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fft_filter.h
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/* -*- c++ -*- */
/*
* Copyright 2010,2012,2014 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#ifndef INCLUDED_FILTER_FFT_FILTER_H
#define INCLUDED_FILTER_FFT_FILTER_H
#include <gnuradio/fft/fft.h>
#include <gnuradio/filter/api.h>
#include <gnuradio/gr_complex.h>
#include <gnuradio/logger.h>
#include <volk/volk_alloc.hh>
#include <vector>
namespace gr {
namespace filter {
namespace kernel {
/*!
* \brief Fast FFT filter with float input, float output and float taps
* \ingroup filter_blk
*
* \details
* This block performs fast convolution using the
* overlap-and-add algorithm. The filtering is performand in
* the frequency domain instead of the time domain (see
* gr::filter::kernel::fir_filter_fff). For an input signal x
* and filter coefficients (taps) t, we compute y as:
*
* \code
* y = ifft(fft(x)*fft(t))
* \endcode
*
* This kernel computes the FFT of the taps when they are set to
* only perform this operation once. The FFT of the input signal
* x is done every time.
*
* Because this is designed as a very low-level kernel
* operation, it is designed for speed and avoids certain checks
* in the filter() function itself. The filter function expects
* that the input signal is a multiple of d_nsamples in the
* class that's computed internally to be as fast as
* possible. The function set_taps will return the value of
* nsamples that can be used externally to check this
* boundary. Notice that all implementations of the fft_filter
* GNU Radio blocks (e.g., gr::filter::fft_filter_fff) use this
* value of nsamples to compute the value to call
* gr::block::set_output_multiple that ensures the scheduler
* always passes this block the right number of samples.
*/
class FILTER_API fft_filter_fff
{
private:
int d_ntaps;
int d_nsamples;
int d_fftsize; // fftsize = ntaps + nsamples - 1
int d_decimation;
std::unique_ptr<fft::fft_real_fwd> d_fwdfft; // forward "plan"
std::unique_ptr<fft::fft_real_rev> d_invfft; // inverse "plan"
int d_nthreads; // number of FFTW threads to use
std::vector<float> d_tail; // state carried between blocks for overlap-add
std::vector<float> d_taps; // stores time domain taps
volk::vector<gr_complex> d_xformed_taps; // Fourier xformed taps
void compute_sizes(int ntaps);
int tailsize() const { return d_ntaps - 1; }
gr::logger_ptr d_logger, d_debug_logger;
public:
/*!
* \brief Construct an FFT filter for float vectors with the given taps and decimation
* rate.
*
* This is the basic implementation for performing FFT filter for fast convolution
* in other blocks (e.g., gr::filter::fft_filter_fff).
*
* \param decimation The decimation rate of the filter (int)
* \param taps The filter taps (vector of float)
* \param nthreads The number of threads for the FFT to use (int)
*/
fft_filter_fff(int decimation, const std::vector<float>& taps, int nthreads = 1);
// Disallow copy.
//
// This prevents accidentally doing needless copies, not just of fft_filter_xxx,
// but every block that contains one.
fft_filter_fff(const fft_filter_fff&) = delete;
fft_filter_fff& operator=(const fft_filter_fff&) = delete;
fft_filter_fff(fft_filter_fff&&) = default;
fft_filter_fff& operator=(fft_filter_fff&&) = default;
/*!
* \brief Set new taps for the filter.
*
* Sets new taps and resets the class properties to handle different sizes
* \param taps The filter taps (complex)
*/
int set_taps(const std::vector<float>& taps);
/*!
* \brief Set number of threads to use.
*/
void set_nthreads(int n);
/*!
* \brief Returns the taps.
*/
std::vector<float> taps() const;
/*!
* \brief Returns the number of taps in the filter.
*/
unsigned int ntaps() const;
/*!
* \brief Get number of threads being used.
*/
int nthreads() const;
/*!
* \brief Perform the filter operation
*
* \param nitems The number of items to produce
* \param input The input vector to be filtered
* \param output The result of the filter operation
*/
int filter(int nitems, const float* input, float* output);
};
/*!
