new venti library.
diff --git a/src/libventi/cvt.h b/src/libventi/cvt.h
new file mode 100644
index 0000000..ef4c2f5
--- /dev/null
+++ b/src/libventi/cvt.h
@@ -0,0 +1,15 @@
+/*
+ * integer conversion routines
+ */
+#define U8GET(p) ((p)[0])
+#define U16GET(p) (((p)[0]<<8)|(p)[1])
+#define U32GET(p) ((u32int)(((p)[0]<<24)|((p)[1]<<16)|((p)[2]<<8)|(p)[3]))
+#define U48GET(p) (((vlong)U16GET(p)<<32)|(vlong)U32GET((p)+2))
+#define U64GET(p) (((vlong)U32GET(p)<<32)|(vlong)U32GET((p)+4))
+
+#define U8PUT(p,v) (p)[0]=(v)
+#define U16PUT(p,v) (p)[0]=(v)>>8;(p)[1]=(v)
+#define U32PUT(p,v) (p)[0]=(v)>>24;(p)[1]=(v)>>16;(p)[2]=(v)>>8;(p)[3]=(v)
+#define U48PUT(p,v,t32) t32=(v)>>32;U16PUT(p,t32);t32=(v);U32PUT((p)+2,t32)
+#define U64PUT(p,v,t32) t32=(v)>>32;U32PUT(p,t32);t32=(v);U32PUT((p)+4,t32)
+
