annotate src/vamp-sdk/ext/vamp_kiss_fft.h @ 501:90571dcc371a vamp-kiss-naming

Extensively rename things in the KissFFT headers to use a Vamp prefix. The motivation is not to change anything about the Vamp SDK library builds, but to avoid confusion in case any other code (for example that pulls in the Vamp SDK as part of a wider project definition) accidentally includes these headers instead of, or as well as, some other copy of KissFFT.

#ifndef VAMP_KISS_FFT_H
#define VAMP_KISS_FFT_H

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>

#ifndef _VAMP_IN_PLUGINSDK
#  ifndef _VAMP_IN_HOSTSDK
#    error "Do not use the Vamp SDK mangled KissFFT header except through the Vamp SDK API"
#  endif
#endif

#ifdef VAMP_KISSFFT_USE_CPP_LINKAGE
#define VAMP_KISS_FFT_MALLOC ::malloc
#define VAMP_KISS_FFT_FREE ::free
#else
#ifdef __cplusplus
extern "C" {
#define VAMP_KISS_FFT_MALLOC malloc
#define VAMP_KISS_FFT_FREE free
#endif
#endif

# ifndef vamp_kiss_fft_scalar
#   error "vamp_kiss_fft_scalar must be defined before inclusion, we don't have a default in this build"
# endif

typedef struct {
    vamp_kiss_fft_scalar r;
    vamp_kiss_fft_scalar i;
} vamp_kiss_fft_cpx;

typedef struct vamp_kiss_fft_state* vamp_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.
 * */

vamp_kiss_fft_cfg vamp_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 vamp_kiss_fft(vamp_kiss_fft_cfg cfg,const vamp_kiss_fft_cpx *fin,vamp_kiss_fft_cpx *fout);

/*
 A more generic version of the above function. It reads its input from every Nth sample.
 * */
void vamp_kiss_fft_stride(vamp_kiss_fft_cfg cfg,const vamp_kiss_fft_cpx *fin,vamp_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*/
void vamp_kiss_fft_free(void *);

/*
 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 vamp_kiss_fft_cleanup(void);
	

/*
 * Returns the smallest integer k, such that k>=n and k has only "fast" factors (2,3,5)
 */
int vamp_kiss_fft_next_fast_size(int n);

/* for real ffts, we need an even size */
#define vamp_kiss_fftr_next_fast_size_real(n) \
        (vamp_kiss_fft_next_fast_size( ((n)+1)>>1)<<1)

#ifndef VAMP_KISSFFT_USE_CPP_LINKAGE
#ifdef __cplusplus
} 
#endif
#endif

#ifdef VAMP_KISSFFT_USE_CPP_LINKAGE
#define VAMP_KISSFFT_USED_CPP_LINKAGE 1
#endif

#endif