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

128 lines
3.2 KiB
C

/*
* Lossless video DSP utils
*
* 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 "config.h"
#include "lossless_videodsp.h"
#include "libavcodec/mathops.h"
// 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size
#define pb_7f (~0UL / 255 * 0x7f)
#define pb_80 (~0UL / 255 * 0x80)
static void add_bytes_c(uint8_t *dst, uint8_t *src, ptrdiff_t w)
{
long i;
for (i = 0; i <= w - (int) sizeof(long); i += sizeof(long)) {
long a = *(long *) (src + i);
long b = *(long *) (dst + i);
*(long *) (dst + i) = ((a & pb_7f) + (b & pb_7f)) ^ ((a ^ b) & pb_80);
}
for (; i < w; i++)
dst[i + 0] += src[i + 0];
}
static void add_median_pred_c(uint8_t *dst, const uint8_t *src1,
const uint8_t *diff, ptrdiff_t w,
int *left, int *left_top)
{
int i;
uint8_t l, lt;
l = *left;
lt = *left_top;
for (i = 0; i < w; i++) {
l = mid_pred(l, src1[i], (l + src1[i] - lt) & 0xFF) + diff[i];
lt = src1[i];
dst[i] = l;
}
*left = l;
*left_top = lt;
}
static int add_left_pred_c(uint8_t *dst, const uint8_t *src, ptrdiff_t w,
int acc)
{
int i;
for (i = 0; i < w - 1; i++) {
acc += src[i];
dst[i] = acc;
i++;
acc += src[i];
dst[i] = acc;
}
for (; i < w; i++) {
acc += src[i];
dst[i] = acc;
}
return acc;
}
static int add_left_pred_int16_c(uint16_t *dst, const uint16_t *src, unsigned mask, ptrdiff_t w, unsigned acc){
int i;
for(i=0; i<w-1; i++){
acc+= src[i];
dst[i]= acc &= mask;
i++;
acc+= src[i];
dst[i]= acc &= mask;
}
for(; i<w; i++){
acc+= src[i];
dst[i]= acc &= mask;
}
return acc;
}
static void add_gradient_pred_c(uint8_t *src, const ptrdiff_t stride, const ptrdiff_t width){
int A, B, C, i;
for (i = 0; i < width; i++) {
A = src[i - stride];
B = src[i - (stride + 1)];
C = src[i - 1];
src[i] = (A - B + C + src[i]) & 0xFF;
}
}
void ff_llviddsp_init(LLVidDSPContext *c)
{
c->add_bytes = add_bytes_c;
c->add_median_pred = add_median_pred_c;
c->add_left_pred = add_left_pred_c;
c->add_left_pred_int16 = add_left_pred_int16_c;
c->add_gradient_pred = add_gradient_pred_c;
#if ARCH_PPC
ff_llviddsp_init_ppc(c);
#elif ARCH_X86
ff_llviddsp_init_x86(c);
#endif
}