WSJT-X/libm65/wrapkarn.c

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#include <math.h>
#include <stdio.h>
#include <float.h>
#include <limits.h>
#include <stdlib.h>
#include "rs.h"
static void *rs;
static int first=1;
void rs_encode_(int *dgen, int *sent)
// Encode JT65 data dgen[12], producing sent[63].
{
int dat1[12];
int b[51];
int i;
if(first) {
// Initialize the JT65 codec
rs=init_rs_int(6,0x43,3,1,51,0);
first=0;
}
// Reverse data order for the Karn codec.
for(i=0; i<12; i++) {
dat1[i]=dgen[11-i];
}
// Compute the parity symbols
encode_rs_int(rs,dat1,b);
// Move parity symbols and data into sent[] array, in reverse order.
for (i = 0; i < 51; i++) sent[50-i] = b[i];
for (i = 0; i < 12; i++) sent[i+51] = dat1[11-i];
}
void rs_decode_(int *recd0, int *era0, int *numera0, int *decoded, int *nerr)
// Decode JT65 received data recd0[63], producing decoded[12].
// Erasures are indicated in era0[numera]. The number of corrected
// errors is *nerr. If the data are uncorrectable, *nerr=-1 is returned.
{
int numera;
int i;
int era_pos[50];
int recd[63];
if(first) {
rs=init_rs_int(6,0x43,3,1,51,0);
first=0;
}
numera=*numera0;
for(i=0; i<12; i++) recd[i]=recd0[62-i];
for(i=0; i<51; i++) recd[12+i]=recd0[50-i];
if(numera)
for(i=0; i<numera; i++) era_pos[i]=era0[i];
*nerr=decode_rs_int(rs,recd,era_pos,numera);
for(i=0; i<12; i++) decoded[i]=recd[11-i];
}
void rs_encode__(int *dgen, int *sent)
{
rs_encode_(dgen, sent);
}
void rs_decode__(int *recd0, int *era0, int *numera0, int *decoded, int *nerr)
{
rs_decode_(recd0, era0, numera0, decoded, nerr);
}