Data encoding method and apparatus, data decoding method and apparatus, data recording medium, and data transmission method

摘要

A signal encoding process comprises the steps of determining a gain control function of an overlapping portion of the present block on the basis of a gain control function of the previous block at the overlapping portion of the present block and the previous block of an input waveform signal; controlling the gain of the input waveform signal corresponding to the present block by using the gain control function of the overlapping portion; extracting a sample overlapping between adjacent blocks on the time axis to convert the sample to a signal on the frequency axis; encoding the converted signal and the control data for gain control; and outputting the encoded signal. A signal decoding process comprises the steps of decoding the encoded signal to take out the conversion signal and the control data; effecting inverse conversion for the converted signal by the interference of the waveform elements between the adjacent blocks; determining the gain control function of the overlapping portion of the present block on the basis of the control data and the gain control function of the previous block at the overlapping portion between the present block and the previous block; controlling the gain of the inversely converted signal corresponding to the present block by using the gain control function of the overlapping portion; and restoring the original waveform signal. According to this method, the amplification in the encoding and the corresponding correction in the decoding can be performed without any contradiction between the blocks in the case or the interference of the waveform elements of both adjacent blocks at the time of inverse conversion such as MDCT, so that the occurence of the pre-echo can be prevented by a simple construction using spectrum conversion having high encoding efficiency. $$