/***************************************************************************** * ac3_decoder.c: core ac3 decoder ***************************************************************************** * Copyright (C) 1999, 2000 VideoLAN * $Id: ac3_decoder.c,v 1.28 2001/03/21 13:42:34 sam Exp $ * * Authors: Michel Kaempf <maxx@via.ecp.fr> * Michel Lespinasse <walken@zoy.org> * Aaron Holtzman <aholtzma@engr.uvic.ca> * * This program 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 of the License, or * (at your option) any later version. * * This program 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 this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. *****************************************************************************/ #include "defs.h" #include "int_types.h" #include "ac3_decoder.h" #include "ac3_internal.h" #include <stdio.h> void imdct_init (imdct_t * p_imdct); int ac3_init (ac3dec_t * p_ac3dec) { //p_ac3dec->bit_stream.buffer = 0; //p_ac3dec->bit_stream.i_available = 0; p_ac3dec->mantissa.lfsr_state = 1; /* dither_gen initialization */ imdct_init(&p_ac3dec->imdct); return 0; } int ac3_decode_frame (ac3dec_t * p_ac3dec, s16 * buffer) { int i; if (parse_bsi (p_ac3dec)) return 1; for (i = 0; i < 6; i++) { if (parse_audblk (p_ac3dec, i)) return 1; if (exponent_unpack (p_ac3dec)) return 1; bit_allocate (p_ac3dec); mantissa_unpack (p_ac3dec); if (p_ac3dec->bsi.acmod == 0x2) rematrix (p_ac3dec); imdct (p_ac3dec, buffer); // downmix (p_ac3dec, buffer); buffer += 2*256; } parse_auxdata (p_ac3dec); return 0; }