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/* -*- c++ -*- */
/*
* Copyright 2012 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 "keep_m_in_n_impl.h"
#include <gr_io_signature.h>
namespace gr {
namespace blocks {
keep_m_in_n::sptr keep_m_in_n::make(size_t itemsize, int m, int n, int offset)
{
return gnuradio::get_initial_sptr(new keep_m_in_n_impl(itemsize, m, n, offset));
}
keep_m_in_n_impl::keep_m_in_n_impl(size_t itemsize, int m, int n, int offset)
: gr_block("keep_m_in_n",
gr_make_io_signature (1, 1, itemsize),
gr_make_io_signature (1, 1, itemsize)),
d_itemsize(itemsize),
d_m(m),
d_n(n),
d_offset(offset)
{
// sanity checking
assert(d_m > 0);
assert(d_n > 0);
assert(d_m <= d_n);
assert(d_offset <= (d_n-d_m));
set_output_multiple(m);
}
void
keep_m_in_n_impl::forecast(int noutput_items, gr_vector_int &ninput_items_required)
{
ninput_items_required[0] = d_n*(noutput_items/d_m);
}
int
keep_m_in_n_impl::general_work(int noutput_items,
gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
uint8_t* out = (uint8_t*)output_items[0];
const uint8_t* in = (const uint8_t*)input_items[0];
// iterate over data blocks of size {n, input : m, output}
int blks = std::min(noutput_items/d_m, ninput_items[0]/d_n);
for(int i=0; i<blks; i++) {
// set up copy pointers
const uint8_t* iptr = &in[(i*d_n + d_offset)*d_itemsize];
uint8_t* optr = &out[i*d_m*d_itemsize];
// perform copy
memcpy( optr, iptr, d_m*d_itemsize );
}
consume_each(d_n);
return d_m;
}
} /* namespace blocks */
} /* namespace gr */
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