GNU Radio's LORA_SDR Package
kiss_fft.h
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1/*
2 * Copyright (c) 2003-2010, Mark Borgerding. All rights reserved.
3 * This file is part of KISS FFT - https://github.com/mborgerding/kissfft
4 *
5 * SPDX-License-Identifier: BSD-3-Clause
6 * See COPYING file for more information.
7 */
8
9#ifndef KISS_FFT_H
10#define KISS_FFT_H
11
12#include <stdlib.h>
13#include <stdio.h>
14#include <math.h>
15#include <string.h>
16
17#ifdef __cplusplus
18extern "C" {
19#endif
20
21/*
22 ATTENTION!
23 If you would like a :
24 -- a utility that will handle the caching of fft objects
25 -- real-only (no imaginary time component ) FFT
26 -- a multi-dimensional FFT
27 -- a command-line utility to perform ffts
28 -- a command-line utility to perform fast-convolution filtering
29
30 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c
31 in the tools/ directory.
32*/
33/* User may override KISS_FFT_MALLOC and/or KISS_FFT_FREE. */
34#ifdef USE_SIMD
35# include <xmmintrin.h>
36# define kiss_fft_scalar __m128
37# ifndef KISS_FFT_MALLOC
38# define KISS_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16)
39# endif
40# ifndef KISS_FFT_FREE
41# define KISS_FFT_FREE _mm_free
42# endif
43#else
44# ifndef KISS_FFT_MALLOC
45# define KISS_FFT_MALLOC malloc
46# endif
47# ifndef KISS_FFT_FREE
48# define KISS_FFT_FREE free
49# endif
50#endif
51
52
53#ifdef FIXED_POINT
54#include <stdint.h>
55# if (FIXED_POINT == 32)
56# define kiss_fft_scalar int32_t
57# else
58# define kiss_fft_scalar int16_t
59# endif
60#else
61# ifndef kiss_fft_scalar
62/* default is float */
63# define kiss_fft_scalar float
64# endif
65#endif
66
67typedef struct {
71
73
74/*
75 * kiss_fft_alloc
76 *
77 * Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
78 *
79 * typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);
80 *
81 * The return value from fft_alloc is a cfg buffer used internally
82 * by the fft routine or NULL.
83 *
84 * If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.
85 * The returned value should be free()d when done to avoid memory leaks.
86 *
87 * The state can be placed in a user supplied buffer 'mem':
88 * If lenmem is not NULL and mem is not NULL and *lenmem is large enough,
89 * then the function places the cfg in mem and the size used in *lenmem
90 * and returns mem.
91 *
92 * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),
93 * then the function returns NULL and places the minimum cfg
94 * buffer size in *lenmem.
95 * */
96
97kiss_fft_cfg kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem);
98
99/*
100 * kiss_fft(cfg,in_out_buf)
101 *
102 * Perform an FFT on a complex input buffer.
103 * for a forward FFT,
104 * fin should be f[0] , f[1] , ... ,f[nfft-1]
105 * fout will be F[0] , F[1] , ... ,F[nfft-1]
106 * Note that each element is complex and can be accessed like
107 f[k].r and f[k].i
108 * */
110
111/*
112 A more generic version of the above function. It reads its input from every Nth sample.
113 * */
114void kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);
115
116/* If kiss_fft_alloc allocated a buffer, it is one contiguous
117 buffer and can be simply free()d when no longer needed*/
118#define kiss_fft_free KISS_FFT_FREE
119
120/*
121 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up
122 your compiler output to call this before you exit.
123*/
125
126
127/*
128 * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5)
129 */
131
132/* for real ffts, we need an even size */
133#define kiss_fftr_next_fast_size_real(n) \
134 (kiss_fft_next_fast_size( ((n)+1)>>1)<<1)
135
136
137#ifdef __cplusplus
138}
139#endif
140
141#endif
void kiss_fft_stride(kiss_fft_cfg cfg, const kiss_fft_cpx *fin, kiss_fft_cpx *fout, int fin_stride)
int kiss_fft_next_fast_size(int n)
#define kiss_fft_scalar
Definition kiss_fft.h:63
void kiss_fft_cleanup(void)
void kiss_fft(kiss_fft_cfg cfg, const kiss_fft_cpx *fin, kiss_fft_cpx *fout)
kiss_fft_cfg kiss_fft_alloc(int nfft, int inverse_fft, void *mem, size_t *lenmem)
struct kiss_fft_state * kiss_fft_cfg
Definition kiss_fft.h:72
Definition kiss_fft.h:67
kiss_fft_scalar r
Definition kiss_fft.h:68
kiss_fft_scalar i
Definition kiss_fft.h:69
Definition _kiss_fft_guts.h:22
int nfft
Definition _kiss_fft_guts.h:23