epan/golay.h

   1 /** @file
   2  * Provides routines for encoding and decoding the extended Golay
   3  * (24,12,8) code.
   4  *
   5  * This implementation will detect up to 4 errors in a codeword (without
   6  * being able to correct them); it will correct up to 3 errors.
   7  *
   8  * We use uint32_t to hold the 24-bit codewords, with the data part in
   9  * the bottom 12 bits and the parity in bits 12-23.
  10  *
  11  *
  12  * Wireshark - Network traffic analyzer
  13  * By Gerald Combs <gerald@wireshark.org>
  14  * Copyright 1998 Gerald Combs
  15  *
  16  * SPDX-License-Identifier: GPL-2.0-or-later
  17  */
  18 #ifndef __GOLAY_H__
  19 #define __GOLAY_H__
  20
  21 #include <stdint.h>
  22
  23 #include "ws_symbol_export.h"
  24
  25 /* encodes a 12-bit word to a 24-bit codeword
  26  */
  27 WS_DLL_PUBLIC
  28 uint32_t golay_encode(unsigned w);
  29
  30 /* return a mask showing the bits which are in error in a received
  31  * 24-bit codeword, or -1 if 4 errors were detected.
  32  */
  33 WS_DLL_PUBLIC
  34 int32_t golay_errors(uint32_t codeword);
  35
  36 /* decode a received codeword. Up to 3 errors are corrected for; 4
  37    errors are detected as uncorrectable (return -1); 5 or more errors
  38    cause an incorrect correction.
  39 */
  40 WS_DLL_PUBLIC
  41 int golay_decode(uint32_t w);
  42
  43 #endif
  44
  45 /*
  46  * Editor modelines
  47  *
  48  * Local Variables:
  49  * c-basic-offset: 4
  50  * tab-width: 8
  51  * indent-tabs-mode: nil
  52  * End:
  53  *
  54  * ex: set shiftwidth=4 tabstop=8 expandtab:
  55  * :indentSize=4:tabSize=8:noTabs=true:
  56  */