libfaad2/sbr_tf_grid.c

   1 /*
   2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
   3 ** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
   4 **
   5 ** This program is free software; you can redistribute it and/or modify
   6 ** it under the terms of the GNU General Public License as published by
   7 ** the Free Software Foundation; either version 2 of the License, or
   8 ** (at your option) any later version.
   9 **
  10 ** This program is distributed in the hope that it will be useful,
  11 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 ** GNU General Public License for more details.
  14 **
  15 ** You should have received a copy of the GNU General Public License
  16 ** along with this program; if not, write to the Free Software
  17 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18 **
  19 ** Any non-GPL usage of this software or parts of this software is strictly
  20 ** forbidden.
  21 **
  22 ** Commercial non-GPL licensing of this software is possible.
  23 ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
  24 **
  25 ** $Id: sbr_tf_grid.c,v 1.15 2004/09/04 14:56:28 menno Exp $
  26 **/
  27
  28 /* Time/Frequency grid */
  29
  30 #include "common.h"
  31 #include "structs.h"
  32
  33 #ifdef SBR_DEC
  34
  35 #include <stdlib.h>
  36
  37 #include "sbr_syntax.h"
  38 #include "sbr_tf_grid.h"
  39
  40
  41 /* static function declarations */
  42 #if 0
  43 static int16_t rel_bord_lead(sbr_info *sbr, uint8_t ch, uint8_t l);
  44 static int16_t rel_bord_trail(sbr_info *sbr, uint8_t ch, uint8_t l);
  45 #endif
  46 static uint8_t middleBorder(sbr_info *sbr, uint8_t ch);
  47
  48
  49 /* function constructs new time border vector */
  50 /* first build into temp vector to be able to use previous vector on error */
  51 uint8_t envelope_time_border_vector(sbr_info *sbr, uint8_t ch)
  52 {
  53     uint8_t l, border, temp;
  54     uint8_t t_E_temp[6] = {0};
  55
  56     t_E_temp[0] = sbr->rate * sbr->abs_bord_lead[ch];
  57     t_E_temp[sbr->L_E[ch]] = sbr->rate * sbr->abs_bord_trail[ch];
  58
  59     switch (sbr->bs_frame_class[ch])
  60     {
  61     case FIXFIX:
  62         switch (sbr->L_E[ch])
  63         {
  64         case 4:
  65             temp = (int) (sbr->numTimeSlots / 4);
  66             t_E_temp[3] = sbr->rate * 3 * temp;
  67             t_E_temp[2] = sbr->rate * 2 * temp;
  68             t_E_temp[1] = sbr->rate * temp;
  69             break;
  70         case 2:
  71             t_E_temp[1] = sbr->rate * (int) (sbr->numTimeSlots / 2);
  72             break;
  73         default:
  74             break;
  75         }
  76         break;
  77
  78     case FIXVAR:
  79         if (sbr->L_E[ch] > 1)
  80         {
  81             int8_t i = sbr->L_E[ch];
  82             border = sbr->abs_bord_trail[ch];
  83
  84             for (l = 0; l < (sbr->L_E[ch] - 1); l++)
  85             {
  86                 if (border < sbr->bs_rel_bord[ch][l])
  87                     return 1;
  88
  89                 border -= sbr->bs_rel_bord[ch][l];
  90                 t_E_temp[--i] = sbr->rate * border;
  91             }
  92         }
  93         break;
  94
  95     case VARFIX:
  96         if (sbr->L_E[ch] > 1)
  97         {
  98             int8_t i = 1;
  99             border = sbr->abs_bord_lead[ch];
 100
 101             for (l = 0; l < (sbr->L_E[ch] - 1); l++)
 102             {
 103                 border += sbr->bs_rel_bord[ch][l];
 104
 105                 if (sbr->rate * border + sbr->tHFAdj > sbr->numTimeSlotsRate+sbr->tHFGen)
 106                     return 1;
 107
 108                 t_E_temp[i++] = sbr->rate * border;
 109             }
 110         }
 111         break;
 112
 113     case VARVAR:
 114         if (sbr->bs_num_rel_0[ch])
 115         {
