1 /** \file fec.h \brief Forward error correction based on Vandermonde matrices 2 * <br>980624<br> (C) 1997-98 Luigi Rizzo (luigi@iet.unipi.it) 3 * 4 * $Author: peltotal $ $Date: 2006/11/07 19:36:19 $ $Revision: 1.11 $ 5 * 6 * Portions derived from code by Phil Karn (karn@ka9q.ampr.org), 7 * Robert Morelos-Zaragoza (robert@spectra.eng.hawaii.edu) and Hari 8 * Thirumoorthy (harit@spectra.eng.hawaii.edu), Aug 1995 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above 17 * copyright notice, this list of conditions and the following 18 * disclaimer in the documentation and/or other materials 19 * provided with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 23 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 24 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS 25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 26 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 28 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR 30 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 32 * OF SUCH DAMAGE. 33 */ 34 35 /* 36 * The following parameter defines how many bits are used for 37 * field elements. The code supports any value from 2 to 16 38 * but fastest operation is achieved with 8 bit elements. 39 */ 40 41 #define GF_BITS 8 /* code over GF(2^^GF_BITS) - change to suit */ 42 #define GF_SIZE ((1 << GF_BITS) - 1) /* powers of \alpha */ 43 44 extern void fec_free(void *p) ; 45 extern void* fec_new(int k, int n) ; 46 47 extern void init_fec(void) ; 48 extern void fec_encode(void *code, void **src, void *dst, int index, int sz) ; 49 extern int fec_decode(void *code, void **pkt, int index[], int sz) ; 50