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FFmpeg/libavcodec/celp_math.c
Andreas Rheinhardt 40e6575aa3 all: Replace if (ARCH_FOO) checks by #if ARCH_FOO
This is more spec-compliant because it does not rely
on dead-code elimination by the compiler. Especially
MSVC has problems with this, as can be seen in
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/296373.html
or
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/297022.html

This commit does not eliminate every instance where we rely
on dead code elimination: It only tackles branching to
the initialization of arch-specific dsp code, not e.g. all
uses of CONFIG_ and HAVE_ checks. But maybe it is already
enough to compile FFmpeg with MSVC with whole-programm-optimizations
enabled (if one does not disable too many components).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-06-15 04:56:37 +02:00

129 lines
3.4 KiB
C

/*
* Various fixed-point math operations
*
* Copyright (c) 2008 Vladimir Voroshilov
*
* 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
*/
#include <stdint.h>
#include "config.h"
#include "libavutil/avassert.h"
#include "libavutil/intmath.h"
#include "mathops.h"
#include "celp_math.h"
#ifdef G729_BITEXACT
static const uint16_t exp2a[]=
{
0, 1435, 2901, 4400, 5931, 7496, 9096, 10730,
12400, 14106, 15850, 17632, 19454, 21315, 23216, 25160,
27146, 29175, 31249, 33368, 35534, 37747, 40009, 42320,
44682, 47095, 49562, 52082, 54657, 57289, 59979, 62727,
};
static const uint16_t exp2b[]=
{
3, 712, 1424, 2134, 2845, 3557, 4270, 4982,
5696, 6409, 7124, 7839, 8554, 9270, 9986, 10704,
11421, 12138, 12857, 13576, 14295, 15014, 15734, 16455,
17176, 17898, 18620, 19343, 20066, 20790, 21514, 22238,
};
int ff_exp2(uint16_t power)
{
unsigned int result= exp2a[power>>10] + 0x10000;
av_assert2(power <= 0x7fff);
result= (result<<3) + ((result*exp2b[(power>>5)&31])>>17);
return result + ((result*(power&31)*89)>>22);
}
#endif
/**
* Table used to compute log2(x)
*
* tab_log2[i] = (1<<15) * log2(1 + i/32), i=0..32
*/
static const uint16_t tab_log2[33] =
{
#ifdef G729_BITEXACT
0, 1455, 2866, 4236, 5568, 6863, 8124, 9352,
10549, 11716, 12855, 13967, 15054, 16117, 17156, 18172,
19167, 20142, 21097, 22033, 22951, 23852, 24735, 25603,
26455, 27291, 28113, 28922, 29716, 30497, 31266, 32023, 32767,
#else
4, 1459, 2870, 4240, 5572, 6867, 8127, 9355,
10552, 11719, 12858, 13971, 15057, 16120, 17158, 18175,
19170, 20145, 21100, 22036, 22954, 23854, 24738, 25605,
26457, 27294, 28116, 28924, 29719, 30500, 31269, 32025, 32769,
#endif
};
int ff_log2_q15(uint32_t value)
{
uint8_t power_int;
uint8_t frac_x0;
uint16_t frac_dx;
// Stripping zeros from beginning
power_int = av_log2(value);
value <<= (31 - power_int);
// b31 is always non-zero now
frac_x0 = (value & 0x7c000000) >> 26; // b26-b31 and [32..63] -> [0..31]
frac_dx = (value & 0x03fff800) >> 11;
value = tab_log2[frac_x0];
value += (frac_dx * (tab_log2[frac_x0+1] - tab_log2[frac_x0])) >> 15;
return (power_int << 15) + value;
}
int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length)
{
int i;
int64_t sum = 0;
for (i = 0; i < length; i++)
sum += MUL16(a[i], b[i]);
return sum;
}
float ff_dot_productf(const float* a, const float* b, int length)
{
float sum = 0;
int i;
for(i=0; i<length; i++)
sum += a[i] * b[i];
return sum;
}
void ff_celp_math_init(CELPMContext *c)
{
c->dot_productf = ff_dot_productf;
#if HAVE_MIPSFPU
ff_celp_math_init_mips(c);
#endif
}