Method and device for encoding signal, method and device for decoding signal and recording medium

摘要

An input signal is divided into blocks and converted into spectrum signals. Each of the spectrum signals are further divided into units and normalized. The normalized spectrum signals are transformed into variable-length codes and outputted together with the normalization coefficients and the number of bits of requantization. An upper limit is put on the number of bits of the outputted signals per block. If the numbers of bits of some signals blocks exceed the upper limit, the normalization coefficients of at least one of the units are forcedly changed. The signals whose normalization coefficients have been forcedly changed are requantized, entropy-coded, and outputted. Thus, without influence of the variation of the numbers of bits due to the variable-length encoding, the hardware scale can be smaller that conventional ones, and the encoding/decoding is efficient and not aurally affected.