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 2, 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., 59 Temple Place - Suite 330, 00020 * Boston, MA 02111-1307, 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 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 */