AUDIO ENCODING DEVICE, AUDIO DECODING DEVICE, AUDIO ENCODING METHOD, AND AUDIO DECODING METHOD

摘要

A basic layer encoding section (101) encodes an input signal and acquires basic layer encoded information. A basic layer decoding section (102) decodes the basic layer encoded information and acquires a basic layer decoded signal and long-term prediction information (pitch lag). An adder (103) reverses polarity of the basic layer decoded signal and adds it to the input signal so as to acquire a residual signal. An extended layer encoding section (104) encodes a long-term prediction coefficient calculated by using the long-term prediction information and the residual signal and acquires extended layer encoded information. A basic layer decoding section (152) decodes the basic layer encoded information and acquires a basic layer decoded signal and long-term prediction information. An extended layer decoding section (153) uses the long-term prediction information to decode the extended layer encoded information and acquires an extended layer decoded signal. An adder (154) adds the basic layer decoded signal to the extended layer decoded signal so as to acquire audio/music composition signal. Thus, it is possible to realize scalable encoding with a small amount of calculation and a small amount of encoded information.