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FFmpeg/libavcodec/huffyuvdsp.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

93 lines
2.7 KiB
C

/*
* 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/attributes.h"
#include "mathops.h"
#include "huffyuvdsp.h"
// 0x00010001 or 0x0001000100010001 or whatever, depending on the cpu's native arithmetic size
#define pw_1 (ULONG_MAX / UINT16_MAX)
static void add_int16_c(uint16_t *dst, const uint16_t *src, unsigned mask, int w){
long i;
unsigned long pw_lsb = (mask >> 1) * pw_1;
unsigned long pw_msb = pw_lsb + pw_1;
for (i = 0; i <= w - (int)sizeof(long)/2; i += sizeof(long)/2) {
long a = *(long*)(src+i);
long b = *(long*)(dst+i);
*(long*)(dst+i) = ((a&pw_lsb) + (b&pw_lsb)) ^ ((a^b)&pw_msb);
}
for(; i<w; i++)
dst[i] = (dst[i] + src[i]) & mask;
}
static void add_hfyu_median_pred_int16_c(uint16_t *dst, const uint16_t *src, const uint16_t *diff, unsigned mask, int w, int *left, int *left_top){
int i;
uint16_t l, lt;
l = *left;
lt = *left_top;
for(i=0; i<w; i++){
l = (mid_pred(l, src[i], (l + src[i] - lt) & mask) + diff[i]) & mask;
lt = src[i];
dst[i] = l;
}
*left = l;
*left_top = lt;
}
static void add_hfyu_left_pred_bgr32_c(uint8_t *dst, const uint8_t *src,
intptr_t w, uint8_t *left)
{
int i;
uint8_t r = left[R], g = left[G], b = left[B], a = left[A];
for (i = 0; i < w; i++) {
b += src[4 * i + B];
g += src[4 * i + G];
r += src[4 * i + R];
a += src[4 * i + A];
dst[4 * i + B] = b;
dst[4 * i + G] = g;
dst[4 * i + R] = r;
dst[4 * i + A] = a;
}
left[B] = b;
left[G] = g;
left[R] = r;
left[A] = a;
}
av_cold void ff_huffyuvdsp_init(HuffYUVDSPContext *c, enum AVPixelFormat pix_fmt)
{
c->add_int16 = add_int16_c;
c->add_hfyu_median_pred_int16 = add_hfyu_median_pred_int16_c;
c->add_hfyu_left_pred_bgr32 = add_hfyu_left_pred_bgr32_c;
#if ARCH_X86
ff_huffyuvdsp_init_x86(c, pix_fmt);
#endif
}