From 27c71e90ba82f7c8e28d2b7298785e76b8e49ece Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Thu, 23 Aug 2007 17:25:22 +0000 Subject: in preparation for de-pluginising h223, move golay code support into libwireshark svn path=/trunk/; revision=22603 --- epan/golay.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 epan/golay.h (limited to 'epan/golay.h') diff --git a/epan/golay.h b/epan/golay.h new file mode 100644 index 0000000000..1a6e7994a8 --- /dev/null +++ b/epan/golay.h @@ -0,0 +1,49 @@ +/* $Id$ + * + * Provides routines for encoding and decoding the extended Golay + * (24,12,8) code. + * + * This implementation will detect up to 4 errors in a codeword (without + * being able to correct them); it will correct up to 3 errors. + * + * We use guint32s to hold the 24-bit codewords, with the data part in + * the bottom 12 bits and the parity in bits 12-23. + * + * + * Wireshark - Network traffic analyzer + * By Gerald Combs + * Copyright 1998 Gerald Combs + * + * This program 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 2 + * of the License, or (at your option) any later version. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ +#ifndef __GOLAY_H__ +#define __GOLAY_H__ + +/* encodes a 12-bit word to a 24-bit codeword + */ +guint32 golay_encode(guint w); + +/* return a mask showing the bits which are in error in a received + * 24-bit codeword, or -1 if 4 errors were detected. + */ +gint32 golay_errors(guint32 codeword); + +/* decode a received codeword. Up to 3 errors are corrected for; 4 + errors are detected as uncorrectable (return -1); 5 or more errors + cause an incorrect correction. +*/ +gint golay_decode(guint32 w); + +#endif -- cgit v1.2.1