Patent ID: 8433581

Claim:
A speech coding apparatus, comprising: a first coder, comprising a processor, that carries out core layer coding for a monaural signal; a second coder that carries out enhancement layer coding for a stereo signal; a correlation comparator that calculates a first intra-channel correlation corresponding to a first single channel signal and a second intra-channel correlation corresponding to a second single channel signal, compares the first intra-channel correlation and the second intra-channel correlation, the first single channel signal and the second single channel signal constituting the stereo signal, and the correlation comparator selects a first channel of the first single channel signal if the first intra-channel correlation is greater than the second intra-channel correlation, and selects a second channel of the second single channel signal if the second intra-channel correlation is greater than the first intra-channel correlation, and an outputter that outputs encoded data so that the encoded data is transmitted to a speech decoding apparatus, wherein: the first coder generates a monaural signal from the first channel signal and the second channel signal; the second coder carries out coding of the first channel using a prediction signal generated by an intra-channel prediction of the channel selected by the correlation comparator; and the encoded data includes selection information representing the channel selected by the correlation comparator, data coded by the second coder and data coded by the first coder.