generic_encoder.h

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/* -*- c++ -*- */
/*
 * Copyright 2013-2014 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 INCLUDED_FEC_GENERIC_ENCODER_H
#define INCLUDED_FEC_GENERIC_ENCODER_H

#include <gnuradio/block.h>
#include <gnuradio/fec/api.h>
#include <gnuradio/logger.h>
#include <boost/shared_ptr.hpp>

namespace gr {
namespace fec {

class FEC_API generic_encoder
{
protected:
    gr::logger_ptr d_logger;

public:
    friend class encoder;
    virtual void generic_work(void* in_buffer, void* out_buffer) = 0;
    static int base_unique_id;
    int my_id;
    int unique_id();
    std::string d_name;
    std::string alias() { return (boost::format("%s%d") % d_name % unique_id()).str(); }

public:
    typedef boost::shared_ptr<generic_encoder> sptr;

    /*!
     * Returns the rate of the code. For every 1 input bit, there
     * are r output bits, so the rate is 1/r. Used for setting
     * things like the encoder block's relative rate.
     *
     * This function MUST be reimplemented by the child class.
     */
    virtual double rate() = 0;

    /*!
     * Returns the input size in items that the encoder object uses
     * to encode a full frame. Often, this number is the number of
     * bits per frame if the input format is unpacked. If the block
     * expects packed bytes, then this value should be the number of
     * bytes (number of bits / 8) per input frame.
     *
     * The child class MUST implement this function.
     */
    virtual int get_input_size() = 0;

    /*!
     * Returns the output size in items that the encoder object
     * produces after encoding a full frame. Often, this number is
     * the number of bits in the outputted frame if the input format
     * is unpacked. If the block produces packed bytes, then this
     * value should be the number of bytes (number of bits / 8) per
     * frame produced. This value is generally something like
     * R*get_input_size() for a 1/R rate code.
     *
     * The child class MUST implement this function.
     */
    virtual int get_output_size() = 0;

    /*!
     * Set up a conversion type required to setup the data properly
     * for this encoder. The encoder itself will not implement the
     * conversion and expects an external wrapper (e.g.,
     * fec.extended_encoder) to read this value and "do the right
     * thing" to format the data.
     *
     * The default behavior is 'none', which means no conversion is
     * required. Whatever the get_input_item_size() value returns,
     * the input is expected to conform directly to this. Generally,
     * this means unpacked bytes.
     *
     * If 'pack', the block expects the inputs to be packed
     * bytes. The wrapper should implement a
     * gr::blocks::pack_k_bits_bb(8) block for this.
     *
     * The child class MAY implement this function. If not
     * reimplemented, it returns "none".
     */
    virtual const char* get_input_conversion();

    /*!
     * Set up a conversion type required to understand the output
     * style of this encoder. Generally an encoder will produce
     * unpacked bytes with a bit set in the LSB.
     *
     * The default behavior is 'none', which means no conversion is
     * required and the encoder produces unpacked bytes.
     *
     * If 'packed_bits', the block produces packed bits and the
     * wrapper should unpack these (using, for instance,
     * gr::block::unpack_k_bits_bb(8)).
     *
     * The child class MAY implement this function. If not
     * reimplemented, it returns "none".
     */
    virtual const char* get_output_conversion();

    /*!
     * Updates the size of the frame to encode.
     *
     * The child class MUST implement this function and interpret
     * how the \p frame_size information affects the block's
     * behavior. It should also provide bounds checks.
     */
    virtual bool set_frame_size(unsigned int frame_size) = 0;

    generic_encoder(void){};
    generic_encoder(std::string name);
    virtual ~generic_encoder();
};

/*! see generic_encoder::get_output_size() */
FEC_API int get_encoder_output_size(generic_encoder::sptr my_encoder);

/*! see generic_encoder::get_input_size() */
FEC_API int get_encoder_input_size(generic_encoder::sptr my_encoder);

/*! see generic_encoder::get_input_conversion() */
FEC_API const char* get_encoder_input_conversion(generic_encoder::sptr my_encoder);

/*! see generic_encoder::get_output_conversion() */
FEC_API const char* get_encoder_output_conversion(generic_encoder::sptr my_encoder);


} /* namespace fec */
} /* namespace gr */

#endif /* INCLUDED_FEC_GENERIC_ENCODER_H */