ac3.h

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/**********************************************************************
** Copyright (C) 2000 Trolltech AS.  All rights reserved.
**
** This file is part of Qtopia Environment.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
**********************************************************************/
#ifndef AC3_H
#define AC3_H

#include "mpeg3real.h"

#define MAX_AC3_FRAMESIZE 1920 * 2 + 512

extern int mpeg3_ac3_samplerates[3];

/* Exponent strategy constants */
#define MPEG3_EXP_REUSE (0)
#define MPEG3_EXP_D15   (1)
#define MPEG3_EXP_D25   (2)
#define MPEG3_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)


typedef mpeg3_real_t mpeg3ac3_stream_samples_t[6][256];

typedef struct
{
/* Bit stream identification == 0x8 */
        int bsid;       
/* Bit stream mode */
        int bsmod;
/* Audio coding mode */
        int acmod;
/* If we're using the centre channel then */
/* centre mix level */
                int cmixlev;
/* If we're using the surround channel then */
/* surround mix level */
                int surmixlev;
/* If we're in 2/0 mode then */
/* Dolby surround mix level - NOT USED - */
                int dsurmod;
/* Low frequency effects on */
        int lfeon;
/* Dialogue Normalization level */
        int dialnorm;
/* Compression exists */
        int compre;
/* Compression level */
                int compr;
/* Language code exists */
        int langcode;
/* Language code */
                int langcod;
/* Audio production info exists*/
        unsigned int audprodie;
                int mixlevel;
                int roomtyp;
/* If we're in dual mono mode (acmod == 0) then extra stuff */
                int dialnorm2;
                int compr2e;
                        int compr2;
                int langcod2e;
                        int langcod2;
                int audprodi2e;
                        int mixlevel2;
                        int roomtyp2;
/* Copyright bit */
        int copyrightb;
/* Original bit */
        int origbs;
/* Timecode 1 exists */
        int timecod1e;
/* Timecode 1 */
                unsigned int timecod1;
/* Timecode 2 exists */
        int timecod2e;
/* Timecode 2 */
                unsigned int timecod2;
/* Additional bit stream info exists */
        int addbsie;
/* Additional bit stream length - 1 (in bytes) */
                int addbsil;
/* Additional bit stream information (max 64 bytes) */
                unsigned char addbsi[64];

/* Information not in the AC-3 bitstream, but derived */
/* Number of channels (excluding LFE)
 * Derived from acmod */
        int nfchans;
} mpeg3_ac3bsi_t;

typedef struct 
{
/* block switch bit indexed by channel num */
        unsigned short blksw[5];
/* dither enable bit indexed by channel num */
        unsigned short dithflag[5];
/* dynamic range gain exists */
        int dynrnge;
/* dynamic range gain */
                int dynrng;
/* if acmod==0 then */
/* dynamic range 2 gain exists */
        int dynrng2e;
/* dynamic range 2 gain */
                int dynrng2;
/* coupling strategy exists */
        int cplstre;
/* coupling in use */
                int cplinu;
/* channel coupled */
                        unsigned short chincpl[5];
/* if acmod==2 then */
/* Phase flags in use */
                                int phsflginu;
/* coupling begin frequency code */
                        int cplbegf;
/* coupling end frequency code */
                        int cplendf;
/* coupling band structure bits */
                        unsigned short cplbndstrc[18];
/* Do coupling co-ords exist for this channel? */
                        unsigned short cplcoe[5];
/* Master coupling co-ordinate */
                        unsigned short mstrcplco[5];
/* Per coupling band coupling co-ordinates */
                        unsigned short cplcoexp[5][18];
                        unsigned short cplcomant[5][18];
/* Phase flags for dual mono */
                        unsigned short phsflg[18];
/* Is there a rematrixing strategy */
        unsigned int rematstr;
/* Rematrixing bits */
                unsigned short rematflg[4];
/* Coupling exponent strategy */
        int cplexpstr;
/* Exponent strategy for full bandwidth channels */
        unsigned short chexpstr[5];
/* Exponent strategy for lfe channel */
        int lfeexpstr;
/* Channel bandwidth for independent channels */
        unsigned short chbwcod[5];
/* The absolute coupling exponent */
                int cplabsexp;
/* Coupling channel exponents (D15 mode gives 18 * 12 /3  encoded exponents */
                unsigned short cplexps[18 * 12 / 3];
/* fbw channel exponents */
        unsigned short exps[5][252 / 3];
/* channel gain range */
        unsigned short gainrng[5];
/* low frequency exponents */
        unsigned short lfeexps[3];