* \brief Fast FFT filter with gr_complex input, gr_complex output and gr_complex taps
* \ingroup filter_blk
*
* \details
* This block performs fast convolution using the
* overlap-and-add algorithm. The filtering is performand in
* the frequency domain instead of the time domain (see
* gr::filter::kernel::fir_filter_ccc). For an input signal x
* and filter coefficients (taps) t, we compute y as:
*
* \code
* y = ifft(fft(x)*fft(t))
* \endcode
*
* This kernel computes the FFT of the taps when they are set to
* only perform this operation once. The FFT of the input signal
* x is done every time.
*
* Because this is designed as a very low-level kernel
* operation, it is designed for speed and avoids certain checks
* in the filter() function itself. The filter function expects
* that the input signal is a multiple of d_nsamples in the
* class that's computed internally to be as fast as
* possible. The function set_taps will return the value of
* nsamples that can be used externally to check this
* boundary. Notice that all implementations of the fft_filter
* GNU Radio blocks (e.g., gr::filter::fft_filter_ccc) use this
* value of nsamples to compute the value to call
* gr::block::set_output_multiple that ensures the scheduler
* always passes this block the right number of samples.
*/
class FILTER_API fft_filter_ccc
{
private:
int d_ntaps;
int d_nsamples;
int d_fftsize; // fftsize = ntaps + nsamples - 1
int d_decimation;
std::unique_ptr<fft::fft_complex_fwd> d_fwdfft; // forward "plan"
std::unique_ptr<fft::fft_complex_rev> d_invfft; // inverse "plan"
int d_nthreads; // number of FFTW threads to use
std::vector<gr_complex> d_tail; // state carried between blocks for overlap-add
std::vector<gr_complex> d_taps; // stores time domain taps
volk::vector<gr_complex> d_xformed_taps; // Fourier xformed taps
void compute_sizes(int ntaps);
int tailsize() const { return d_ntaps - 1; }
gr::logger_ptr d_logger, d_debug_logger;
public:
/*!
* \brief Construct an FFT filter for complex vectors with the given taps and
* decimation rate.
*
* This is the basic implementation for performing FFT filter for fast convolution
* in other blocks (e.g., gr::filter::fft_filter_ccc).
*
* \param decimation The decimation rate of the filter (int)
* \param taps The filter taps (vector of complex)
* \param nthreads The number of threads for the FFT to use (int)
*/
fft_filter_ccc(int decimation, const std::vector<gr_complex>& taps, int nthreads = 1);
// Disallow copy.
//
// This prevents accidentally doing needless copies, not just of fft_filter_xxx,
// but every block that contains one.
fft_filter_ccc(const fft_filter_ccc&) = delete;
fft_filter_ccc& operator=(const fft_filter_ccc&) = delete;
fft_filter_ccc(fft_filter_ccc&&) = default;
fft_filter_ccc& operator=(fft_filter_ccc&&) = default;
/*!
* \brief Set new taps for the filter.
*
* Sets new taps and resets the class properties to handle different sizes
* \param taps The filter taps (complex)
*/
int set_taps(const std::vector<gr_complex>& taps);
/*!
* \brief Set number of threads to use.
*/
void set_nthreads(int n);
/*!
* \brief Returns the taps.
*/
std::vector<gr_complex> taps() const;
/*!
* \brief Returns the number of taps in the filter.
*/
unsigned int ntaps() const;
/*!
* \brief Get number of threads being used.
*/
int nthreads() const;
/*!
* \brief Perform the filter operation
*
* \param nitems The number of items to produce
* \param input The input vector to be filtered
* \param output The result of the filter operation
*/
int filter(int nitems, const gr_complex* input, gr_complex* output);
};
/*!
* \brief Fast FFT filter with gr_complex input, gr_complex output and float taps
* \ingroup filter_blk
*
* \details
* This block performs fast convolution using the
* overlap-and-add algorithm. The filtering is performand in
* the frequency domain instead of the time domain (see
* gr::filter::kernel::fir_filter_ccf). For an input signal x
* and filter coefficients (taps) t, we compute y as:
*
* \code
* y = ifft(fft(x)*fft(t))
* \endcode
*
* This kernel computes the FFT of the taps when they are set to
* only perform this operation once. The FFT of the input signal
* x is done every time.
