gri_fft.h

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/* -*- c++ -*- */
/*
 * Copyright 2003,2008 Free Software Foundation, Inc.
 * 
 * This file is part of GNU Radio
 * 
 * GNU Radio 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, or (at your option)
 * any later version.
 * 
 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */
#ifndef _GRI_FFT_H_
#define _GRI_FFT_H_

/*
 * Wrappers for FFTW single precision 1d dft
 */

#include <gr_core_api.h>
#include <gr_complex.h>
#include <boost/thread.hpp>

/*! \brief Helper function for allocating complex fft buffers
 */
gr_complex* gri_fft_malloc_complex(int size);

/*! \brief Helper function for allocating float fft buffers
 */
float* gri_fft_malloc_float(int size);

/*! \brief Helper function for freeing fft buffers
 */
void gri_fft_free(void *b);


/*!
 * \brief Export reference to planner mutex for those apps that
 * want to use FFTW w/o using the gri_fftw* classes.
 */
class GR_CORE_API gri_fft_planner {
public:
  typedef boost::mutex::scoped_lock scoped_lock;
  /*!
   * Return reference to planner mutex
   */
  static boost::mutex &mutex();
};

/*!
 * \brief FFT: complex in, complex out
 * \ingroup misc
 */
class GR_CORE_API gri_fft_complex {
  int         d_fft_size;
  int         d_nthreads;
  gr_complex *d_inbuf;
  gr_complex *d_outbuf;
  void       *d_plan;
  
public:
  gri_fft_complex (int fft_size, bool forward = true, int nthreads=1);
  virtual ~gri_fft_complex ();

  /*
   * These return pointers to buffers owned by gri_fft_complex into which
   * input and output take place.  It's done this way in order to
   * ensure optimal alignment for SIMD instructions.
   */
  gr_complex *get_inbuf ()  const { return d_inbuf; }
  gr_complex *get_outbuf () const { return d_outbuf; }

  int inbuf_length ()  const { return d_fft_size; }
  int outbuf_length () const { return d_fft_size; }

  /*!
   *  Set the number of threads to use for caclulation.
   */
  void set_nthreads(int n);

  /*!
   *  Get the number of threads being used by FFTW
   */
  int nthreads() const { return d_nthreads; }

  /*!
   * compute FFT.  The input comes from inbuf, the output is placed in outbuf.
   */
  void execute ();
};

/*!
 * \brief FFT: real in, complex out
 * \ingroup misc
 */
class GR_CORE_API gri_fft_real_fwd {
  int         d_fft_size;
  int         d_nthreads;
  float      *d_inbuf;
  gr_complex *d_outbuf;
  void       *d_plan;
  
public:
  gri_fft_real_fwd (int fft_size, int nthreads=1);
  virtual ~gri_fft_real_fwd ();

  /*
   * These return pointers to buffers owned by gri_fft_real_fwd into
   * which input and output take place.  It's done this way in order
   * to ensure optimal alignment for SIMD instructions.
   */
  float *get_inbuf ()      const { return d_inbuf; }
  gr_complex *get_outbuf () const { return d_outbuf; }

  int inbuf_length ()  const { return d_fft_size; }
  int outbuf_length () const { return d_fft_size / 2 + 1; }

  /*!
   *  Set the number of threads to use for caclulation.
   */
  void set_nthreads(int n);

  /*!
   *  Get the number of threads being used by FFTW
   */
  int nthreads() const { return d_nthreads; }

  /*!
   * compute FFT.  The input comes from inbuf, the output is placed in outbuf.
   */
  void execute ();
};

/*!
 * \brief FFT: complex in, float out
 * \ingroup misc
 */
class GR_CORE_API gri_fft_real_rev {
  int         d_fft_size;
  int         d_nthreads;
  gr_complex *d_inbuf;
  float      *d_outbuf;
  void       *d_plan;
  
public:
  gri_fft_real_rev (int fft_size, int nthreads=1);
  virtual ~gri_fft_real_rev ();

  /*
   * These return pointers to buffers owned by gri_fft_real_rev into
   * which input and output take place.  It's done this way in order
   * to ensure optimal alignment for SIMD instructions.
   */
  gr_complex *get_inbuf () const { return d_inbuf; }
  float *get_outbuf () const { return d_outbuf; }

  int inbuf_length ()  const { return d_fft_size / 2 + 1; }
  int outbuf_length () const { return d_fft_size; }

  /*!
   *  Set the number of threads to use for caclulation.
   */
  void set_nthreads(int n);

  /*!
   *  Get the number of threads being used by FFTW
   */
  int nthreads() const { return d_nthreads; }

  /*!
   * compute FFT.  The input comes from inbuf, the output is placed in outbuf.
   */
  void execute ();
};

#endif