fft.h

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// ##########################################################################
// ####                                                                  ####
// ####                      RTP Audio Server Project                    ####
// ####                    ============================                  ####
// ####                                                                  ####
// #### Fast Fourier Transformation                                      ####
// ####                                                                  ####
// ####           Copyright (C) 1999-2012 by Thomas Dreibholz            ####
// ####                                                                  ####
// #### Contact:                                                         ####
// ####    EMail: dreibh@iem.uni-due.de                                  ####
// ####    WWW:   https://www.nntb.no/~dreibh/rtpaudio                ####
// ####                                                                  ####
// #### ---------------------------------------------------------------- ####
// ####                                                                  ####
// #### 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 3 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, see                    ####
// #### <http://www.gnu.org/licenses/>.                                  ####
// ####                                                                  ####
// ##########################################################################
// $Id: fft.h 1286 2011-12-18 13:43:16Z dreibh $


#ifndef FFT_H
#define FFT_H


#include "tdsystem.h"
#include "audiowriterinterface.h"


class FastFourierTransformation {
   // ====== Constructor/Destructor =========================================
   public:
   FastFourierTransformation(const integer fftlen);

   ~FastFourierTransformation();


   // ====== FFT functions ==================================================
   void fft(int16* buffer);

   integer* getBitReversed();


   // ====== Private data ===================================================
   private:
   integer* BitReversed;
   int16*   SinTable;
   integer  Points;

   int16    *A,*B;
   int16    *sptr;
   int16    *endptr1,*endptr2;
   integer  *br1,*br2;
   integer  HRplus,HRminus,HIplus,HIminus;
};


#endif