+ /** @brief Version, padding, extension and CSRC
+ *
+ * Version is bits 6 and 7; currently always 2.
+ *
+ * Padding is bit 5; if set frame includes padding octets.
+ *
+ * eXtension is bit 4; if set there is a header extension.
+ *
+ * CSRC Count is bits 0-3 and is the number of CSRC identifiers following the
+ * header.
+ */