1 files changed, 160 insertions, 0 deletions
diff --git a/kiss/kiss_fft.h b/kiss/kiss_fft.h
new file mode 100644
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--- /dev/null
+++ b/kiss/kiss_fft.h
@@ -0,0 +1,160 @@
+/*
+ *  Copyright (c) 2003-2010, Mark Borgerding. All rights reserved.
+ *  This file is part of KISS FFT - https://github.com/mborgerding/kissfft
+ *
+ *  SPDX-License-Identifier: BSD-3-Clause
+ *  See COPYING file for more information.
+ */
+
+#ifndef KISS_FFT_H
+#define KISS_FFT_H
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+
+// Define KISS_FFT_SHARED macro to properly export symbols
+#ifdef KISS_FFT_SHARED
+# ifdef _WIN32
+#  ifdef KISS_FFT_BUILD
+#   define KISS_FFT_API __declspec(dllexport)
+#  else
+#   define KISS_FFT_API __declspec(dllimport)
+#  endif
+# else
+#  define KISS_FFT_API __attribute__ ((visibility ("default")))
+# endif
+#else
+# define KISS_FFT_API
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ ATTENTION!
+ If you would like a :
+ -- a utility that will handle the caching of fft objects
+ -- real-only (no imaginary time component ) FFT
+ -- a multi-dimensional FFT
+ -- a command-line utility to perform ffts
+ -- a command-line utility to perform fast-convolution filtering
+
+ Then see kfc.h kiss_fftr.h kiss_fftnd.h fftutil.c kiss_fastfir.c
+  in the tools/ directory.
+*/
+
+/* User may override KISS_FFT_MALLOC and/or KISS_FFT_FREE. */
+#ifdef USE_SIMD
+# include <xmmintrin.h>
+# define kiss_fft_scalar __m128
+# ifndef KISS_FFT_MALLOC
+#  define KISS_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16)
+#  define KISS_FFT_ALIGN_CHECK(ptr) 
+#  define KISS_FFT_ALIGN_SIZE_UP(size) ((size + 15UL) & ~0xFUL)
+# endif
+# ifndef KISS_FFT_FREE
+#  define KISS_FFT_FREE _mm_free
+# endif
+#else
+# define KISS_FFT_ALIGN_CHECK(ptr)
+# define KISS_FFT_ALIGN_SIZE_UP(size) (size)
+# ifndef KISS_FFT_MALLOC
+#  define KISS_FFT_MALLOC malloc
+# endif
+# ifndef KISS_FFT_FREE
+#  define KISS_FFT_FREE free
+# endif
+#endif
+
+
+#ifdef FIXED_POINT
+#include <stdint.h>
+# if (FIXED_POINT == 32)
+#  define kiss_fft_scalar int32_t
+# else	
+#  define kiss_fft_scalar int16_t
+# endif
+#else
+# ifndef kiss_fft_scalar
+/*  default is float */
+#   define kiss_fft_scalar float
+# endif
+#endif
+
+typedef struct {
+    kiss_fft_scalar r;
+    kiss_fft_scalar i;
+}kiss_fft_cpx;
+
+typedef struct kiss_fft_state* kiss_fft_cfg;
+
+/* 
+ *  kiss_fft_alloc
+ *  
+ *  Initialize a FFT (or IFFT) algorithm's cfg/state buffer.
+ *
+ *  typical usage:      kiss_fft_cfg mycfg=kiss_fft_alloc(1024,0,NULL,NULL);
+ *
+ *  The return value from fft_alloc is a cfg buffer used internally
+ *  by the fft routine or NULL.
+ *
+ *  If lenmem is NULL, then kiss_fft_alloc will allocate a cfg buffer using malloc.
+ *  The returned value should be free()d when done to avoid memory leaks.
+ *  
+ *  The state can be placed in a user supplied buffer 'mem':
+ *  If lenmem is not NULL and mem is not NULL and *lenmem is large enough,
+ *      then the function places the cfg in mem and the size used in *lenmem
+ *      and returns mem.
+ *  
+ *  If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough),
+ *      then the function returns NULL and places the minimum cfg 
+ *      buffer size in *lenmem.
+ * */
+
+kiss_fft_cfg KISS_FFT_API kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem);
+
+/*
+ * kiss_fft(cfg,in_out_buf)
+ *
+ * Perform an FFT on a complex input buffer.
+ * for a forward FFT,
+ * fin should be  f[0] , f[1] , ... ,f[nfft-1]
+ * fout will be   F[0] , F[1] , ... ,F[nfft-1]
+ * Note that each element is complex and can be accessed like
+    f[k].r and f[k].i
+ * */
+void KISS_FFT_API kiss_fft(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
+
+/*
+ A more generic version of the above function. It reads its input from every Nth sample.
+ * */
+void KISS_FFT_API kiss_fft_stride(kiss_fft_cfg cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout,int fin_stride);
+
+/* If kiss_fft_alloc allocated a buffer, it is one contiguous 
+   buffer and can be simply free()d when no longer needed*/
+#define kiss_fft_free KISS_FFT_FREE
+
+/*
+ Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up 
+ your compiler output to call this before you exit.
+*/
+void KISS_FFT_API kiss_fft_cleanup(void);
+	
+
+/*
+ * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5)
+ */
+int KISS_FFT_API kiss_fft_next_fast_size(int n);
+
+/* for real ffts, we need an even size */
+#define kiss_fftr_next_fast_size_real(n) \
+        (kiss_fft_next_fast_size( ((n)+1)>>1)<<1)
+
+#ifdef __cplusplus
+} 
+#endif
+
+#endif