Signal coding method and apparatus

摘要

The present invention provides a signal coding apparatus including the following. A normalization circuit 101 carries out a linear prediction or the like to extract features of an input signal and carries out whitening. The signal whitened is transmitted to a T/F (time axis/frequency axis) conversion circuit 102 where the signal is subjected to a conversion such as the MDCT so as to obtain a coefficient y on the frequency axis. This coefficient y is supplied to a quantization (scalar quantization (SQ) and vector quantization (VQ)) circuit 103. A bit allocation circuit 104 uses the coefficient y ad parameters such as an LPC coefficient and a pitch from the normalization circuit 101 for carrying out quantization bit allocation for each coefficient. The quantization (SQ and VQ) circuit 103, acccrding to this allocation bit, controls whether to carry out the SQ or VQ for each coefficient.