Fremgangsmåde til afkodning med variabel længde, lagringsmedium, indretning til afkodning med variabel længde

摘要

The present invention correctly decodes data encoded with a variable-length encoding method that improves the compression ratio. The variable-length encoding method encodes a unit data composed of a plurality of sub-data while referencing parameter tables, and includes the following steps: an initialization step in which an obtained parameter table is set to initial values; a parameter table information encoding step in which information related to the initialized parameter table is encoded; a parameter obtainment step in which encoding parameters to be used in the encoding of sub-data are obtained from the parameter table; a sub-data encoding step in which variable-length encoding of the sub-data is performed with reference to the obtained encoding parameters, and an encoded information placement step in which the encoded information is placed in a position in which the information can be obtained before the encoded unit data.