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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.
*/
#ifndef _GRATSCSYMBOLMAPPER_H_
#define _GRATSCSYMBOLMAPPER_H_
#include <VrInterpolatingSigProcNoWork.h>
#include <atsc_types.h>
#include <gr_nco.h>
/*!
* \brief take atsc_data_segments and map them to symbols.
*
* Input is a stream of atsc_data_segments.
* Output is a stream of symbols at 1x the symbol rate
*
* This module performs the signal mapping & pilot addition.
*/
template<class oType>
class GrAtscSymbolMapper
: public VrInterpolatingSigProcNoWork<atsc_data_segment, oType> {
public:
GrAtscSymbolMapper ()
: VrInterpolatingSigProcNoWork<atsc_data_segment, oType>(1, INTERP_FACTOR) {};
~GrAtscSymbolMapper () {};
const char *name () { return "GrAtscSymbolMapper"; }
int work (VrSampleRange output, void *ao[],
VrSampleRange inputs[], void *ai[]);
protected:
static const int INTERP_FACTOR = ATSC_DATA_SEGMENT_LENGTH;
};
template<class oType>
int
GrAtscSymbolMapper<oType>::work (VrSampleRange output, void *ao[],
VrSampleRange inputs[], void *ai[])
{
atsc_data_segment *in = ((atsc_data_segment **) ai)[0];
oType *out = ((oType **) ao)[0];
assert ((output.size % INTERP_FACTOR) == 0);
static const float pilot_add = 1.25;
static const float map[8] = {
-7 + pilot_add,
-5 + pilot_add,
-3 + pilot_add,
-1 + pilot_add,
1 + pilot_add,
3 + pilot_add,
5 + pilot_add,
7 + pilot_add
};
unsigned int oo = 0;
unsigned int nsegs = output.size / INTERP_FACTOR;
for (unsigned int n = 0; n < nsegs; n++){
unsigned char *symbol = in[n].data;
for (int i = 0; i < ATSC_DATA_SEGMENT_LENGTH; i++){
out[oo++] = (oType) map[symbol[i] & 0x7];
}
}
assert (oo == output.size);
return output.size;
}
#endif /* _GRATSCSYMBOLMAPPER_H_ */
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