mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2025-10-25 01:50:30 -04:00
39 lines
973 B
C
39 lines
973 B
C
|
/* 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);
|