Patent ID: 7899676

Claim:
A signal encoding device for encoding an input time-series signal, comprising: partitioning means for partitioning the time-series signal into plural subbands to generate a low-frequency subband signal including plural low-frequency subbands and a high-frequency subband signal including plural high-frequency subbands; low-frequency encoding means for quantizing and encoding the low-frequency subband signal to generate low-frequency encoding data; high-frequency gain information generating means for generating high-frequency gain information by generating a new high-frequency subband signal from the low-frequency subband signal and comparing the gain of the new high-frequency subband signal and the gain of the high-frequency subband signal of each subband at a predetermined time interval; low-frequency reference value information generating means for generating low-frequency reference value information on the basis of at least the low-frequency subband signal; high-frequency gain difference information generating means for generating high-frequency gain difference information by acquiring a difference value between the high-frequency gain information generated in each subband at a predetermined time interval and high-frequency gain information at a time position corresponding to an adjacent low-frequency subband, and acquiring a difference value between high-frequency gain information of a lowest-frequency subband in the high-frequency subband signal and the low-frequency reference value information; high-frequency gain difference information encoding means for quantizing and encoding the high-frequency gain difference information to generate high-frequency gain difference information encoding data; and multiplexing means for multiplexing at least the low-frequency encoding data and the high-frequency gain difference information encoding data to output the multiplexed data as compressed data.