GNU Radio 3.4.0 C++ API
gr_sync_decimator.h
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00001 /* -*- c++ -*- */
00002 /*
00003  * Copyright 2004 Free Software Foundation, Inc.
00004  * 
00005  * This file is part of GNU Radio
00006  * 
00007  * GNU Radio is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 3, or (at your option)
00010  * any later version.
00011  * 
00012  * GNU Radio is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  * 
00017  * You should have received a copy of the GNU General Public License
00018  * along with GNU Radio; see the file COPYING.  If not, write to
00019  * the Free Software Foundation, Inc., 51 Franklin Street,
00020  * Boston, MA 02110-1301, USA.
00021  */
00022 
00023 #ifndef INCLUDED_GR_SYNC_DECIMATOR_H
00024 #define INCLUDED_GR_SYNC_DECIMATOR_H
00025 
00026 #include <gr_sync_block.h>
00027 
00028 /*!
00029  * \brief synchronous N:1 input to output with history
00030  * \ingroup base_blk
00031  *
00032  * Override work to provide the signal processing implementation.
00033  */
00034 class gr_sync_decimator : public gr_sync_block
00035 {
00036  private:
00037   unsigned      d_decimation;
00038 
00039  protected:
00040 
00041   gr_sync_decimator (const std::string &name,
00042                      gr_io_signature_sptr input_signature,
00043                      gr_io_signature_sptr output_signature,
00044                      unsigned decimation);
00045  public:
00046 
00047   unsigned decimation () const { return d_decimation; }
00048   void set_decimation (unsigned decimation)
00049   {
00050     d_decimation = decimation;
00051     set_relative_rate (1.0 / decimation);
00052   }
00053 
00054   // gr_sync_decimator overrides these to assist work
00055   void forecast (int noutput_items, gr_vector_int &ninput_items_required);
00056   int  general_work (int noutput_items,
00057                      gr_vector_int &ninput_items,
00058                      gr_vector_const_void_star &input_items,
00059                      gr_vector_void_star &output_items);
00060 
00061   // derived classes should override work
00062 
00063   int fixed_rate_ninput_to_noutput(int ninput);
00064   int fixed_rate_noutput_to_ninput(int noutput);
00065 };
00066 
00067 
00068 #endif /* INCLUDED_GR_SYNC_DECIMATOR_H */