/*

 * 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"

#if CONFIG_HARDCODED_TABLES

#define mpegaudio_tableinit()

#include "libavcodec/mpegaudio_tables.h"

#else

#if defined(BUILD_TABLES) || !USE_FLOATS

#define FIXED_TABLE

static uint32_t exp_table_fixed[512];

static uint32_t expval_table_fixed[512][16];

#endif

#if defined(BUILD_TABLES) || USE_FLOATS

#define FLOAT_TABLE

static float exp_table_float[512];

static float expval_table_float[512][16];

#endif

#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) */

    };

    double pow43_lut[16];

    double exp2_base = 2.11758236813575084767080625169910490512847900390625e-22; // 2^(-72)

    double exp2_val;

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

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

    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;

#ifdef FIXED_TABLE

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

#endif

#ifdef FLOAT_TABLE

            expval_table_float[exponent][value] = f;

#endif

        }

#ifdef FIXED_TABLE

        exp_table_fixed[exponent] = expval_table_fixed[exponent][1];

#endif

#ifdef FLOAT_TABLE

        exp_table_float[exponent] = expval_table_float[exponent][1];

#endif

    }

}

mpegaudiodec_float.c:mpegaudio_tableinit

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{

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    int i, value, exponent;

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    static const double exp2_lut[4] = {

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        1.00000000000000000000, /* 2 ^ (0 * 0.25) */

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        1.18920711500272106672, /* 2 ^ (1 * 0.25) */

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        M_SQRT2               , /* 2 ^ (2 * 0.25) */

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        1.68179283050742908606, /* 2 ^ (3 * 0.25) */

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    };

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    double pow43_lut[16];

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    double exp2_base = 2.11758236813575084767080625169910490512847900390625e-22; // 2^(-72)

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    double exp2_val;

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

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

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    for (exponent = 0; exponent < 512; exponent++) {

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

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            exp2_base *= 2;

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

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

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            double f = pow43_lut[value] * exp2_val;

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#ifdef FIXED_TABLE

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

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#endif

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#ifdef FLOAT_TABLE

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            expval_table_float[exponent][value] = f;

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#endif

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        }

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#ifdef FIXED_TABLE

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        exp_table_fixed[exponent] = expval_table_fixed[exponent][1];

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#endif

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#ifdef FLOAT_TABLE

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        exp_table_float[exponent] = expval_table_float[exponent][1];

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#endif

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    }

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}

mpegaudiodec_fixed.c:mpegaudio_tableinit

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{

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    int i, value, exponent;

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    static const double exp2_lut[4] = {

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        1.00000000000000000000, /* 2 ^ (0 * 0.25) */

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        1.18920711500272106672, /* 2 ^ (1 * 0.25) */

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        M_SQRT2               , /* 2 ^ (2 * 0.25) */

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        1.68179283050742908606, /* 2 ^ (3 * 0.25) */

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    };

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    double pow43_lut[16];

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    double exp2_base = 2.11758236813575084767080625169910490512847900390625e-22; // 2^(-72)

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    double exp2_val;

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

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

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    for (exponent = 0; exponent < 512; exponent++) {

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

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            exp2_base *= 2;

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

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

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            double f = pow43_lut[value] * exp2_val;

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#ifdef FIXED_TABLE

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

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#endif

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#ifdef FLOAT_TABLE

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            expval_table_float[exponent][value] = f;

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#endif

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        }

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#ifdef FIXED_TABLE

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        exp_table_fixed[exponent] = expval_table_fixed[exponent][1];

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#endif

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#ifdef FLOAT_TABLE

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        exp_table_float[exponent] = expval_table_float[exponent][1];

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#endif

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    }

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}

#undef FLOAT_TABLE

#undef FIXED_TABLE

#endif /* CONFIG_HARDCODED_TABLES */

#endif /* AVCODEC_MPEGAUDIO_TABLEGEN_H */