Multistandard video decoder and decompression system for processing encoded bit streams including expanding run length codes and methods relating thereto

Abstract

A pipeline video decoder and decompression system handles a plurality of separately encoded bit streams arranged as a single serial bit stream of digital bits and having separately encoded pairs of control codes and corresponding data carried in the serial bit stream. The pipeline system employs a plurality of interconnected stages to decode and decompress the single bit stream, including a start code detector. When in a search mode, the start code detector searches for a specific start code corresponding to one of multiple compression standards. The start code detector responding to the single serial bit stream generates control tokens and data tokens. A respective one of the tokens includes a plurality of data words. Each data word has an extension bit which indicates a presence of additional words therein. The data words are thereby unlimited in number. A token decode circuit positioned in certain of the stages recognizes certain of the tokens as control tokens pertinent to that stage and passes unrecognized control tokens to a succeeding stage. A reconfigurable decode and parser processing means positioned in certain of the stages is responsive to a recognized control token and reconfigures a particular stage to handle an identified data token. Methods relating to the decoder and decompression system include processing steps relating thereto

1 . A method of operating on a data stream of data having portions encoded according to different standards comprising: 
 receiving the data in the form of control tokens and data tokens;    processing the portions of the data according to a respective one of the different standards identified by the control tokens;    assembling the processed portions into new data tokens, the new data tokens including a run length code; and    expanding the run length code to a run of zero data followed by a level.    
     
     
         2 . The method of  claim 1 , wherein the run length code specifies a run count.  
     
     
         3 . A method of  claim 1 , wherein expanding comprises: 
 producing zeros based on the run count.    
     
     
         4 . A method of  claim 1 , further comprising: 
 determining if the new data tokens have at least a specified number of values.    
     
     
         5 . The method of  claim 4 , wherein the values correspond to coefficients and the specified number of coefficents is 64.  
     
     
         6 . The method of  claim 4 , further comprising: 
 blocking ones of the new data tokens which lack the at least a specified number of values.    
     
     
         7 . The method of  claim 6 , further comprising: 
 padding the new data tokens which lack the at least a specified number of values with zero values.    
     
     
         8 . The method of  claim 1 , wherein the new data tokens each comprise data words and the run length code comprises a run and a level in each of the data words.