/*  *    rematrix.c * *	Copyright (C) Aaron Holtzman - July 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 "rematrix.h"struct rematrix_band_s{	uint_32 start;	uint_32 end;};struct rematrix_band_s rematrix_band[] = { {13,24}, {25,36}, {37 ,60}, {61,252}};static inline uint_32 min(uint_32 a,uint_32 b);static inline uint_32min(uint_32 a,uint_32 b){	return (a < b ? a : b);}/* This routine simply does stereo rematixing for the 2 channel  * stereo mode */void rematrix(audblk_t *audblk, stream_coeffs_t *coeffs){	uint_32 num_bands;	uint_32 start;	uint_32 end;	uint_32 i,j;	float left,right;	if(audblk->cplinu || audblk->cplbegf > 2)		num_bands = 4;	else if (audblk->cplbegf > 0)		num_bands = 3;	else		num_bands = 2;	for(i=0;i < num_bands; i++)	{		if(!audblk->rematflg[i])			continue;		start = rematrix_band[i].start;		end = min(rematrix_band[i].end ,12 * audblk->cplbegf + 36);			for(j=start;j < end; j++)		{			left  = 0.5 * (coeffs->fbw[0][j] + coeffs->fbw[1][j]);			right = 0.5 * (coeffs->fbw[0][j] - coeffs->fbw[1][j]);			coeffs->fbw[0][j] = left;			coeffs->fbw[1][j] = right;		}	}}