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vdr/ac3dec/ac3_internal.h

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2001-08-03 14:18:08 +02:00
/*
* ac3_internal.h
*
* Copyright (C) Aaron Holtzman - May 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.
*
*/
#ifndef __GNUC__
#define inline
#endif
/* Exponent strategy constants */
#define EXP_REUSE (0)
#define EXP_D15 (1)
#define EXP_D25 (2)
#define EXP_D45 (3)
/* Delta bit allocation constants */
#define DELTA_BIT_REUSE (0)
#define DELTA_BIT_NEW (1)
#define DELTA_BIT_NONE (2)
#define DELTA_BIT_RESERVED (3)
/* samples work structure */
typedef float stream_samples_t[6][256];
/* global config structure */
extern ac3_config_t ac3_config;
/* global error flag */
extern uint_32 error_flag;
/* Everything you wanted to know about band structure */
/*
* The entire frequency domain is represented by 256 real
* floating point fourier coefficients. Only the lower 253
* coefficients are actually utilized however. We use arrays
* of 256 to be efficient in some cases.
*
* The 5 full bandwidth channels (fbw) can have their higher
* frequencies coupled together. These coupled channels then
* share their high frequency components.
*
* This coupling band is broken up into 18 sub-bands starting
* at mantissa number 37. Each sub-band is 12 bins wide.
*
* There are 50 bit allocation sub-bands which cover the entire
* frequency range. The sub-bands are of non-uniform width, and
* approximate a 1/6 octave scale.
*/
/* The following structures are filled in by their corresponding parse_*
* functions. See http://www.atsc.org/Standards/A52/a_52.pdf for
* full details on each field. Indented fields are used to denote
* conditional fields.
*/
typedef struct syncinfo_s
{
uint_32 magic;
/* Sync word == 0x0B77 */
uint_16 syncword;
/* crc for the first 5/8 of the sync block */
/* uint_16 crc1; */
/* Stream Sampling Rate (kHz) 0 = 48, 1 = 44.1, 2 = 32, 3 = reserved */
uint_16 fscod;
/* Frame size code */
uint_16 frmsizecod;
/* Information not in the AC-3 bitstream, but derived */
/* Frame size in 16 bit words */
uint_16 frame_size;
/* Bit rate in kilobits */
uint_16 bit_rate;
/* sampling rate in hertz */
uint_32 sampling_rate;
} syncinfo_t;
typedef struct bsi_s
{
uint_32 magic;
/* Bit stream identification == 0x8 */
uint_16 bsid;
/* Bit stream mode */
uint_16 bsmod;
/* Audio coding mode */
uint_16 acmod;
/* If we're using the centre channel then */
/* centre mix level */
uint_16 cmixlev;
/* If we're using the surround channel then */
/* surround mix level */
uint_16 surmixlev;
/* If we're in 2/0 mode then */
/* Dolby surround mix level - NOT USED - */
uint_16 dsurmod;
/* Low frequency effects on */
uint_16 lfeon;
/* Dialogue Normalization level */
uint_16 dialnorm;
/* Compression exists */
uint_16 compre;
/* Compression level */
uint_16 compr;
/* Language code exists */
uint_16 langcode;
/* Language code */
uint_16 langcod;
/* Audio production info exists*/
uint_16 audprodie;
uint_16 mixlevel;
uint_16 roomtyp;
/* If we're in dual mono mode (acmod == 0) then extra stuff */
uint_16 dialnorm2;
uint_16 compr2e;
uint_16 compr2;
uint_16 langcod2e;
uint_16 langcod2;
uint_16 audprodi2e;
uint_16 mixlevel2;
uint_16 roomtyp2;
/* Copyright bit */
uint_16 copyrightb;
/* Original bit */
uint_16 origbs;
/* Timecode 1 exists */
uint_16 timecod1e;
/* Timecode 1 */
uint_16 timecod1;
/* Timecode 2 exists */
uint_16 timecod2e;
/* Timecode 2 */
uint_16 timecod2;
/* Additional bit stream info exists */
uint_16 addbsie;
/* Additional bit stream length - 1 (in bytes) */
uint_16 addbsil;
/* Additional bit stream information (max 64 bytes) */
uint_8 addbsi[64];
/* Information not in the AC-3 bitstream, but derived */
/* Number of channels (excluding LFE)
* Derived from acmod */
uint_16 nfchans;
} bsi_t;
/* more pain */
typedef struct audblk_s
{
uint_32 magic1;
/* block switch bit indexed by channel num */
uint_16 blksw[5];
/* dither enable bit indexed by channel num */
uint_16 dithflag[5];
/* dynamic range gain exists */
uint_16 dynrnge;