*
* Because this is designed as a very low-level kernel
* operation, it is designed for speed and avoids certain checks
* in the filter() function itself. The filter function expects
* that the input signal is a multiple of d_nsamples in the
* class that's computed internally to be as fast as
* possible. The function set_taps will return the value of
* nsamples that can be used externally to check this
* boundary. Notice that all implementations of the fft_filter
* GNU Radio blocks (e.g., gr::filter::fft_filter_ccf) use this
* value of nsamples to compute the value to call
* gr::block::set_output_multiple that ensures the scheduler
* always passes this block the right number of samples.
*/
class FILTER_API fft_filter_ccf
{
private:
int d_ntaps;
int d_nsamples;
int d_fftsize; // fftsize = ntaps + nsamples - 1
int d_decimation;
std::unique_ptr<fft::fft_complex_fwd> d_fwdfft; // forward "plan"
std::unique_ptr<fft::fft_complex_rev> d_invfft; // inverse "plan"
int d_nthreads; // number of FFTW threads to use
std::vector<gr_complex> d_tail; // state carried between blocks for overlap-add
std::vector<float> d_taps; // stores time domain taps
volk::vector<gr_complex> d_xformed_taps; // Fourier xformed taps
void compute_sizes(int ntaps);
int tailsize() const { return d_ntaps - 1; }
gr::logger_ptr d_logger, d_debug_logger;
public:
/*!
* \brief Construct an FFT filter for complex vectors with the given taps and
* decimation rate.
*
* This is the basic implementation for performing FFT filter for fast convolution
* in other blocks (e.g., gr::filter::fft_filter_ccf).
*
* \param decimation The decimation rate of the filter (int)
* \param taps The filter taps (float)
* \param nthreads The number of threads for the FFT to use (int)
*/
fft_filter_ccf(int decimation, const std::vector<float>& taps, int nthreads = 1);
// Disallow copy.
//
// This prevents accidentally doing needless copies, not just of fft_filter_xxx,
// but every block that contains one.
fft_filter_ccf(const fft_filter_ccf&) = delete;
fft_filter_ccf& operator=(const fft_filter_ccf&) = delete;
fft_filter_ccf(fft_filter_ccf&&) = default;
fft_filter_ccf& operator=(fft_filter_ccf&&) = default;
/*!
* \brief Set new taps for the filter.
*
* Sets new taps and resets the class properties to handle different sizes
* \param taps The filter taps (complex)
*/
int set_taps(const std::vector<float>& taps);
/*!
* \brief Set number of threads to use.
*/
void set_nthreads(int n);
/*!
* \brief Returns the taps.
*/
std::vector<float> taps() const;
/*!
* \brief Returns the number of taps in the filter.
*/
unsigned int ntaps() const;
/*!
* \brief Returns the actual size of the filter.
*
* \details This value could be equal to ntaps, but we often
* build a longer filter to allow us to calculate a more
* efficient FFT. This value is the actual size of the filters
* used in the calculation of the overlap-and-add operation.
*/
unsigned int filtersize() const;
/*!
* \brief Get number of threads being used.
*/
int nthreads() const;
/*!
* \brief Perform the filter operation
*
* \param nitems The number of items to produce
* \param input The input vector to be filtered
* \param output The result of the filter operation
*/
int filter(int nitems, const gr_complex* input, gr_complex* output);
};
} /* namespace kernel */
} /* namespace filter */
} /* namespace gr */
#endif /* INCLUDED_FILTER_FFT_FILTER_H */
gr::filter::kernel::fft_filter_ccc::fft_filter_ccc
fft_filter_ccc(const fft_filter_ccc &)=delete
gr::filter::kernel::fft_filter_ccc::ntaps
unsigned int ntaps() const
Returns the number of taps in the filter.
gr::filter::kernel::fft_filter_ccc::set_nthreads
void set_nthreads(int n)
Set number of threads to use.
gr::filter::kernel::fft_filter_ccc::fft_filter_ccc
fft_filter_ccc(int decimation, const std::vector< gr_complex > &taps, int nthreads=1)
Construct an FFT filter for complex vectors with the given taps and decimation rate.
gr::filter::kernel::fft_filter_ccc::fft_filter_ccc
fft_filter_ccc(fft_filter_ccc &&)=default
gr::filter::kernel::fft_filter_ccc::operator=
fft_filter_ccc & operator=(fft_filter_ccc &&)=default
gr::filter::kernel::fft_filter_ccc::operator=
fft_filter_ccc & operator=(const fft_filter_ccc &)=delete
gr::filter::kernel::fft_filter_ccc::filter
int filter(int nitems, const gr_complex *input, gr_complex *output)
Perform the filter operation.
