tagged_stream_mux.h

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/* -*- c++ -*- */
/* Copyright 2012 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 */
 
#ifndef INCLUDED_TAGGED_STREAM_MUX_H
#define INCLUDED_TAGGED_STREAM_MUX_H
 
#include <gnuradio/blocks/api.h>
#include <gnuradio/tagged_stream_block.h>
 
namespace gr {
namespace blocks {
 
/*!
 * \brief Combines tagged streams.
 * \ingroup stream_operators_blk
 *
 * \details
 * Takes N streams as input. Each stream is tagged with packet lengths.
 * Packets are output sequentially from each input stream.
 *
 * The output signal has a new length tag, which is the sum of all
 * individual length tags. The old length tags are discarded.
 *
 * All other tags are propagated as expected, i.e. they stay associated
 * with the same input item.
 * There are cases when this behaviour is undesirable. One special case
 * is when a tag at the first element (the head item) of one input port
 * must stay on the head item of the output port. To achieve this,
 * set \p tag_preserve_head_pos to the port that will receive these special
 * tags.
 */
class BLOCKS_API tagged_stream_mux : virtual public tagged_stream_block
{
public:
    typedef std::shared_ptr<tagged_stream_mux> sptr;
 
    /*!
     * Make a tagged stream mux block.
     *
     * \param itemsize Items size (number of bytes per item)
     * \param lengthtagname Length tag key
     * \param tag_preserve_head_pos Preserves the head position of tags on this input port
     */
    static sptr make(size_t itemsize,
                     const std::string& lengthtagname,
                     unsigned int tag_preserve_head_pos = 0);
};
 
} // namespace blocks
} // namespace gr
 
#endif /* INCLUDED_TAGGED_STREAM_MUX_H */