mirror of https://github.com/gnss-sdr/gnss-sdr
117 lines
3.7 KiB
C++
117 lines
3.7 KiB
C++
/*!
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* \file direct_resampler_conditioner_cb.cc
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* \brief Nearest neighborhood resampler with std::complex<signed char>
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* input and std::complex<signed char> output
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* \author Luis Esteve, 2011. luis(at)epsilon-formacion.com
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*
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*
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* -----------------------------------------------------------------------------
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*
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* GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
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* This file is part of GNSS-SDR.
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*
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* Copyright (C) 2010-2020 (see AUTHORS file for a list of contributors)
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* SPDX-License-Identifier: GPL-3.0-or-later
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*
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* -----------------------------------------------------------------------------
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*/
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#include "direct_resampler_conditioner_cb.h"
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#include <gnuradio/io_signature.h>
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#include <volk/volk.h> // for lv_8sc_t
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#include <algorithm> // for min
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direct_resampler_conditioner_cb_sptr direct_resampler_make_conditioner_cb(
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double sample_freq_in, double sample_freq_out)
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{
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return direct_resampler_conditioner_cb_sptr(
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new direct_resampler_conditioner_cb(sample_freq_in,
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sample_freq_out));
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}
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direct_resampler_conditioner_cb::direct_resampler_conditioner_cb(
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double sample_freq_in,
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double sample_freq_out)
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: gr::block("direct_resampler_make_conditioner_cb",
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gr::io_signature::make(1, 1, sizeof(lv_8sc_t)),
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gr::io_signature::make(1, 1, sizeof(lv_8sc_t))),
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d_sample_freq_in(sample_freq_in),
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d_sample_freq_out(sample_freq_out),
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d_phase(0),
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d_lphase(0)
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{
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const double two_32 = 4294967296.0;
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// Computes the phase step multiplying the resampling ratio by 2^32 = 4294967296
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if (d_sample_freq_in >= d_sample_freq_out)
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{
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d_phase_step = static_cast<uint32_t>(floor(two_32 * sample_freq_out / sample_freq_in));
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}
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else
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{
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d_phase_step = static_cast<uint32_t>(floor(two_32 * sample_freq_in / sample_freq_out));
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}
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#ifdef GR_GREATER_38
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this->set_relative_rate(static_cast<uint64_t>(sample_freq_out), static_cast<uint64_t>(sample_freq_in));
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#else
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this->set_relative_rate(sample_freq_out / sample_freq_in);
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#endif
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}
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void direct_resampler_conditioner_cb::forecast(int noutput_items,
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gr_vector_int &ninput_items_required)
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{
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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);
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std::fill(ninput_items_required.begin(), ninput_items_required.end(), nreqd);
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}
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int direct_resampler_conditioner_cb::general_work(int noutput_items,
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gr_vector_int &ninput_items, gr_vector_const_void_star &input_items,
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gr_vector_void_star &output_items)
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{
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const auto *in = reinterpret_cast<const lv_8sc_t *>(input_items[0]);
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auto *out = reinterpret_cast<lv_8sc_t *>(output_items[0]);
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int lcv = 0;
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int count = 0;
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if (d_sample_freq_in >= d_sample_freq_out)
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{
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while ((lcv < noutput_items))
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{
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if (d_phase <= d_lphase)
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{
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out[lcv] = *in;
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lcv++;
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}
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d_lphase = d_phase;
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d_phase += d_phase_step;
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in++;
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count++;
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}
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}
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else
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{
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while ((lcv < noutput_items))
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{
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d_lphase = d_phase;
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d_phase += d_phase_step;
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if (d_phase <= d_lphase)
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{
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in++;
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count++;
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}
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out[lcv] = *in;
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lcv++;
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}
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}
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consume_each(std::min(count, ninput_items[0]));
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return lcv;
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}
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