PARAMETER DECODING DEVICE, PARAMETER ENCODING DEVICE, AND PARAMETER DECODING METHOD

摘要

Provided is a parameter decoding device which performs parameter compensation process so as to suppress degradation of a main observation quality in a prediction quantization. The parameter decoding device includes amplifiers (305-1 to 305-M) which multiply inputted quantization prediction residual vectors xn-1 to xn-M by a weighting coefficient ss1 to ssM. The amplifier (306) multiplies the preceding frame decoding LSF vector YN-1 by the weighting coefficientss-1. The amplifier (307) multiplies the code vector xn+1 outputted from a codebook (301) by the weighting coefficientsso. An adder (308) calculates the total of the vectors outputted from the amplifiers (305-1 to 305- M), the amplifier (306), and the amplifier (307). A selector switch (309) selects the vector outputted from the adder (308) if the frame erasure coding Bn of the current frame indicates that 'the n-th frame is an erased frame' and the frame erasure coding Bn+1 of the next frame indicates that 'the n+l-th frame is a normal frame'.