GNU Radio 3.6.2 C++ API
gri_fft_filter_ccc_generic.h
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1 /* -*- c++ -*- */
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3  * Copyright 2010 Free Software Foundation, Inc.
4  *
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22 
23 #ifndef INCLUDED_GRI_FFT_FILTER_CCC_GENERIC_H
24 #define INCLUDED_GRI_FFT_FILTER_CCC_GENERIC_H
25 
26 #include <gr_core_api.h>
27 #include <gr_complex.h>
28 #include <vector>
29 
30 class gri_fft_complex;
31 
32 /*!
33  * \brief Fast FFT filter with gr_complex input, gr_complex output and gr_complex taps
34  * \ingroup filter_blk
35  */
37 {
38  private:
39  int d_ntaps;
40  int d_nsamples;
41  int d_fftsize; // fftsize = ntaps + nsamples - 1
42  int d_decimation;
43  gri_fft_complex *d_fwdfft; // forward "plan"
44  gri_fft_complex *d_invfft; // inverse "plan"
45  int d_nthreads; // number of FFTW threads to use
46  std::vector<gr_complex> d_tail; // state carried between blocks for overlap-add
47  std::vector<gr_complex> d_new_taps;
48  gr_complex *d_xformed_taps; // Fourier xformed taps
49 
50  void compute_sizes(int ntaps);
51  int tailsize() const { return d_ntaps - 1; }
52 
53  public:
54  /*!
55  * \brief Construct an FFT filter for complex vectors with the given taps and decimation rate.
56  *
57  * This is the basic implementation for performing FFT filter for fast convolution
58  * in other blocks for complex vectors (such as gr_fft_filter_ccc).
59  * \param decimation The decimation rate of the filter (int)
60  * \param taps The filter taps (complex)
61  * \param nthreads The number of threads for the FFT to use (int)
62  */
63  gri_fft_filter_ccc_generic (int decimation, const std::vector<gr_complex> &taps,
64  int nthreads=1);
66 
67  /*!
68  * \brief Set new taps for the filter.
69  *
70  * Sets new taps and resets the class properties to handle different sizes
71  * \param taps The filter taps (complex)
72  */
73  int set_taps (const std::vector<gr_complex> &taps);
74 
75  /*!
76  * \brief Set number of threads to use.
77  */
78  void set_nthreads(int n);
79 
80  /*!
81  * \brief Get number of threads being used.
82  */
83  int nthreads() const;
84 
85  /*!
86  * \brief Perform the filter operation
87  *
88  * \param nitems The number of items to produce
89  * \param input The input vector to be filtered
90  * \param output The result of the filter operation
91  */
92  int filter (int nitems, const gr_complex *input, gr_complex *output);
93 
94 };
95 
96 #endif /* INCLUDED_GRI_FFT_FILTER_CCC_GENERIC_H */