repositories / deb_ffmpeg.git / blame
| Commit | Line | Data |
|---|---|---|
| 2ba45a60 DM |
1 | /* |
| 2 | * Header file for hardcoded mpegaudiodec tables | |
| 3 | * | |
| 4 | * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de> | |
| 5 | * | |
| 6 | * This file is part of FFmpeg. | |
| 7 | * | |
| 8 | * FFmpeg is free software; you can redistribute it and/or | |
| 9 | * modify it under the terms of the GNU Lesser General Public | |
| 10 | * License as published by the Free Software Foundation; either | |
| 11 | * version 2.1 of the License, or (at your option) any later version. | |
| 12 | * | |
| 13 | * FFmpeg is distributed in the hope that it will be useful, | |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 16 | * Lesser General Public License for more details. | |
| 17 | * | |
| 18 | * You should have received a copy of the GNU Lesser General Public | |
| 19 | * License along with FFmpeg; if not, write to the Free Software | |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| 21 | */ | |
| 22 | ||
| 23 | #ifndef AVCODEC_MPEGAUDIO_TABLEGEN_H | |
| 24 | #define AVCODEC_MPEGAUDIO_TABLEGEN_H | |
| 25 | ||
| 26 | #include <stdint.h> | |
| 27 | #include <math.h> | |
| 28 | #include "libavutil/attributes.h" | |
| 29 | ||
| 30 | #define TABLE_4_3_SIZE (8191 + 16)*4 | |
| 31 | #if CONFIG_HARDCODED_TABLES | |
| 32 | #define mpegaudio_tableinit() | |
| 33 | #include "libavcodec/mpegaudio_tables.h" | |
| 34 | #else | |
| 35 | static int8_t table_4_3_exp[TABLE_4_3_SIZE]; | |
| 36 | static uint32_t table_4_3_value[TABLE_4_3_SIZE]; | |
| 37 | static uint32_t exp_table_fixed[512]; | |
| 38 | static uint32_t expval_table_fixed[512][16]; | |
| 39 | static float exp_table_float[512]; | |
| 40 | static float expval_table_float[512][16]; | |
| 41 | ||
| 42 | #define FRAC_BITS 23 | |
| 43 | #define IMDCT_SCALAR 1.759 | |
| 44 | ||
| 45 | static av_cold void mpegaudio_tableinit(void) | |
| 46 | { | |
| 47 | int i, value, exponent; | |
| 48 | for (i = 1; i < TABLE_4_3_SIZE; i++) { | |
| 49 | double value = i / 4; | |
| 50 | double f, fm; | |
| 51 | int e, m; | |
| 52 | /* cbrtf() isn't available on all systems, so we use powf(). */ | |
| 53 | f = value / IMDCT_SCALAR * pow(value, 1.0 / 3.0) * pow(2, (i & 3) * 0.25); | |
| 54 | fm = frexp(f, &e); | |
| 55 | m = (uint32_t)(fm * (1LL << 31) + 0.5); | |
| 56 | e += FRAC_BITS - 31 + 5 - 100; | |
| 57 | ||
| 58 | /* normalized to FRAC_BITS */ | |
| 59 | table_4_3_value[i] = m; | |
| 60 | table_4_3_exp[i] = -e; | |
| 61 | } | |
| 62 | for (exponent = 0; exponent < 512; exponent++) { | |
| 63 | for (value = 0; value < 16; value++) { | |
| 64 | /* cbrtf() isn't available on all systems, so we use powf(). */ | |
| 65 | double f = (double)value * pow(value, 1.0 / 3.0) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5) / IMDCT_SCALAR; | |
| 66 | /* llrint() isn't always available, so round and cast manually. */ | |
| 67 | expval_table_fixed[exponent][value] = (long long int) (f < 0xFFFFFFFF ? floor(f + 0.5) : 0xFFFFFFFF); | |
| 68 | expval_table_float[exponent][value] = f; | |
| 69 | } | |
| 70 | exp_table_fixed[exponent] = expval_table_fixed[exponent][1]; | |
| 71 | exp_table_float[exponent] = expval_table_float[exponent][1]; | |
| 72 | } | |
| 73 | } | |
| 74 | #endif /* CONFIG_HARDCODED_TABLES */ | |
| 75 | ||
| 76 | #endif /* AVCODEC_MPEGAUDIO_TABLEGEN_H */ |