first case reading values from part of the areas in the first block storing unit and generating the two original signal sets from the read values, and (b) in the second case reading values from part of the areas in the first block storing unit and from part of the areas in the second block storing unit, and generating the two original signal sets from the read values.
With the above construction, in both the decoding of the single compressed code stream and the decoding of the two compressed code streams, generated signals can be written into at least one buffer independently of the processing of an external unit which reads out the signals.
Here, the compressed code stream may include a plurality of codewords that have each been generatedas first and second codewords, and includes: a position storing unit for storing position information which specifies a position of the first codeword in the compressed code stream; and an extracting unit for extracting from the compressed code stream the first codeword located in the position specified by the position information, calculating a length of the first codeword, and extracting from the compressed code stream the second codeword located in a position specified by a sum of the position information and the calculated length, wherein the code decoding unit entropy decodes the extracted first and second codewords to generate first and second run-level pairs as the two decoded words, and includes: a ninth table having areas which each have an address obtained by concatenating two codewords each being