--- /dev/null
+/*
+ * xpress_constants.h
+ *
+ * Constants for the XPRESS compression format.
+ */
+
+#ifndef _XPRESS_CONSTANTS_H
+#define _XPRESS_CONSTANTS_H
+
+#define XPRESS_NUM_CHARS 256
+#define XPRESS_NUM_SYMBOLS 512
+#define XPRESS_MAX_CODEWORD_LEN 15
+
+#define XPRESS_END_OF_DATA 256
+
+#define XPRESS_MIN_OFFSET 1
+#define XPRESS_MAX_OFFSET 65535
+
+#define XPRESS_MIN_MATCH_LEN 3
+#define XPRESS_MAX_MATCH_LEN 65538
+
+#endif /* _XPRESS_CONSTANTS_H */