Speech encoding apparatus and speech encoding method that encode speech signals in a scalable manner, and speech decoding apparatus and speech decoding method that decode scalable encoded signals

摘要

An audio encoding device for correcting a component having insufficient encoding capability in a core layer by an extended layer. A core layer encoder encodes an audio signal. An extended layer encoder encodes an encoding residual of the core layer encoder. A characteristic correction inverse filter arranged at a pre-stage of an LPC synthesis filter subjects the component having insufficient encoding capability in the core layer to an inverse characteristic correction process, and a characteristic correction filter arranged at a post-stage of the LPC synthesis filter performs a process for characteristic correction of the synthesis signal inputted from the LPC synthesis filter.