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109 lines
3.5 KiB
C
109 lines
3.5 KiB
C
/*
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* ac3.h
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*
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* Copyright (C) Aaron Holtzman - May 1999
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*
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* This file is part of ac3dec, a free Dolby AC-3 stream decoder.
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*
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* ac3dec is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* ac3dec is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU Make; see the file COPYING. If not, write to
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* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*
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*/
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typedef struct ac3_ba_s {
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uint16_t fsnroffst; // fine SNR offset
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uint16_t fgaincod; // fast gain
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uint16_t deltbae; // delta bit allocation exists
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int8_t deltba[50]; // per-band delta bit allocation
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} ac3_ba_t;
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typedef struct ac3_state_s {
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uint8_t fscod; // sample rate
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uint8_t halfrate; // halfrate factor
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uint8_t acmod; // coded channels
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float clev; // centre channel mix level
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float slev; // surround channels mix level
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uint8_t lfeon; // coded lfe channel
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int output; // type of output
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float level; // output level
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float bias; // output bias
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uint16_t cplinu; // coupling in use
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uint16_t chincpl[5]; // channel coupled
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uint16_t phsflginu; // phase flags in use (stereo only)
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uint16_t cplbndstrc[18]; // coupling band structure
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uint16_t cplstrtmant; // coupling channel start mantissa
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uint16_t cplendmant; // coupling channel end mantissa
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float cplco[5][18]; // coupling coordinates
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// derived information
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uint16_t cplstrtbnd; // coupling start band (for bit allocation)
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uint16_t ncplbnd; // number of coupling bands
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uint16_t rematflg[4]; // stereo rematrixing
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uint16_t endmant[5]; // channel end mantissa
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uint8_t cpl_exp[256]; // decoded coupling channel exponents
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uint8_t fbw_exp[5][256]; // decoded channel exponents
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uint8_t lfe_exp[7]; // decoded lfe channel exponents
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uint16_t sdcycod; // slow decay
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uint16_t fdcycod; // fast decay
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uint16_t sgaincod; // slow gain
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uint16_t dbpbcod; // dB per bit - encodes the dbknee value
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uint16_t floorcod; // masking floor
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uint16_t csnroffst; // coarse SNR offset
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ac3_ba_t cplba; // coupling bit allocation parameters
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ac3_ba_t ba[5]; // channel bit allocation parameters
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ac3_ba_t lfeba; // lfe bit allocation parameters
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uint16_t cplfleak; // coupling fast leak init
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uint16_t cplsleak; // coupling slow leak init
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// derived bit allocation information
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int8_t fbw_bap[5][256];
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int8_t cpl_bap[256];
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int8_t lfe_bap[7];
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} ac3_state_t;
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/* samples work structure */
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typedef float stream_samples_t[6][256];
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#define AC3_CHANNEL 0
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#define AC3_MONO 1
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#define AC3_STEREO 2
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#define AC3_3F 3
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#define AC3_2F1R 4
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#define AC3_3F1R 5
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#define AC3_2F2R 6
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#define AC3_3F2R 7
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#define AC3_CHANNEL1 8
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#define AC3_CHANNEL2 9
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#define AC3_DOLBY 10
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#define AC3_CHANNEL_MASK 15
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#define AC3_LFE 16
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#define AC3_ADJUST_LEVEL 32
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void ac3_init (void);
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int ac3_syncinfo (uint8_t * buf, int * flags,
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int * sample_rate, int * bit_rate);
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int ac3_frame (ac3_state_t * state, uint8_t * buf, int * flags,
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float * level, float bias);
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int ac3_block (ac3_state_t * state);
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