HIERARCHICAL LOSSLESS ENCODING AND DECODING METHOD, HIERARCHICAL LOSSLESS ENCODING METHOD, HIERARCHICAL LOSSLESS DECODING METHOD, APPARATUS AND PROGRAM THEREFOR

摘要

A hierarchical lossless encoding/decoding technique for a digital signal of music or audio. Even if the calculation accuracy on the encoding side is different from that on the decoding side, the reproduced lossless reproducti on signal is the same as the input signal. The encoding side sends, to the inpu t terminal of the decoding side, low-bit rate coded data created by encoding t he input signal at a low bit rate, lossless coded data created by lossless- encoding the differential signal of the input signal and the low-bit rate decoded signal generated by encoding and decoding the input signal at low bi t rate, and correction information extracted from the low-bit rate decoded signal. A low-bit rate decoding unit decodes the low-bit rate coded data. A lossless decoding unit decodes the differential signal. A correction unit corrects the low-bit rate decoded signal according to the correction information. An adding unit adds the differential signal and the corrected l ow- bit rate decoded signal so as to calculate a lossless reproduction signal.