding_of_the_coded_Log_Area_Ratios( LARcr, LARpp_j );

 	Coefficients_0_12( LARpp_j_1, LARpp_j, LARp );
 	LARp_to_rp( LARp );
 	FILTER( S, LARp, 13, wt, s );

 	Coefficients_13_26( LARpp_j_1, LARpp_j, LARp);
 	LARp_to_rp( LARp );
 	FILTER( S, LARp, 14, wt + 13, s + 13 );

 	Coefficients_27_39( LARpp_j_1, LARpp_j, LARp);
 	LARp_to_rp( LARp );
 	FILTER( S, LARp, 13, wt + 27, s + 27 );

 	Coefficients_40_159( LARpp_j, LARp );
 	LARp_to_rp( LARp );
 	FILTER(S, LARp, 120, wt + 40, s + 40);
 }
	/*
	* 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: /tmp_amd/presto/export/kbs/jutta/src/gsm/RCS/short_term.c,v 1.2 1994/05/10 20:18:47 jutta Exp $ */

	#include <stdio.h>
	#include <assert.h>

	#include "private.h"

	#include "gsm.h"
	#include "proto.h"

	/*
	* SHORT TERM ANALYSIS FILTERING SECTION
	*/

	/* 4.2.8 */

	static void Decoding_of_the_coded_Log_Area_Ratios P2((LARc,LARpp),
	word * LARc, /* coded log area ratio [0..7] IN */
	word * LARpp) /* out: decoded .. */
	{
	register word temp1 /* , temp2 */;
	register long ltmp; /* for GSM_ADD */

	/* This procedure requires for efficient implementation
	* two tables.
	*
	* INVA[1..8] = integer( (32768 * 8) / real_A[1..8])
	* MIC[1..8] = minimum value of the LARc[1..8]
	*/

	/* Compute the LARpp[1..8]
	*/

	/* for (i = 1; i <= 8; i++, B++, MIC++, INVA++, LARc++, LARpp++) {
	*
	* temp1 = GSM_ADD( LARc, MIC ) << 10;
	* temp2 = *B << 1;
	* temp1 = GSM_SUB( temp1, temp2 );
	*
	* assert(*INVA != MIN_WORD);
	*
	* temp1 = GSM_MULT_R( *INVA, temp1 );
	* *LARpp = GSM_ADD( temp1, temp1 );
	* }
	*/

	#undef STEP
	#define STEP( B_TIMES_TWO, MIC, INVA ) \
	temp1 = GSM_ADD( *LARc++, MIC ) << 10; \
	temp1 = GSM_SUB( temp1, B_TIMES_TWO ); \
	temp1 = GSM_MULT_R( INVA, temp1 ); \
	*LARpp++ = GSM_ADD( temp1, temp1 );

	STEP( 0, -32, 13107 );
	STEP( 0, -32, 13107 );
	STEP( 4096, -16, 13107 );
	STEP( -5120, -16, 13107 );

	STEP( 188, -8, 19223 );
	STEP( -3584, -8, 17476 );
	STEP( -682, -4, 31454 );
	STEP( -2288, -4, 29708 );

	/* NOTE: the addition of *MIC is used to restore
	* the sign of *LARc.
	*/
	}

	/* 4.2.9 */
	/* Computation of the quantized reflection coefficients
	*/

	/* 4.2.9.1 Interpolation of the LARpp[1..8] to get the LARp[1..8]
	*/

	/*
	* Within each frame of 160 analyzed speech samples the short term
	* analysis and synthesis filters operate with four different sets of
	* coefficients, derived from the previous set of decoded LARs(LARpp(j-1))
	* and the actual set of decoded LARs (LARpp(j))
	*
	* (Initial value: LARpp(j-1)[1..8] = 0.)
	*/

	static void Coefficients_0_12 P3((LARpp_j_1, LARpp_j, LARp),
	register word * LARpp_j_1,
	register word * LARpp_j,
	register word * LARp)
	{
	register int i;
	register longword ltmp;

	for (i = 1; i <= 8; i++, LARp++, LARpp_j_1++, LARpp_j++) {
	LARp = GSM_ADD( SASR( LARpp_j_1, 2 ), SASR( *LARpp_j, 2 ));
	LARp = GSM_ADD( LARp, SASR( *LARpp_j_1, 1));
	}
	}

	static void Coefficients_13_26 P3((LARpp_j_1, LARpp_j, LARp),
	register word * LARpp_j_1,
	register word * LARpp_j,
	register word * LARp)
	{
	register int i;
	register longword ltmp;
	for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) {
	LARp = GSM_ADD( SASR( LARpp_j_1, 1), SASR( *LARpp_j, 1 ));
	}
	}

	static void Coefficients_27_39 P3((LARpp_j_1, LARpp_j, LARp),
	register word * LARpp_j_1,
	register word * LARpp_j,
	register word * LARp)
	{
	register int i;
	register longword ltmp;

