Moving picture coding and/or decoding systems, and variable-length coding and/or decoding system

A variable-length coding system for assigning, to a plurality of source symbols, a code word of a code length corresponding to an occurrence probability of each of the source symbols, and for outputting coded data corresponding to an inputted source symbol, said variable-length coding system comprising:

• a code word table for storing a plurality of code words corresponding to respective source symbols, the code words being able to be decoded in either of a forward direction and a backward direction;
• and
• coding means for selecting a code word corresponding to the inputted source symbol from said code word table if a code word corresponding to the inputted source symbol is stored in the code word table, and for generating a code word comprising an escape code including a prefix and a suffix added to a fixed length code representing the inputted source symbol when no code word corresponding to the inputted source symbol is stored in the code word table, the escape code word being decodable in either of a forward and a backward direction, and for outputting coded data corresponding to the inputted source symbol and comprising one of a selected code word and a generated code word.

A variable-length coding system for assigning to a plurality of source symbols, a code word of a code length corresponding to an occurrence probability of each of the source symbols, and for outputting coded data corresponding to an inputted source symbol, said variable-length coding system comprising:

• a code word table for storing a plurality of code words corresponding to respective source symbols, the code words being able to be decoded in either of a forward direction and a backward direction;
• and
• coding means for selecting a code word corresponding to the inputted source symbol from the code word table if a code word corresponding to the inputted source symbol is stored in the code word table, and for generating a code word corresponding to the inputted source symbol comprising a variable-length escape code and a predetermined code corresponding to the inputted source symbols when no code word corresponding to the inputted source symbol is stored in the code word table, a variable-length escape code of a generated code word being able to be decoded in either of a forward direction and a backward direction, and for outputting coded data corresponding to the inputted source symbol and comprising one of a selected code word and a generated code word.

A variable-length coding system for assigning, to a plurality of source symbols, a code word of a code length corresponding to an occurrence probability of each of the source symbols, and for outputting coded data corresponding to an inputted source symbol, said variable-length coding system comprising:

• a code word table for storing a plurality of code words corresponding to respective source symbols, the code words being able to be decoded in either of a forward direction and a backward direction;
• and
• coding means for selecting a code word corresponding to the inputted source symbol from the code word table if a code word corresponding to the inputted source symbol is stored in the code word table, and for generating a code word corresponding to the inputted source symbol comprising a variable-length escape code and a fixed-length code corresponding to the inputted source symbols when no code word corresponding to the inputted source symbol is stored in the code word table, a variable-length escape code of a generated code word being able to be decoded in either of a forward direction and a backward direction, and for outputting coded data corresponding to the inputted source symbol and comprising one of a selected code word and a generated code word.