libfaad2/codebook/hcb.h

   1 /*
   2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
   3 ** Copyright (C) 2003 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: hcb.h,v 1.6 2003/09/09 18:12:01 menno Exp $
  26 **/
  27
  28 #ifndef __HCB_H__
  29 #define __HCB_H__
  30
  31 #ifdef __cplusplus
  32 extern "C" {
  33 #endif
  34
  35 /*
  36  *  Optimal huffman decoding for AAC taken from:
  37  *  "SELECTING AN OPTIMAL HUFFMAN DECODER FOR AAC" by
  38  *  VLADIMIR Z. MESAROVIC , RAGHUNATH RAO, MIROSLAV V. DOKIC, and SACHIN DEO
  39  *  AES paper 5436
  40  *
  41  *   2 methods are used for huffman decoding:
  42  *   - binary search
  43  *   - 2-step table lookup
  44  *
  45  *   The choice of the "optimal" method is based on the fact that if the
  46  *   memory size for the Two-step is exorbitantly high then the decision
  47  *   is Binary search for that codebook. However, for marginally more memory
  48  *   size, if Twostep outperforms even the best case of Binary then the
  49  *   decision is Two-step for that codebook.
  50  *
  51  *   The following methods are used for the different tables.
  52  *   codebook   "optimal" method
  53  *    HCB_1      2-Step
  54  *    HCB_2      2-Step
  55  *    HCB_3      Binary
  56  *    HCB_4      2-Step
  57  *    HCB_5      Binary
  58  *    HCB_6      2-Step
  59  *    HCB_7      Binary
  60  *    HCB_8      2-Step
  61  *    HCB_9      Binary
  62  *    HCB_10     2-Step
  63  *    HCB_11     2-Step
  64  *    HCB_SF     Binary
  65  *
  66  */
  67
  68
  69 #define ZERO_HCB       0
  70 #define FIRST_PAIR_HCB 5
  71 #define ESC_HCB        11
  72 #define QUAD_LEN       4
  73 #define PAIR_LEN       2
  74 #define NOISE_HCB      13
  75 #define INTENSITY_HCB2 14
  76 #define INTENSITY_HCB  15
  77
  78 /* 1st step table */
  79 typedef struct
  80 {
  81     uint8_t offset;
  82     uint8_t extra_bits;
  83 } hcb;
  84
  85 /* 2nd step table with quadruple data */
  86 typedef struct
  87 {
  88     uint8_t bits;
  89     int8_t x;
  90     int8_t y;
  91 } hcb_2_pair;
  92
  93 typedef struct
  94 {
  95     uint8_t bits;
  96     int8_t x;
  97     int8_t y;
  98     int8_t v;
  99     int8_t w;
 100 } hcb_2_quad;
 101
 102 /* binary search table */
 103 typedef struct
 104 {
 105     uint8_t is_leaf;
 106     int8_t data[4];
 107 } hcb_bin_quad;
 108
 109 typedef struct
 110 {
 111     uint8_t is_leaf;
 112     int8_t data[2];
 113 } hcb_bin_pair;
 114
 115 hcb *hcb_table[];
 116 hcb_2_quad *hcb_2_quad_table[];
 117 hcb_2_pair *hcb_2_pair_table[];
 118 hcb_bin_pair *hcb_bin_table[];
 119 uint8_t hcbN[];
 120 uint8_t unsigned_cb[];
 121 int hcb_2_quad_table_size[];
 122 int hcb_2_pair_table_size[];
 123 int hcb_bin_table_size[];
 124
 125 #include "codebook/hcb_1.h"
 126 #include "codebook/hcb_2.h"
 127 #include "codebook/hcb_3.h"
 128 #include "codebook/hcb_4.h"
 129 #include "codebook/hcb_5.h"
 130 #include "codebook/hcb_6.h"
 131 #include "codebook/hcb_7.h"
 132 #include "codebook/hcb_8.h"
 133 #include "codebook/hcb_9.h"
 134 #include "codebook/hcb_10.h"
 135 #include "codebook/hcb_11.h"
 136 #include "codebook/hcb_sf.h"
 137
 138
 139 #ifdef __cplusplus
 140 }
 141 #endif
 142 #endif