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69 lines
2.3 KiB
69 lines
2.3 KiB
/* |
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* Header file for hardcoded mpegaudiodec tables |
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* |
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* Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de> |
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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 MPEGAUDIO_TABLEGEN_H |
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#define MPEGAUDIO_TABLEGEN_H |
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#include <stdint.h> |
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#include <math.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 mpegaudio_tableinit() |
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#include "libavcodec/mpegaudio_tables.h" |
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#else |
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static int8_t table_4_3_exp[TABLE_4_3_SIZE]; |
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static uint32_t table_4_3_value[TABLE_4_3_SIZE]; |
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static uint32_t exp_table[512]; |
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static uint32_t expval_table[512][16]; |
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static float exp_table_float[512]; |
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static float expval_table_float[512][16]; |
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static void mpegaudio_tableinit(void) |
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{ |
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int i, value, exponent; |
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for (i = 1; i < TABLE_4_3_SIZE; i++) { |
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double value = i / 4; |
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double f, fm; |
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int e, m; |
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f = value * cbrtf(value) * pow(2, (i & 3) * 0.25); |
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fm = frexp(f, &e); |
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m = (uint32_t)(fm * (1LL << 31) + 0.5); |
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e += FRAC_BITS - 31 + 5 - 100; |
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/* normalized to FRAC_BITS */ |
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table_4_3_value[i] = m; |
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table_4_3_exp[i] = -e; |
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} |
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for (exponent = 0; exponent < 512; exponent++) { |
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for (value = 0; value < 16; value++) { |
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double f = (double)value * cbrtf(value) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5); |
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expval_table[exponent][value] = llrint(f); |
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expval_table_float[exponent][value] = f; |
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} |
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exp_table[exponent] = expval_table[exponent][1]; |
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exp_table_float[exponent] = expval_table_float[exponent][1]; |
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} |
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} |
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#endif /* CONFIG_HARDCODED_TABLES */ |
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#endif /* MPEGAUDIO_TABLEGEN_H */
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