Encoder, decoder and method

摘要

An encoder for encoding input data to generate corresponding encoded data is provided. In addition to identifying 206, 210 exact duplicates of reference blocks/packets, partial reoccurrences of data blocks or data packets withinthe input data are also determined 210. At least one reference value is employed to relate reoccurrences of mutually similar data blocks or data packets within the input data 212. A plurality of mask bits are employed to indicate changed and unchanged data elements of partial reoccurrences of data blocks or data packets within the input data. The at least one reference value 212, 214, the plurality of mask bits and data values of changed data elements 208 are then encoded into the encoded data. Typical de-duplication compression techniques identify exact re-occurrences of data whereas the arrangement described additionally identifies and utilises partial re-occurrences. Pointers may be used to indicate relative positions to the partially re-occurring elements of a reference block/packet. The output may be additionally encoded with further encoding such as entropy encoding. A most optimal size for the blocks/packets of the processed input data may also be determined. A corresponding method of decoding and a decoder is also described.