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Diffstat (limited to 'ac3dec/ac3_internal.h')
| -rw-r--r-- | ac3dec/ac3_internal.h | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/ac3dec/ac3_internal.h b/ac3dec/ac3_internal.h new file mode 100644 index 00000000..235189ed --- /dev/null +++ b/ac3dec/ac3_internal.h @@ -0,0 +1,344 @@ +/* + * 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; + + |