/*

** 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: sbr_tf_grid.c,v 1.20 2008/09/19 22:50:20 menno Exp $

**/

/* Time/Frequency grid */

#include "common.h"

#include "structs.h"

#ifdef SBR_DEC

#include <stdlib.h>

#include "sbr_syntax.h"

#include "sbr_tf_grid.h"

/* static function declarations */

#if 0

static int16_t rel_bord_lead(sbr_info *sbr, uint8_t ch, uint8_t l);

static int16_t rel_bord_trail(sbr_info *sbr, uint8_t ch, uint8_t l);

#endif

static uint8_t middleBorder(sbr_info *sbr, uint8_t ch);

/* function constructs new time border vector */

/* first build into temp vector to be able to use previous vector on error */

uint8_t envelope_time_border_vector(sbr_info *sbr, uint8_t ch)

{

    uint8_t l, border, temp, trail;

    uint8_t t_E_temp[6] = {0};

    trail = sbr->abs_bord_trail[ch];

    t_E_temp[0] = sbr->rate * sbr->abs_bord_lead[ch];

    t_E_temp[sbr->L_E[ch]] = sbr->rate * trail;

    switch (sbr->bs_frame_class[ch])

    {

    case FIXFIX:

        switch (sbr->L_E[ch])

        {

        case 4:

            temp = (sbr->numTimeSlots / 4);

            t_E_temp[3] = sbr->rate * 3 * temp;

            t_E_temp[2] = sbr->rate * 2 * temp;

            t_E_temp[1] = sbr->rate * temp;

            break;

        case 2:

            t_E_temp[1] = sbr->rate * (sbr->numTimeSlots / 2);

            break;

        default:

            break;

        }

        break;

    case FIXVAR:

        if (sbr->L_E[ch] > 1)

        {

            int8_t i = sbr->L_E[ch];

            border = sbr->abs_bord_trail[ch];

            for (l = 0; l < (sbr->L_E[ch] - 1); l++)

            {

                if (border < sbr->bs_rel_bord[ch][l])

                    return 1;

                border -= sbr->bs_rel_bord[ch][l];

                t_E_temp[--i] = sbr->rate * border;

            }

        }

        break;

    case VARFIX:

        if (sbr->L_E[ch] > 1)

        {

            int8_t i = 1;

            border = sbr->abs_bord_lead[ch];

            for (l = 0; l < (sbr->L_E[ch] - 1); l++)

            {

                border += sbr->bs_rel_bord[ch][l];

                if (border > trail)

                    return 1;

                t_E_temp[i++] = sbr->rate * border;

            }

        }

        break;

    case VARVAR:

        if (sbr->bs_num_rel_0[ch])

        {

            int8_t i = 1;

            border = sbr->abs_bord_lead[ch];

            for (l = 0; l < sbr->bs_num_rel_0[ch]; l++)

            {

                border += sbr->bs_rel_bord_0[ch][l];

                if (border > trail)

                    return 1;

                t_E_temp[i++] = sbr->rate * border;

            }

        }

        if (sbr->bs_num_rel_1[ch])

        {

            int8_t i = sbr->L_E[ch];

            border = sbr->abs_bord_trail[ch];

            for (l = 0; l < sbr->bs_num_rel_1[ch]; l++)

            {

                if (border < sbr->bs_rel_bord_1[ch][l])

                    return 1;

                border -= sbr->bs_rel_bord_1[ch][l];

                t_E_temp[--i] = sbr->rate * border;

            }

        }

        break;

    }

    /* no error occured, we can safely use this t_E vector */

    for (l = 0; l < 6; l++)

    {

        sbr->t_E[ch][l] = t_E_temp[l];

    }

    return 0;

}

void noise_floor_time_border_vector(sbr_info *sbr, uint8_t ch)

{

    sbr->t_Q[ch][0] = sbr->t_E[ch][0];

    if (sbr->L_E[ch] == 1)

    {

        sbr->t_Q[ch][1] = sbr->t_E[ch][1];

        sbr->t_Q[ch][2] = 0;

    } else {

        uint8_t index = middleBorder(sbr, ch);

        sbr->t_Q[ch][1] = sbr->t_E[ch][index];

        sbr->t_Q[ch][2] = sbr->t_E[ch][sbr->L_E[ch]];

    }

}

#if 0

static int16_t rel_bord_lead(sbr_info *sbr, uint8_t ch, uint8_t l)

{

    uint8_t i;

    int16_t acc = 0;

    switch (sbr->bs_frame_class[ch])

    {

    case FIXFIX:

        return sbr->numTimeSlots/sbr->L_E[ch];

    case FIXVAR:

        return 0;

    case VARFIX:

        for (i = 0; i < l; i++)

        {

            acc += sbr->bs_rel_bord[ch][i];

        }

        return acc;

    case VARVAR:

        for (i = 0; i < l; i++)

        {

            acc += sbr->bs_rel_bord_0[ch][i];

        }

        return acc;

    }

    return 0;

}

static int16_t rel_bord_trail(sbr_info *sbr, uint8_t ch, uint8_t l)

{

    uint8_t i;

    int16_t acc = 0;

    switch (sbr->bs_frame_class[ch])

    {

    case FIXFIX:

    case VARFIX:

        return 0;

    case FIXVAR:

        for (i = 0; i < l; i++)

        {

            acc += sbr->bs_rel_bord[ch][i];

        }

        return acc;

    case VARVAR:

        for (i = 0; i < l; i++)

        {

            acc += sbr->bs_rel_bord_1[ch][i];

        }

        return acc;

    }

    return 0;

}

#endif

static uint8_t middleBorder(sbr_info *sbr, uint8_t ch)

{

    int8_t retval = 0;

    switch (sbr->bs_frame_class[ch])

    {

    case FIXFIX:

        retval = sbr->L_E[ch]/2;

        break;

    case VARFIX:

        if (sbr->bs_pointer[ch] == 0)

            retval = 1;

        else if (sbr->bs_pointer[ch] == 1)

            retval = sbr->L_E[ch] - 1;

        else

            retval = sbr->bs_pointer[ch] - 1;

        break;

    case FIXVAR:

    case VARVAR:

        if (sbr->bs_pointer[ch] > 1)

            retval = sbr->L_E[ch] + 1 - sbr->bs_pointer[ch];

        else

            retval = sbr->L_E[ch] - 1;

        break;

    }

    return (retval > 0) ? retval : 0;

}

#endif