36be9962adf4fb0b5504f78bbc09eb7f8f88c250
[libav.git] / libavcodec / fft.h
1 /*
2 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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_FFT_H
23 #define AVCODEC_FFT_H
24
25 #include <stdint.h>
26 #include "config.h"
27 #include "libavutil/mem.h"
28 #include "avfft.h"
29
30 /* FFT computation */
31
32 struct FFTContext {
33 int nbits;
34 int inverse;
35 uint16_t *revtab;
36 FFTComplex *tmp_buf;
37 int mdct_size; /* size of MDCT (i.e. number of input data * 2) */
38 int mdct_bits; /* n = 2^nbits */
39 /* pre/post rotation tables */
40 FFTSample *tcos;
41 FFTSample *tsin;
42 /**
43 * Do the permutation needed BEFORE calling fft_calc().
44 */
45 void (*fft_permute)(struct FFTContext *s, FFTComplex *z);
46 /**
47 * Do a complex FFT with the parameters defined in ff_fft_init(). The
48 * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
49 */
50 void (*fft_calc)(struct FFTContext *s, FFTComplex *z);
51 void (*imdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
52 void (*imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
53 void (*mdct_calc)(struct FFTContext *s, FFTSample *output, const FFTSample *input);
54 int fft_permutation;
55 #define FF_FFT_PERM_DEFAULT 0
56 #define FF_FFT_PERM_SWAP_LSBS 1
57 int mdct_permutation;
58 #define FF_MDCT_PERM_NONE 0
59 #define FF_MDCT_PERM_INTERLEAVE 1
60 };
61
62 #if CONFIG_HARDCODED_TABLES
63 #define COSTABLE_CONST const
64 #else
65 #define COSTABLE_CONST
66 #endif
67
68 #define COSTABLE(size) \
69 COSTABLE_CONST DECLARE_ALIGNED(16, FFTSample, ff_cos_##size)[size/2]
70
71 extern COSTABLE(16);
72 extern COSTABLE(32);
73 extern COSTABLE(64);
74 extern COSTABLE(128);
75 extern COSTABLE(256);
76 extern COSTABLE(512);
77 extern COSTABLE(1024);
78 extern COSTABLE(2048);
79 extern COSTABLE(4096);
80 extern COSTABLE(8192);
81 extern COSTABLE(16384);
82 extern COSTABLE(32768);
83 extern COSTABLE(65536);
84 extern COSTABLE_CONST FFTSample* const ff_cos_tabs[17];
85
86 /**
87 * Initialize the cosine table in ff_cos_tabs[index]
88 * \param index index in ff_cos_tabs array of the table to initialize
89 */
90 void ff_init_ff_cos_tabs(int index);
91
92 /**
93 * Set up a complex FFT.
94 * @param nbits log2 of the length of the input array
95 * @param inverse if 0 perform the forward transform, if 1 perform the inverse
96 */
97 int ff_fft_init(FFTContext *s, int nbits, int inverse);
98
99 void ff_fft_init_altivec(FFTContext *s);
100 void ff_fft_init_mmx(FFTContext *s);
101 void ff_fft_init_arm(FFTContext *s);
102
103 void ff_fft_end(FFTContext *s);
104
105 int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale);
106 void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
107 void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input);
108 void ff_mdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input);
109 void ff_mdct_end(FFTContext *s);
110
111 #endif /* AVCODEC_FFT_H */