diff options
Diffstat (limited to 'src/libac3/ac3_internal.h')
| -rw-r--r-- | src/libac3/ac3_internal.h | 134 |
1 files changed, 13 insertions, 121 deletions
diff --git a/src/libac3/ac3_internal.h b/src/libac3/ac3_internal.h index d90fc598a..b414578bd 100644 --- a/src/libac3/ac3_internal.h +++ b/src/libac3/ac3_internal.h @@ -21,9 +21,10 @@ * */ -#ifndef __GNUC__ -#define inline -#endif +#define LEVEL_PLUS3DB 1.4142135623730951 +#define LEVEL_3DB 0.7071067811865476 +#define LEVEL_45DB 0.5946035575013605 +#define LEVEL_6DB 0.5 /* Exponent strategy constants */ #define EXP_REUSE (0) @@ -40,123 +41,14 @@ /* samples work structure */ typedef float stream_samples_t[6][256]; -/* global error flag */ -extern uint32_t 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 ac3_state_s { - int nfchans; // number of channels, derived from acmod - - /* from syncinfo */ - uint8_t fscod; // sample rate - - /* from bsi */ - uint8_t acmod; // coded channels - uint8_t cmixlev; // centre channel mix level - uint8_t surmixlev; // surround channels mix level - uint8_t lfeon; // coded lfe channel -} ac3_state_t; - -typedef struct ac3_ba_s { - uint16_t fsnroffst; // fine SNR offset - uint16_t fgaincod; // fast gain - uint16_t deltbae; // delta bit allocation exists - int8_t deltba[50]; // per-band delta bit allocation -} ac3_ba_t; - -/* more pain */ -typedef struct audblk_s { - uint32_t magic1; - - // not reused between blocks - uint16_t blksw[5]; // imdct block transform switch - uint16_t dithflag[5]; // channel dither flag - - uint16_t cplinu; // coupling in use - uint16_t chincpl[5]; // channel coupled - uint16_t phsflginu; // phase flags in use (stereo only) - uint16_t cplbegf; // coupling begin frequency code - uint16_t cplendf; // coupling end frequency code - uint16_t cplbndstrc[18]; // coupling band structure - // derived information - uint16_t cplstrtmant; // coupling channel start mantissa - uint16_t cplendmant; // coupling channel end mantissa - uint16_t ncplsubnd; // number of coupling sub-bands - uint16_t ncplbnd; // number of coupling bands - - // should we simply have float cplco[5][18] instead of these 4 ? - uint8_t mstrcplco[5]; // per channel master coupling coordinate - uint8_t cplcoexp[5][18]; // per band coupling exponent - uint8_t cplcomant[5][18]; // per band coupling mantissa - uint8_t phsflg[18]; // per band phase flags for stereo - - uint16_t rematflg[4]; // stereo rematrixing - - uint16_t chbwcod[5]; // channel bandwidth for independant channels - - uint32_t magic2; - - uint16_t sdcycod; // slow decay - uint16_t fdcycod; // fast decay - uint16_t sgaincod; // slow gain - uint16_t dbpbcod; // dB per bit - encodes the dbknee value - uint16_t floorcod; // masking floor - - uint16_t csnroffst; // coarse SNR offset - ac3_ba_t cplba; // coupling bit allocation parameters - ac3_ba_t ba[5]; // channel bit allocation parameters - ac3_ba_t lfeba; // lfe bit allocation parameters - - uint16_t cplfleak; // coupling fast leak init - uint16_t cplsleak; // coupling slow leak init - - - - - /* coupling mantissas */ - uint16_t cplmant[256]; - - - /* -- Information not in the bitstream, but derived thereof -- */ - - /* End mantissa numbers of fbw channels */ - uint16_t endmant[5]; - - /* Decoded exponent info */ - uint8_t fbw_exp[5][256]; - uint8_t cpl_exp[256]; - uint8_t lfe_exp[7]; - - /* Bit allocation pointer results */ - int8_t fbw_bap[5][256]; - int8_t cpl_bap[256]; - int8_t lfe_bap[7]; - - uint32_t magic3; -} audblk_t; +void bit_allocate (ac3_state_t * state, ac3_ba_t * ba, int bndstart, + int start, int end, int fastleak, int slowleak, + uint8_t * exp, int8_t * bap); +int downmix_init (int input, int flags, float * level, float clev, float slev); +void downmix (float * samples, int acmod, int output, float level, float bias, + float clev, float slev); +void imdct_init (void); +extern void (* imdct_256) (float data[], float delay[]); +extern void (* imdct_512) (float data[], float delay[]); |