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:
Oct. 05, 2004
Filed:
Nov. 17, 2000
Wan-Chieh Pai, Fremont, CA (US);
Fengduo Hu, Cupertino, CA (US);
Other;
Abstract
A system for improved digital data compression in an audio encoder. A threshold is established which depends on the bit rate of the input data. A determination is made whether the bit rate is above or below the established threshold. A masking index is calculated for the input data according to a first formula if the input data is being transmitted at a rate at or below the threshold. A second formula is used to calculate the masking index if the input data is being transmitted at a rate above the threshold. The masking index is used to generate a masking threshold, and data deemed insignificant relative to the masking threshold is ignored. In the preferred embodiment of the present invention, a psycho-acoustic modeler, which is included in the encoding section of an encoding/decoding (CODEC) circuit, is used to determine a masking index. The masking index is then used to generate a masking threshold. A masking threshold is an information curve generated for and unique to each piece of audio data which enters the CODEC circuit. The psycho-acoustic modeler uses experimentally determined information about human hearing and, through a process called perceptive encoding, determines which parts of the input audio data will not be perceived by the human ear. The masking threshold is a curve below which the human ear cannot perceive sounds. The psycho-acoustic modeler compares the masking threshold uniquely generated for the specific piece of input audio data and compares the masking threshold to the input audio data. This comparison dictates to the encoding section of the CODEC circuit which of the tones and noises contained within the input audio data can be ignored without sacrificing sound quality.