The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 04, 1997
Filed:
Nov. 23, 1994
Harumitsu Miyakawa, Shiki-gun, JP;
Shuichi Kawama, Kyoto, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
There is provided an encoding and decoding apparatus which can provide a high quality of reproduction of sound. There are provided an encoding section and a decoding section. A block length determining section of the encoding section time-sharingly divides an input signal into blocks having a block length corresponding to the degree of change of the input signal. A frequency band dividing section divides the signal of each block into a plurality of frequency bands. A bit allocating section obtains a masking threshold value-to-noise ratio of each frequency band from the magnitude of the power of each frequency band reflecting a psychoacoustic characteristic, and determines the number of quantization bits to be allocated to each frequency band based on the magnitude of the masking threshold value-to-noise ratio. A quantizing section generates a code string by quantizing the signal while allocating a specified amount of bits to each frequency band based on information from the bit allocating section. The bit allocating section receives information representing the block length from the block length determining section, and adopts a different psychoacoustic characteristic depending upon the block length.