	for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) {
	LARp = GSM_ADD( SASR( LARpp_j_1, 2 ), SASR( *LARpp_j, 2 ));
	LARp = GSM_ADD( LARp, SASR( *LARpp_j, 1 ));
	}
	}


	static void Coefficients_40_159 P2((LARpp_j, LARp),
	register word * LARpp_j,
	register word * LARp)
	{
	register int i;

	for (i = 1; i <= 8; i++, LARp++, LARpp_j++)
	LARp = LARpp_j;
	}

	/* 4.2.9.2 */

	static void LARp_to_rp P1((LARp),
	register word * LARp) /* [0..7] IN/OUT */
	/*
	* The input of this procedure is the interpolated LARp[0..7] array.
	* The reflection coefficients, rp[i], are used in the analysis
	* filter and in the synthesis filter.
	*/
	{
	register int i;
	register word temp;
	register longword ltmp;

	for (i = 1; i <= 8; i++, LARp++) {

	/* temp = GSM_ABS( *LARp );
	*
	* if (temp < 11059) temp <<= 1;
	* else if (temp < 20070) temp += 11059;
	* else temp = GSM_ADD( temp >> 2, 26112 );
	*
	* LARp = LARp < 0 ? -temp : temp;
	*/

	if (*LARp < 0) {
	temp = LARp == MIN_WORD ? MAX_WORD : -(LARp);
	*LARp = - ((temp < 11059) ? temp << 1
	: ((temp < 20070) ? temp + 11059
	: GSM_ADD( temp >> 2, 26112 )));
	} else {
	temp = *LARp;
	*LARp = (temp < 11059) ? temp << 1
	: ((temp < 20070) ? temp + 11059
	: GSM_ADD( temp >> 2, 26112 ));
	}
	}
	}


	/* 4.2.10 */
	static void Short_term_analysis_filtering P4((S,rp,k_n,s),
	struct gsm_state * S,
	register word * rp, /* [0..7] IN */
	register int k_n, /* k_end - k_start */
	register word * s /* [0..n-1] IN/OUT */
	)
	/*
	* This procedure computes the short term residual signal d[..] to be fed
	* to the RPE-LTP loop from the s[..] signal and from the local rp[..]
	* array (quantized reflection coefficients). As the call of this
	* procedure can be done in many ways (see the interpolation of the LAR
	* coefficient), it is assumed that the computation begins with index
	* k_start (for arrays d[..] and s[..]) and stops with index k_end
	* (k_start and k_end are defined in 4.2.9.1). This procedure also
	* needs to keep the array u[0..7] in memory for each call.
	*/
	{
	register word * u = S->u;
	register int i;
	register word di, zzz, ui, sav, rpi;
	register longword ltmp;

	for (; k_n--; s++) {

	di = sav = *s;

	for (i = 0; i < 8; i++) { /* YYY */

	ui = u[i];
	rpi = rp[i];
	u[i] = sav;

	zzz = GSM_MULT_R(rpi, di);
	sav = GSM_ADD( ui, zzz);

	zzz = GSM_MULT_R(rpi, ui);
	di = GSM_ADD( di, zzz );
	}

	*s = di;
	}
	}

	#if defined(USE_FLOAT_MUL) && defined(FAST)

	static void Fast_Short_term_analysis_filtering P4((S,rp,k_n,s),
	struct gsm_state * S,
	register word * rp, /* [0..7] IN */
	register int k_n, /* k_end - k_start */
	register word * s /* [0..n-1] IN/OUT */
	)
	{
	register word * u = S->u;
	register int i;

	float uf[8],
	rpf[8];

	register float scalef = 3.0517578125e-5;
	register float sav, di, temp;

	for (i = 0; i < 8; ++i) {
	uf[i] = u[i];
	rpf[i] = rp[i] * scalef;
	}
	for (; k_n--; s++) {
	sav = di = *s;
	for (i = 0; i < 8; ++i) {
	register float rpfi = rpf[i];
	register float ufi = uf[i];

	uf[i] = sav;
	temp = rpfi * di + ufi;
	di += rpfi * ufi;
	sav = temp;
	}
	*s = di;
	}
	for (i = 0; i < 8; ++i) u[i] = uf[i];
	}
	#endif /* ! (defined (USE_FLOAT_MUL) && defined (FAST)) */

	static void Short_term_synthesis_filtering P5((S,rrp,k,wt,sr),
	struct gsm_state * S,
	register word * rrp, /* [0..7] IN */
	register int k, /* k_end - k_start */
	register word * wt, /* [0..k-1] IN */
	register word * sr /* [0..k-1] OUT */
	)
	{
	register word * v = S->v;
	register int i;
	register word sri, tmp1, tmp2;
	register longword ltmp; /* for GSM_ADD & GSM_SUB */

	while (k--) {
	sri = *wt++;
	for (i = 8; i--;) {

	/* sri = GSM_SUB( sri, gsm_mult_r( rrp[i], v[i] ) );
	*/
	tmp1 = rrp[i];
	tmp2 = v[i];
	tmp2 = ( tmp1 == MIN_WORD && tmp2 == MIN_WORD
	? MAX_WORD
	: 0x0FFFF & (( (longword)tmp1 * (longword)tmp2
	+ 16384) >> 15)) ;

	sri = GSM_SUB( sri, tmp2 );

