gnss-sdr/src/algorithms/resampler/gnuradio_blocks/direct_resampler_conditione...

115 lines
3.7 KiB
C++

/*!
* \file direct_resampler_conditioner_cc.cc
* \brief Nearest neighborhood resampler with
* gr_complex input and gr_complex output
* \author Luis Esteve, 2011. luis(at)epsilon-formacion.com
*
*
* -----------------------------------------------------------------------------
*
* GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
* This file is part of GNSS-SDR.
*
* Copyright (C) 2010-2020 (see AUTHORS file for a list of contributors)
* SPDX-License-Identifier: GPL-3.0-or-later
*
* -----------------------------------------------------------------------------
*/
#include "direct_resampler_conditioner_cc.h"
#include <gnuradio/io_signature.h>
#include <volk/volk.h> // for gr_complex
#include <algorithm> // for min
direct_resampler_conditioner_cc_sptr direct_resampler_make_conditioner_cc(
double sample_freq_in, double sample_freq_out)
{
return direct_resampler_conditioner_cc_sptr(
new direct_resampler_conditioner_cc(sample_freq_in,
sample_freq_out));
}
direct_resampler_conditioner_cc::direct_resampler_conditioner_cc(
double sample_freq_in,
double sample_freq_out)
: gr::block("direct_resampler_conditioner_cc",
gr::io_signature::make(1, 1, sizeof(gr_complex)),
gr::io_signature::make(1, 1, sizeof(gr_complex))),
d_sample_freq_in(sample_freq_in),
d_sample_freq_out(sample_freq_out),
d_phase(0),
d_lphase(0)
{
// Computes the phase step multiplying the resampling ratio by 2^32 = 4294967296
const double two_32 = 4294967296.0;
if (d_sample_freq_in >= d_sample_freq_out)
{
d_phase_step = static_cast<uint32_t>(floor(two_32 * sample_freq_out / sample_freq_in));
}
else
{
d_phase_step = static_cast<uint32_t>(floor(two_32 * sample_freq_in / sample_freq_out));
}
#ifdef GR_GREATER_38
this->set_relative_rate(static_cast<uint64_t>(sample_freq_out), static_cast<uint64_t>(sample_freq_in));
#else
this->set_relative_rate(sample_freq_out / sample_freq_in);
#endif
}
void direct_resampler_conditioner_cc::forecast(int noutput_items,
gr_vector_int &ninput_items_required)
{
int nreqd = std::max(static_cast<unsigned>(1), static_cast<int>(static_cast<double>(noutput_items + 1) * sample_freq_in() / sample_freq_out()) + history() - 1);
std::fill(ninput_items_required.begin(), ninput_items_required.end(), nreqd);
}
int direct_resampler_conditioner_cc::general_work(int noutput_items,
gr_vector_int &ninput_items, gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
const auto *in = reinterpret_cast<const gr_complex *>(input_items[0]);
auto *out = reinterpret_cast<gr_complex *>(output_items[0]);
int lcv = 0;
int count = 0;
if (d_sample_freq_in >= d_sample_freq_out)
{
while ((lcv < noutput_items))
{
if (d_phase <= d_lphase)
{
out[lcv] = *in;
lcv++;
}
d_lphase = d_phase;
d_phase += d_phase_step;
in++;
count++;
}
}
else
{
while ((lcv < noutput_items))
{
d_lphase = d_phase;
d_phase += d_phase_step;
if (d_phase <= d_lphase)
{
in++;
count++;
}
out[lcv] = *in;
lcv++;
}
}
consume_each(std::min(count, ninput_items[0]));
return lcv;
}