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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((double)(my_decoder->get_output_size())/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 (int)(0.5 + ninput*relative_rate());
}
int
decoder_impl::fixed_rate_noutput_to_ninput(int noutput)
{
return (int)(0.5 + noutput/relative_rate());
}
void
decoder_impl::forecast(int noutput_items,
gr_vector_int& ninput_items_required)
{
ninput_items_required[0] = 0.5 + 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 = (int)(((1.0/relative_rate()) * noutput_items) + 0.5);
int innum = (int)(relative_rate() * (ninput_items[0] - d_decoder->get_history()) + 0.5)/(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;
GR_LOG_DEBUG(d_debug_logger, boost::format("%1%, %2%, %3%") \
% outnum % ninput_items[0] % items);
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 = static_cast<int>(items/relative_rate()*(output_multiple() - d_decoder->get_history()) + 0.5);
int returned = items*(output_multiple() - d_decoder->get_history());
GR_LOG_DEBUG(d_debug_logger, boost::format("consumed %1%") % consumed);
GR_LOG_DEBUG(d_debug_logger, boost::format("returned %1%") % returned);
consume_each(consumed);
return returned;
}
} /* namespace fec */
} /* namespace gr */
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