1 /* Include file to configure the RS codec for character symbols
3 * Copyright 2002, Phil Karn, KA9Q
4 * May be used under the terms of the GNU General Public License (GPL)
7 #define DTYPE unsigned char
9 /* Reed-Solomon codec control block */
11 unsigned int mm; /* Bits per symbol */
12 unsigned int nn; /* Symbols per block (= (1<<mm)-1) */
13 unsigned char *alpha_to; /* log lookup table */
14 unsigned char *index_of; /* Antilog lookup table */
15 unsigned char *genpoly; /* Generator polynomial */
16 unsigned int nroots; /* Number of generator roots = number of parity symbols */
17 unsigned char fcr; /* First consecutive root, index form */
18 unsigned char prim; /* Primitive element, index form */
19 unsigned char iprim; /* prim-th root of 1, index form */
22 static inline int modnn(struct rs *rs,int x){
25 x = (x >> rs->mm) + (x & rs->nn);
29 #define MODNN(x) modnn(rs,x)
33 #define ALPHA_TO (rs->alpha_to)
34 #define INDEX_OF (rs->index_of)
35 #define GENPOLY (rs->genpoly)
36 #define NROOTS (rs->nroots)
38 #define PRIM (rs->prim)
39 #define IPRIM (rs->iprim)
42 #define ENCODE_RS encode_rs_char
43 #define DECODE_RS decode_rs_char
44 #define INIT_RS init_rs_char
45 #define FREE_RS free_rs_char
47 void ENCODE_RS(void *p,DTYPE *data,DTYPE *parity);
48 int DECODE_RS(void *p,DTYPE *data,int *eras_pos,int no_eras);
49 void *INIT_RS(unsigned int symsize,unsigned int gfpoly,unsigned int fcr,
50 unsigned int prim,unsigned int nroots);
51 void FREE_RS(void *p);