/* * Common code between AC3 encoder and decoder * Copyright (c) 2000, 2001, 2002 Fabrice Bellard. * * This file is part of FFmpeg. * * FFmpeg 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 2.1 of the License, or (at your option) any later version. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file ac3.h * Common code between AC3 encoder and decoder. */ #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; #if 0 extern const uint16_t ac3_freqs[3]; extern const uint16_t ac3_bitratetab[19]; extern const int16_t ac3_window[256]; extern const uint8_t sdecaytab[4]; extern const uint8_t fdecaytab[4]; extern const uint16_t sgaintab[4]; extern const uint16_t dbkneetab[4]; extern const uint16_t floortab[8]; extern const uint16_t fgaintab[8]; #endif void ac3_common_init(void); void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, uint8_t *bap, int8_t *exp, int start, int end, int snroffset, int fgain, int is_lfe, int deltbae,int deltnseg, uint8_t *deltoffst, uint8_t *deltlen, uint8_t *deltba);