Mercurial > hg > peckfft
comparison peck_fft.h @ 0:723f588b82ac
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| author | Peter Meerwald <p.meerwald@bct-electronic.com> |
|---|---|
| date | Fri, 16 Sep 2011 12:53:08 +0200 |
| parents | |
| children | 3d08140650d8 |
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| -1:000000000000 | 0:723f588b82ac |
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| 1 #ifndef PECK_FFT_H | |
| 2 #define PECK_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 #ifdef USE_SIMD | |
| 14 # include <xmmintrin.h> | |
| 15 # define peck_fft_scalar __m128 | |
| 16 #define PECK_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16) | |
| 17 #define PECK_FFT_FREE _mm_free | |
| 18 #else | |
| 19 #define PECK_FFT_MALLOC malloc | |
| 20 #define PECK_FFT_FREE free | |
| 21 #endif | |
| 22 | |
| 23 | |
| 24 #ifdef FIXED_POINT | |
| 25 #include <sys/types.h> | |
| 26 # if (FIXED_POINT == 32) | |
| 27 # define peck_fft_scalar int32_t | |
| 28 # else | |
| 29 # define peck_fft_scalar int16_t | |
| 30 # endif | |
| 31 #else | |
| 32 # ifndef peck_fft_scalar | |
| 33 /* default is float */ | |
| 34 # define peck_fft_scalar float | |
| 35 # endif | |
| 36 #endif | |
| 37 | |
| 38 typedef struct { | |
| 39 peck_fft_scalar r; | |
| 40 peck_fft_scalar i; | |
| 41 }peck_fft_cpx; | |
| 42 | |
| 43 typedef struct peck_fft_state* peck_fft_cfg; | |
| 44 | |
| 45 /* | |
| 46 * peck_fft_alloc | |
| 47 * | |
| 48 * Initialize a FFT (or IFFT) algorithm's cfg/state buffer. | |
| 49 * | |
| 50 * typical usage: peck_fft_cfg mycfg=peck_fft_alloc(1024,0,NULL,NULL); | |
| 51 * | |
| 52 * The return value from fft_alloc is a cfg buffer used internally | |
| 53 * by the fft routine or NULL. | |
| 54 * | |
| 55 * If lenmem is NULL, then peck_fft_alloc will allocate a cfg buffer using malloc. | |
| 56 * The returned value should be free()d when done to avoid memory leaks. | |
| 57 * | |
| 58 * The state can be placed in a user supplied buffer 'mem': | |
| 59 * If lenmem is not NULL and mem is not NULL and *lenmem is large enough, | |
| 60 * then the function places the cfg in mem and the size used in *lenmem | |
| 61 * and returns mem. | |
| 62 * | |
| 63 * If lenmem is not NULL and ( mem is NULL or *lenmem is not large enough), | |
| 64 * then the function returns NULL and places the minimum cfg | |
| 65 * buffer size in *lenmem. | |
| 66 * */ | |
| 67 | |
| 68 peck_fft_cfg peck_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem); | |
| 69 | |
| 70 /* | |
| 71 * peck_fft(cfg,in_out_buf) | |
| 72 * | |
| 73 * Perform an FFT on a complex input buffer. | |
| 74 * for a forward FFT, | |
| 75 * fin should be f[0] , f[1] , ... ,f[nfft-1] | |
| 76 * fout will be F[0] , F[1] , ... ,F[nfft-1] | |
| 77 * Note that each element is complex and can be accessed like | |
| 78 f[k].r and f[k].i | |
| 79 * */ | |
| 80 void peck_fft(peck_fft_cfg cfg,const peck_fft_cpx *fin,peck_fft_cpx *fout); | |
| 81 | |
| 82 /* | |
| 83 A more generic version of the above function. It reads its input from every Nth sample. | |
| 84 * */ | |
| 85 void peck_fft_stride(peck_fft_cfg cfg,const peck_fft_cpx *fin,peck_fft_cpx *fout,int fin_stride); | |
| 86 | |
| 87 /* If peck_fft_alloc allocated a buffer, it is one contiguous | |
| 88 buffer and can be simply free()d when no longer needed*/ | |
| 89 #define peck_fft_free free | |
| 90 | |
| 91 /* | |
| 92 Cleans up some memory that gets managed internally. Not necessary to call, but it might clean up | |
| 93 your compiler output to call this before you exit. | |
| 94 */ | |
| 95 void peck_fft_cleanup(void); | |
| 96 | |
| 97 | |
| 98 /* | |
| 99 * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5) | |
| 100 */ | |
| 101 int peck_fft_next_fast_size(int n); | |
| 102 | |
| 103 /* for real ffts, we need an even size */ | |
| 104 #define peck_fftr_next_fast_size_real(n) \ | |
| 105 (peck_fft_next_fast_size( ((n)+1)>>1)<<1) | |
| 106 | |
| 107 #ifdef __cplusplus | |
| 108 } | |
| 109 #endif | |
| 110 | |
| 111 #endif |