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
AAC_RENAME(ff_cbrt_tableinit)40 av_cold void AAC_RENAME(ff_cbrt_tableinit)(void)
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 */
74