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 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 38static 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 74static 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 82static int16_t filter_bank[512]; 83 84static int scale_factor_table[64]; 85#ifdef USE_FLOATS 86static float scale_factor_inv_table[64]; 87#else 88static int8_t scale_factor_shift[64]; 89static unsigned short scale_factor_mult[64]; 90#endif 91static unsigned char scale_diff_table[128]; 92 93/* total number of bits per allocation group */ 94static 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*/ 99static 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 */ 109static 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 116static const unsigned char nb_scale_factors[4] = { 3, 2, 1, 2 }; 117 118#endif /* AVCODEC_MPEGAUDIOTAB_H */ 119