FEAPIExamplePluginLoudness/zplFFTGen.cpp

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//     /*! \file zplFFTGen.cpp: \brief interface of the CzplFFTGen class. */
//
//        Copyright (c) 2004-2006  
//        zplane.development
//        Flohrer Lerch Schwerdtfeger GbR
//        All rights reserved.
//
//    This program is free software; you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation; either version 2 of the License, or
//    (at your option) any later version.
//
//    This program is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with this program; if not, write to the Free Software
//    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//

// standard headers
#include <string.h>
#include <math.h>

// project headers
#include "zplVecLib.h"
#include "fft.h"

#if !defined(_2PI)
#define _2PI                    (float)(6.283185307179586476925286766559)    
#endif

class CzplfFFTGen : public CzplfFFT_If
{
public:

    
    CzplfFFTGen (int iBlockLength, int iZeroPadFactor, _Fft_Windows_ eWindowType);
    virtual ~CzplfFFTGen ();


    void           zplfFFT         (zCOMPLEX *pfDest, float *pfSrc);

    void           zplfIFFT        (float *pfDest, zCOMPLEX *pfSrc);

    int      m_eLastError;

protected:

    int      BuildFFTTables ();
    void       FreeFFTTables ();

    float    *m_pfSinTable,
                *m_pfCosTable;

};



CzplfFFTGen::CzplfFFTGen (int iBlockLength, int iZeroPadFactor, _Fft_Windows_ eWindowType)
{
    m_eLastError    = 0;
    m_iBlockLength  = iBlockLength;
    m_iFFTLength    = m_iBlockLength * iZeroPadFactor;

    m_pfWindow      = 0;
    m_pfWindow      = zplfMalloc (m_iBlockLength);

    if (!m_pfWindow)
        m_eLastError    = -1;
    else
        this->CalculateWindow (eWindowType);

    m_pfSinTable    = 0;
    m_pfCosTable    = 0;

    m_eLastError   |= this->BuildFFTTables ();
}


CzplfFFTGen::~CzplfFFTGen ()
{
    if (m_pfWindow)
        zplfFree (m_pfWindow);

    this->FreeFFTTables ();
}
    

void CzplfFFTGen::zplfFFT         (zCOMPLEX *pfDest, float *pfSrc)
{
    ZASSERT ((pfDest == 0) || (pfSrc == 0));
    ZASSERT ((m_pfSinTable == 0) || (m_pfCosTable == 0) || (m_pfWindow == 0));
    ZASSERT (m_eLastError != 0);

    // copy buffer
    if (pfDest != pfSrc)
        memcpy (pfDest, pfSrc, sizeof (float) * m_iBlockLength);

    // zeropad
    if (m_iFFTLength-m_iBlockLength > 0)
        zplfSetZero (&pfDest[m_iBlockLength], (m_iFFTLength - m_iBlockLength));

    // window
    zplfRealMul_I (pfDest, m_pfWindow, m_iBlockLength);

    // calc FFT
    zRealFFTSplitGeneric (pfDest, m_iFFTLength, m_pfSinTable, m_pfCosTable);

    return;
}

void CzplfFFTGen::zplfIFFT         (float *pfDest, zCOMPLEX *pfSrc)
{
    ZASSERT ((pfDest == 0) || (pfSrc == 0));
    ZASSERT ((m_pfSinTable == 0) || (m_pfCosTable == 0) || (m_pfWindow == 0));
    ZASSERT (m_eLastError != 0);

    // calc FFT
    zRealIFFTSplitGeneric (pfSrc, m_iFFTLength, m_pfSinTable, m_pfCosTable);

    // copy buffer
    memcpy (pfDest, pfSrc, sizeof (float) * m_iBlockLength);

    return;
}

int CzplfFFTGen::BuildFFTTables ()
{
    int    iQuarterBlockSize   = (m_iFFTLength>>3)-1;
    float  fPiBlock            = _2PI / m_iFFTLength,
            f3PiBlock           = 3.0F * fPiBlock;

    m_pfSinTable        = zplfMalloc (1+(iQuarterBlockSize<<1));
    if (m_pfSinTable == 0)
        return -1;
    m_pfCosTable        = zplfMalloc (1+(iQuarterBlockSize<<1));
    if (m_pfCosTable == 0)
        return -1;

    for (int i = 0; i < iQuarterBlockSize; i++)
    {
        m_pfSinTable[i]                     = sinf ((i+1) * fPiBlock);
        m_pfCosTable[i]                     = cosf ((i+1) * fPiBlock);

        m_pfSinTable[i+iQuarterBlockSize]   = sinf ((i+1) * f3PiBlock);
        m_pfCosTable[i+iQuarterBlockSize]   = cosf ((i+1) * f3PiBlock);
    }

    return 0;
}

void CzplfFFTGen::FreeFFTTables ()
{
    if (m_pfSinTable)
        zplfFree (m_pfSinTable);
    if (m_pfCosTable)
        zplfFree (m_pfCosTable);
}



int zplfFFTCreateInstance_Gen (CzplfFFT_If*& pCFFT, int iBlockLength, int iZeroPadFactor, CzplfFFT_If::_Fft_Windows_ eWindowType)
{
    int          rErr        = 0;
    CzplfFFTGen     *pCNewFFT   = 0;
    pCFFT                       = 0;

    // check parameters
    if ((iZeroPadFactor <= 0))
        return -1;
    if ((iBlockLength <= 0))
        return -1;
    if ((iBlockLength%4 != 0))
        return -1;
    if ((iZeroPadFactor != Int2PowTwo (iZeroPadFactor)))
        return -1;
    if ((iBlockLength != Int2PowTwo (iBlockLength)))
        return -1;
    
    pCNewFFT = new CzplfFFTGen (iBlockLength, iZeroPadFactor, eWindowType);
    
    if ((pCNewFFT == 0) || (pCNewFFT->m_eLastError != 0))
        return -1;
    else
        pCFFT   = pCNewFFT;

    return 0;
}


int zplfFFTDestroyInstance_Gen (CzplfFFT_If*& pCFFT)
{
    CzplfFFTGen     *pCRealFFT   = (CzplfFFTGen*)pCFFT;
    if (pCRealFFT == 0)
        return -1;
    
    delete pCRealFFT;
    pCFFT = 0;

    return 0;

}

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