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/* -*- c++ -*- */
/*
* Copyright 2013-2014 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 "decoder_impl.h"
#include <gnuradio/io_signature.h>
#include <stdio.h>
namespace gr {
namespace fec {
decoder::sptr decoder::make(generic_decoder::sptr my_decoder,
size_t input_item_size,
size_t output_item_size)
{
return gnuradio::get_initial_sptr(
new decoder_impl(my_decoder, input_item_size, output_item_size));
}
decoder_impl::decoder_impl(generic_decoder::sptr my_decoder,
size_t input_item_size,
size_t output_item_size)
: block("fec_decoder",
io_signature::make(1, 1, input_item_size),
io_signature::make(1, 1, output_item_size)),
d_input_item_size(input_item_size),
d_output_item_size(output_item_size)
{
set_fixed_rate(true);
set_relative_rate((uint64_t)my_decoder->get_output_size(),
(uint64_t)my_decoder->get_input_size());
// want to guarantee you have enough to run at least one time...
// remember! this is not a sync block... set_output_multiple does not
// actually guarantee the output multiple... it DOES guarantee how many
// outputs (hence inputs) are made available... this is WEIRD to do in
// GNU Radio, and the algorithm is sensitive to this value
set_output_multiple(my_decoder->get_output_size() + (my_decoder->get_history()));
d_decoder = my_decoder;
}
int decoder_impl::fixed_rate_ninput_to_noutput(int ninput)
{
return std::lround(ninput * relative_rate());
}
int decoder_impl::fixed_rate_noutput_to_ninput(int noutput)
{
return std::lround(noutput / relative_rate());
}
void decoder_impl::forecast(int noutput_items, gr_vector_int& ninput_items_required)
{
ninput_items_required[0] = std::lround(fixed_rate_noutput_to_ninput(noutput_items));
}
int decoder_impl::general_work(int noutput_items,
gr_vector_int& ninput_items,
gr_vector_const_void_star& input_items,
gr_vector_void_star& output_items)
{
const unsigned char* in = (unsigned char*)input_items[0];
unsigned char* out = (unsigned char*)output_items[0];
int outnum = std::lround((1.0 / relative_rate()) * noutput_items);
int innum =
std::lround(relative_rate() * (ninput_items[0] - d_decoder->get_history())) /
(output_multiple() - d_decoder->get_history());
int items = (outnum <= ninput_items[0] - d_decoder->get_history())
? noutput_items / (output_multiple() - d_decoder->get_history())
: innum;
for (int i = 0; i < items; ++i) {
d_decoder->generic_work(
(void*)(in + (i * d_decoder->get_input_size() * d_input_item_size)),
(void*)(out + (i * d_decoder->get_output_size() * d_output_item_size)));
add_item_tag(0,
nitems_written(0) +
((i + 1) * d_decoder->get_output_size() * d_output_item_size),
pmt::intern(d_decoder->alias()),
pmt::PMT_T,
pmt::intern(alias()));
}
int consumed = std::lround(
items / relative_rate() * (output_multiple() - d_decoder->get_history()));
int returned = items * (output_multiple() - d_decoder->get_history());
consume_each(consumed);
return returned;
}
} /* namespace fec */
} /* namespace gr */
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