| 摘要 |
PROBLEM TO BE SOLVED: To constitute a device which decodes a generated bit stream high in coding efficiency, keeping its high quality, by efficiently analyzing the frequency of an audio signal by general harmonic analysis method. SOLUTION: A decoder sets a frame period adaptably for a digital audio signal to be supplied, and performs harmonic analysis, as regards a signal easy to be perceived in view of psychoacoustics, with high accuracy by small frequency interval. Further, the decoder performs general harmonic analysis, as regards a signal hard to be perceived, with low accuracy by detecting the level of the residual signal obtained by the results of general harmonic analysis having dropped, and generates a bit stream and transmits it and, for the decoding of the transmitted beat stream, gets the frame period information set adaptably and the results of general harmonic analysis, and regenerates a digital audio signal high in sound quality and high in coding efficiency. |
