Diffstat (limited to 'core/multimedia/opieplayer/libmpeg3/audio/exponents.c') (more/less context) (ignore whitespace changes)
| -rw-r--r-- | core/multimedia/opieplayer/libmpeg3/audio/exponents.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/core/multimedia/opieplayer/libmpeg3/audio/exponents.c b/core/multimedia/opieplayer/libmpeg3/audio/exponents.c new file mode 100644 index 0000000..deda9b9 --- a/dev/null +++ b/core/multimedia/opieplayer/libmpeg3/audio/exponents.c @@ -0,0 +1,141 @@ +/* + * + * exponents.c Copyright (C) Aaron Holtzman - May 1999 + * + * This file is part of libmpeg3 + * + * libmpeg3 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. + * + * libmpeg3 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. + * + */ + +#include "mpeg3audio.h" +#include "../libmpeg3.h" +#include "../mpeg3protos.h" +#include <stdio.h> + +/* Exponent defines */ +#define UNPACK_FBW 1 +#define UNPACK_CPL 2 +#define UNPACK_LFE 4 + +static inline int mpeg3audio_ac3_exp_unpack_ch(unsigned int type, + unsigned int expstr, + unsigned int ngrps, + unsigned int initial_exp, + unsigned short exps[], + unsigned short *dest) +{ + int i, j; + int exp_acc; + int exp_1, exp_2, exp_3; + + if(expstr == MPEG3_EXP_REUSE) + return 0; + +/* Handle the initial absolute exponent */ + exp_acc = initial_exp; + j = 0; + +/* In the case of a fbw channel then the initial absolute value is + * also an exponent */ + if(type != UNPACK_CPL) + dest[j++] = exp_acc; + +/* Loop through the groups and fill the dest array appropriately */ + for(i = 0; i < ngrps; i++) + { + if(exps[i] > 124) + { + fprintf(stderr, "mpeg3audio_ac3_exp_unpack_ch: Invalid exponent %d\n", exps[i]); + return 1; + } + + exp_1 = exps[i] / 25; + exp_2 = (exps[i] % 25) / 5; + exp_3 = (exps[i] % 25) % 5; + + exp_acc += (exp_1 - 2); + + switch(expstr) + { + case MPEG3_EXP_D45: + dest[j++] = exp_acc; + dest[j++] = exp_acc; + case MPEG3_EXP_D25: + dest[j++] = exp_acc; + case MPEG3_EXP_D15: + dest[j++] = exp_acc; + } + + exp_acc += (exp_2 - 2); + + switch(expstr) + { + case MPEG3_EXP_D45: + dest[j++] = exp_acc; + dest[j++] = exp_acc; + case MPEG3_EXP_D25: + dest[j++] = exp_acc; + case MPEG3_EXP_D15: + dest[j++] = exp_acc; + } + + exp_acc += (exp_3 - 2); + + switch(expstr) + { + case MPEG3_EXP_D45: + dest[j++] = exp_acc; + dest[j++] = exp_acc; + case MPEG3_EXP_D25: + dest[j++] = exp_acc; + case MPEG3_EXP_D15: + dest[j++] = exp_acc; + } + } + return 0; +} + +int mpeg3audio_ac3_exponent_unpack(mpeg3audio_t *audio, + mpeg3_ac3bsi_t *bsi, + mpeg3_ac3audblk_t *audblk) +{ + int i, result = 0; + + for(i = 0; i < bsi->nfchans; i++) + result |= mpeg3audio_ac3_exp_unpack_ch(UNPACK_FBW, + audblk->chexpstr[i], + audblk->nchgrps[i], + audblk->exps[i][0], + &audblk->exps[i][1], + audblk->fbw_exp[i]); + + if(audblk->cplinu && !result) + result |= mpeg3audio_ac3_exp_unpack_ch(UNPACK_CPL, + audblk->cplexpstr, + audblk->ncplgrps, + audblk->cplabsexp << 1, + audblk->cplexps, + &audblk->cpl_exp[audblk->cplstrtmant]); + + if(bsi->lfeon && !result) + result |= mpeg3audio_ac3_exp_unpack_ch(UNPACK_LFE, + audblk->lfeexpstr, + 2, + audblk->lfeexps[0], + &audblk->lfeexps[1], + audblk->lfe_exp); + return result; +} |