| 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 | |
| 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 | /* signal to noise ratio of each quantification step (could be |
| 83 | computed from quant_steps[]). The values are dB multiplied by 10 |
| 84 | */ |
| 85 | static const unsigned short quant_snr[17] = { |
| 86 | 70, 110, 160, 208, |
| 87 | 253, 316, 378, 439, |
| 88 | 499, 559, 620, 680, |
| 89 | 740, 800, 861, 920, |
| 90 | 980 |
| 91 | }; |
| 92 | |
| 93 | /* fixed psycho acoustic model. Values of SNR taken from the 'toolame' |
| 94 | project */ |
| 95 | static const float fixed_smr[SBLIMIT] = { |
| 96 | 30, 17, 16, 10, 3, 12, 8, 2.5, |
| 97 | 5, 5, 6, 6, 5, 6, 10, 6, |
| 98 | -4, -10, -21, -30, -42, -55, -68, -75, |
| 99 | -75, -75, -75, -75, -91, -107, -110, -108 |
| 100 | }; |
| 101 | |
| 102 | static const unsigned char nb_scale_factors[4] = { 3, 2, 1, 2 }; |
| 103 | |
| 104 | #endif /* AVCODEC_MPEGAUDIOTAB_H */ |