Extract fec-3.0.1

1 files changed, 66 insertions, 0 deletions

diff --git a/fec.c b/fec.c
new file mode 100644
index 0000000..35960c3
--- /dev/null
+++ b/fec.c
@@ -0,0 +1,66 @@
+/* Utility routines for FEC support
+ * Copyright 2004, Phil Karn, KA9Q
+ */
+
+#include <stdio.h>
+#include "fec.h"
+
+unsigned char Partab[256];
+int P_init;
+
+/* Create 256-entry odd-parity lookup table
+ * Needed only on non-ia32 machines
+ */
+void partab_init(void){
+  int i,cnt,ti;
+
+  /* Initialize parity lookup table */
+  for(i=0;i<256;i++){
+    cnt = 0;
+    ti = i;
+    while(ti){
+      if(ti & 1)
+	cnt++;
+      ti >>= 1;
+    }
+    Partab[i] = cnt & 1;
+  }
+  P_init=1;
+}
+
+/* Lookup table giving count of 1 bits for integers 0-255 */
+int Bitcnt[] = {
+ 0, 1, 1, 2, 1, 2, 2, 3,
+ 1, 2, 2, 3, 2, 3, 3, 4,
+ 1, 2, 2, 3, 2, 3, 3, 4,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 1, 2, 2, 3, 2, 3, 3, 4,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 1, 2, 2, 3, 2, 3, 3, 4,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 4, 5, 5, 6, 5, 6, 6, 7,
+ 1, 2, 2, 3, 2, 3, 3, 4,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 4, 5, 5, 6, 5, 6, 6, 7,
+ 2, 3, 3, 4, 3, 4, 4, 5,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 4, 5, 5, 6, 5, 6, 6, 7,
+ 3, 4, 4, 5, 4, 5, 5, 6,
+ 4, 5, 5, 6, 5, 6, 6, 7,
+ 4, 5, 5, 6, 5, 6, 6, 7,
+ 5, 6, 6, 7, 6, 7, 7, 8,
+};
+