/* dynamic range gain */
uint_16 dynrng;
/* if acmod==0 then */
/* dynamic range 2 gain exists */
uint_16 dynrng2e;
/* dynamic range 2 gain */
uint_16 dynrng2;
/* coupling strategy exists */
uint_16 cplstre;
/* coupling in use */
uint_16 cplinu;
/* channel coupled */
uint_16 chincpl[5];
/* if acmod==2 then */
/* Phase flags in use */
uint_16 phsflginu;
/* coupling begin frequency code */
uint_16 cplbegf;
/* coupling end frequency code */
uint_16 cplendf;
/* coupling band structure bits */
uint_16 cplbndstrc[18];
/* Do coupling co-ords exist for this channel? */
uint_16 cplcoe[5];
/* Master coupling co-ordinate */
uint_16 mstrcplco[5];
/* Per coupling band coupling co-ordinates */
uint_16 cplcoexp[5][18];
uint_16 cplcomant[5][18];
/* Phase flags for dual mono */
uint_16 phsflg[18];
/* Is there a rematrixing strategy */
uint_16 rematstr;
/* Rematrixing bits */
uint_16 rematflg[4];
/* Coupling exponent strategy */
uint_16 cplexpstr;
/* Exponent strategy for full bandwidth channels */
uint_16 chexpstr[5];
/* Exponent strategy for lfe channel */
uint_16 lfeexpstr;
/* Channel bandwidth for independent channels */
uint_16 chbwcod[5];
/* The absolute coupling exponent */
uint_16 cplabsexp;
/* Coupling channel exponents (D15 mode gives 18 * 12 /3 encoded exponents */
uint_16 cplexps[18 * 12 / 3];
/* Sanity checking constant */
uint_32 magic2;
/* fbw channel exponents */
uint_16 exps[5][252 / 3];
/* channel gain range */
uint_16 gainrng[5];
/* low frequency exponents */
uint_16 lfeexps[3];
/* Bit allocation info */
uint_16 baie;
/* Slow decay code */
uint_16 sdcycod;
/* Fast decay code */
uint_16 fdcycod;
/* Slow gain code */
uint_16 sgaincod;
/* dB per bit code */
uint_16 dbpbcod;
/* masking floor code */
uint_16 floorcod;
/* SNR offset info */
uint_16 snroffste;
/* coarse SNR offset */
uint_16 csnroffst;
/* coupling fine SNR offset */
uint_16 cplfsnroffst;
/* coupling fast gain code */
uint_16 cplfgaincod;
/* fbw fine SNR offset */
uint_16 fsnroffst[5];
/* fbw fast gain code */
uint_16 fgaincod[5];
/* lfe fine SNR offset */
uint_16 lfefsnroffst;
/* lfe fast gain code */
uint_16 lfefgaincod;
/* Coupling leak info */
uint_16 cplleake;
/* coupling fast leak initialization */
uint_16 cplfleak;
/* coupling slow leak initialization */
uint_16 cplsleak;
/* delta bit allocation info */
uint_16 deltbaie;
/* coupling delta bit allocation exists */
uint_16 cpldeltbae;
/* fbw delta bit allocation exists */
uint_16 deltbae[5];
/* number of cpl delta bit segments */
uint_16 cpldeltnseg;
/* coupling delta bit allocation offset */
uint_16 cpldeltoffst[8];
/* coupling delta bit allocation length */
uint_16 cpldeltlen[8];
/* coupling delta bit allocation length */
uint_16 cpldeltba[8];
/* number of delta bit segments */
uint_16 deltnseg[5];
/* fbw delta bit allocation offset */
uint_16 deltoffst[5][8];
/* fbw delta bit allocation length */
uint_16 deltlen[5][8];
/* fbw delta bit allocation length */
uint_16 deltba[5][8];
/* skip length exists */
uint_16 skiple;
/* skip length */
uint_16 skipl;
//Removed Feb 2000 -ah
/* channel mantissas */
//uint_16 chmant[5][256];
/* coupling mantissas */
uint_16 cplmant[256];
//Removed Feb 2000 -ah
/* coupling mantissas */
//uint_16 lfemant[7];
/* -- Information not in the bitstream, but derived thereof -- */
/* Number of coupling sub-bands */
uint_16 ncplsubnd;
/* Number of combined coupling sub-bands
* Derived from ncplsubnd and cplbndstrc */
uint_16 ncplbnd;
/* Number of exponent groups by channel
* Derived from strmant, endmant */
uint_16 nchgrps[5];
/* Number of coupling exponent groups
* Derived from cplbegf, cplendf, cplexpstr */
uint_16 ncplgrps;
/* End mantissa numbers of fbw channels */
uint_16 endmant[5];
/* Start and end mantissa numbers for the coupling channel */
uint_16 cplstrtmant;
uint_16 cplendmant;
/* Decoded exponent info */
uint_16 fbw_exp[5][256];
uint_16 cpl_exp[256];
uint_16 lfe_exp[7];
/* Bit allocation pointer results */
uint_16 fbw_bap[5][256];
uint_16 cpl_bap[256];
uint_16 lfe_bap[7];
uint_32 magic3;
} audblk_t;