/*** 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 "sbr_syntax.h"#include "sbr_tf_grid.h"  /* static function declarations */#if 0static 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);#endifstatic 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 0static 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