FFmpeg
cbrt_tablegen.h
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1 /*
2  * Header file for hardcoded AAC cube-root table
3  *
4  * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #ifndef AVCODEC_CBRT_TABLEGEN_H
24 #define AVCODEC_CBRT_TABLEGEN_H
25 
26 #include <stdint.h>
27 #include <math.h>
28 #include "libavutil/attributes.h"
29 #include "libavutil/intfloat.h"
30 #include "libavcodec/aac_defines.h"
31 
32 #if USE_FIXED
33 #define CBRT(x) lrint((x) * 8192)
34 #else
35 #define CBRT(x) av_float2int((float)(x))
36 #endif
37 
38 uint32_t AAC_RENAME(ff_cbrt_tab)[1 << 13];
39 
41 {
42  static double cbrt_tab_dbl[1 << 13];
43  if (!AAC_RENAME(ff_cbrt_tab)[(1<<13) - 1]) {
44  int i, j, k;
45  double cbrt_val;
46 
47  for (i = 1; i < 1<<13; i++)
48  cbrt_tab_dbl[i] = 1;
49 
50  /* have to take care of non-squarefree numbers */
51  for (i = 2; i < 90; i++) {
52  if (cbrt_tab_dbl[i] == 1) {
53  cbrt_val = i * cbrt(i);
54  for (k = i; k < 1<<13; k *= i)
55  for (j = k; j < 1<<13; j += k)
56  cbrt_tab_dbl[j] *= cbrt_val;
57  }
58  }
59 
60  for (i = 91; i <= 8191; i+= 2) {
61  if (cbrt_tab_dbl[i] == 1) {
62  cbrt_val = i * cbrt(i);
63  for (j = i; j < 1<<13; j += i)
64  cbrt_tab_dbl[j] *= cbrt_val;
65  }
66  }
67 
68  for (i = 0; i < 1<<13; i++)
69  AAC_RENAME(ff_cbrt_tab)[i] = CBRT(cbrt_tab_dbl[i]);
70  }
71 }
72 
73 #endif /* AVCODEC_CBRT_TABLEGEN_H */
Macro definitions for various function/variable attributes.
#define av_cold
Definition: attributes.h:82
uint32_t AAC_RENAME(ff_cbrt_tab)[1<< 13]
uint32_t ff_cbrt_tab[1<< 13]
#define cbrt
Definition: tablegen.h:35
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
av_cold void AAC_RENAME() ff_cbrt_tableinit(void)
Definition: cbrt_tablegen.h:40
#define CBRT(x)
Definition: cbrt_tablegen.h:35