GNU Radio 3.5.3.2 C++ API
gr_align_on_samplenumbers_ss.h
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00001 /* -*- c++ -*- */
00002 /*
00003  * Copyright 2005 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_ALIGN_ON_SAMPLE_NUMBERS_SS_H
00024 #define INCLUDED_GR_ALIGN_ON_SAMPLE_NUMBERS_SS_H
00025 
00026 #include <gr_core_api.h>
00027 #include <gr_block.h>
00028 
00029 /*!
00030  * \brief align several complex short (interleaved short) input channels with corresponding unsigned 32 bit sample_counters (provided as interleaved 16 bit values)
00031  * \ingroup misc
00032  * \param number of complex_short input channels (including the 32 bit counting channel)
00033  * \param align_interval is after how much samples (minimally) the sample-alignement is refreshed. Default is 128.
00034  * A bigger value means less processing power but also requests more buffer space, which has a maximum.
00035  * Decrease the align_interval if you get an error like:
00036  * "sched: <gr_block align_on_samplenumbers_ss (0)> is requesting more input data  than we can provide.
00037  *  ninput_items_required = 32768
00038  *  max_possible_items_available = 16383
00039  *  If this is a filter, consider reducing the number of taps."
00040  * \ingroup block
00041  * Pay attention on how you connect this block.
00042  * It expects a minimum of 2 usrp_source_s with nchan number of channels and FPGA_MODE_COUNTING_32BIT enabled.
00043  * This means that the first complex_short channel on every input is an interleaved 32 bit counter. 
00044  * The samples are aligned by dropping samples untill the samplenumbers match.
00045  */
00046 class gr_align_on_samplenumbers_ss;
00047 typedef boost::shared_ptr<gr_align_on_samplenumbers_ss> gr_align_on_samplenumbers_ss_sptr;
00048 
00049 GR_CORE_API gr_align_on_samplenumbers_ss_sptr gr_make_align_on_samplenumbers_ss (int nchan=2, int align_interval=128);
00050 
00051 
00052 
00053 
00054 class GR_CORE_API gr_align_on_samplenumbers_ss : public gr_block
00055 {
00056   int  d_align_interval;
00057   int  d_sample_counter;
00058   int  d_nchan;
00059   bool d_in_presync;
00060   unsigned int d_ninputs;
00061   class GR_CORE_API align_state {
00062       public:
00063         unsigned int ucounter_end;
00064         unsigned int ucounter_begin;
00065         int diff;
00066         int diff_comp;
00067         int diff_end;
00068         int diff_comp_end;
00069         bool sync_found;
00070         bool sync_end_found;
00071         int ninput_items;
00072         int ninput_items_used;
00073       };
00074   std::vector<align_state>   d_state;
00075     
00076   friend GR_CORE_API gr_align_on_samplenumbers_ss_sptr gr_make_align_on_samplenumbers_ss (int nchan,int align_interval);
00077   gr_align_on_samplenumbers_ss (int nchan,int align_interval);
00078 
00079  public:
00080    ~gr_align_on_samplenumbers_ss();
00081   bool check_topology (int ninputs, int noutputs);
00082   void forecast (int noutput_items,
00083         gr_vector_int &ninput_items_required);
00084 
00085   int general_work (int noutput_items,
00086         gr_vector_int &ninput_items,
00087         gr_vector_const_void_star &input_items,
00088         gr_vector_void_star &output_items);
00089 };
00090 
00091 
00092 #endif /* INCLUDED_GR_ALIGN_ON_SAMPLE_NUMBERS_SS_H */