media/kiss_fft/kiss_fft.h
author Gregory Szorc <gps@mozilla.com>
Thu, 19 Feb 2015 10:58:41 -0800
changeset 245738 c97c977c92b97c9585011651b13a088f0cd4ed4f
parent 126975 3f7d9ca669a8dc85a101f1e61b6ce4b6d15e6a9f
permissions -rw-r--r--
Bug 1132771 - moz.build fixups to enable execution in no config mode Various moz.build files fail to execute when a build config is not present. Many of these are due to assuming certain CONFIG entries are present. This patch attempts to fix that and enable every moz.build to be read without a build config.

#ifndef KISS_FFT_H
#define KISS_FFT_H

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

#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.
*/

#ifdef USE_SIMD
# include <xmmintrin.h>
# define kiss_fft_scalar __m128
#define KISS_FFT_MALLOC(nbytes) _mm_malloc(nbytes,16)
#define KISS_FFT_FREE _mm_free
#else	
#define KISS_FFT_MALLOC malloc
#define KISS_FFT_FREE free
#endif	


#ifdef FIXED_POINT
#include <sys/types.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_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(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_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 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_cleanup(void);
	

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