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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 6148 | serge | 1 | /* |
| 2 | * Header file for hardcoded mpegaudiodec tables |
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| 3 | * |
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| 4 | * Copyright (c) 2009 Reimar Döffinger |
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| 5 | * |
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| 6 | * This file is part of FFmpeg. |
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| 7 | * |
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| 8 | * FFmpeg is free software; you can redistribute it and/or |
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| 9 | * modify it under the terms of the GNU Lesser General Public |
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| 10 | * License as published by the Free Software Foundation; either |
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| 11 | * version 2.1 of the License, or (at your option) any later version. |
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| 12 | * |
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| 13 | * FFmpeg is distributed in the hope that it will be useful, |
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| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 16 | * Lesser General Public License for more details. |
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| 17 | * |
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| 18 | * You should have received a copy of the GNU Lesser General Public |
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| 19 | * License along with FFmpeg; if not, write to the Free Software |
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| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 21 | */ |
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| 22 | |||
| 23 | #ifndef AVCODEC_MPEGAUDIO_TABLEGEN_H |
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| 24 | #define AVCODEC_MPEGAUDIO_TABLEGEN_H |
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| 25 | |||
| 26 | #include |
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| 27 | #include |
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| 28 | |||
| 29 | #define TABLE_4_3_SIZE (8191 + 16)*4 |
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| 30 | #if CONFIG_HARDCODED_TABLES |
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| 31 | #define mpegaudio_tableinit() |
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| 32 | #include "libavcodec/mpegaudio_tables.h" |
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| 33 | #else |
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| 34 | static int8_t table_4_3_exp[TABLE_4_3_SIZE]; |
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| 35 | static uint32_t table_4_3_value[TABLE_4_3_SIZE]; |
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| 36 | static uint32_t exp_table_fixed[512]; |
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| 37 | static uint32_t expval_table_fixed[512][16]; |
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| 38 | static float exp_table_float[512]; |
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| 39 | static float expval_table_float[512][16]; |
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| 40 | |||
| 41 | #define FRAC_BITS 23 |
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| 42 | #define IMDCT_SCALAR 1.759 |
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| 43 | |||
| 44 | static void mpegaudio_tableinit(void) |
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| 45 | { |
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| 46 | int i, value, exponent; |
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| 47 | for (i = 1; i < TABLE_4_3_SIZE; i++) { |
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| 48 | double value = i / 4; |
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| 49 | double f, fm; |
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| 50 | int e, m; |
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| 51 | /* cbrtf() isn't available on all systems, so we use powf(). */ |
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| 52 | f = value / IMDCT_SCALAR * pow(value, 1.0 / 3.0) * pow(2, (i & 3) * 0.25); |
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| 53 | fm = frexp(f, &e); |
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| 54 | m = (uint32_t)(fm * (1LL << 31) + 0.5); |
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| 55 | e += FRAC_BITS - 31 + 5 - 100; |
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| 56 | |||
| 57 | /* normalized to FRAC_BITS */ |
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| 58 | table_4_3_value[i] = m; |
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| 59 | table_4_3_exp[i] = -e; |
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| 60 | } |
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| 61 | for (exponent = 0; exponent < 512; exponent++) { |
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| 62 | for (value = 0; value < 16; value++) { |
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| 63 | /* cbrtf() isn't available on all systems, so we use powf(). */ |
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| 64 | double f = (double)value * pow(value, 1.0 / 3.0) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5) / IMDCT_SCALAR; |
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| 65 | /* llrint() isn't always available, so round and cast manually. */ |
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| 66 | expval_table_fixed[exponent][value] = (long long int) (f < 0xFFFFFFFF ? floor(f + 0.5) : 0xFFFFFFFF); |
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| 67 | expval_table_float[exponent][value] = f; |
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| 68 | } |
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| 69 | exp_table_fixed[exponent] = expval_table_fixed[exponent][1]; |
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| 70 | exp_table_float[exponent] = expval_table_float[exponent][1]; |
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| 71 | } |
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| 72 | } |
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| 73 | #endif /* CONFIG_HARDCODED_TABLES */ |
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| 74 | |||
| 75 | #endif /* AVCODEC_MPEGAUDIO_TABLEGEN_H */ |