1 /* Include file to configure the RS codec for integer symbols
2 *
3 * Copyright 2002, Phil Karn, KA9Q
4 * May be used under the terms of the GNU General Public License (GPL)
5 */
6 #define DTYPE int
7
8 #include <gnuradio/fec/api.h>
9
10 /* Reed-Solomon codec control block */
11 struct FEC_API rs {
12 unsigned int mm; /* Bits per symbol */
13 unsigned int nn; /* Symbols per block (= (1<<mm)-1) */
14 int* alpha_to; /* log lookup table */
15 int* index_of; /* Antilog lookup table */
16 int* genpoly; /* Generator polynomial */
17 unsigned int nroots; /* Number of generator roots = number of parity symbols */
18 unsigned int fcr; /* First consecutive root, index form */
19 unsigned int prim; /* Primitive element, index form */
20 unsigned int iprim; /* prim-th root of 1, index form */
21 };
22
modnn(struct rs * rs,int x)23 static inline int modnn(struct rs* rs, int x)
24 {
25 while (x >= rs->nn) {
26 x -= rs->nn;
27 x = (x >> rs->mm) + (x & rs->nn);
28 }
29 return x;
30 }
31 #define MODNN(x) modnn(rs, x)
32
33 #define MM (rs->mm)
34 #define NN (rs->nn)
35 #define ALPHA_TO (rs->alpha_to)
36 #define INDEX_OF (rs->index_of)
37 #define GENPOLY (rs->genpoly)
38 #define NROOTS (rs->nroots)
39 #define FCR (rs->fcr)
40 #define PRIM (rs->prim)
41 #define IPRIM (rs->iprim)
42 #define A0 (NN)
43
44 #define ENCODE_RS encode_rs_int
45 #define DECODE_RS decode_rs_int
46 #define INIT_RS init_rs_int
47 #define FREE_RS free_rs_int
48
49 FEC_API void ENCODE_RS(void* p, DTYPE* data, DTYPE* parity);
50 FEC_API int DECODE_RS(void* p, DTYPE* data, int* eras_pos, int no_eras);
51 void* INIT_RS(unsigned int symsize,
52 unsigned int gfpoly,
53 unsigned int fcr,
54 unsigned int prim,
55 unsigned int nroots);
56 FEC_API void FREE_RS(void* p);
57