GNU Radio 3.6.1 C++ API
gri_fft_filter_fff_generic.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2010 Free Software Foundation, Inc.
4  *
5  * This file is part of GNU Radio
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22 
23 #ifndef INCLUDED_GRI_FFT_FILTER_FFF_GENERIC_H
24 #define INCLUDED_GRI_FFT_FILTER_FFF_GENERIC_H
25 
26 #include <gr_core_api.h>
27 #include <gr_complex.h>
28 #include <vector>
29 
30 class gri_fft_real_fwd;
31 class gri_fft_real_rev;
32 
34 {
35  private:
36  int d_ntaps;
37  int d_nsamples;
38  int d_fftsize; // fftsize = ntaps + nsamples - 1
39  int d_decimation;
40  gri_fft_real_fwd *d_fwdfft; // forward "plan"
41  gri_fft_real_rev *d_invfft; // inverse "plan"
42  int d_nthreads; // number of FFTW threads to use
43  std::vector<float> d_tail; // state carried between blocks for overlap-add
44  std::vector<float> d_new_taps;
45  gr_complex *d_xformed_taps; // Fourier xformed taps
46 
47 
48  void compute_sizes(int ntaps);
49  int tailsize() const { return d_ntaps - 1; }
50 
51  public:
52  /*!
53  * \brief Construct a FFT filter for float vectors with the given taps and decimation rate.
54  *
55  * This is the basic implementation for performing FFT filter for fast convolution
56  * in other blocks for floating point vectors (such as gr_fft_filter_fff).
57  * \param decimation The decimation rate of the filter (int)
58  * \param taps The filter taps (float)
59  * \param nthreads The number of threads for the FFT to use (int)
60  */
61  gri_fft_filter_fff_generic (int decimation, const std::vector<float> &taps,
62  int nthreads=1);
64 
65  /*!
66  * \brief Set new taps for the filter.
67  *
68  * Sets new taps and resets the class properties to handle different sizes
69  * \param taps The filter taps (float)
70  */
71  int set_taps (const std::vector<float> &taps);
72 
73  /*!
74  * \brief Set number of threads to use.
75  */
76  void set_nthreads(int n);
77 
78  /*!
79  * \brief Get number of threads being used.
80  */
81  int nthreads() const;
82 
83  /*!
84  * \brief Perform the filter operation
85  *
86  * \param nitems The number of items to produce
87  * \param input The input vector to be filtered
88  * \param output The result of the filter operation
89  */
90  int filter (int nitems, const float *input, float *output);
91 
92 };
93 
94 #endif /* INCLUDED_GRI_FFT_FILTER_FFF_GENERIC_H */