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/* -*- c++ -*- */
/*
* Copyright 2006 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 2, 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef INCLUDED_DECODER_H
#define INCLUDED_DECODER_H
#include "code_io.h"
class decoder
{
/*
* class decoder
* A virtual class upon which all decoder types can be built.
* This class provides the basic methods and variables
* generic for all decoders.
*/
public:
decoder () {};
virtual ~decoder () {};
/*
* compute_n_...: to be defined by inheriting classes, in order to
* allow for user-functions to figure out how many inputs are
* required to generate a given number of outputs, and vice versa.
* Can't define them without knowing the decoder type.
*
* Compute the number of input items (metrics, floats, whatevers)
* needed to produce 'n_output' bits, and the number of output bits
* which will be produced by 'n_input' items ... for a single stream
* only.
*/
virtual size_t compute_n_input_items (size_t n_output_bits) = 0;
virtual size_t compute_n_output_bits (size_t n_input_items) = 0;
/*
* decode: given the input and output buffers, either decode up to
* the number of output bits or decode the number of input items
* ... if the buffers support either decoding amounts.
*/
virtual size_t decode (const code_input_ptr in_buf,
code_output_ptr out_buf,
size_t n_bits_to_output);
virtual size_t decode (const code_input_ptr in_buf,
size_t n_items_to_input,
code_output_ptr out_buf);
/* for remote access to internal info */
inline const size_t block_size_bits () {return (d_block_size_bits);};
inline const size_t n_code_inputs () {return (d_n_code_inputs);};
inline const size_t n_code_outputs () {return (d_n_code_outputs);};
inline const size_t total_n_dec_bits () {return (d_total_n_dec_bits);};
protected:
/*
* decode_private: decode the given in_buf and write the output bits
* to the out_buf, using internal class variables. This function is
* called from the publically available "encode()" methods, which
* first set the internal class variables before executing.
*/
virtual void decode_private () = 0;
size_t d_block_size_bits, d_n_code_inputs, d_n_code_outputs;
size_t d_total_n_dec_bits, d_n_items_to_input, d_n_bits_to_output;
code_input_ptr d_in_buf;
code_output_ptr d_out_buf;
};
#endif /* INCLUDED_DECODER_H */
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