A filter unit performs an analysis filtering operation by segmenting a frequency component to generate a plurality of subbands composed of coefficient data segmented on a per frequency band basis. A coefficient storage unit stores the coefficient data on a subband by subband basis, with each subband corresponding to a respective area of the coefficient storage unit. The filter unit writes the coefficient data onto the coefficient storage unit via a write buffer in response to a determination that the analysis filtering operation has not reached a final segmentation level. An entropy encoding unit entropy encodes the coefficient data. The filter unit writes the coefficient data on an area of the coefficient storage unit corresponding to the subband to which the coefficient data belongs. The entropy encoding unit reads the coefficient data, stored on different areas on a subband by subband basis, from the coefficient storage unit.