Interleaver apparatus and method

One embodimennt of the invention relates to a method of data processing. In the method, an initial data stream is received. A series of bytes having a total byte length is selected from the initial data stream, the series of bytes having a span in the initial data stream that is greater than the total byte length. At least one redundancy byte is calculated based on the series of bytes. An output data stream is transmitted over a transmission medium (406), where the output data stream includes the initial data stream with the at least one redundancy byte therein, and where consecutive bytes in the output data stream have an order that corresponds to an order of consecutive bytes in the initial data stream. Other devices and methods are also described.