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rdft.h
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1 /*
2  * (I)RDFT transforms
3  * Copyright (c) 2009 Alex Converse <alex dot converse at gmail dot com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVCODEC_RDFT_H
23 #define AVCODEC_RDFT_H
24 
25 #include "config.h"
26 #include "fft.h"
27 
28 #if CONFIG_HARDCODED_TABLES
29 # define SINTABLE_CONST const
30 #else
31 # define SINTABLE_CONST
32 #endif
33 
34 #define SINTABLE(size) \
35  SINTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_sin_##size)[size/2]
36 
37 extern SINTABLE(16);
38 extern SINTABLE(32);
39 extern SINTABLE(64);
40 extern SINTABLE(128);
41 extern SINTABLE(256);
42 extern SINTABLE(512);
43 extern SINTABLE(1024);
44 extern SINTABLE(2048);
45 extern SINTABLE(4096);
46 extern SINTABLE(8192);
47 extern SINTABLE(16384);
48 extern SINTABLE(32768);
49 extern SINTABLE(65536);
50 
51 struct RDFTContext {
52  int nbits;
53  int inverse;
55 
56  /* pre/post rotation tables */
57  const FFTSample *tcos;
61 };
62 
63 /**
64  * Set up a real FFT.
65  * @param nbits log2 of the length of the input array
66  * @param trans the type of transform
67  */
68 int ff_rdft_init(RDFTContext *s, int nbits, enum RDFTransformType trans);
70 
72 
73 
74 #endif /* AVCODEC_RDFT_H */