gnss-sdr/src/algorithms/signal_source/gnuradio_blocks/unpack_intspir_1bit_samples.cc

85 lines
2.9 KiB
C++

/*!
* \file unpack_intspir_1bit_samples.cc
*
* \brief Unpacks SPIR int samples to NSR 1 bit samples
* \author Fran Fabra fabra (at) ice.csic.es
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2015 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
*
* This file is not part of GNSS-SDR.
*
* GNSS-SDR 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 of the License, or
* (at your option) any later version.
*
* GNSS-SDR 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 GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "unpack_intspir_1bit_samples.h"
#include <iostream>
#include <gnuradio/io_signature.h>
unpack_intspir_1bit_samples_sptr make_unpack_intspir_1bit_samples()
{
return unpack_intspir_1bit_samples_sptr(new unpack_intspir_1bit_samples());
}
unpack_intspir_1bit_samples::unpack_intspir_1bit_samples() : sync_interpolator("unpack_intspir_1bit_samples",
gr::io_signature::make(1, 1, sizeof(int)),
gr::io_signature::make(1, 1, sizeof(float)),
2)
{}
unpack_intspir_1bit_samples::~unpack_intspir_1bit_samples()
{}
int unpack_intspir_1bit_samples::work(int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
const signed int *in = (const signed int *)input_items[0];
float *out = (float*)output_items[0];
int n = 0;
int channel = 1;
for(int i = 0; i < noutput_items/2; i++)
{
// Read packed input sample (1 byte = 1 complex sample)
// For historical reasons, values are float versions of short int limits (32767)
signed int val = in[i];
if(((val >> ((channel - 1)*2)) & 1) == 1)
{
out[n++] = static_cast<float>(32767.0);
}
else
{
out[n++] = static_cast<float>(-32767.0);
}
if(((val >> (2*channel - 1)) & 1) == 1)
{
out[n++] = static_cast<float>(32767.0);
}
else
{
out[n++] = static_cast<float>(-32767.0);
}
}
return noutput_items;
}