FFmpeg
xvididct_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 "config.h"
20 #include "libavutil/attributes.h"
21 #include "libavutil/cpu.h"
22 #include "libavutil/x86/cpu.h"
23 #include "libavcodec/idctdsp.h"
24 #include "libavcodec/xvididct.h"
25 
26 #include "xvididct.h"
27 
29  unsigned high_bit_depth)
30 {
31 #if HAVE_X86ASM
33 
34  if (high_bit_depth ||
35  !(avctx->idct_algo == FF_IDCT_AUTO ||
36  avctx->idct_algo == FF_IDCT_XVID))
37  return;
38 
39  if (EXTERNAL_SSE2(cpu_flags)) {
40  c->idct_put = ff_xvid_idct_put_sse2;
41  c->idct_add = ff_xvid_idct_add_sse2;
42  c->idct = ff_xvid_idct_sse2;
43  c->perm_type = FF_IDCT_PERM_SSE2;
44  }
45 #endif /* HAVE_X86ASM */
46 }
cpu.h
xvididct.h
av_get_cpu_flags
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:103
cpu_flags
static atomic_int cpu_flags
Definition: cpu.c:52
FF_IDCT_AUTO
#define FF_IDCT_AUTO
Definition: avcodec.h:1548
FF_IDCT_XVID
#define FF_IDCT_XVID
Definition: avcodec.h:1555
av_cold
#define av_cold
Definition: attributes.h:90
xvididct.h
ff_xvid_idct_init_x86
av_cold void ff_xvid_idct_init_x86(IDCTDSPContext *c, AVCodecContext *avctx, unsigned high_bit_depth)
Definition: xvididct_init.c:28
ff_xvid_idct_put_sse2
void ff_xvid_idct_put_sse2(uint8_t *dest, ptrdiff_t line_size, short *block)
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_xvid_idct_sse2
void ff_xvid_idct_sse2(short *block)
attributes.h
EXTERNAL_SSE2
#define EXTERNAL_SSE2(flags)
Definition: cpu.h:59
AVCodecContext::idct_algo
int idct_algo
IDCT algorithm, see FF_IDCT_* below.
Definition: avcodec.h:1547
idctdsp.h
IDCTDSPContext
Definition: idctdsp.h:43
FF_IDCT_PERM_SSE2
@ FF_IDCT_PERM_SSE2
Definition: idctdsp.h:33
AVCodecContext
main external API structure.
Definition: avcodec.h:445
ff_xvid_idct_add_sse2
void ff_xvid_idct_add_sse2(uint8_t *dest, ptrdiff_t line_size, short *block)