1/* 2 * Header file for hardcoded mpegaudiodec tables 3 * 4 * Copyright (c) 2009 Reimar D��ffinger <Reimar.Doeffinger@gmx.de> 5 * 6 * This file is part of Libav. 7 * 8 * Libav 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 * Libav 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 Libav; 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 29#define TABLE_4_3_SIZE (8191 + 16)*4 30#if CONFIG_HARDCODED_TABLES 31#define mpegaudio_tableinit() 32#include "libavcodec/mpegaudio_tables.h" 33#else 34static int8_t table_4_3_exp[TABLE_4_3_SIZE]; 35static uint32_t table_4_3_value[TABLE_4_3_SIZE]; 36static uint32_t exp_table_fixed[512]; 37static uint32_t expval_table_fixed[512][16]; 38static float exp_table_float[512]; 39static float expval_table_float[512][16]; 40 41#define FRAC_BITS 23 42 43static void mpegaudio_tableinit(void) 44{ 45 int i, value, exponent; 46 for (i = 1; i < TABLE_4_3_SIZE; i++) { 47 double value = i / 4; 48 double f, fm; 49 int e, m; 50 f = value * cbrtf(value) * pow(2, (i & 3) * 0.25); 51 fm = frexp(f, &e); 52 m = (uint32_t)(fm * (1LL << 31) + 0.5); 53 e += FRAC_BITS - 31 + 5 - 100; 54 55 /* normalized to FRAC_BITS */ 56 table_4_3_value[i] = m; 57 table_4_3_exp[i] = -e; 58 } 59 for (exponent = 0; exponent < 512; exponent++) { 60 for (value = 0; value < 16; value++) { 61 double f = (double)value * cbrtf(value) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5); 62 expval_table_fixed[exponent][value] = llrint(f); 63 expval_table_float[exponent][value] = f; 64 } 65 exp_table_fixed[exponent] = expval_table_fixed[exponent][1]; 66 exp_table_float[exponent] = expval_table_float[exponent][1]; 67 } 68} 69#endif /* CONFIG_HARDCODED_TABLES */ 70 71#endif /* AVCODEC_MPEGAUDIO_TABLEGEN_H */ 72