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/* Include file to configure the RS codec for character symbols
*
* Copyright 2002, Phil Karn, KA9Q
* May be used under the terms of the GNU General Public License (GPL)
*/
#define DTYPE unsigned char
#include <gr_core_api.h>
/* Reed-Solomon codec control block */
struct rs {
unsigned int mm; /* Bits per symbol */
unsigned int nn; /* Symbols per block (= (1<<mm)-1) */
unsigned char *alpha_to; /* log lookup table */
unsigned char *index_of; /* Antilog lookup table */
unsigned char *genpoly; /* Generator polynomial */
unsigned int nroots; /* Number of generator roots = number of parity symbols */
unsigned char fcr; /* First consecutive root, index form */
unsigned char prim; /* Primitive element, index form */
unsigned char iprim; /* prim-th root of 1, index form */
};
static inline int modnn(struct rs *rs,int x){
while (x >= rs->nn) {
x -= rs->nn;
x = (x >> rs->mm) + (x & rs->nn);
}
return x;
}
#define MODNN(x) modnn(rs,x)
#define MM (rs->mm)
#define NN (rs->nn)
#define ALPHA_TO (rs->alpha_to)
#define INDEX_OF (rs->index_of)
#define GENPOLY (rs->genpoly)
#define NROOTS (rs->nroots)
#define FCR (rs->fcr)
#define PRIM (rs->prim)
#define IPRIM (rs->iprim)
#define A0 (NN)
#define ENCODE_RS encode_rs_char
#define DECODE_RS decode_rs_char
#define INIT_RS init_rs_char
#define FREE_RS free_rs_char
GR_CORE_API void ENCODE_RS(void *p,DTYPE *data,DTYPE *parity);
GR_CORE_API int DECODE_RS(void *p,DTYPE *data,int *eras_pos,int no_eras);
GR_CORE_API void *INIT_RS(unsigned int symsize,unsigned int gfpoly,unsigned int fcr,
unsigned int prim,unsigned int nroots);
GR_CORE_API void FREE_RS(void *p);
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