libavcodec/mpegaudiotab.h

   1 /*
   2  * mpeg audio layer 2 tables. Most of them come from the mpeg audio
   3  * specification.
   4  *
   5  * Copyright (c) 2000, 2001 Fabrice Bellard
   6  *
   7  * This file is part of FFmpeg.
   8  *
   9  * FFmpeg is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * FFmpeg is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with FFmpeg; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 /**
  25  * @file libavcodec/mpegaudiotab.h
  26  * mpeg audio layer 2 tables.
  27  * Most of them come from the mpeg audio specification.
  28  */
  29
  30 #ifndef AVCODEC_MPEGAUDIOTAB_H
  31 #define AVCODEC_MPEGAUDIOTAB_H
  32
  33 #include <stdint.h>
  34 #include "mpegaudio.h"
  35
  36 #define SQRT2 1.41421356237309514547
  37
  38 static const int costab32[30] = {
  39     FIX(0.54119610014619701222),
  40     FIX(1.3065629648763763537),
  41
  42     FIX(0.50979557910415917998),
  43     FIX(2.5629154477415054814),
  44     FIX(0.89997622313641556513),
  45     FIX(0.60134488693504528634),
  46
  47     FIX(0.5024192861881556782),
  48     FIX(5.1011486186891552563),
  49     FIX(0.78815462345125020249),
  50     FIX(0.64682178335999007679),
  51     FIX(0.56694403481635768927),
  52     FIX(1.0606776859903470633),
  53     FIX(1.7224470982383341955),
  54     FIX(0.52249861493968885462),
  55
  56     FIX(10.19000812354803287),
  57     FIX(0.674808341455005678),
  58     FIX(1.1694399334328846596),
  59     FIX(0.53104259108978413284),
  60     FIX(2.0577810099534108446),
  61     FIX(0.58293496820613388554),
  62     FIX(0.83934964541552681272),
  63     FIX(0.50547095989754364798),
  64     FIX(3.4076084184687189804),
  65     FIX(0.62250412303566482475),
  66     FIX(0.97256823786196078263),
  67     FIX(0.51544730992262455249),
  68     FIX(1.4841646163141661852),
  69     FIX(0.5531038960344445421),
  70     FIX(0.74453627100229857749),
  71     FIX(0.5006029982351962726),
  72 };
  73
  74 static const int bitinv32[32] = {
  75     0,  16,  8, 24,  4,  20,  12,  28,
  76     2,  18, 10, 26,  6,  22,  14,  30,
  77     1,  17,  9, 25,  5,  21,  13,  29,
  78     3,  19, 11, 27,  7,  23,  15,  31
  79 };
  80
  81
  82 static int16_t filter_bank[512];
  83
  84 static int scale_factor_table[64];
  85 #ifdef USE_FLOATS
  86 static float scale_factor_inv_table[64];
  87 #else
  88 static int8_t scale_factor_shift[64];
  89 static unsigned short scale_factor_mult[64];
  90 #endif
  91 static unsigned char scale_diff_table[128];
  92
  93 /* total number of bits per allocation group */
  94 static unsigned short total_quant_bits[17];
  95
  96 /* signal to noise ratio of each quantification step (could be
  97    computed from quant_steps[]). The values are dB multiplied by 10
  98 */
  99 static const unsigned short quant_snr[17] = {
 100      70, 110, 160, 208,
 101     253, 316, 378, 439,
 102     499, 559, 620, 680,
 103     740, 800, 861, 920,
 104     980
 105 };
 106
 107 /* fixed psycho acoustic model. Values of SNR taken from the 'toolame'
 108    project */
 109 static const float fixed_smr[SBLIMIT] =  {
 110     30, 17, 16, 10, 3, 12, 8, 2.5,
 111     5, 5, 6, 6, 5, 6, 10, 6,
 112     -4, -10, -21, -30, -42, -55, -68, -75,
 113     -75, -75, -75, -75, -91, -107, -110, -108
 114 };
 115
 116 static const unsigned char nb_scale_factors[4] = { 3, 2, 1, 2 };
 117
 118 #endif /* AVCODEC_MPEGAUDIOTAB_H */