APPARATUS AND METHOD FOR ORTHOGONAL TRANSFORMATION, APPARATUS AND METHOD FOR INVERSE ORTHOGONAL TRANSFORMATION, APPARATUS AND METHOD FOR TRANSFORMATION ENCODING AS WELL AS APPARATUS AND METHOD FOR DECODING

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and a method for transformation encoding wherein the delimiter of an overlap is decided arbitrarily and a signal can be reproduced completely by adding the overlap. SOLUTION: A linear and nonlinear prediction analyzer 3 executes a linear and nonlinear prediction analysis processing operation to an audio signal which is input from an input terminal 2, and outputs a prediction residue. A stationality estimation part 7 estimates the stationality of the audio signal. A block-length decision part 8 decides the length of a block in an MDCT based on a result estimated by the part 7. An MDCT 5 executes an MDCT processing operation to a time-series sample M in the prediction residue to be input via a buffer 4 at the length of the block decided in the part 8, and it generates MDCT coefficients. A quantization part 6 quantizes the MDCT coefficients generated in the MDCT 5.