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/* -*- c++ -*- */
/*
* Copyright 2009 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* GNU Radio is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <noaa_hrpt_deframer.h>
#include <gr_io_signature.h>
#define ST_IDLE 0
#define ST_SYNCED 1
#define HRPT_MINOR_FRAME_SYNC 0x0A116FD719D83C95LL
#define HRPT_BITS_PER_MINOR_FRAME 11090*10
#define HRPT_SYNC_LENGTH 6*10
static int frames_seen = 0;
noaa_hrpt_deframer_sptr
noaa_make_hrpt_deframer()
{
return gnuradio::get_initial_sptr(new noaa_hrpt_deframer());
}
noaa_hrpt_deframer::noaa_hrpt_deframer()
: gr_sync_block("noaa_hrpt_deframer",
gr_make_io_signature(1, 1, sizeof(char)),
gr_make_io_signature(0, 0, 0))
{
enter_idle();
}
void
noaa_hrpt_deframer::enter_idle()
{
d_state = ST_IDLE;
}
void
noaa_hrpt_deframer::enter_synced()
{
d_state = ST_SYNCED;
d_count = HRPT_BITS_PER_MINOR_FRAME-HRPT_SYNC_LENGTH;
}
int
noaa_hrpt_deframer::work(int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
const char *in = (const char *)input_items[0];
int i = 0;
while (i < noutput_items) {
char bit = in[i++];
if (d_state != ST_SYNCED)
fprintf(stderr, ".");
switch (d_state) {
case ST_IDLE:
d_shifter = (d_shifter << 1) | bit; // MSB transmitted first
if ((d_shifter & 0x0FFFFFFFFFFFFFFF) == HRPT_MINOR_FRAME_SYNC) {
fprintf(stderr, "\nSYNC #%i...", frames_seen++);
enter_synced();
}
break;
case ST_SYNCED:
if (--d_count == 0) {
fprintf(stderr, "done.");
enter_idle();
}
break;
default:
throw std::runtime_error("noaa_hrpt_deframer: bad state\n");
}
}
return i;
}
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