WSJT-X/lib/sfrsd/fixed.h

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/* Configure the RS codec with fixed parameters for CCSDS standard
* (255,223) code over GF(256). Note: the conventional basis is still
* used; the dual-basis mappings are performed in [en|de]code_rs_ccsds.c
*
* Copyright 2002 Phil Karn, KA9Q
* May be used under the terms of the GNU General Public License (GPL)
*/
#define DTYPE unsigned char
static inline int mod255(int x){
while (x >= 255) {
x -= 255;
x = (x >> 8) + (x & 255);
}
return x;
}
#define MODNN(x) mod255(x)
extern unsigned char CCSDS_alpha_to[];
extern unsigned char CCSDS_index_of[];
extern unsigned char CCSDS_poly[];
#define MM 8
#define NN 255
#define ALPHA_TO CCSDS_alpha_to
#define INDEX_OF CCSDS_index_of
#define GENPOLY CCSDS_poly
#define NROOTS 32
#define FCR 112
#define PRIM 11
#define IPRIM 116
#define A0 (NN)
#define ENCODE_RS encode_rs_8
#define DECODE_RS decode_rs_8
void ENCODE_RS(DTYPE *data,DTYPE *parity);
int DECODE_RS(DTYPE *data, int *eras_pos, int no_eras);