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:
Apr. 20, 2004
Filed:
Jun. 15, 1999
Tadashi Araki, Kanagawa, JP;
Ricoh Company, Ltd., , JP;
Abstract
In an audio coding and quantization method, each of spectral subband components of an audio signal is quantized whereby a quantizer step size for a related one of spectral subbands is obtained from a bit allocation. The bit allocation is controlled for each subband by using a psychoacoustic model. During the controlling, a quantization of frequency domain values of a related one of blocks is calculated through a first control loop, the first control loop being repeated until a bit rate requirement is met. A quantization noise for each subband, produced within the first control loop, is calculated through a second control loop, the second control loop being repeated until a masking requirement is met. The first control loop and the second control loop are alternately performed for the related block such that both the requirements are met, and, thereafter, an output vector of quantized frequency domain values is finally produced.