Initial Commit

lib/wrapkarn.c

@@ -0,0 +1,70 @@
+#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);
+}
+