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Trying to decide what to do about real odd FFTs

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This commit is contained in:
Mark Borgerding 2004-01-29 03:26:48 +00:00
parent 49a6ad07e0
commit 80eccb4e3c
3 changed files with 11 additions and 12 deletions
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19
tools/kiss_fftnd.c
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@ -17,12 +17,11 @@ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
#include "_kiss_fft_guts.h" #include "_kiss_fft_guts.h"
typedef struct { typedef struct {
int minus4; /*magic to signify a N-d transform*/
int dimprod; /* dimsum would be mighty tasty right now */ int dimprod; /* dimsum would be mighty tasty right now */
int ndims; int ndims;
int *dims; int *dims;
void **states; void **states; /* cfg states for each dimension */
kiss_fft_cpx * tmpbuf; kiss_fft_cpx * tmpbuf; /*buffer capable of hold the entire buffer */
}kiss_fftnd_state; }kiss_fftnd_state;
void * kiss_fftnd_alloc(int *dims,int ndims,int inverse_fft,void*mem,size_t*lenmem) void * kiss_fftnd_alloc(int *dims,int ndims,int inverse_fft,void*mem,size_t*lenmem)
@ -43,17 +42,16 @@ void * kiss_fftnd_alloc(int *dims,int ndims,int inverse_fft,void*mem,size_t*lenm
memneeded += sizeof(void*) * ndims;/* st->states */ memneeded += sizeof(void*) * ndims;/* st->states */
memneeded += sizeof(kiss_fft_cpx) * dimprod; /* st->tmpbuf */ memneeded += sizeof(kiss_fft_cpx) * dimprod; /* st->tmpbuf */
if (lenmem == NULL) { if (lenmem == NULL) {/* allocate for the caller*/
st = (kiss_fftnd_state *) malloc (memneeded); st = (kiss_fftnd_state *) malloc (memneeded);
} else { } else { /* initialize supplied buffer if big enough */
if (*lenmem >= memneeded) if (*lenmem >= memneeded)
st = (kiss_fftnd_state *) mem; st = (kiss_fftnd_state *) mem;
*lenmem = memneeded; *lenmem = memneeded; /*tell caller how big struct is (or would be) */
} }
if (!st) if (!st)
return NULL; return NULL; /*malloc failed or buffer too small */
st->minus4 = -4;
st->dimprod = dimprod; st->dimprod = dimprod;
st->ndims = ndims; st->ndims = ndims;
ptr=(char*)(st+1); ptr=(char*)(st+1);
@ -140,7 +138,7 @@ Stage 2 ( D=4) treats this buffer as a 4*6 matrix,
, i.e. the summation of all 24 input elements. , i.e. the summation of all 24 input elements.
*/ */
void kiss_fftnd(const void * cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout) void kiss_fftnd(void * cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout)
{ {
int i,k; int i,k;
kiss_fftnd_state *st = ( kiss_fftnd_state *)cfg; kiss_fftnd_state *st = ( kiss_fftnd_state *)cfg;
@ -156,6 +154,7 @@ void kiss_fftnd(const void * cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout)
for ( k=0; k < st->ndims; ++k) { for ( k=0; k < st->ndims; ++k) {
int curdim = st->dims[k]; int curdim = st->dims[k];
int stride = st->dimprod / curdim; int stride = st->dimprod / curdim;
for ( i=0 ; i<stride ; ++i ) for ( i=0 ; i<stride ; ++i )
kiss_fft_stride( st->states[k], bufin+i , bufout+i*curdim, stride ); kiss_fft_stride( st->states[k], bufin+i , bufout+i*curdim, stride );

2
tools/kiss_fftnd.h
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@ -4,6 +4,6 @@
#include "kiss_fft.h" #include "kiss_fft.h"
void * kiss_fftnd_alloc(int *dims,int ndims,int inverse_fft,void*mem,size_t*lenmem); void * kiss_fftnd_alloc(int *dims,int ndims,int inverse_fft,void*mem,size_t*lenmem);
void kiss_fftnd(const void * cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout); void kiss_fftnd(void * cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
#endif #endif

2
tools/kiss_fftr.c
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@ -28,7 +28,7 @@ void * kiss_fftr_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem)
size_t subsize, memneeded; size_t subsize, memneeded;
if (nfft & 1) { if (nfft & 1) {
/*fprintf(stderr,"Real FFT optimization must be even.\n"); */ fprintf(stderr,"Real FFT optimization must be even.\n");
return NULL; return NULL;
} }
nfft >>= 1; nfft >>= 1;