/**
* Computes the complex (inverse) fast Fourier transform.
*
* @param RE
* Pointer to an array containing the real part of the input, will be
* overwritten with real part of output.
* @param IM
* Pointer to an array containing the imaginary part of the input, will
* be overwritten with imaginary part of output.
* @param nXL
* Length of signals, must be a power of 2 (otherwise the function will
* return an <code>ERR_MDIM</code> error)
* @param bInv
* If non-zero the function computes the inverse complex Fourier
* transform
* @return <code>O_K</code> if successfull, a (begative) error code otherwise
*
* <h4>Remarks</h4>
* <ul>
* <li>The function creates the tables by its own, stores them in static arrays and
* reuses them for all subsequent calls with the same value of <code>nXL</code>.</li>
* </ul>
*/
INT16 dlm_fft
(
FLOAT64* RE,
FLOAT64* IM,
INT32 nXL,
INT16 bInv
)
{
extern int ifft(FLOAT64*,FLOAT64*,const int);
extern int fft(FLOAT64*,FLOAT64*,const int);
INT16 order;
/* Initialize */ /* --------------------------------- */
order = (INT16)dlm_log2_i(nXL); /* Compute FFT order */
if (order<=0) return ERR_MDIM; /* nXL is not power of 2 --> :// */
#ifndef __NOXALLOC
DLPASSERT(dlp_size(RE)>=nXL*sizeof(FLOAT64)); /* Assert RE has the right length */
DLPASSERT(dlp_size(IM)>=nXL*sizeof(FLOAT64)); /* Assert IM has the right length */
#endif
if(bInv) {
if(ifft(RE,IM,nXL) != 0) return NOT_EXEC;
} else {
if(fft(RE,IM,nXL) != 0) return NOT_EXEC;
}
return O_K; /* All done */
}
/**
* Analyse a frame
*
* Derived instances of FBAproc should override method
* Analyse() to add the desired functionality
*
* @return O_K if successfull, NOT_EXEC otherwise
*/
INT16 CGEN_PROTECTED CFWTproc::AnalyzeFrame()
{
INT16 ret = NOT_EXEC;
if(dlm_log2_i(m_nLen) == -1) /* handle to short signal array */
{
return ret = FWT_DIM_ERROR;
}
if(m_bHaar == true)
{
ret = dlm_fwt_haar((FLOAT64*)m_idRealFrame->XAddr(0,0),
(FLOAT64*)m_idRealFrame->XAddr(0,0),
m_nLen,
m_nLevel);
}
else
{
ret = dlm_fwt_d4((FLOAT64*)m_idRealFrame->XAddr(0,0),
(FLOAT64*)m_idRealFrame->XAddr(0,0),
m_nLen,
m_nLevel);
}
return ret;
}
/**
* Analyse a frame
*
* Derived instances of FBAproc should override method
* Analyse() to add the desired functionality
*
* @return O_K if successfull, NOT_EXEC otherwise
*/
INT16 CGEN_PROTECTED CFWTproc::AnalyzeFrame()
{
INT16 ret = NOT_EXEC;
INT16 di=GetDindex();
if(dlm_log2_i(m_nLen) == -1) /* handle to short signal array */
{
return ret = FWT_DIM_ERROR;
}
if(!di) return IERROR(this,ERR_INVALARG,"wvltype invalid",0,0);
return dlm_fwt_dx((FLOAT64*)m_idRealFrame->XAddr(0,0),
(FLOAT64*)m_idRealFrame->XAddr(0,0),
m_nLen,
di,
m_nLevel);
}
