Decoding apparatus, decoding method, storage medium and program software

A decoding method for inputting and decoding variable-length coded data, comprising:

• a table selection step of, in correspondence with M types of variable-length code tables, selecting one table corresponding to the variable-length coded data from M tables holding minimum code words or maximum code words of classes of variable-length code words constructing a variable-length code table;
• a comparison step of comparing input coded data with the minimum code words or maximum code words outputted from the table selected at said table selection step by using N comparators;
• a class discrimination step of obtaining a class number corresponding to an initial code word of the input coded data based on results of comparison by the N comparators;
• a code length conversion step of converting the class number into a code length;
• and
• a step of accessing a memory holding decoded data, from the class number and the code length obtained at said code length conversion step, and obtaining decoded data.

A computer-readable storage medium holding a program for executing a decoding method for inputting and decoding variable-length coded data, having:

• a table selection process module for, in correspondence with M types of variable-length code tables, selecting one table corresponding to the variable-length coded data from M tables holding minimum code words or maximum code words of classes of variable-length code words constructing a variable-length code table;
• a comparison process module for comparing input coded data with the minimum code words or maximum code words outputted from the table selected at said table selection process module;
• a class discrimination module for obtaining a class number corresponding to an initial code word of the input coded data based on results of comparison at said comparison module;
• a code length conversion module for converting the class number into a code length;
• and
• a module for accessing a memory holding decoded data, from the class number and the code length obtained at said code length conversion module, and obtaining decoded data.

Program software for executing a decoding method for inputting and decoding variable-length coded data, by a computer, having:

• a table selection process for, in correspondence with M types of variable-length code tables, selecting one table corresponding to the variable-length coded data from M tables holding minimum code words or maximum code words of classes of variable-length code words constructing a variable-length code table;
• a comparison process for comparing input coded data with the minimum code words or maximum code words outputted from the table selected at said table selection process;
• a process for obtaining a class number corresponding to an initial code word of the input coded data based on results of comparison at said comparison process;
• a code length conversion process for converting the class number into a code length;
• and
• a process for accessing a memory holding decoded data, from the class number and the code length obtained at the code length conversion module, and obtaining decoded data.