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