/*
 * 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: /cvsroot/speak-freely-w/speak_freely/gsm/code.c,v 1.1.1.1 2003/02/04 22:31:16 johnwalker Exp $ */

#include        "config.h"


#ifdef	HAS_STDLIB_H
#include		<stdlib.h>
#else
#       include "proto.h"
		extern char 	* memcpy P((char *, char *, int));
#endif

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

/* 
 *	4.2 FIXED POINT IMPLEMENTATION OF THE RPE-LTP CODER 
 */

void Gsm_Coder P8((S,s,LARc,Nc,bc,Mc,xmaxc,xMc),

		struct gsm_state		* S,

		word	* s,	/* [0..159] samples 					IN		*/

/*
 * The RPE-LTD coder works on a frame by frame basis.  The length of
 * the frame is equal to 160 samples.  Some computations are done
 * once per frame to produce at the output of the coder the
 * LARc[1..8] parameters which are the coded LAR coefficients and 
 * also to realize the inverse filtering operation for the entire
 * frame (160 samples of signal d[0..159]).  These parts produce at
 * the output of the coder:
 */

		word	* LARc, /* [0..7] LAR coefficients				OUT 	*/

/*
 * Procedure 4.2.11 to 4.2.18 are to be executed four times per
 * frame.  That means once for each sub-segment RPE-LTP analysis of
 * 40 samples.	These parts produce at the output of the coder:
 */

		word	* Nc,	/* [0..3] LTP lag						OUT 	*/
		word	* bc,	/* [0..3] coded LTP gain				OUT 	*/
		word	* Mc,	/* [0..3] RPE grid selection			OUT 	*/
		word	* xmaxc,/* [0..3] Coded maximum amplitude		OUT 	*/
		word	* xMc	/* [13*4] normalized RPE samples		OUT 	*/
)
{
		int 	k;
		word	* dp  = S->dp0 + 120;	/* [ -120...-1 ] */
		word	* dpp = dp; 			/* [ 0...39 ]	 */

//		word			ep[40];
		static word 	e [50] = {0};

		word	so[160];

		Gsm_Preprocess					(S, s, so);
		Gsm_LPC_Analysis				(S, so, LARc);
		Gsm_Short_Term_Analysis_Filter	(S, LARc, so);

		for (k = 0; k <= 3; k++, xMc += 13) {

				Gsm_Long_Term_Predictor ( S,
										 so+k*40, /* d		[0..39] IN	*/
										 dp,	  /* dp  [-120..-1] IN	*/
										e + 5,	  /* e		[0..39] OUT */
										dpp,	  /* dpp	[0..39] OUT */
										 Nc++,
										 bc++);

				Gsm_RPE_Encoding		( S,
										e + 5,	/* e	  ][0..39][ IN/OUT */
										  xmaxc++, Mc++, xMc );
				/*
				 * Gsm_Update_of_reconstructed_short_time_residual_signal
				 *						( dpp, e + 5, dp );
				 */

				{ register int i;
				  register longword ltmp;
				  for (i = 0; i <= 39; i++)
						dp[ i ] = (word) (GSM_ADD( e[5 + i], dpp[i] ));
				}
				dp	+= 40;
				dpp += 40;

		}
		(void)memcpy( (char *)S->dp0, (char *)(S->dp0 + 160),
				120 * sizeof(*S->dp0) );
}
