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FFmpeg/libavcodec/qdm2_tablegen.h
Michael Niedermayer 5c8ffbaa7f qdm2: simplify arithmetic coder tables generation
Someone should rename the variables, theres nothing random in there

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
2013-03-06 04:56:33 +01:00

98 lines
2.9 KiB
C

/*
* Header file for hardcoded QDM2 tables
*
* Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_QDM2_TABLEGEN_H
#define AVCODEC_QDM2_TABLEGEN_H
#include <stdint.h>
#include <math.h>
#include "libavutil/attributes.h"
#define SOFTCLIP_THRESHOLD 27600
#define HARDCLIP_THRESHOLD 35716
#if CONFIG_HARDCODED_TABLES
#define softclip_table_init()
#define rnd_table_init()
#define init_noise_samples()
#include "libavcodec/qdm2_tables.h"
#else
static uint16_t softclip_table[HARDCLIP_THRESHOLD - SOFTCLIP_THRESHOLD + 1];
static float noise_table[4096 + 20];
static uint8_t random_dequant_index[256][5];
static uint8_t random_dequant_type24[128][3];
static float noise_samples[128];
static av_cold void softclip_table_init(void) {
int i;
double dfl = SOFTCLIP_THRESHOLD - 32767;
float delta = 1.0 / -dfl;
for (i = 0; i < HARDCLIP_THRESHOLD - SOFTCLIP_THRESHOLD + 1; i++)
softclip_table[i] = SOFTCLIP_THRESHOLD - ((int)(sin((float)i * delta) * dfl) & 0x0000FFFF);
}
// random generated table
static av_cold void rnd_table_init(void) {
int i,j;
uint32_t ldw;
uint64_t random_seed = 0;
float delta = 1.0 / 16384.0;
for(i = 0; i < 4096 ;i++) {
random_seed = random_seed * 214013 + 2531011;
noise_table[i] = (delta * (float)(((int32_t)random_seed >> 16) & 0x00007FFF)- 1.0) * 1.3;
}
for (i = 0; i < 256 ;i++) {
random_seed = 81;
ldw = i;
for (j = 0; j < 5 ;j++) {
random_dequant_index[i][j] = ldw / random_seed;
ldw %= random_seed;
random_seed /= 3;
}
}
for (i = 0; i < 128 ;i++) {
random_seed = 25;
ldw = i;
for (j = 0; j < 3 ;j++) {
random_dequant_type24[i][j] = ldw / random_seed;
ldw %= random_seed;
random_seed /= 5;
}
}
}
static av_cold void init_noise_samples(void) {
int i;
unsigned random_seed = 0;
float delta = 1.0 / 16384.0;
for (i = 0; i < 128;i++) {
random_seed = random_seed * 214013 + 2531011;
noise_samples[i] = (delta * (float)((random_seed >> 16) & 0x00007fff) - 1.0);
}
}
#endif /* CONFIG_HARDCODED_TABLES */
#endif /* AVCODEC_QDM2_TABLEGEN_H */