• Sam Hocevar's avatar
    · 4f551c2b
    Sam Hocevar authored
      * Header cleaning: filled all empty authors fields, added CVS $Id stuff.
      * Fixes to aout_darwin.c by Colin Delacroix <colin@zoy.org>.
      * Fixes to configure.in, Makefile.in and main.c (Altivec detection)
        by Eugenio Jarosiewicz <ej0@cise.ufl.edu>.
      * Added Colin and Eugenio to the AUTHORS file.
    4f551c2b
ac3_exponent.c 6.63 KB
/*****************************************************************************
 * ac3_exponent.c: ac3 exponent calculations
 *****************************************************************************
 * Copyright (C) 1999, 2000 VideoLAN
 * $Id: ac3_exponent.c,v 1.21 2001/03/21 13:42:34 sam Exp $
 *
 * Authors: Michel Kaempf <maxx@via.ecp.fr>
 *          Michel Lespinasse <walken@zoy.org>
 *          Aaron Holtzman <aholtzma@engr.uvic.ca>
 *
 * 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, USA.
 *****************************************************************************/
#include "defs.h"

#include "config.h"
#include "common.h"
#include "threads.h"
#include "mtime.h"

#include "stream_control.h"
#include "input_ext-dec.h"

#include "audio_output.h"

#include "ac3_decoder.h"
#include "ac3_decoder_thread.h"

#include "intf_msg.h"

#include "ac3_bit_stream.h"
#include "ac3_internal.h"

static const s16 exps_1[128] =
{
    -2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,-2,
    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
     2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
     0, 0, 0
};

static const s16 exps_2[128] =
{
    -2,-2,-2,-2,-2,-1,-1,-1,-1,-1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
    -2,-2,-2,-2,-2,-1,-1,-1,-1,-1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
    -2,-2,-2,-2,-2,-1,-1,-1,-1,-1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
    -2,-2,-2,-2,-2,-1,-1,-1,-1,-1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
    -2,-2,-2,-2,-2,-1,-1,-1,-1,-1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
     0, 0, 0
};

static const s16 exps_3[128] =
{
    -2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,
    -2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,
    -2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,
    -2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,
    -2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,
     0, 0, 0
};

#define UNPACK_FBW 1 
#define UNPACK_CPL 2 
#define UNPACK_LFE 4

static __inline__ int exp_unpack_ch (ac3dec_t * p_ac3dec, u16 type,
                                     u16 expstr, u16 ngrps, u16 initial_exp,
                                     u16 exps[], u16 * dest)
{
    u16 i,j;
    s16 exp_acc;

    if  (expstr == 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 values is
     * also an exponent */
    if (type != UNPACK_CPL)
    {
        dest[j++] = exp_acc;
    }

    /* Loop through the groups and fill the dest array appropriately */
    switch (expstr)
    {
    case EXP_D15:        /* 1 */
        for (i = 0; i < ngrps; i++)
        {
            if (exps[i] > 124)
            {
                intf_ErrMsg ( "ac3dec error: invalid exponent" );
                return 1;
            }
            exp_acc += (exps_1[exps[i]] /*- 2*/);
            dest[j++] = exp_acc;
            exp_acc += (exps_2[exps[i]] /*- 2*/);
            dest[j++] = exp_acc;
            exp_acc += (exps_3[exps[i]] /*- 2*/);
            dest[j++] = exp_acc;
        }
        break;

    case EXP_D25:        /* 2 */
        for (i = 0; i < ngrps; i++)
        {
            if (exps[i] > 124)
            {
                intf_ErrMsg ( "ac3dec error: invalid exponent" );
                return 1;
            }
            exp_acc += (exps_1[exps[i]] /*- 2*/);
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            exp_acc += (exps_2[exps[i]] /*- 2*/);
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            exp_acc += (exps_3[exps[i]] /*- 2*/);
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
        }
        break;

    case EXP_D45:        /* 3 */
        for (i = 0; i < ngrps; i++)
        {
            if (exps[i] > 124)
            {
                intf_ErrMsg ( "ac3dec error: invalid exponent" );
                return 1;
            }
            exp_acc += (exps_1[exps[i]] /*- 2*/);
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            exp_acc += (exps_2[exps[i]] /*- 2*/);
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            exp_acc += (exps_3[exps[i]] /*- 2*/);
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
            dest[j++] = exp_acc;
        }
        break;
    }

    return 0;
}

int exponent_unpack (ac3dec_t * p_ac3dec)
{
    u16 i;

    for (i = 0; i < p_ac3dec->bsi.nfchans; i++)
    {
        if (exp_unpack_ch (p_ac3dec, UNPACK_FBW, p_ac3dec->audblk.chexpstr[i],
                           p_ac3dec->audblk.nchgrps[i],
                           p_ac3dec->audblk.exps[i][0],
                           &p_ac3dec->audblk.exps[i][1],
                           p_ac3dec->audblk.fbw_exp[i]))
        {
            return 1;
        }
    }

    if (p_ac3dec->audblk.cplinu)
    {
        if (exp_unpack_ch (p_ac3dec, UNPACK_CPL, p_ac3dec->audblk.cplexpstr,
                           p_ac3dec->audblk.ncplgrps,
                           p_ac3dec->audblk.cplabsexp << 1,
                           p_ac3dec->audblk.cplexps,
                           &p_ac3dec->audblk.cpl_exp[p_ac3dec->audblk.cplstrtmant]))
        {
            return 1;
        }
    }

    if (p_ac3dec->bsi.lfeon)
    {
        if (exp_unpack_ch (p_ac3dec, UNPACK_LFE, p_ac3dec->audblk.lfeexpstr,
                           2, p_ac3dec->audblk.lfeexps[0],
                           &p_ac3dec->audblk.lfeexps[1],
                           p_ac3dec->audblk.lfe_exp))
        {
            return 1;
        }
    }

    return 0;
}