DECODING DEVICE AND DECODING METHOD

摘要

Provided is a decoding device that can reduce abrupt changes in the number of channels in a decoded signal when transmission errors occur as a result of lost frames in an encoding/decoding system for multichannel signals. Said decoding device is also capable of per-sample smoothing and can reduce degradation of audio quality. In the provided device, a demultiplexer (301) receives an encoded monaural signal and an encoded differential signal and detects change over time in the received encoded differential signal. An M signal decoder (302) decodes the encoded monaural signal and obtains a decoded monaural signal. An S signal decoder (303) decodes the encoded differential signal and obtains a decoded differential signal. A smoothing unit (304) performs smoothing on the decoded differential signal by means of a computation involving the decoded differential signal and coefficients corresponding to the change over time detected by the demultiplexer (301). An L/R signal computation unit (305) computes a decoded stereo signal from the decoded monaural signal and the smoothed decoded differential signal.