| 1 | /*
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| 2 | * mpeg audio layer 2 tables. Most of them come from the mpeg audio
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| 3 | * specification.
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| 4 | *
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| 5 | * Copyright (c) 2000, 2001 Fabrice Bellard.
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| 6 | *
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| 7 | * The licence of this code is contained in file LICENCE found in the
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| 8 | * same archive
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| 9 | */
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| 10 |
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| 11 | /**
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| 12 | * @file mpegaudiotab.h
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| 13 | * mpeg audio layer 2 tables.
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| 14 | * Most of them come from the mpeg audio specification.
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| 15 | */
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| 16 |
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| 17 | #define SQRT2 1.41421356237309514547
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| 18 |
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| 19 | static const int costab32[30] = {
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| 20 | FIX(0.54119610014619701222),
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| 21 | FIX(1.3065629648763763537),
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| 22 |
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| 23 | FIX(0.50979557910415917998),
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| 24 | FIX(2.5629154477415054814),
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| 25 | FIX(0.89997622313641556513),
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| 26 | FIX(0.60134488693504528634),
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| 27 |
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| 28 | FIX(0.5024192861881556782),
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| 29 | FIX(5.1011486186891552563),
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| 30 | FIX(0.78815462345125020249),
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| 31 | FIX(0.64682178335999007679),
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| 32 | FIX(0.56694403481635768927),
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| 33 | FIX(1.0606776859903470633),
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| 34 | FIX(1.7224470982383341955),
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| 35 | FIX(0.52249861493968885462),
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| 36 |
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| 37 | FIX(10.19000812354803287),
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| 38 | FIX(0.674808341455005678),
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| 39 | FIX(1.1694399334328846596),
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| 40 | FIX(0.53104259108978413284),
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| 41 | FIX(2.0577810099534108446),
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| 42 | FIX(0.58293496820613388554),
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| 43 | FIX(0.83934964541552681272),
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| 44 | FIX(0.50547095989754364798),
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| 45 | FIX(3.4076084184687189804),
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| 46 | FIX(0.62250412303566482475),
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| 47 | FIX(0.97256823786196078263),
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| 48 | FIX(0.51544730992262455249),
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| 49 | FIX(1.4841646163141661852),
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| 50 | FIX(0.5531038960344445421),
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| 51 | FIX(0.74453627100229857749),
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| 52 | FIX(0.5006029982351962726),
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| 53 | };
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| 54 |
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| 55 | static const int bitinv32[32] = {
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| 56 | 0, 16, 8, 24, 4, 20, 12, 28,
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| 57 | 2, 18, 10, 26, 6, 22, 14, 30,
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| 58 | 1, 17, 9, 25, 5, 21, 13, 29,
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| 59 | 3, 19, 11, 27, 7, 23, 15, 31
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| 60 | };
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| 61 |
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| 62 |
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| 63 | static int16_t filter_bank[512];
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| 64 |
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| 65 | static int scale_factor_table[64];
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| 66 | #ifdef USE_FLOATS
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| 67 | static float scale_factor_inv_table[64];
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| 68 | #else
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| 69 | static int8_t scale_factor_shift[64];
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| 70 | static unsigned short scale_factor_mult[64];
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| 71 | #endif
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| 72 | static unsigned char scale_diff_table[128];
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| 73 |
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| 74 | /* total number of bits per allocation group */
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| 75 | static unsigned short total_quant_bits[17];
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| 76 |
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| 77 | /* signal to noise ratio of each quantification step (could be
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| 78 | computed from quant_steps[]). The values are dB multiplied by 10
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| 79 | */
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| 80 | static const unsigned short quant_snr[17] = {
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| 81 | 70, 110, 160, 208,
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| 82 | 253, 316, 378, 439,
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| 83 | 499, 559, 620, 680,
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| 84 | 740, 800, 861, 920,
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| 85 | 980
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| 86 | };
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| 87 |
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| 88 | /* fixed psycho acoustic model. Values of SNR taken from the 'toolame'
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| 89 | project */
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| 90 | static const float fixed_smr[SBLIMIT] = {
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| 91 | 30, 17, 16, 10, 3, 12, 8, 2.5,
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| 92 | 5, 5, 6, 6, 5, 6, 10, 6,
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| 93 | -4, -10, -21, -30, -42, -55, -68, -75,
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| 94 | -75, -75, -75, -75, -91, -107, -110, -108
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| 95 | };
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| 96 |
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| 97 | static const unsigned char nb_scale_factors[4] = { 3, 2, 1, 2 };
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| 98 |
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