/*
  * 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>

 #include "libavutil/attributes.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 av_cold void mpegaudio_tableinit(void)

 {

     int i, value, exponent;

     static const double exp2_lut[4] = {

         1.00000000000000000000, /* 2 ^ (0 * 0.25) */
         1.18920711500272106672, /* 2 ^ (1 * 0.25) */
         M_SQRT2               , /* 2 ^ (2 * 0.25) */
         1.68179283050742908606, /* 2 ^ (3 * 0.25) */
     };

     static double pow43_lut[16];
     double exp2_base = 2.11758236813575084767080625169910490512847900390625e-22; // 2^(-72)
     double exp2_val;
     double pow43_val = 0;

     for (i = 0; i < 16; ++i)

         pow43_lut[i] = i * cbrt(i);

     for (i = 1; i < TABLE_4_3_SIZE; i++) {

         double f, fm;
         int e, m;

         double value = i / 4;

         if ((i & 3) == 0)

             pow43_val = value / IMDCT_SCALAR * cbrt(value);
         f  = pow43_val * exp2_lut[i & 3];

         fm = frexp(f, &e);

         m  = llrint(fm * (1LL << 31));

         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++) {

         if (exponent && (exponent & 3) == 0)

             exp2_base *= 2;
         exp2_val = exp2_base * exp2_lut[exponent & 3] / IMDCT_SCALAR;

         for (value = 0; value < 16; value++) {

             double f = pow43_lut[value] * exp2_val;

             expval_table_fixed[exponent][value] = (f < 0xFFFFFFFF ? llrint(f) : 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 */