	/* v[i+1] = GSM_ADD( v[i], gsm_mult_r( rrp[i], sri ) );
	*/
	tmp1 = ( tmp1 == MIN_WORD && sri == MIN_WORD
	? MAX_WORD
	: 0x0FFFF & (( (longword)tmp1 * (longword)sri
	+ 16384) >> 15)) ;

	v[i+1] = GSM_ADD( v[i], tmp1);
	}
	*sr++ = v[0] = sri;
	}
	}


	#if defined(FAST) && defined(USE_FLOAT_MUL)

	static void Fast_Short_term_synthesis_filtering P5((S,rrp,k,wt,sr),
	struct gsm_state * S,
	register word * rrp, /* [0..7] IN */
	register int k, /* k_end - k_start */
	register word * wt, /* [0..k-1] IN */
	register word * sr /* [0..k-1] OUT */
	)
	{
	register word * v = S->v;
	register int i;

	float va[9], rrpa[8];
	register float scalef = 3.0517578125e-5, temp;

	for (i = 0; i < 8; ++i) {
	va[i] = v[i];
	rrpa[i] = (float)rrp[i] * scalef;
	}
	while (k--) {
	register float sri = *wt++;
	for (i = 8; i--;) {
	sri -= rrpa[i] * va[i];
	if (sri < -32768.) sri = -32768.;
	else if (sri > 32767.) sri = 32767.;

	temp = va[i] + rrpa[i] * sri;
	if (temp < -32768.) temp = -32768.;
	else if (temp > 32767.) temp = 32767.;
	va[i+1] = temp;
	}
	*sr++ = va[0] = sri;
	}
	for (i = 0; i < 9; ++i) v[i] = va[i];
	}

	#endif /* defined(FAST) && defined(USE_FLOAT_MUL) */

	void Gsm_Short_Term_Analysis_Filter P3((S,LARc,s),

	struct gsm_state * S,

	word * LARc, /* coded log area ratio [0..7] IN */
	word * s /* signal [0..159] IN/OUT */
	)
	{
	word * LARpp_j = S->LARpp[ S->j ];
	word * LARpp_j_1 = S->LARpp[ S->j ^= 1 ];

	word LARp[8];

	#undef FILTER
	#if defined(FAST) && defined(USE_FLOAT_MUL)
	# define FILTER (* (S->fast \
	? Fast_Short_term_analysis_filtering \
	: Short_term_analysis_filtering ))

	#else
	# define FILTER Short_term_analysis_filtering
	#endif

	Decoding_of_the_coded_Log_Area_Ratios( LARc, LARpp_j );

	Coefficients_0_12( LARpp_j_1, LARpp_j, LARp );
	LARp_to_rp( LARp );
	FILTER( S, LARp, 13, s);

	Coefficients_13_26( LARpp_j_1, LARpp_j, LARp);
	LARp_to_rp( LARp );
	FILTER( S, LARp, 14, s + 13);

	Coefficients_27_39( LARpp_j_1, LARpp_j, LARp);
	LARp_to_rp( LARp );
	FILTER( S, LARp, 13, s + 27);

	Coefficients_40_159( LARpp_j, LARp);
	LARp_to_rp( LARp );
	FILTER( S, LARp, 120, s + 40);
	}

	void Gsm_Short_Term_Synthesis_Filter P4((S, LARcr, wt, s),
	struct gsm_state * S,

	word * LARcr, /* received log area ratios [0..7] IN */
	word * wt, /* received d [0..159] IN */

	word * s /* signal s [0..159] OUT */
	)
	{
	word * LARpp_j = S->LARpp[ S->j ];
	word * LARpp_j_1 = S->LARpp[ S->j ^=1 ];

	word LARp[8];

	#undef FILTER
	#if defined(FAST) && defined(USE_FLOAT_MUL)

	# define FILTER (* (S->fast \
	? Fast_Short_term_synthesis_filtering \
	: Short_term_synthesis_filtering ))
	#else
	# define FILTER Short_term_synthesis_filtering
	#endif

	Decoding_of_the_coded_Log_Area_Ratios( LARcr, LARpp_j );

	Coefficients_0_12( LARpp_j_1, LARpp_j, LARp );
	LARp_to_rp( LARp );
	FILTER( S, LARp, 13, wt, s );

	Coefficients_13_26( LARpp_j_1, LARpp_j, LARp);
	LARp_to_rp( LARp );
	FILTER( S, LARp, 14, wt + 13, s + 13 );

	Coefficients_27_39( LARpp_j_1, LARpp_j, LARp);
	LARp_to_rp( LARp );
	FILTER( S, LARp, 13, wt + 27, s + 27 );

	Coefficients_40_159( LARpp_j, LARp );
	LARp_to_rp( LARp );
	FILTER(S, LARp, 120, wt + 40, s + 40);
	}