ENCODER AND DECODER

摘要

There is provided an encoder capable of improving inter-channel prediction (ICP) performance in scalable stereo sound encoding using an ICP. In the encoder, ICP analysis units (113, 114, 115) use, as reference signal candidates, a frequency coefficient (sL'(f)) in the low-band portion of a side residual signal, a frequency coefficient (mM,i(f)) in each sub-band portion of a monaural residual signal, and a frequency coefficient (mL(f)) in the low-band portion of the monaural residual signal, respectively, and perform an ICP analysis between the respective these candidates and a frequency coefficient (sM,i(f)) in each sub-band portion of the side residual signal to generate first, second, and third ICP coefficients. A selection unit (116) selects an optimum reference signal from among the reference signal candidates by checking the relationship between the respective reference signal candidates and the frequency coefficient (sM,i(f)) in each sub-band portion of the side residual signal and outputs, to an ICP parameter quantization unit (117), a reference signal ID indicating the selected reference signal and an ICP coefficient corresponding to the reference signal.