/*

** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding

** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com

**

** This program 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 of the License, or

** (at your option) any later version.

**

** This program 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 this program; if not, write to the Free Software

** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

**

** Any non-GPL usage of this software or parts of this software is strictly

** forbidden.

**

** The "appropriate copyright message" mentioned in section 2c of the GPLv2

** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"

**

** Commercial non-GPL licensing of this software is possible.

** For more info contact Nero AG through Mpeg4AAClicense@nero.com.

**

** $Id: drc.c,v 1.29 2015/02/22 10:09:29 knik Exp $

**/

#include "common.h"

#include "structs.h"

#include <stdlib.h>

#include "syntax.h"

#include "drc.h"

drc_info *drc_init(real_t cut, real_t boost)

{

    drc_info *drc = (drc_info*)faad_malloc(sizeof(drc_info));

    memset(drc, 0, sizeof(drc_info));

    drc->ctrl1 = cut;

    drc->ctrl2 = boost;

    drc->num_bands = 1;

    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) faad_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;

#ifdef FIXED_POINT

    int32_t exp, frac;

#else

    real_t factor, exp;

#endif

    uint16_t bottom = 0;

    if (drc->num_bands == 1)

        drc->band_top[0] = 1024/4 - 1;

    for (bd = 0; bd < drc->num_bands; bd++)

    {

        top = 4 * (drc->band_top[bd] + 1);

#ifndef FIXED_POINT

        /* Decode DRC gain factor */

        if (drc->dyn_rng_sgn[bd])  /* compress */

            exp = ((-drc->ctrl1 * drc->dyn_rng_ctl[bd]) - (DRC_REF_LEVEL - drc->prog_ref_level))/REAL_CONST(24.0);

        else /* boost */

            exp = ((drc->ctrl2 * drc->dyn_rng_ctl[bd]) - (DRC_REF_LEVEL - drc->prog_ref_level))/REAL_CONST(24.0);

        factor = (real_t)pow(2.0, exp);

        /* Apply gain factor */

        for (i = bottom; i < top; i++)

            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_R(spec[i],drc_pow2_table[frac+23]);

            }

        } else {

            for (i = bottom; i < top; i++)

            {

                spec[i] = (int32_t)(((uint32_t)spec[i]) << exp);

                if (frac)

                    spec[i] = MUL_R(spec[i],drc_pow2_table[frac+23]);

            }

        }

#endif

        bottom = top;

    }

}