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