mirror of https://github.com/saitohirga/WSJT-X.git
138 lines
3.9 KiB
C
138 lines
3.9 KiB
C
/*
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sfrsd.c
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A soft-decision decoder for the JT65 (63,12) Reed-Solomon code.
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This decoding scheme is built around Phil Karn's Berlekamp-Massey
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errors and erasures decoder. The approach is inspired by a number of
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publications, including the stochastic Chase decoder described
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in "Stochastic Chase Decoding of Reed-Solomon Codes", by Leroux et al.,
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IEEE Communications Letters, Vol. 14, No. 9, September 2010 and
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"Soft-Decision Decoding of Reed-Solomon Codes Using Successive Error-
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and-Erasure Decoding," by Soo-Woong Lee and B. V. K. Vijaya Kumar.
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Steve Franke K9AN, Urbana IL, September 2015
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <time.h>
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#include <string.h>
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#include "sfrsd2.h"
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//***************************************************************************
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void usage(void)
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{
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printf("Usage: sfrsd [options...] <path to kvasd.dat>\n");
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printf(" input file should be in kvasd format\n");
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printf("\n");
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printf("Options:\n");
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printf(" -n number of random erasure vectors to try\n");
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printf(" -v verbose\n");
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}
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int main(int argc, char *argv[]){
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extern char *optarg;
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extern int optind;
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int correct[63], indx[63], param[8];
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int c,i;
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char *infile;
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FILE *datfile, *logfile;
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int nsec, maxe, nads;
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float xlambda;
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int mrsym[63],mrprob[63],mr2sym[63],mr2prob[63];
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int nsec2,ncount,dat4[12];
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int ntrials, nverbose, ntry;
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int nhard;
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double tt;
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ntrials=10000;
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nverbose=1;
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while ( (c = getopt(argc, argv, "n:qv")) !=-1 ) {
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switch (c) {
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case 'n':
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ntrials=(int)strtof(optarg,NULL);
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printf("ntrials set to %d\n",ntrials);
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break;
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case 'v':
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nverbose=1;
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break;
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case 'q': //accept (and ignore) -q option for WSJT10 compatibility
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break;
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case '?':
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usage();
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exit(1);
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}
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}
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if( optind+1 > argc) {
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// usage();
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// exit(1);
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infile="kvasd.dat";
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} else {
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infile=argv[optind];
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}
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logfile=fopen("/tmp/sfrsd.log","a");
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if( !logfile ) {
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printf("Unable to open sfrsd.log\n");
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exit(1);
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}
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datfile=fopen(infile,"rb");
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if( !datfile ) {
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printf("Unable to open kvasd.dat\n");
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exit(1);
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} else {
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fread(&nsec,sizeof(int),1,datfile);
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fread(&xlambda,sizeof(float),1,datfile);
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fread(&maxe,sizeof(int),1,datfile);
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fread(&nads,sizeof(int),1,datfile);
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fread(&mrsym,sizeof(int),63,datfile);
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fread(&mrprob,sizeof(int),63,datfile);
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fread(&mr2sym,sizeof(int),63,datfile);
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fread(&mr2prob,sizeof(int),63,datfile);
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fread(&nsec2,sizeof(int),1,datfile);
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fread(&ncount,sizeof(int),1,datfile);
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fread(&dat4,sizeof(int),12,datfile);
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fclose(datfile);
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}
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sfrsd2_(mrsym,mrprob,mr2sym,mr2prob,&ntrials,&nverbose,correct,param,indx,&tt,&ntry);
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nhard=param[1];
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if( nhard>=0 ) {
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for (i=0; i<12; i++) {
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dat4[i]=correct[11-i];
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}
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} else {
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nhard=-1;
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memset(dat4,0,12*sizeof(int));
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}
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datfile=fopen(infile,"wb");
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if( !datfile ) {
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printf("Unable to open kvasd.dat\n");
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return 1;
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} else {
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fwrite(&nsec,sizeof(int),1,datfile);
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fwrite(&xlambda,sizeof(float),1,datfile);
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fwrite(&maxe,sizeof(int),1,datfile);
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fwrite(&nads,sizeof(int),1,datfile);
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fwrite(&mrsym,sizeof(int),63,datfile);
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fwrite(&mrprob,sizeof(int),63,datfile);
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fwrite(&mr2sym,sizeof(int),63,datfile);
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fwrite(&mr2prob,sizeof(int),63,datfile);
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fwrite(&nsec2,sizeof(int),1,datfile);
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fwrite(&nhard,sizeof(int),1,datfile);
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fwrite(&dat4,sizeof(int),12,datfile);
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fclose(datfile);
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}
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exit(0);
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}
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