Length of a processing block is rendered variable responsive to input signals

摘要

In a recording/reproducing or transmitting/receiving device for compressed data the temporal size of a processing block during the compression process is rendered variable responsive to larger amplitude changes in the input signals. The device includes power calculating circuits for calculating the masking effect on a processing block based on amplitude changes in the waveform on the time axis of various frequency bands of the processing block and based on the power of a processing block(s) other than the subject processing block. A primary block size decision circuit and a block size correction circuit are utilized to determine the temporal size of the subject processing block.