FFmpeg
blockdsp_init.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include <stdint.h>
20 
21 #include "config.h"
22 #include "libavutil/attributes.h"
23 #include "libavutil/internal.h"
24 #include "libavutil/cpu.h"
25 #include "libavutil/x86/cpu.h"
26 #include "libavcodec/blockdsp.h"
27 #include "libavcodec/version.h"
28 
29 void ff_clear_block_mmx(int16_t *block);
30 void ff_clear_block_sse(int16_t *block);
31 void ff_clear_block_avx(int16_t *block);
32 void ff_clear_blocks_mmx(int16_t *blocks);
33 void ff_clear_blocks_sse(int16_t *blocks);
34 void ff_clear_blocks_avx(int16_t *blocks);
35 
37  AVCodecContext *avctx)
38 {
39 #if HAVE_X86ASM
41 
42  if (EXTERNAL_MMX(cpu_flags)) {
43  c->clear_block = ff_clear_block_mmx;
44  c->clear_blocks = ff_clear_blocks_mmx;
45  }
46 
47  /* XvMCCreateBlocks() may not allocate 16-byte aligned blocks */
48  if (CONFIG_XVMC && avctx->hwaccel && avctx->hwaccel->decode_mb)
49  return;
50 
51  if (EXTERNAL_SSE(cpu_flags)) {
52  c->clear_block = ff_clear_block_sse;
53  c->clear_blocks = ff_clear_blocks_sse;
54  }
56  c->clear_block = ff_clear_block_avx;
57  c->clear_blocks = ff_clear_blocks_avx;
58  }
59 #endif /* HAVE_X86ASM */
60 }
AVCodecContext::hwaccel
const struct AVHWAccel * hwaccel
Hardware accelerator in use.
Definition: avcodec.h:1465
cpu.h
blockdsp.h
ff_clear_block_mmx
void ff_clear_block_mmx(int16_t *block)
ff_clear_blocks_sse
void ff_clear_blocks_sse(int16_t *blocks)
version.h
av_get_cpu_flags
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:95
BlockDSPContext
Definition: blockdsp.h:35
cpu_flags
static atomic_int cpu_flags
Definition: cpu.c:50
av_cold
#define av_cold
Definition: attributes.h:90
EXTERNAL_SSE
#define EXTERNAL_SSE(flags)
Definition: cpu.h:58
EXTERNAL_AVX_FAST
#define EXTERNAL_AVX_FAST(flags)
Definition: cpu.h:71
ff_blockdsp_init_x86
av_cold void ff_blockdsp_init_x86(BlockDSPContext *c, AVCodecContext *avctx)
Definition: blockdsp_init.c:36
ff_clear_blocks_avx
void ff_clear_blocks_avx(int16_t *blocks)
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
cpu.h
ff_clear_block_avx
void ff_clear_block_avx(int16_t *block)
attributes.h
ff_clear_block_sse
void ff_clear_block_sse(int16_t *block)
internal.h
ff_clear_blocks_mmx
void ff_clear_blocks_mmx(int16_t *blocks)
AVHWAccel::decode_mb
void(* decode_mb)(struct MpegEncContext *s)
Called for every Macroblock in a slice.
Definition: avcodec.h:2264
AVCodecContext
main external API structure.
Definition: avcodec.h:501
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
EXTERNAL_MMX
#define EXTERNAL_MMX(flags)
Definition: cpu.h:56