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US 5,566,089 AGranted
Syntax parser for a video decompression processor
AssigneeGeneral Instrument Corporation of Delaware
InventorChris Hoogenboom
Life of this patent
Estimating the term…
Abstract
A video syntax parser is provided for a video decompression processor. A compressed bitstream is examined until a start code is located. The start code is decoded to enable a particular parser state corresponding thereto to be initiated. The parser state is communicated to a plurality of subsystems of the video decompression processor. Each subsystem monitors the parser state to determine which parsed data following the start code, if any, is intended for that subsystem. The subsystem then retrieves the parsed data it requires via a data bus which receives the parsed data from the parser.
Claims20
In a video decompression processor, a video syntax parser comprising:
- an input for receiving a compressed bitstream having data to be parsed;
- means for parsing said data from said compressed bitstream;
- means for decoding start codes contained in the data parsed from said compressed bitstream;
- means responsive to a start code decoded by said decoding means for initiating a particular parser state corresponding to said start code;
- a parser state output for communicating said parser state to a plurality of subsystems of said video decompression processor;
- and
- a data output for communicating parsed data from said parsing means to a data bus serving said plurality of subsystems;
- wherein:
- each of said plurality of subsystems monitors said parser state to determine which parsed data on said data bus, if any, is intended for that subsystem so that the subsystem can retrieve the parsed data intended therefor;
- and
- said decoding means continue to decode the data parsed from said data stream after said start code has been decoded to update said parser state during successive parser cycles until a new start code occurs.
8 more elements
In a video decompression processor, a video syntax parser comprising:
- an input for receiving a compressed bitstream having data to be parsed;
- means for parsing said data from said compressed bitstream;
- means for decoding start codes contained in the data parsed from said compressed bitstream;
- means responsive to a start code decoded by said decoding means for initiating a particular parser state corresponding to said start code;
- a parser state output for communicating said parser state to a plurality of subsystems of said video decompression processor;
- and
- a data output for communicating parsed data from said parsing means to a data bus serving said plurality of subsystems;
- wherein:
- each of said plurality of subsystems monitors said parser state to determine which parsed data on said data bus, if any, is intended for that subsystem so that the subsystem can retrieve the parsed data intended therefor;
- said parsing means comprise shift means coupled to receive and shift data from said compressed bitstream, said shift means being responsive to a shift length command for outputting successive portions of said compressed bitstream to said decoding means;
- said shift length command is a cumulative value which is incremented by a field length during successive parsing cycles to control the number of bits by which said shift register is shifted each cycle;
- said field length is dictated by said parser state during each cycle;
- and
- means are provided for truncating said cumulative value to provide a set of least significant bits for use as said shift length command and a more significant bit for providing said enable signal.
11 more elements
In a video decompression processor, a video syntax parser comprising:
- an input for receiving a compressed bitstream having data to be parsed;
- means for parsing said data from said compressed bitstream;
- means for decoding start codes contained in the data parsed from said compressed bitstream;
- means responsive to a start code decoded by said decoding means for initiating a particular parser state corresponding to said start code;
- a parser state output for communicating said parser state to a plurality of subsystems of said video decompression processor;
- a data output for communicating parsed data from said parsing means to a data bus serving said plurality of subsystems;
- wherein each of said plurality of subsystems monitors said parser state to determine which parsed data on said data bus, if any, is intended for that subsystem so that the subsystem can retrieve the parsed data intended therefor;
- wherein said parsing means comprise shift means coupled to receive and shift data from said compressed bitstream, said shift means being responsive to a shift length command for outputting successive portions of said compressed bitstream to said decoding means;
- wherein said successive portions of said compressed bitstream are also output from said data output;
- and
- a rate flow buffer coupled between said source and said register means, said rate flow buffer being responsive to said enable signal for buffering successive portions of said compressed bitstream data from said source.
8 more elements
Dependencies are inferred from the claim text.