/* Bit allocation info */
        int baie;
/* Slow decay code */
                int sdcycod;
/* Fast decay code */
                int fdcycod;
/* Slow gain code */
                int sgaincod;
/* dB per bit code */
                int dbpbcod;
/* masking floor code */
                int floorcod;

/* SNR offset info */
        int snroffste;
/* coarse SNR offset */
                int csnroffst;
/* coupling fine SNR offset */
                int cplfsnroffst;
/* coupling fast gain code */
                int cplfgaincod;
/* fbw fine SNR offset */
                unsigned short fsnroffst[5];
/* fbw fast gain code */
                unsigned short fgaincod[5];
/* lfe fine SNR offset */
                int lfefsnroffst;
/* lfe fast gain code */
                int lfefgaincod;
        
/* Coupling leak info */
        int cplleake;
/* coupling fast leak initialization */
                int cplfleak;
/* coupling slow leak initialization */
                int cplsleak;
        
/* delta bit allocation info */
        int deltbaie;
/* coupling delta bit allocation exists */
                int cpldeltbae;
/* fbw delta bit allocation exists */
                unsigned short deltbae[5];
/* number of cpl delta bit segments */
                int cpldeltnseg;
/* coupling delta bit allocation offset */
                        short cpldeltoffst[8];
/* coupling delta bit allocation length */
                        short cpldeltlen[8];
/* coupling delta bit allocation length */
                        short cpldeltba[8];
/* number of delta bit segments */
                unsigned short deltnseg[5];
/* fbw delta bit allocation offset */
                        short deltoffst[5][8];
/* fbw delta bit allocation length */
                        short deltlen[5][8];
/* fbw delta bit allocation length */
                        short deltba[5][8];

/* skip length exists */
        int skiple;
/* skip length */
        int skipl;

/* channel mantissas */
        short chmant[5][256];

/* coupling mantissas */
        unsigned short cplmant[256];

/* coupling mantissas */
        unsigned short lfemant[7];

/*  -- Information not in the bitstream, but derived thereof  -- */

/* Number of coupling sub-bands */
        int ncplsubnd;

/* Number of combined coupling sub-bands
 * Derived from ncplsubnd and cplbndstrc */
        int ncplbnd;

/* Number of exponent groups by channel
 * Derived from strmant, endmant */
        int nchgrps[5];

/* Number of coupling exponent groups
 * Derived from cplbegf, cplendf, cplexpstr */
        int ncplgrps;
                        
/* End mantissa numbers of fbw channels */
        unsigned short endmant[5];

/* Start and end mantissa numbers for the coupling channel */
        int cplstrtmant;
        int cplendmant;

/* Decoded exponent info */
        unsigned short fbw_exp[5][256];
        unsigned short cpl_exp[256];
        unsigned short lfe_exp[7];

/* Bit allocation pointer results */
        short fbw_bap[5][256];
/*FIXME figure out exactly how many entries there should be (253-37?)  */
        short cpl_bap[256];
        short lfe_bap[7];
} mpeg3_ac3audblk_t;

/* Bit allocation data */
typedef struct
{
        int sdecay;
        int fdecay;
        int sgain;
        int dbknee;
        int floor;
        short psd[256];
        short bndpsd[256];
        short excite[256];
        short mask[256];
} mpeg3_ac3_bitallocation_t;

/* Mantissa data */
typedef struct
{
        unsigned short m_1[3];
        unsigned short m_2[3];
        unsigned short m_4[2];
        unsigned short m_1_pointer;
        unsigned short m_2_pointer;
        unsigned short m_4_pointer;
} mpeg3_ac3_mantissa_t;

#endif

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