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// Define KISS_FFT_SHARED macro to properly export symbols
18#ifdef KISS_FFT_SHARED
19# ifdef _WIN32
20# ifdef KISS_FFT_BUILD
21# define KISS_FFT_API __declspec(dllexport)
22# else
23# define KISS_FFT_API __declspec(dllimport)
24# endif
25# else
26# define KISS_FFT_API __attribute__ ((visibility ("default")))
27# endif
28#else
29# define KISS_FFT_API
30#endif
31
32#ifdef __cplusplus
33extern "C" {
34#endif
35
36/*
37 ATTENTION!
38 If you would like a :
39 -- a utility that will handle the caching of fft objects
40 -- real-only (no imaginary time component ) FFT
41 -- a multi-dimensional FFT
42 -- a command-line utility to perform ffts
43 -- a command-line utility to perform fast-convolution filtering
44
45 Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c
46 in the tools/ directory.
47*/
48
49/* User may override KISS_FFT_MALLOC and/or KISS_FFT_FREE. */
50#ifdef USE_SIMD
51# include <xmmintrin.h>
52# define kiss_fft_scalar __m128
53# ifndef KISS_FFT_MALLOC
54# define KISS_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16)
55# define KISS_FFT_ALIGN_CHECK(ptr)
56# define KISS_FFT_ALIGN_SIZE_UP(size) ((size + 15UL) & ~0xFUL)
57# endif
58# ifndef KISS_FFT_FREE
59# define KISS_FFT_FREE _mm_free
60# endif
61#else
62# define KISS_FFT_ALIGN_CHECK(ptr)
63# define KISS_FFT_ALIGN_SIZE_UP(size) (size)
64# ifndef KISS_FFT_MALLOC
65# define KISS_FFT_MALLOC malloc
66# endif
67# ifndef KISS_FFT_FREE
68# define KISS_FFT_FREE free
69# endif
70#endif
71
72
73#ifdef FIXED_POINT
74#include <stdint.h>
75# if (FIXED_POINT == 32)
76# define kiss_fft_scalar int32_t
77# else
78# define kiss_fft_scalar int16_t
79# endif
80#else
81# ifndef kiss_fft_scalar
82/* default is float */
83# define kiss_fft_scalar float
84# endif
85#endif
86
87typedef struct {
88 kiss_fft_scalar r;
89 kiss_fft_scalar i;
90}kiss_fft_cpx;
91
92typedef struct kiss_fft_state* kiss_fft_cfg;
93
94/*
95 * kiss_fft_alloc
96 *
97 * Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
98 *
99 * typical usage: kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);
100 *
101 * The return value from fft_alloc is a cfg buffer used internally
102 * by the fft routine or NULL.
103 *
104 * If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.
105 * The returned value should be free()d when done to avoid memory leaks.
106 *
107 * The state can be placed in a user supplied buffer 'mem':
108 * If lenmem is not NULL and mem is not NULL and *lenmem is large enough,
109 * then the function places the cfg in mem and the size used in *lenmem
110 * and returns mem.
111 *
112 * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),
113 * then the function returns NULL and places the minimum cfg
114 * buffer size in *lenmem.
115 * */
116
117kiss_fft_cfg KISS_FFT_API kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem);
118
119/*
120 * kiss_fft(cfg,in_out_buf)
121 *
122 * Perform an FFT on a complex input buffer.
123 * for a forward FFT,
124 * fin should be f[0] , f[1] , ... ,f[nfft-1]
125 * fout will be F[0] , F[1] , ... ,F[nfft-1]
126 * Note that each element is complex and can be accessed like
127 f[k].r and f[k].i
128 * */
129void KISS_FFT_API kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
130
131/*
132 A more generic version of the above function. It reads its input from every Nth sample.
133 * */
134void KISS_FFT_API kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);
135
136/* If kiss_fft_alloc allocated a buffer, it is one contiguous
137 buffer and can be simply free()d when no longer needed*/
138#define kiss_fft_free KISS_FFT_FREE
139
140/*
141 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up
142 your compiler output to call this before you exit.
143*/
144void KISS_FFT_API kiss_fft_cleanup(void);
145
146
147/*
148 * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5)
149 */
150int KISS_FFT_API kiss_fft_next_fast_size(int n);
151
152/* for real ffts, we need an even size */
153#define kiss_fftr_next_fast_size_real(n) \
154 (kiss_fft_next_fast_size( ((n)+1)>>1)<<1)
155
156#ifdef __cplusplus
157}
158#endif
159
160#endif
161