/*  *    exponent.c * *	Copyright (C) Aaron Holtzman - May 1999 * *  This file is part of ac3dec, a free Dolby AC-3 stream decoder. *	 *  ac3dec is free software; you can redistribute it and/or modify *  it under the terms of the GNU General Public License as published by *  the Free Software Foundation; either version 2, or (at your option) *  any later version. *    *  ac3dec is distributed in the hope that it will be useful, *  but WITHOUT ANY WARRANTY; without even the implied warranty of *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the *  GNU General Public License for more details. *    *  You should have received a copy of the GNU General Public License *  along with GNU Make; see the file COPYING.  If not, write to *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  * */#include <stdlib.h>#include <stdio.h>#include "ac3.h"#include "decode.h"#include "exponent.h"static void exp_unpack_ch(uint_16 type,uint_16 expstr,uint_16 ngrps,uint_16 initial_exp, 		uint_16 exps[], uint_16 *dest);voidexponent_unpack( bsi_t *bsi, audblk_t *audblk, stream_coeffs_t *coeffs){	uint_16 i;	for(i=0; i< bsi->nfchans; i++)		exp_unpack_ch(UNPACK_FBW, audblk->chexpstr[i], audblk->nchgrps[i], audblk->exps[i][0], 				&audblk->exps[i][1], audblk->fbw_exp[i]);	if(audblk->cplinu)		exp_unpack_ch(UNPACK_CPL, audblk->cplexpstr, audblk->ncplgrps, audblk->cplabsexp << 1,					audblk->cplexps, &audblk->cpl_exp[audblk->cplstrtmant]);	if(bsi->lfeon)		exp_unpack_ch(UNPACK_LFE, audblk->lfeexpstr, 2, audblk->lfeexps[0], 				&audblk->lfeexps[1], audblk->lfe_exp);}static voidexp_unpack_ch(uint_16 type,uint_16 expstr,uint_16 ngrps,uint_16 initial_exp, 		uint_16 exps[], uint_16 *dest){	uint_16 i,j;	sint_16 exp_acc;	sint_16 exp_1,exp_2,exp_3;	if(expstr == EXP_REUSE)		return;	/* Handle the initial absolute exponent */	exp_acc = initial_exp;	j = 0;	/* In the case of a fbw channel then the initial absolute values is 	 * also an exponent */	if(type != UNPACK_CPL)		dest[j++] = exp_acc;	/* Loop through the groups and fill the dest array appropriately */	for(i=0; i< ngrps; i++)	{		if(exps[i] > 124)		{			//FIXME set an error flag and mute the frame			printf("\n!! Invalid exponent !!\n");			exit(1);		}		exp_1 = exps[i] / 25;		exp_2 = (exps[i] - (exp_1 * 25)) / 5;		exp_3 = exps[i] - (exp_1 * 25) - (exp_2 * 5) ;		exp_acc += (exp_1 - 2);		switch(expstr)		{			case EXP_D45:				dest[j++] = exp_acc;				dest[j++] = exp_acc;			case EXP_D25:				dest[j++] = exp_acc;			case EXP_D15:				dest[j++] = exp_acc;		}		exp_acc += (exp_2 - 2);		switch(expstr)		{			case EXP_D45:				dest[j++] = exp_acc;				dest[j++] = exp_acc;			case EXP_D25:				dest[j++] = exp_acc;			case EXP_D15:				dest[j++] = exp_acc;		}		exp_acc += (exp_3 - 2);		switch(expstr)		{			case EXP_D45:				dest[j++] = exp_acc;				dest[j++] = exp_acc;			case EXP_D25:				dest[j++] = exp_acc;			case EXP_D15:				dest[j++] = exp_acc;		}	}	}