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+/* Stuff common to all the general-purpose Reed-Solomon codecs
+ * Copyright 2004 Phil Karn, KA9Q
+ * May be used under the terms of the GNU Lesser General Public License (LGPL)
+ */
+
+/* Reed-Solomon codec control block */
+struct rs {
+ int mm; /* Bits per symbol */
+ int nn; /* Symbols per block (= (1<<mm)-1) */
+ data_t *alpha_to; /* log lookup table */
+ data_t *index_of; /* Antilog lookup table */
+ data_t *genpoly; /* Generator polynomial */
+ int nroots; /* Number of generator roots = number of parity symbols */
+ int fcr; /* First consecutive root, index form */
+ int prim; /* Primitive element, index form */
+ int iprim; /* prim-th root of 1, index form */
+ int pad; /* Padding bytes in shortened block */
+};
+
+static inline int modnn(struct rs *rs,int x){
+ while (x >= rs->nn) {
+ x -= rs->nn;
+ x = (x >> rs->mm) + (x & rs->nn);
+ }
+ return x;
+}