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17966ae5bb
This prevents out of array reads. An alternative solution would be
to check the index but this would require several checks in the
inner loops
Yet another alternative would be to change the index reset logic
but this likely would introduce a difference to the binary decoder
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 8c4aebb58d)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
103 lines
3.3 KiB
C
103 lines
3.3 KiB
C
/*
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* Header file for hardcoded QDM2 tables
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*
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* Copyright (c) 2010 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 AVCODEC_QDM2_TABLEGEN_H
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#define AVCODEC_QDM2_TABLEGEN_H
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#include <stdint.h>
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#include <math.h>
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#include "libavutil/attributes.h"
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#define SOFTCLIP_THRESHOLD 27600
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#define HARDCLIP_THRESHOLD 35716
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#if CONFIG_HARDCODED_TABLES
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#define softclip_table_init()
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#define rnd_table_init()
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#define init_noise_samples()
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#include "libavcodec/qdm2_tables.h"
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#else
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static uint16_t softclip_table[HARDCLIP_THRESHOLD - SOFTCLIP_THRESHOLD + 1];
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static float noise_table[4096 + 20];
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static uint8_t random_dequant_index[256][5];
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static uint8_t random_dequant_type24[128][3];
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static float noise_samples[128];
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static av_cold void softclip_table_init(void) {
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int i;
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double dfl = SOFTCLIP_THRESHOLD - 32767;
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float delta = 1.0 / -dfl;
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for (i = 0; i < HARDCLIP_THRESHOLD - SOFTCLIP_THRESHOLD + 1; i++)
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softclip_table[i] = SOFTCLIP_THRESHOLD - ((int)(sin((float)i * delta) * dfl) & 0x0000FFFF);
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}
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// random generated table
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static av_cold void rnd_table_init(void) {
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int i,j;
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uint32_t ldw,hdw;
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uint64_t tmp64_1;
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uint64_t random_seed = 0;
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float delta = 1.0 / 16384.0;
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for(i = 0; i < 4096 ;i++) {
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random_seed = random_seed * 214013 + 2531011;
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noise_table[i] = (delta * (float)(((int32_t)random_seed >> 16) & 0x00007FFF)- 1.0) * 1.3;
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}
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for (i = 0; i < 256 ;i++) {
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random_seed = 81;
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ldw = i;
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for (j = 0; j < 5 ;j++) {
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random_dequant_index[i][j] = (uint8_t)((ldw / random_seed) & 0xFF);
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ldw = (uint32_t)ldw % (uint32_t)random_seed;
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tmp64_1 = (random_seed * 0x55555556);
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hdw = (uint32_t)(tmp64_1 >> 32);
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random_seed = (uint64_t)(hdw + (ldw >> 31));
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}
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}
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for (i = 0; i < 128 ;i++) {
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random_seed = 25;
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ldw = i;
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for (j = 0; j < 3 ;j++) {
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random_dequant_type24[i][j] = (uint8_t)((ldw / random_seed) & 0xFF);
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ldw = (uint32_t)ldw % (uint32_t)random_seed;
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tmp64_1 = (random_seed * 0x66666667);
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hdw = (uint32_t)(tmp64_1 >> 33);
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random_seed = hdw + (ldw >> 31);
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}
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}
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}
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static av_cold void init_noise_samples(void) {
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int i;
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int random_seed = 0;
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float delta = 1.0 / 16384.0;
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for (i = 0; i < 128;i++) {
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random_seed = random_seed * 214013 + 2531011;
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noise_samples[i] = (delta * (float)((random_seed >> 16) & 0x00007fff) - 1.0);
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}
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}
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#endif /* CONFIG_HARDCODED_TABLES */
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#endif /* AVCODEC_QDM2_TABLEGEN_H */
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