/*

 * 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, MIC, INVA )	\

		temp1    = GSM_ADD( *LARc++, MIC ) << 10;	\

		temp1    = GSM_SUB( temp1, B << 1 );		\

		temp1    = GSM_MULT_R( INVA, temp1 );		\

		*LARpp++ = GSM_ADD( temp1, temp1 );

	STEP(      0,  -32,  13107 );

	STEP(      0,  -32,  13107 );

	STEP(   2048,  -16,  13107 );

	STEP(  -2560,  -16,  13107 );

	STEP(     94,   -8,  19223 );

	STEP(  -1792,   -8,  17476 );

	STEP(   -341,   -4,  31454 );

	STEP(  -1144,   -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);

}