unpack_k_bits.h

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/* -*- c++ -*- */
/*
 * Copyright 2014 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 */
 
#ifndef INCLUDED_GR_BLOCKS_UNPACK_K_BITS_H
#define INCLUDED_GR_BLOCKS_UNPACK_K_BITS_H
 
#include <gnuradio/blocks/api.h>
 
namespace gr {
namespace blocks {
namespace kernel {
 
/*!
 * \brief Converts a byte with k relevant bits to k output bytes with 1 bit in the LSB.
 *
 * This is the algorithm kernel for the gr::blocks::unpack_k_bits_bb block.
 *
 * Example:
 * k = 4
 * in = [0xf5, 0x08]
 * out = [0,1,0,1, 1,0,0,0]
 *
 * k = 8
 * in = [0xf5, 0x08]
 * out = [1,1,1,1, 0,1,0,1, 0,0,0,0, 1,0,0,0]
 * \ingroup byte_operators_blk
 */
class BLOCKS_API unpack_k_bits
{
public:
    /*!
     * \brief Make an unpack_k_bits object.
     * \param k number of bits to unpack.
     */
    unpack_k_bits(unsigned k);
    ~unpack_k_bits();
 
    /*!
     * \brief Perform the unpacking.
     *
     * This function performs no bounds checking. It assumes that the
     * input, \p in, has of length \p nbytes and that the output
     * vector, \p out, has k*nbytes available for writing.
     *
     * \param bits output vector (1-bit per byte) of the unpacked data
     * \param bytes The input vector of bytes to unpack
     * \param nbytes The number of input bytes
     */
    void unpack(unsigned char* bits, const unsigned char* bytes, int nbytes) const;
 
    /*!
     * Unpacks in reverse order from unpack().
     */
    void unpack_rev(unsigned char* bits, const unsigned char* bytes, int nbytes) const;
 
    int k() const;
 
private:
    unsigned d_k;
};
 
} /* namespace kernel */
} /* namespace blocks */
} /* namespace gr */
 
#endif /* INCLUDED_GR_BLOCKS_UNPACK_K_BITS_BB_H */