diff options
Diffstat (limited to 'src/libfaad/drc.c')
| -rw-r--r-- | src/libfaad/drc.c | 123 |
1 files changed, 105 insertions, 18 deletions
diff --git a/src/libfaad/drc.c b/src/libfaad/drc.c index 0da3ed110..14f3a2b1f 100644 --- a/src/libfaad/drc.c +++ b/src/libfaad/drc.c @@ -16,17 +16,20 @@ ** along with this program; if not, write to the Free Software ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ** -** $Id: drc.c,v 1.1 2002/07/14 23:43:01 miguelfreitas Exp $ +** $Id: drc.c,v 1.2 2002/12/16 19:00:00 miguelfreitas Exp $ **/ #include "common.h" +#include "structs.h" -#include <memory.h> +#include <stdlib.h> +#include <string.h> #include "syntax.h" #include "drc.h" -void init_drc(drc_info *drc, real_t cut, real_t boost) +drc_info *drc_init(real_t cut, real_t boost) { + drc_info *drc = (drc_info*)malloc(sizeof(drc_info)); memset(drc, 0, sizeof(drc_info)); drc->ctrl1 = cut; @@ -36,12 +39,76 @@ void init_drc(drc_info *drc, real_t cut, real_t boost) drc->band_top[0] = 1024/4 - 1; drc->dyn_rng_sgn[0] = 1; drc->dyn_rng_ctl[0] = 0; + + return drc; +} + +void drc_end(drc_info *drc) +{ + if (drc) free(drc); } +#ifdef FIXED_POINT +static real_t drc_pow2_table[] = +{ + COEF_CONST(0.5146511183), + COEF_CONST(0.5297315472), + COEF_CONST(0.5452538663), + COEF_CONST(0.5612310242), + COEF_CONST(0.5776763484), + COEF_CONST(0.5946035575), + COEF_CONST(0.6120267717), + COEF_CONST(0.6299605249), + COEF_CONST(0.6484197773), + COEF_CONST(0.6674199271), + COEF_CONST(0.6869768237), + COEF_CONST(0.7071067812), + COEF_CONST(0.7278265914), + COEF_CONST(0.7491535384), + COEF_CONST(0.7711054127), + COEF_CONST(0.7937005260), + COEF_CONST(0.8169577266), + COEF_CONST(0.8408964153), + COEF_CONST(0.8655365610), + COEF_CONST(0.8908987181), + COEF_CONST(0.9170040432), + COEF_CONST(0.9438743127), + COEF_CONST(0.9715319412), + COEF_CONST(1.0000000000), + COEF_CONST(1.0293022366), + COEF_CONST(1.0594630944), + COEF_CONST(1.0905077327), + COEF_CONST(1.1224620483), + COEF_CONST(1.1553526969), + COEF_CONST(1.1892071150), + COEF_CONST(1.2240535433), + COEF_CONST(1.2599210499), + COEF_CONST(1.2968395547), + COEF_CONST(1.3348398542), + COEF_CONST(1.3739536475), + COEF_CONST(1.4142135624), + COEF_CONST(1.4556531828), + COEF_CONST(1.4983070769), + COEF_CONST(1.5422108254), + COEF_CONST(1.5874010520), + COEF_CONST(1.6339154532), + COEF_CONST(1.6817928305), + COEF_CONST(1.7310731220), + COEF_CONST(1.7817974363), + COEF_CONST(1.8340080864), + COEF_CONST(1.8877486254), + COEF_CONST(1.9430638823) +}; +#endif + void drc_decode(drc_info *drc, real_t *spec) { uint16_t i, bd, top; - real_t factor; +#ifdef FIXED_POINT + int32_t exp, frac; +#else + real_t factor, exp; +#endif uint16_t bottom = 0; if (drc->num_bands == 1) @@ -51,26 +118,46 @@ void drc_decode(drc_info *drc, real_t *spec) { top = 4 * (drc->band_top[bd] + 1); +#ifndef FIXED_POINT /* Decode DRC gain factor */ if (drc->dyn_rng_sgn[bd]) /* compress */ - factor = (real_t)exp(LN2 * (-drc->ctrl1 * drc->dyn_rng_ctl[bd]/24.0)); + exp = -drc->ctrl1 * (drc->dyn_rng_ctl[bd] - (DRC_REF_LEVEL - drc->prog_ref_level))/24.0; else /* boost */ - factor = (real_t)exp(LN2 * (drc->ctrl2 * drc->dyn_rng_ctl[bd]/24.0)); - - /* Level alignment between different programs (if desired) */ - /* If program reference normalization is done in the digital domain, - modify factor to perform normalization. - prog_ref_level can alternatively be passed to the system for - modification of the level in the analog domain. Analog level - modification avoids problems with reduced DAC SNR (if signal is - attenuated) or clipping (if signal is boosted) - */ - factor = MUL(factor, - (real_t)exp(LN05 * ((DRC_REF_LEVEL - drc->prog_ref_level)/24.0))); + exp = drc->ctrl2 * (drc->dyn_rng_ctl[bd] - (DRC_REF_LEVEL - drc->prog_ref_level))/24.0; + factor = (real_t)pow(2.0, exp); /* Apply gain factor */ for (i = bottom; i < top; i++) - spec[i] = MUL(spec[i], factor); + spec[i] *= factor; +#else + /* Decode DRC gain factor */ + if (drc->dyn_rng_sgn[bd]) /* compress */ + { + exp = -1 * (drc->dyn_rng_ctl[bd] - (DRC_REF_LEVEL - drc->prog_ref_level))/ 24; + frac = -1 * (drc->dyn_rng_ctl[bd] - (DRC_REF_LEVEL - drc->prog_ref_level)) % 24; + } else { /* boost */ + exp = (drc->dyn_rng_ctl[bd] - (DRC_REF_LEVEL - drc->prog_ref_level))/ 24; + frac = (drc->dyn_rng_ctl[bd] - (DRC_REF_LEVEL - drc->prog_ref_level)) % 24; + } + + /* Apply gain factor */ + if (exp < 0) + { + for (i = bottom; i < top; i++) + { + spec[i] >>= -exp; + if (frac) + spec[i] = MUL(spec[i],drc_pow2_table[frac+23]); + } + } else { + for (i = bottom; i < top; i++) + { + spec[i] <<= exp; + if (frac) + spec[i] = MUL(spec[i],drc_pow2_table[frac+23]); + } + } +#endif bottom = top; } |