FFmpeg
fdctdsp_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 "libavutil/attributes.h"
20 #include "libavutil/cpu.h"
21 #include "libavutil/x86/cpu.h"
22 #include "libavcodec/avcodec.h"
23 #include "libavcodec/fdctdsp.h"
24 #include "fdct.h"
25 
27  unsigned high_bit_depth)
28 {
30  const int dct_algo = avctx->dct_algo;
31 
32  if (!high_bit_depth) {
33  if ((dct_algo == FF_DCT_AUTO || dct_algo == FF_DCT_MMX)) {
34  if (INLINE_MMX(cpu_flags))
35  c->fdct = ff_fdct_mmx;
36 
38  c->fdct = ff_fdct_mmxext;
39 
41  c->fdct = ff_fdct_sse2;
42  }
43  }
44 }
INLINE_MMX
#define INLINE_MMX(flags)
Definition: cpu.h:86
cpu.h
ff_fdct_mmxext
void ff_fdct_mmxext(int16_t *block)
fdct.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
cpu_flags
static atomic_int cpu_flags
Definition: cpu.c:50
FDCTDSPContext
Definition: fdctdsp.h:26
AVCodecContext::dct_algo
int dct_algo
DCT algorithm, see FF_DCT_* below.
Definition: avcodec.h:1490
ff_fdct_sse2
void ff_fdct_sse2(int16_t *block)
av_cold
#define av_cold
Definition: attributes.h:90
INLINE_SSE2
#define INLINE_SSE2(flags)
Definition: cpu.h:89
FF_DCT_MMX
#define FF_DCT_MMX
Definition: avcodec.h:1494
ff_fdctdsp_init_x86
av_cold void ff_fdctdsp_init_x86(FDCTDSPContext *c, AVCodecContext *avctx, unsigned high_bit_depth)
Definition: fdctdsp_init.c:26
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_fdct_mmx
void ff_fdct_mmx(int16_t *block)
attributes.h
fdctdsp.h
avcodec.h
AVCodecContext
main external API structure.
Definition: avcodec.h:501
FF_DCT_AUTO
#define FF_DCT_AUTO
Definition: avcodec.h:1491
INLINE_MMXEXT
#define INLINE_MMXEXT(flags)
Definition: cpu.h:87