yading@10: /*
yading@10:  * Header file for hardcoded mpegaudiodec tables
yading@10:  *
yading@10:  * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: #ifndef AVCODEC_MPEGAUDIO_TABLEGEN_H
yading@10: #define AVCODEC_MPEGAUDIO_TABLEGEN_H
yading@10: 
yading@10: #include <stdint.h>
yading@10: #include <math.h>
yading@10: 
yading@10: #define TABLE_4_3_SIZE (8191 + 16)*4
yading@10: #if CONFIG_HARDCODED_TABLES
yading@10: #define mpegaudio_tableinit()
yading@10: #include "libavcodec/mpegaudio_tables.h"
yading@10: #else
yading@10: static int8_t   table_4_3_exp[TABLE_4_3_SIZE];
yading@10: static uint32_t table_4_3_value[TABLE_4_3_SIZE];
yading@10: static uint32_t exp_table_fixed[512];
yading@10: static uint32_t expval_table_fixed[512][16];
yading@10: static float exp_table_float[512];
yading@10: static float expval_table_float[512][16];
yading@10: 
yading@10: #define FRAC_BITS 23
yading@10: #define IMDCT_SCALAR 1.759
yading@10: 
yading@10: static void mpegaudio_tableinit(void)
yading@10: {
yading@10:     int i, value, exponent;
yading@10:     for (i = 1; i < TABLE_4_3_SIZE; i++) {
yading@10:         double value = i / 4;
yading@10:         double f, fm;
yading@10:         int e, m;
yading@10:         f  = value / IMDCT_SCALAR * cbrtf(value) * pow(2, (i & 3) * 0.25);
yading@10:         fm = frexp(f, &e);
yading@10:         m  = (uint32_t)(fm * (1LL << 31) + 0.5);
yading@10:         e += FRAC_BITS - 31 + 5 - 100;
yading@10: 
yading@10:         /* normalized to FRAC_BITS */
yading@10:         table_4_3_value[i] =  m;
yading@10:         table_4_3_exp[i]   = -e;
yading@10:     }
yading@10:     for (exponent = 0; exponent < 512; exponent++) {
yading@10:         for (value = 0; value < 16; value++) {
yading@10:             double f = (double)value * cbrtf(value) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5) / IMDCT_SCALAR;
yading@10:             expval_table_fixed[exponent][value] = llrint(f);
yading@10:             expval_table_float[exponent][value] = f;
yading@10:         }
yading@10:         exp_table_fixed[exponent] = expval_table_fixed[exponent][1];
yading@10:         exp_table_float[exponent] = expval_table_float[exponent][1];
yading@10:     }
yading@10: }
yading@10: #endif /* CONFIG_HARDCODED_TABLES */
yading@10: 
yading@10: #endif /* AVCODEC_MPEGAUDIO_TABLEGEN_H */