d5d1c697bd
Both the fixed as well as the floating point mpegaudio decoders use LUTs of type int8_t and uint32_t with 32K entries each; these tables are completely the same, yet they are not shared. This commit makes them shared. When both fixed as well as floating point decoders are enabled, this saves 160KiB from the bss segment for a normal build (translating into 160KiB less memory usage if both a shared as well as a floating point decoder have actually been used) and 160KiB from the binary for a build with hardcoded tables. It also means that the code to create said LUTs is no longer duplicated (for a normal build). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
73 lines
2.3 KiB
C
73 lines
2.3 KiB
C
/*
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* Header file for hardcoded shared mpegaudiodec tables
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*
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* Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
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* Copyright (c) 2020 Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef AVCODEC_MPEGAUDIODEC_COMMON_TABLEGEN_H
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#define AVCODEC_MPEGAUDIODEC_COMMON_TABLEGEN_H
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#include <stdint.h>
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#define TABLE_4_3_SIZE ((8191 + 16)*4)
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#if CONFIG_HARDCODED_TABLES
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#define mpegaudiodec_common_tableinit()
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#include "libavcodec/mpegaudiodec_common_tables.h"
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#else
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#include <math.h>
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#include "libavutil/attributes.h"
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int8_t ff_table_4_3_exp [TABLE_4_3_SIZE];
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uint32_t ff_table_4_3_value[TABLE_4_3_SIZE];
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#define FRAC_BITS 23
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#define IMDCT_SCALAR 1.759
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static av_cold void mpegaudiodec_common_tableinit(void)
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{
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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_val = 0;
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for (int i = 1; i < TABLE_4_3_SIZE; i++) {
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double f, fm;
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int e, m;
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double value = i / 4;
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if ((i & 3) == 0)
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pow43_val = value / IMDCT_SCALAR * cbrt(value);
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f = pow43_val * exp2_lut[i & 3];
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fm = frexp(f, &e);
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m = llrint(fm * (1LL << 31));
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e += FRAC_BITS - 31 + 5 - 100;
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/* normalized to FRAC_BITS */
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ff_table_4_3_value[i] = m;
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ff_table_4_3_exp [i] = -e;
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}
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}
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#endif /* CONFIG_HARDCODED_TABLES */
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#endif /* AVCODEC_MPEGAUDIODEC_COMMON_TABLEGEN_H */
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