The present disclosure relates to a compression/encoding apparatus and method, a decoding apparatus and method, and a program that allow for provision of a lossless compression technology with higher compression ratio.A GOB data configuration section configures GOB data with a group of digital data that includes a plurality of blocks by treating a frame of delta-sigma-modulated digital data as a block. A table generation section generates a conversion table for encoding the GOB data. An encoding section compresses and encodes the digital data of each block included in the GOB data by using the conversion table. The present technology is applicable, for example, to audio signal compression and encoding, and so on.