A decoding device checks whether there is free space in each of channel-by-channel buffers, specifies a channel corresponding to a buffer having free space as an input channel for receiving an input of compressed data, analyzes codes of the compressed data received through the input channel, and detects a delimit position in the compressed data on the basis of a result of the analysis. The decoding device expands the compressed data received through the input channel, and sorts the expanded data so as to be stored in the buffer corresponding to the input channel. The decoding device cancels specification of the input channel in accordance with detection of the delimit position, and checks whether there is free space in each of the channel-by-channel buffers, and then specifies a channel corresponding to a buffer having free space as a next input channel.