/* * Common code between AC3 encoder and decoder * Copyright (c) 2000, 2001, 2002 Fabrice Bellard. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #define AC3_MAX_CODED_FRAME_SIZE 3840 /* in bytes */ #define AC3_MAX_CHANNELS 6 /* including LFE channel */ #define NB_BLOCKS 6 /* number of PCM blocks inside an AC3 frame */ #define AC3_FRAME_SIZE (NB_BLOCKS * 256) /* exponent encoding strategy */ #define EXP_REUSE 0 #define EXP_NEW 1 #define EXP_D15 1 #define EXP_D25 2 #define EXP_D45 3 typedef struct AC3BitAllocParameters { int fscod; /* frequency */ int halfratecod; int sgain, sdecay, fdecay, dbknee, floor; int cplfleak, cplsleak; } AC3BitAllocParameters; extern const UINT16 ac3_freqs[3]; extern const UINT16 ac3_bitratetab[19]; extern const INT16 ac3_window[256]; extern const UINT8 sdecaytab[4]; extern const UINT8 fdecaytab[4]; extern const UINT16 sgaintab[4]; extern const UINT16 dbkneetab[4]; extern const UINT16 floortab[8]; extern const UINT16 fgaintab[8]; void ac3_common_init(void); void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, UINT8 *bap, INT8 *exp, int start, int end, int snroffset, int fgain, int is_lfe, int deltbae,int deltnseg, UINT8 *deltoffst, UINT8 *deltlen, UINT8 *deltba);