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/* -*- c++ -*- */
/*
* Copyright 2002 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.
*/
#include <GrAtscConvert2xTo20.h>
#include <atsc_consts.h>
#include <cmath>
#include <cstdio>
static const int N_OUTPUTS = 1;
static const double DEC_RATIO = (2.0 * ATSC_SYMBOL_RATE) / 20e6; // ~ 1.076
GrAtscConvert2xTo20::GrAtscConvert2xTo20 ()
: VrDecimatingSigProc<float,float> (N_OUTPUTS, (int) rint (DEC_RATIO))
{
d_next_input = 0;
d_frac_part = 0;
history = 2 * d_interp.ntaps (); // some slack
}
GrAtscConvert2xTo20::~GrAtscConvert2xTo20 ()
{
// Nop
}
void
GrAtscConvert2xTo20::pre_initialize ()
{
fprintf (stderr,
"GrAtscConvert2xTo20: input freq = %g\n", getInputSamplingFrequencyN(0));
fprintf (stderr,
"GrAtscConvert2xTo20: DEC_RATIO = %g\n", DEC_RATIO);
fprintf (stderr,
"GrAtscConvert2xTo20: argument to setSamplingFrequency = %g\n",
getInputSamplingFrequencyN(0) / DEC_RATIO);
int r;
r = setSamplingFrequency (getInputSamplingFrequencyN (0) / DEC_RATIO);
fprintf (stderr, "GrAtscConvert2xTo20: result = %d\n", r);
fprintf (stderr, "GrAtscConvert2xTo20: getSamplingFrequency = %g\n",
getSamplingFrequency ());
}
int
GrAtscConvert2xTo20::forecast (VrSampleRange output,
VrSampleRange inputs[])
{
assert (numberInputs == 1); // I hate these free references to
// superclass's instance variables...
inputs[0].index = d_next_input;
inputs[0].size =
((long unsigned int) (output.size * DEC_RATIO) + history - 1);
return 0;
}
int
GrAtscConvert2xTo20::work (VrSampleRange output, void *ao[],
VrSampleRange inputs[], void *ai[])
{
float *in = ((float **) ai)[0];
float *out = ((float **) ao)[0];
sync (output.index);
unsigned long si = 0; // source index
unsigned long oi = 0; // output index
double frac_part = d_frac_part;
for (oi = 0; oi < output.size; oi++){
assert (si + d_interp.ntaps () < inputs[0].size);
out[oi] = d_interp.interpolate (&in[si], (1. - frac_part));
double s = frac_part + DEC_RATIO;
double float_incr = floor (s);
frac_part = s - float_incr;
int incr = (int) float_incr;
si += incr;
}
d_next_input += si;
d_frac_part = frac_part;
return output.size;
}
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