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/* -*- c++ -*- */
/*
* Copyright 2015 Free Software Foundation, Inc.
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#ifndef INCLUDED_ATSC_TRELLIS_ENCODER_H
#define INCLUDED_ATSC_TRELLIS_ENCODER_H
/*!
* \brief ATSC trellis encoder building block.
*
* Note this is NOT the 12x interleaved interface.
*
* This implements a single instance of the ATSC trellis encoder.
* This is a rate 2/3 encoder (really a constraint length 3, rate 1/2
* encoder with the top bit passed through unencoded. This does not
* implement the "precoding" of the top bit, because the NTSC rejection
* filter is not supported.
*/
namespace gr {
namespace dtv {
class atsc_basic_trellis_encoder
{
private:
int state; // two bit state;
public:
atsc_basic_trellis_encoder() : state(0) {}
/*!
* Encode two bit INPUT into 3 bit return value. Domain is [0,3],
* Range is [0,7]. The mapping to bipolar levels is not done.
*/
int encode(unsigned int input);
//! reset encoder state
void reset() { state = 0; }
static const unsigned char next_state[32];
static const unsigned char out_symbol[32];
};
} /* namespace dtv */
} /* namespace gr */
#endif /* INCLUDED_ATSC_TRELLIS_ENCODER_H */
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