The Directv Group, Inc.

Hughes Electronics Corporation

Ashish Banerji

Kumar Swaminathan

Saching Goel

A system and method for compressing video is disclosed, in which video frames that are only between consecutive I-frames are grouped into a video data set. The video data set is split into separate homogeneous files, and each of the homogeneous files are individually compressed. In one embodiment, the individually compressed files are multiplexed to form a bit stream.

System and methodology for video compression

A system and method for compressing video is disclosed, in which video frames that between consecutive I-frames are grouped into a video data set. The video data set is split into separate homogeneous files, and each of the homogeneous files are individually compressed. In one embodiment, the individually compressed files are multiplexed to form a bit stream.

An improved system and method for performing lossless data compression of a data string by parsing the data string and representing the parsed characters of the data string as irreducible grammar that is efficiently updatable. The system and method are each capable of parsing the data string into a least one variable of irreducible grammar, such that each variable represents a respective plurality of data characters of the data string, and formatting each variable of irreducible grammar as a linked list data structure having at least one pointer pointing to a linked list data structure representing another variable. The system and method are each further capable of updating the irreducible grammar based on at least one character to be parsed in the input string by changing at least one pointer of at least one of the linked list data structures to point to a linked list data structure different than that to which the at least one pointer pointed prior to updating. The system and method is further capable of encoding the irreducible grammar into a string of bits. Also, the system and method can employ a separate parse module, grammar transform module, and arithmetic coder module to perform the parsing, linked list formatting, and encoding operations, respectively.

System and method for implementation of the YK lossless data compression algorithm using a modular computational architecture

A system and method employing an improved data compression and decompression technique for use in a communication system Specifically, the system and method employs an improved YK algorithm which uses an appropriate form of the trie data structure for the parsing operation. With the use of this data structure, the parsing complexity using this data structure is essentially proportional to the data size, and hence is very fast. The improved YK algorithm also is capable of handling errors in data without getting into an ambiguous state or causing the hardware or software system to crash. Furthermore, the improved YK algorithm is also capable of parsing the data based on predefined frequency characteristics and predefined grammar. The improved YK algorithm also sequentially updates the grammar, while keeping the number of variables below a pre-defined limit. This changes the grammar gradually, and can potentially increase the compression efficiency. The system and method are also capable of performing the above operations for data compression and decompression of packetized data based on the nature in which the data is packetized, that is, whether the data packets have forced or natural boundaries.

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Gaithersburg, MD, United States of America

Ashish Banerji