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/* -*- c++ -*- */
/*
* Copyright 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_ASYNC_DECODER_H
#define INCLUDED_FEC_ASYNC_DECODER_H
#include <gnuradio/fec/api.h>
#include <gnuradio/fec/generic_decoder.h>
#include <gnuradio/block.h>
#include <boost/shared_ptr.hpp>
namespace gr {
namespace fec {
/*!
* \brief Creates the decoder block for use in GNU Radio
* flowgraphs from a given FEC API object derived from the
* generic_decoder class.
* \ingroup error_coding_blk
*
* \details
*
* Decodes frames received as async messages over a message
* port. This decoder deployment expects messages of soft decision
* symbols in and can produce either packed, PDU messages (\p
* packed = True) or messages full of unpacked bits (\p packed =
* False).
*
* This decoder works off a full message as one frame or block to
* decode. The message length is used to calculate the frame
* length. To support this, the decoder variable used will have
* had its frame_size set. This block treats that initial
* frame_size value as the maximum transmission unit (MTU) and
* will not process frames larger than that after being decoded.
*
* The packed PDU form of this deployment is designed to work well
* with other PDU-based blocks to operate within the processing
* flow of data packets or frames.
*
* Due to differences in how data is packed and processed, this
* block also offers the ability to change the direction of how
* bits are packed. All inputs messages are one soft decision per
* item. By default, the \p rev_pack mode is set to True. Using
* this setup allows the async block to behave with PDUs in the
* same operation and format as the tagged stream decoders. That
* is, putting the same data into both the tagged stream decoder
* deployment and this with the default setting should produce the
* same data.
*
* Because the block handles data as a full frame per message,
* this decoder deployment cannot work with any decoders that
* require history. For example, the gr::fec::code::cc_decoder
* decoder in streaming mode requires an extra rate*(K-1) bits to
* complete the decoding, so it would have to wait for the next
* message to come in and finish processing. Therefore, the
* streaming mode of the CC decoder is not allowed. The other
* three modes will work with this deployment since the frame is
* self-contained for decoding.
*/
class FEC_API async_decoder : virtual public block
{
public:
typedef boost::shared_ptr<async_decoder> sptr;
/*!
* Build the PDU-based FEC decoder block from an FECAPI decoder object.
*
* \param my_decoder An FECAPI decoder object child of the generic_decoder class.
* \param packed Sets output to packed bytes if true; otherwise, 1 bit per byte.
* \param rev_pack If packing bits, should they be reversed?
* \param mtu The Maximum Transmission Unit (MTU) of the output
* frame that the block will be able to
* process. Specified in bytes and defaults to 1500.
*/
static sptr make(generic_decoder::sptr my_decoder,
bool packed=false, bool rev_pack=true,
int mtu=1500);
virtual int general_work(int noutput_items,
gr_vector_int& ninput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items) = 0;
};
} /* namespace fec */
} /* namespace gr */
#endif /* INCLUDED_FEC_ASYNC_DECODER_H */
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