/* * Header file for hardcoded mpegaudiodec tables * * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVCODEC_MPEGAUDIO_TABLEGEN_H #define AVCODEC_MPEGAUDIO_TABLEGEN_H #include <stdint.h> #include <math.h> #define TABLE_4_3_SIZE (8191 + 16)*4 #if CONFIG_HARDCODED_TABLES #define mpegaudio_tableinit() #include "libavcodec/mpegaudio_tables.h" #else static int8_t table_4_3_exp[TABLE_4_3_SIZE]; static uint32_t table_4_3_value[TABLE_4_3_SIZE]; static uint32_t exp_table_fixed[512]; static uint32_t expval_table_fixed[512][16]; static float exp_table_float[512]; static float expval_table_float[512][16]; #define FRAC_BITS 23 #define IMDCT_SCALAR 1.759 static void mpegaudio_tableinit(void) { int i, value, exponent; for (i = 1; i < TABLE_4_3_SIZE; i++) { double value = i / 4; double f, fm; int e, m; /* cbrtf() isn't available on all systems, so we use powf(). */ f = value / IMDCT_SCALAR * pow(value, 1.0 / 3.0) * pow(2, (i & 3) * 0.25); fm = frexp(f, &e); m = (uint32_t)(fm * (1LL << 31) + 0.5); e += FRAC_BITS - 31 + 5 - 100; /* normalized to FRAC_BITS */ table_4_3_value[i] = m; table_4_3_exp[i] = -e; } for (exponent = 0; exponent < 512; exponent++) { for (value = 0; value < 16; value++) { /* cbrtf() isn't available on all systems, so we use powf(). */ double f = (double)value * pow(value, 1.0 / 3.0) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5) / IMDCT_SCALAR; /* llrint() isn't always available, so round and cast manually. */ expval_table_fixed[exponent][value] = (long long int) (f < 0xFFFFFFFF ? floor(f + 0.5) : 0xFFFFFFFF); expval_table_float[exponent][value] = f; } exp_table_fixed[exponent] = expval_table_fixed[exponent][1]; exp_table_float[exponent] = expval_table_float[exponent][1]; } } #endif /* CONFIG_HARDCODED_TABLES */ #endif /* AVCODEC_MPEGAUDIO_TABLEGEN_H */