 116             int8_t i = 1;
 117             border = sbr->abs_bord_lead[ch];
 118
 119             for (l = 0; l < sbr->bs_num_rel_0[ch]; l++)
 120             {
 121                 border += sbr->bs_rel_bord_0[ch][l];
 122
 123                 if (sbr->rate * border + sbr->tHFAdj > sbr->numTimeSlotsRate+sbr->tHFGen)
 124                     return 1;
 125
 126                 t_E_temp[i++] = sbr->rate * border;
 127             }
 128         }
 129
 130         if (sbr->bs_num_rel_1[ch])
 131         {
 132             int8_t i = sbr->L_E[ch];
 133             border = sbr->abs_bord_trail[ch];
 134
 135             for (l = 0; l < sbr->bs_num_rel_1[ch]; l++)
 136             {
 137                 if (border < sbr->bs_rel_bord_1[ch][l])
 138                     return 1;
 139
 140                 border -= sbr->bs_rel_bord_1[ch][l];
 141                 t_E_temp[--i] = sbr->rate * border;
 142             }
 143         }
 144         break;
 145     }
 146
 147     /* no error occured, we can safely use this t_E vector */
 148     for (l = 0; l < 6; l++)
 149     {
 150         sbr->t_E[ch][l] = t_E_temp[l];
 151     }
 152
 153     return 0;
 154 }
 155
 156 void noise_floor_time_border_vector(sbr_info *sbr, uint8_t ch)
 157 {
 158     sbr->t_Q[ch][0] = sbr->t_E[ch][0];
 159
 160     if (sbr->L_E[ch] == 1)
 161     {
 162         sbr->t_Q[ch][1] = sbr->t_E[ch][1];
 163         sbr->t_Q[ch][2] = 0;
 164     } else {
 165         uint8_t index = middleBorder(sbr, ch);
 166         sbr->t_Q[ch][1] = sbr->t_E[ch][index];
 167         sbr->t_Q[ch][2] = sbr->t_E[ch][sbr->L_E[ch]];
 168     }
 169 }
 170
 171 #if 0
 172 static int16_t rel_bord_lead(sbr_info *sbr, uint8_t ch, uint8_t l)
 173 {
 174     uint8_t i;
 175     int16_t acc = 0;
 176
 177     switch (sbr->bs_frame_class[ch])
 178     {
 179     case FIXFIX:
 180         return sbr->numTimeSlots/sbr->L_E[ch];
 181     case FIXVAR:
 182         return 0;
 183     case VARFIX:
 184         for (i = 0; i < l; i++)
 185         {
 186             acc += sbr->bs_rel_bord[ch][i];
 187         }
 188         return acc;
 189     case VARVAR:
 190         for (i = 0; i < l; i++)
 191         {
 192             acc += sbr->bs_rel_bord_0[ch][i];
 193         }
 194         return acc;
 195     }
 196
 197     return 0;
 198 }
 199
 200 static int16_t rel_bord_trail(sbr_info *sbr, uint8_t ch, uint8_t l)
 201 {
 202     uint8_t i;
 203     int16_t acc = 0;
 204
 205     switch (sbr->bs_frame_class[ch])
 206     {
 207     case FIXFIX:
 208     case VARFIX:
 209         return 0;
 210     case FIXVAR:
 211         for (i = 0; i < l; i++)
 212         {
 213             acc += sbr->bs_rel_bord[ch][i];
 214         }
 215         return acc;
 216     case VARVAR:
 217         for (i = 0; i < l; i++)
 218         {
 219             acc += sbr->bs_rel_bord_1[ch][i];
 220         }
 221         return acc;
 222     }
 223
 224     return 0;
 225 }
 226 #endif
 227
 228 static uint8_t middleBorder(sbr_info *sbr, uint8_t ch)
 229 {
 230     int8_t retval = 0;
 231
 232     switch (sbr->bs_frame_class[ch])
 233     {
 234     case FIXFIX:
 235         retval = sbr->L_E[ch]/2;
 236         break;
 237     case VARFIX:
 238         if (sbr->bs_pointer[ch] == 0)
 239             retval = 1;
 240         else if (sbr->bs_pointer[ch] == 1)
 241             retval = sbr->L_E[ch] - 1;
 242         else
 243             retval = sbr->bs_pointer[ch] - 1;
 244         break;
 245     case FIXVAR:
 246     case VARVAR:
 247         if (sbr->bs_pointer[ch] > 1)
 248             retval = sbr->L_E[ch] + 1 - sbr->bs_pointer[ch];
 249         else
 250             retval = sbr->L_E[ch] - 1;
 251         break;
 252     }
 253
 254     return (retval > 0) ? retval : 0;
 255 }
 256
 257
 258 #endif