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
38uint32_t AAC_RENAME(ff_cbrt_tab)[1 << 13];
39
40av_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