1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-07 11:13:41 +02:00
FFmpeg/libavcodec/takdsp.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

84 lines
2.1 KiB
C

/*
* TAK decoder
* Copyright (c) 2015 Paul B Mahol
*
* 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 "libavutil/attributes.h"
#include "takdsp.h"
#include "config.h"
static void decorrelate_ls(int32_t *p1, int32_t *p2, int length)
{
int i;
for (i = 0; i < length; i++) {
int32_t a = p1[i];
int32_t b = p2[i];
p2[i] = a + b;
}
}
static void decorrelate_sr(int32_t *p1, int32_t *p2, int length)
{
int i;
for (i = 0; i < length; i++) {
int32_t a = p1[i];
int32_t b = p2[i];
p1[i] = b - a;
}
}
static void decorrelate_sm(int32_t *p1, int32_t *p2, int length)
{
int i;
for (i = 0; i < length; i++) {
int32_t a = p1[i];
int32_t b = p2[i];
a -= b >> 1;
p1[i] = a;
p2[i] = a + b;
}
}
static void decorrelate_sf(int32_t *p1, int32_t *p2, int length, int dshift, int dfactor)
{
int i;
for (i = 0; i < length; i++) {
int32_t a = p1[i];
int32_t b = p2[i];
b = (unsigned)((int)(dfactor * (unsigned)(b >> dshift) + 128) >> 8) << dshift;
p1[i] = b - a;
}
}
av_cold void ff_takdsp_init(TAKDSPContext *c)
{
c->decorrelate_ls = decorrelate_ls;
c->decorrelate_sr = decorrelate_sr;
c->decorrelate_sm = decorrelate_sm;
c->decorrelate_sf = decorrelate_sf;
#if ARCH_X86
ff_takdsp_init_x86(c);
#endif
}