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:
Jul. 01, 1997
Filed:
Sep. 13, 1993
Sangil Park, Austin, TX (US);
Dion M Funderburk, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A signal processing system (50) performs real-time pitch shifting for applications such as karaoke, tapeless answering machines, and the like while minimizing distortion. A digital input signal is sampled and stored at successive locations in a variable-size buffer (62) at an input sample rate. Data from the variable-size buffer (62) is interpolated according to a pitch-shifting ratio. An adaptive pitch estimator (61) continually estimates the fundamental frequency of the digital input signal, and the signal processing system (50) adjusts the buffer size of the variable-size buffer (62) in response thereto. The signal processing system (50) changes the buffer size to store the digital input signal for an integral number of periods of the estimated fundamental frequency.