ref: 8ab8622bc39fb152ab2062b78bfe19f44236c00a
dir: /libfaad/sbr_tf_grid.c/
/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003-2004 M. Bakker, Ahead Software 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.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
**
** $Id: sbr_tf_grid.c,v 1.15 2004/09/04 14:56:28 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;
uint8_t t_E_temp[6] = {0};
t_E_temp[0] = sbr->rate * sbr->abs_bord_lead[ch];
t_E_temp[sbr->L_E[ch]] = sbr->rate * sbr->abs_bord_trail[ch];
switch (sbr->bs_frame_class[ch])
{
case FIXFIX:
switch (sbr->L_E[ch])
{
case 4:
temp = (int) (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 * (int) (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 (sbr->rate * border + sbr->tHFAdj > sbr->numTimeSlotsRate+sbr->tHFGen)
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 (sbr->rate * border + sbr->tHFAdj > sbr->numTimeSlotsRate+sbr->tHFGen)
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