radiosonde_auto_rx/ecc/ecc-rs_vaisala.c

198 wiersze
5.5 KiB
C

/*
ka9q-fec:
gcc -c init_rs_char.c
gcc -c encode_rs_char.c
gcc -c decode_rs_char.c
gcc init_rs_char.o encode_rs_char.o decode_rs_char.o ecc-rs_vaisala.c -o ecc-rs_vaisala
*/
#include <stdio.h>
#include <string.h>
#include "fec.h"
const unsigned char
header_rs92sgp[] = { 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x10},
//header_rs92bgp[], header_rs92bgpx[],
header_rs41x[] = { 0x86, 0x35, 0xf4, 0x40, 0x93, 0xdf, 0x1a, 0x60},
header_rs41[] = { 0x10, 0xB6, 0xCA, 0x11, 0x22, 0x96, 0x12, 0xF8};
typedef struct {
int typ;
int msglen;
int msgpos;
int parpos;
int hdrlen;
int frmlen;
} rscfg_t;
rscfg_t cfg, cfg0 = { 0, 0, 0, 0, 0, 0},
cfg_rs92 = { 92, 240-6-24, 6, 240-24, 6, 240},
cfg_rs41 = { 41, (320-56)/2, 56, 8, 8, 320};
#define BFSIZE 520
#define N 255
#define R 24
#define K (N-R)
void *rs;
unsigned char data[BFSIZE], frame[BFSIZE],
codeword1[N], codeword2[N];
int errors1, errors2,
errpos1[R], errpos2[R];
rscfg_t detect(unsigned char data[], int len) {
int i;
rscfg_t cfg;
for (i = 0; i < cfg_rs92.hdrlen; i++) {
if (data[i] != header_rs92sgp[i]) break;
}
if (i == cfg_rs92.hdrlen) return cfg_rs92;
/*
for (i = 0; i < cfg_rs92.hdrlen; i++) {
if (data[i] != header_rs92bgp[i]) break;
}
if (i == cfg_rs92.hdrlen) return cfg_rs92;
*/
for (i = 0; i < cfg_rs41.hdrlen; i++) {
if (data[i] != header_rs41[i]) break;
}
if (i < cfg_rs41.hdrlen) {
for (i = 0; i < cfg_rs41.hdrlen; i++) {
if (data[i] != header_rs41x[i]) break;
}
}
if (i == cfg_rs41.hdrlen) {
cfg = cfg_rs41;
if (len > 518) len = 518;
if (len > 320) {
cfg.msglen = (len-56)/2;
cfg.frmlen = len;
}
}
else cfg = cfg0;
return cfg;
}
int main(int argc, char *argv[]) {
int i, len, l;
char *str = NULL, strbuf[2*BFSIZE+1];
FILE *fp = NULL;
rs = init_rs_char( 8, 0x11d, 0, 1, R, 0);
if (argc < 2) {
fp = stdin;
str = fgets(strbuf, 2*BFSIZE, fp);
}
else {
str = argv[1];
}
while (str) {
len = strlen(str)/2;
if (len > BFSIZE) return -1;
for (i = 0; i < BFSIZE; i++) data[i] = 0;
for (i = 0; i < N; i++) codeword1[i] = codeword2[i] = 0;
for (i = 0; i < len; i++) {
l = sscanf(str+2*i, "%2hhx", data+i); if (l < 1) {/*len = i;*/}
}
cfg = detect(data, len);
if ( cfg.typ == 92 ) {
for (i = 0; i < cfg.msglen; i++) codeword1[K-1-i] = data[cfg.msgpos+i];
for (i = 0; i < R; i++) codeword1[N-1-i] = data[cfg.parpos+i];
errors1 = decode_rs_char(rs, codeword1, errpos1, 0);
if (fp == NULL) {
printf("RS%d\n", cfg.typ);
printf("codeword\n");
printf("errors: %d\n", errors1);
if (errors1 > 0) {
printf("pos: ");
for (i = 0; i < errors1; i++) printf(" %d", errpos1[i]);
printf("\n");
}
for (i = 0; i < N; i++) printf("%02X", codeword1[i]); printf("\n");
printf("frame:\n");
}
for (i = 0; i < cfg.hdrlen; i++) frame[i] = data[i];
for (i = 0; i < cfg.msglen; i++) frame[cfg.msgpos+i] = codeword1[K-1-i];
for (i = 0; i < R; i++) frame[cfg.parpos+i] = codeword1[N-1-i];
for (i = 0; i < cfg.frmlen; i++) printf("%02x", frame[i]); printf("\n");
}
else
if ( cfg.typ == 41 ) {
for (i = 0; i < cfg.msglen; i++) {
codeword1[K-1-i] = data[cfg.msgpos+ 2*i];
codeword2[K-1-i] = data[cfg.msgpos+1+2*i];
}
for (i = 0; i < R; i++) {
codeword1[N-1-i] = data[cfg.parpos+ i];
codeword2[N-1-i] = data[cfg.parpos+R+i];
}
errors1 = decode_rs_char(rs, codeword1, errpos1, 0);
errors2 = decode_rs_char(rs, codeword2, errpos2, 0);
if (fp == NULL) {
printf("RS%d\n", cfg.typ);
printf("codeword1\n");
printf("errors: %d\n", errors1);
if (errors1 > 0) {
printf("pos: ");
for (i = 0; i < errors1; i++) printf(" %d", errpos1[i]);
printf("\n");
}
for (i = 0; i < N; i++) printf("%02X", codeword1[i]); printf("\n");
printf("codeword2\n");
printf("errors: %d\n", errors2);
if (errors2 > 0) {
printf("pos: ");
for (i = 0; i < errors2; i++) printf(" %d", errpos2[i]);
printf("\n");
}
for (i = 0; i < N; i++) printf("%02X", codeword2[i]); printf("\n");
printf("frame:\n");
}
for (i = 0; i < cfg.hdrlen; i++) frame[i] = data[i];
for (i = 0; i < R; i++) {
frame[cfg.parpos+ i] = codeword1[N-1-i];
frame[cfg.parpos+R+i] = codeword2[N-1-i];
}
for (i = 0; i < cfg.msglen; i++) {
frame[cfg.msgpos+ 2*i] = codeword1[K-1-i];
frame[cfg.msgpos+1+2*i] = codeword2[K-1-i];
}
for (i = 0; i < cfg.frmlen; i++) printf("%02x", frame[i]); printf("\n");
}
if (fp) str = fgets(strbuf, 2*BFSIZE, fp);
else str = NULL;
}
return 0;
}