gr::filter::kernel::fft_filter_ccc::set_taps
int set_taps(const std::vector< gr_complex > &taps)
Set new taps for the filter.
gr::filter::kernel::fft_filter_ccc::taps
std::vector< gr_complex > taps() const
Returns the taps.
gr::filter::kernel::fft_filter_ccc::nthreads
int nthreads() const
Get number of threads being used.
gr::filter::kernel::fft_filter_ccf::fft_filter_ccf
fft_filter_ccf(fft_filter_ccf &&)=default
gr::filter::kernel::fft_filter_ccf::operator=
fft_filter_ccf & operator=(const fft_filter_ccf &)=delete
gr::filter::kernel::fft_filter_ccf::ntaps
unsigned int ntaps() const
Returns the number of taps in the filter.
gr::filter::kernel::fft_filter_ccf::operator=
fft_filter_ccf & operator=(fft_filter_ccf &&)=default
gr::filter::kernel::fft_filter_ccf::set_nthreads
void set_nthreads(int n)
Set number of threads to use.
gr::filter::kernel::fft_filter_ccf::filter
int filter(int nitems, const gr_complex *input, gr_complex *output)
Perform the filter operation.
gr::filter::kernel::fft_filter_ccf::set_taps
int set_taps(const std::vector< float > &taps)
Set new taps for the filter.
gr::filter::kernel::fft_filter_ccf::fft_filter_ccf
fft_filter_ccf(int decimation, const std::vector< float > &taps, int nthreads=1)
Construct an FFT filter for complex vectors with the given taps and decimation rate.
gr::filter::kernel::fft_filter_ccf::fft_filter_ccf
fft_filter_ccf(const fft_filter_ccf &)=delete
gr::filter::kernel::fft_filter_ccf::filtersize
unsigned int filtersize() const
Returns the actual size of the filter.
gr::filter::kernel::fft_filter_ccf::nthreads
int nthreads() const
Get number of threads being used.
gr::filter::kernel::fft_filter_ccf::taps
std::vector< float > taps() const
Returns the taps.
gr::filter::kernel::fft_filter_fff::operator=
fft_filter_fff & operator=(fft_filter_fff &&)=default
gr::filter::kernel::fft_filter_fff::nthreads
int nthreads() const
Get number of threads being used.
gr::filter::kernel::fft_filter_fff::ntaps
unsigned int ntaps() const
Returns the number of taps in the filter.
gr::filter::kernel::fft_filter_fff::fft_filter_fff
fft_filter_fff(const fft_filter_fff &)=delete
gr::filter::kernel::fft_filter_fff::fft_filter_fff
fft_filter_fff(fft_filter_fff &&)=default
gr::filter::kernel::fft_filter_fff::operator=
fft_filter_fff & operator=(const fft_filter_fff &)=delete
gr::filter::kernel::fft_filter_fff::fft_filter_fff
fft_filter_fff(int decimation, const std::vector< float > &taps, int nthreads=1)
Construct an FFT filter for float vectors with the given taps and decimation rate.
gr::filter::kernel::fft_filter_fff::set_nthreads
void set_nthreads(int n)
Set number of threads to use.
gr::filter::kernel::fft_filter_fff::set_taps
int set_taps(const std::vector< float > &taps)
Set new taps for the filter.
gr::filter::kernel::fft_filter_fff::taps
std::vector< float > taps() const
Returns the taps.
gr::filter::kernel::fft_filter_fff::filter
int filter(int nitems, const float *input, float *output)
Perform the filter operation.
fft.h
api.h
FILTER_API
#define FILTER_API
Definition gr-filter/include/gnuradio/filter/api.h:18
gr_complex.h
gr_complex
std::complex< float > gr_complex
Definition gr_complex.h:15
logger.h
gr::filter::kernel
Definition fft_filter.h:23
gr::filter
Definition dc_blocker_cc.h:18
gr
GNU Radio logging wrapper.
Definition basic_block.h:29
gr::logger_ptr
std::shared_ptr< logger > logger_ptr
Definition logger.h:250