FFmpeg
pixblockdsp_init.c
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1 /*
2  * SIMD-optimized pixel operations
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "libavutil/attributes.h"
22 #include "libavutil/cpu.h"
23 #include "libavutil/x86/cpu.h"
24 #include "libavcodec/pixblockdsp.h"
25 
26 void ff_get_pixels_sse2(int16_t *block, const uint8_t *pixels, ptrdiff_t stride);
27 void ff_diff_pixels_sse2(int16_t *block, const uint8_t *s1, const uint8_t *s2,
28  ptrdiff_t stride);
29 
31  AVCodecContext *avctx,
32  unsigned high_bit_depth)
33 {
35 
36  if (EXTERNAL_SSE2(cpu_flags)) {
37  if (!high_bit_depth) {
38  c->get_pixels_unaligned =
39  c->get_pixels = ff_get_pixels_sse2;
40  }
41  c->diff_pixels_unaligned =
42  c->diff_pixels = ff_diff_pixels_sse2;
43  }
44 }
cpu.h
ff_diff_pixels_sse2
void ff_diff_pixels_sse2(int16_t *block, const uint8_t *s1, const uint8_t *s2, ptrdiff_t stride)
ff_pixblockdsp_init_x86
av_cold void ff_pixblockdsp_init_x86(PixblockDSPContext *c, AVCodecContext *avctx, unsigned high_bit_depth)
Definition: pixblockdsp_init.c:30
av_get_cpu_flags
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:101
cpu_flags
static atomic_int cpu_flags
Definition: cpu.c:52
av_cold
#define av_cold
Definition: attributes.h:90
s1
#define s1
Definition: regdef.h:38
PixblockDSPContext
Definition: pixblockdsp.h:28
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
s2
#define s2
Definition: regdef.h:39
cpu.h
attributes.h
EXTERNAL_SSE2
#define EXTERNAL_SSE2(flags)
Definition: cpu.h:59
ff_get_pixels_sse2
void ff_get_pixels_sse2(int16_t *block, const uint8_t *pixels, ptrdiff_t stride)
stride
#define stride
Definition: h264pred_template.c:537
AVCodecContext
main external API structure.
Definition: avcodec.h:389
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
pixblockdsp.h