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/*
* mpeg audio layer 2 tables. Most of them come from the mpeg audio
* specification.
*
* Copyright (c) 2000, 2001 Gerard Lantau.
*
* The licence of this code is contained in file LICENCE found in the
* same archive
*/
#define SQRT2 1.41421356237309514547
static const int costab32[30] = {
FIX(0.54119610014619701222),
FIX(1.3065629648763763537),
FIX(0.50979557910415917998),
FIX(2.5629154477415054814),
FIX(0.89997622313641556513),
FIX(0.60134488693504528634),
FIX(0.5024192861881556782),
FIX(5.1011486186891552563),
FIX(0.78815462345125020249),
FIX(0.64682178335999007679),
FIX(0.56694403481635768927),
FIX(1.0606776859903470633),
FIX(1.7224470982383341955),
FIX(0.52249861493968885462),
FIX(10.19000812354803287),
FIX(0.674808341455005678),
FIX(1.1694399334328846596),
FIX(0.53104259108978413284),
FIX(2.0577810099534108446),
FIX(0.58293496820613388554),
FIX(0.83934964541552681272),
FIX(0.50547095989754364798),
FIX(3.4076084184687189804),
FIX(0.62250412303566482475),
FIX(0.97256823786196078263),
FIX(0.51544730992262455249),
FIX(1.4841646163141661852),
FIX(0.5531038960344445421),
FIX(0.74453627100229857749),
FIX(0.5006029982351962726),
};
static const int bitinv32[32] = {
0, 16, 8, 24, 4, 20, 12, 28,
2, 18, 10, 26, 6, 22, 14, 30,
1, 17, 9, 25, 5, 21, 13, 29,
3, 19, 11, 27, 7, 23, 15, 31
};
static INT16 filter_bank[512];
static int scale_factor_table[64];
#ifdef USE_FLOATS
static float scale_factor_inv_table[64];
#else
static INT8 scale_factor_shift[64];
static unsigned short scale_factor_mult[64];
#endif
static unsigned char scale_diff_table[128];
/* total number of bits per allocation group */
static unsigned short total_quant_bits[17];
/* signal to noise ratio of each quantification step (could be
computed from quant_steps[]). The values are dB multiplied by 10
*/
static unsigned short quant_snr[17] = {
70, 110, 160, 208,
253, 316, 378, 439,
499, 559, 620, 680,
740, 800, 861, 920,
980
};
/* fixed psycho acoustic model. Values of SNR taken from the 'toolame'
project */
static const float fixed_smr[SBLIMIT] = {
30, 17, 16, 10, 3, 12, 8, 2.5,
5, 5, 6, 6, 5, 6, 10, 6,
-4, -10, -21, -30, -42, -55, -68, -75,
-75, -75, -75, -75, -91, -107, -110, -108
};
static const unsigned char nb_scale_factors[4] = { 3, 2, 1, 2 };
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