//referenced from:
//http://www.intersrv.com/~dcross/fft.html



#ifdef __cplusplus
extern "C" {
#endif
#define  DDC_PI  (3.14159265358979323846)


void FFT(
    unsigned  p,          /* must be a power of 2 */
    int     tornot,    /* 0=forward FFT, 1=inverse FFT */
    long   *In1,              /* array of input*/
	long   *In2,
    long   *Out1,             /* array of output's reals */
    long   *Out2 );      /* array of output's imaginaries */


int IsPowerOfTwo ( unsigned x );
unsigned NumberOfBitsNeeded ( unsigned PowerOfTwo );
unsigned ReverseBits ( unsigned index, unsigned NumBits );

int findthepower(int num);

void multiply(long * RealIn1, long * ImagIn1,
				 long * RealIn2, long * ImagIn2,
				 long * RealOut, long * ImagOut,
				 int size);





#ifdef __cplusplus
}
#endif