GNU Radio 3.6.3.1 C++ API
kiss_fft.h
Go to the documentation of this file.
1
#ifndef KISS_FFT_H
2
#define KISS_FFT_H
3
4
#include <stdlib.h>
5
#include <stdio.h>
6
#include <math.h>
7
#include <string.h>
8
9
#ifdef __cplusplus
10
extern
"C"
{
11
#endif
12
13
/*
14
ATTENTION!
15
If you would like a :
16
-- a utility that will handle the caching of fft objects
17
-- real-only (no imaginary time component ) FFT
18
-- a multi-dimensional FFT
19
-- a command-line utility to perform ffts
20
-- a command-line utility to perform fast-convolution filtering
21
22
Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c
23
in the tools/ directory.
24
*/
25
26
#ifdef USE_SIMD
27
# include <xmmintrin.h>
28
# define kiss_fft_scalar __m128
29
#define KISS_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16)
30
#define KISS_FFT_FREE _mm_free
31
#else
32
#define KISS_FFT_MALLOC malloc
33
#define KISS_FFT_FREE free
34
#endif
35
36
37
#ifdef FIXED_POINT
38
#include <sys/types.h>
39
# if (FIXED_POINT == 32)
40
# define kiss_fft_scalar int32_t
41
# else
42
# define kiss_fft_scalar int16_t
43
# endif
44
#else
45
# ifndef kiss_fft_scalar
46
/* default is float */
47
# define kiss_fft_scalar float
48
# endif
49
#endif
50
51
typedef
struct
{
52
kiss_fft_scalar
r
;
53
kiss_fft_scalar
i
;
54
}
kiss_fft_cpx
;
55
56
typedef
struct
kiss_fft_state
*
kiss_fft_cfg
;
57
58
/*
59
* kiss_fft_alloc
60
*
61
* Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
62
*
63
* typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);
64
*
65
* The return value from fft_alloc is a cfg buffer used internally
66
* by the fft routine or NULL.
67
*
68
* If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.
69
* The returned value should be free()d when done to avoid memory leaks.
70
*
71
* The state can be placed in a user supplied buffer 'mem':
72
* If lenmem is not NULL and mem is not NULL and *lenmem is large enough,
73
* then the function places the cfg in mem and the size used in *lenmem
74
* and returns mem.
75
*
76
* If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),
77
* then the function returns NULL and places the minimum cfg
78
* buffer size in *lenmem.
79
* */
80
81
kiss_fft_cfg
kiss_fft_alloc
(
int
nfft
,
int
inverse_fft,
void
* mem,
size_t
* lenmem);
82
83
/*
84
* kiss_fft(cfg,in_out_buf)
85
*
86
* Perform an FFT on a complex input buffer.
87
* for a forward FFT,
88
* fin should be f[0] , f[1] , ... ,f[nfft-1]
89
* fout will be F[0] , F[1] , ... ,F[nfft-1]
90
* Note that each element is complex and can be accessed like
91
f[k].r and f[k].i
92
* */
93
void
kiss_fft
(kiss_fft_cfg cfg,
const
kiss_fft_cpx
*fin,
kiss_fft_cpx
*fout);
94
95
/*
96
A more generic version of the above function. It reads its input from every Nth sample.
97
* */
98
void
kiss_fft_stride
(kiss_fft_cfg cfg,
const
kiss_fft_cpx
*fin,
kiss_fft_cpx
*fout,
int
fin_stride);
99
100
/* If kiss_fft_alloc allocated a buffer, it is one contiguous
101
buffer and can be simply free()d when no longer needed*/
102
#define kiss_fft_free free
103
104
/*
105
Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up
106
your compiler output to call this before you exit.
107
*/
108
void
kiss_fft_cleanup
(
void
);
109
110
111
/*
112
* Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5)
113
*/
114
int
kiss_fft_next_fast_size
(
int
n);
115
116
/* for real ffts, we need an even size */
117
#define kiss_fftr_next_fast_size_real(n) \
118
(kiss_fft_next_fast_size( ((n)+1)>>1)<<1)
119
120
#ifdef __cplusplus
121
}
122
#endif
123
124
#endif
gnuradio
gr-vocoder
lib
codec2
kiss_fft.h
Generated by
1.8.1.2