GNU Radio 3.6.3 C++ API
char.h
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1 /* Include file to configure the RS codec for character symbols
2  *
3  * Copyright 2002, Phil Karn, KA9Q
4  * May be used under the terms of the GNU General Public License (GPL)
5  */
6 
7 #define DTYPE unsigned char
8 
9 #include <gr_core_api.h>
10 
11 /* Reed-Solomon codec control block */
12 struct rs {
13  unsigned int mm; /* Bits per symbol */
14  unsigned int nn; /* Symbols per block (= (1<<mm)-1) */
15  unsigned char *alpha_to; /* log lookup table */
16  unsigned char *index_of; /* Antilog lookup table */
17  unsigned char *genpoly; /* Generator polynomial */
18  unsigned int nroots; /* Number of generator roots = number of parity symbols */
19  unsigned char fcr; /* First consecutive root, index form */
20  unsigned char prim; /* Primitive element, index form */
21  unsigned char iprim; /* prim-th root of 1, index form */
22 };
23 
24 static inline unsigned int modnn(struct rs *rs, unsigned int x){
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_char
45 #define DECODE_RS decode_rs_char
46 #define INIT_RS init_rs_char
47 #define FREE_RS free_rs_char
48 
49 GR_CORE_API void ENCODE_RS(void *p,DTYPE *data,DTYPE *parity);
50 GR_CORE_API int DECODE_RS(void *p,DTYPE *data,int *eras_pos,int no_eras);
51 GR_CORE_API void *INIT_RS(unsigned int symsize,unsigned int gfpoly,unsigned int fcr,
52  unsigned int prim,unsigned int nroots);
53 GR_CORE_API void FREE_RS(void *p);
54 
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