Stereo signal encoding device including setting of threshold frequencies and stereo signal encoding method including setting of threshold frequencies

摘要

An encoding device can achieve both highly effective encoding/decoding and high-quality decoding audio when executing a scalable stereo audio encoding by using MDCT and ICP. In the encoding device, an MDCT converter executes an MDCT conversion on a residual signal of left channel/right channel subjected to window processing. An MDCT converter executes an MDCT conversion on the monaural residual signal which has been subjected to the window processing. An ICP analyzer executes an ICP analysis by using the correlation between a frequency coefficient of a high-band portion of the left channel/right channel and a frequency coefficient of a high-band portion of the monaural residual signal so as to generate an ICP parameter of the left channel/right channel residual signal. An ICP parameter quantizes each of the ICP parameters. A low-band encoding unit encoder executes highly-accurate encoding on the frequency coefficient of the low-band portion of the left channel/right channel residual signal.