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 #if !defined(AVCODEC_RDFT_H) && (!defined(FFT_FLOAT) || FFT_FLOAT)
23 #define AVCODEC_RDFT_H
24 
25 #include "config.h"
26 
27 #include "fft.h"
28 
29 #if CONFIG_HARDCODED_TABLES
30 #   define SINTABLE_CONST const
31 #else
32 #   define SINTABLE_CONST
33 #endif
34 
35 #define SINTABLE(size) \
36     SINTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_sin_##size)[size/2]
37 
38 extern SINTABLE(16);
39 extern SINTABLE(32);
40 extern SINTABLE(64);
41 extern SINTABLE(128);
42 extern SINTABLE(256);
43 extern SINTABLE(512);
44 extern SINTABLE(1024);
45 extern SINTABLE(2048);
46 extern SINTABLE(4096);
47 extern SINTABLE(8192);
48 extern SINTABLE(16384);
49 extern SINTABLE(32768);
50 extern SINTABLE(65536);
51 
52 struct RDFTContext {
53     int nbits;
54     int inverse;
55     int sign_convention;
56 
57     /* pre/post rotation tables */
58     const FFTSample *tcos;
59     SINTABLE_CONST FFTSample *tsin;
60     FFTContext fft;
61     void (*rdft_calc)(struct RDFTContext *s, FFTSample *z);
62 };
63 
64 /**
65  * Set up a real FFT.
66  * @param nbits           log2 of the length of the input array
67  * @param trans           the type of transform
68  */
69 int ff_rdft_init(RDFTContext *s, int nbits, enum RDFTransformType trans);
70 void ff_rdft_end(RDFTContext *s);
71 
72 void ff_rdft_init_arm(RDFTContext *s);
73 
74 
75 #endif /* AVCODEC_RDFT_H */
76