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The code to initialize the ungrouped bap mantissa tables (bap 3 or 5) takes more bytes of .text than the tables itself; they have therefore been hardcoded. For GCC (14, -O3, albeit in an av_cold function), the initialization code takes 99B each for the fixed and floating point decoders (the code is currently duplicated), whereas the hardcoded tables only take 96B. For Clang 19 it were 374B each (I don't now what Clang was doing there). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
97 lines
3.0 KiB
C
97 lines
3.0 KiB
C
/*
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* AC-3 and E-AC-3 decoder tables
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* Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec@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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/**
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* @file
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* Tables taken directly from the AC-3 spec or derived from it.
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*/
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#include "ac3dec_data.h"
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/**
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* Table used to ungroup 3 values stored in 5 bits.
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* Used by bap=1 mantissas and GAQ.
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* ff_ac3_ungroup_3_in_5_bits_tab[i] = { i/9, (i%9)/3, (i%9)%3 }
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*/
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const uint8_t ff_ac3_ungroup_3_in_5_bits_tab[32][3] = {
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{ 0, 0, 0 }, { 0, 0, 1 }, { 0, 0, 2 }, { 0, 1, 0 },
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{ 0, 1, 1 }, { 0, 1, 2 }, { 0, 2, 0 }, { 0, 2, 1 },
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{ 0, 2, 2 }, { 1, 0, 0 }, { 1, 0, 1 }, { 1, 0, 2 },
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{ 1, 1, 0 }, { 1, 1, 1 }, { 1, 1, 2 }, { 1, 2, 0 },
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{ 1, 2, 1 }, { 1, 2, 2 }, { 2, 0, 0 }, { 2, 0, 1 },
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{ 2, 0, 2 }, { 2, 1, 0 }, { 2, 1, 1 }, { 2, 1, 2 },
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{ 2, 2, 0 }, { 2, 2, 1 }, { 2, 2, 2 }, { 3, 0, 0 },
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{ 3, 0, 1 }, { 3, 0, 2 }, { 3, 1, 0 }, { 3, 1, 1 }
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};
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/**
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* Ungrouped mantissa tables; the extra entry is padding to avoid range checks
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*/
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#define SYMMETRIC_DEQUANT(code, levels) (((code - (levels >> 1)) * (1 << 24)) / levels)
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/**
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* Table 7.21
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*/
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const int ff_ac3_bap3_mantissas[7 + 1] = {
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SYMMETRIC_DEQUANT(0, 7),
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SYMMETRIC_DEQUANT(1, 7),
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SYMMETRIC_DEQUANT(2, 7),
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SYMMETRIC_DEQUANT(3, 7),
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SYMMETRIC_DEQUANT(4, 7),
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SYMMETRIC_DEQUANT(5, 7),
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SYMMETRIC_DEQUANT(6, 7),
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};
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/**
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* Table 7.23
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*/
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const int ff_ac3_bap5_mantissas[15 + 1] = {
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SYMMETRIC_DEQUANT(0, 15),
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SYMMETRIC_DEQUANT(1, 15),
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SYMMETRIC_DEQUANT(2, 15),
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SYMMETRIC_DEQUANT(3, 15),
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SYMMETRIC_DEQUANT(4, 15),
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SYMMETRIC_DEQUANT(5, 15),
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SYMMETRIC_DEQUANT(6, 15),
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SYMMETRIC_DEQUANT(7, 15),
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SYMMETRIC_DEQUANT(8, 15),
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SYMMETRIC_DEQUANT(9, 15),
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SYMMETRIC_DEQUANT(10, 15),
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SYMMETRIC_DEQUANT(11, 15),
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SYMMETRIC_DEQUANT(12, 15),
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SYMMETRIC_DEQUANT(13, 15),
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SYMMETRIC_DEQUANT(14, 15),
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};
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const uint8_t ff_eac3_hebap_tab[64] = {
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0, 1, 2, 3, 4, 5, 6, 7, 8, 8,
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8, 8, 9, 9, 9, 10, 10, 10, 10, 11,
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11, 11, 11, 12, 12, 12, 12, 13, 13, 13,
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13, 14, 14, 14, 14, 15, 15, 15, 15, 16,
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16, 16, 16, 17, 17, 17, 17, 18, 18, 18,
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18, 18, 18, 18, 18, 19, 19, 19, 19, 19,
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19, 19, 19, 19,
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};
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/**
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* Table E2.15 Default Spectral Extension Banding Structure
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*/
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const uint8_t ff_eac3_default_spx_band_struct[17] =
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{ 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1 };
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