www.pudn.com > dtmffft.zip > fft.h

// FFT.H (c) 2004 Howard Long (G6LVB), Hanlincrest Ltd. All rights reserved. 
// 72 Princes Gate 
// London SW7 2PA 
// United Kingdom 
// howard@hanlincrest.com 
// Free for educational and non-profit use. For commercial use please contact the author. 
 
typedef __int8 S8, *PS8; 
typedef unsigned __int8 U8, *PU8; 
typedef __int16 S16, *PS16; 
typedef unsigned __int16 U16, *PU16; 
typedef __int32 S32, *PS32; 
typedef unsigned __int32 U32, *PU32; 
typedef __int64 S64, *PS64; 
typedef unsigned __int64 U64, *PU64; 
 
typedef struct 
{ 
	S16 s16Sin; 
	S16 s16Cos; 
} FFTSINCOSSTRUCT, *PFFTSINCOSSTRUCT; 
 
typedef union 
{ 
	PS16 ps16SinCos; 
	PFFTSINCOSSTRUCT pfscs; 
} FFTSINCOSUNION; 
 
typedef struct 
{ 
	CRITICAL_SECTION cs; 
	int nLen; // Number of bins 
	BOOL bClip; // Input too high? 
	S16 *ps16BitRev; // Array to hold bit reversal table 
	S32 s32Average; // Mean level 
	S32 s32Max; // Max level 
	FFTSINCOSUNION fscu; // Array of 16 bit integer-ized sin and cos values 
	S16 *ps16Window; // Array to hold Window function values 
	 
} FFTSTRUCT, *PFFTSTRUCT; 
 
extern void FFTTerm(PFFTSTRUCT pfs); 
extern BOOL FFTInit(PFFTSTRUCT pfs,int nLen); 
extern void FFTRun(PFFTSTRUCT pfs,PS16 ps16BufferIn,PS32 ps32BufferOut); 
extern S32 FFTGetMax(PFFTSTRUCT pfs); 
extern S32 FFTGetAverage(PFFTSTRUCT pfs);