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:
Jan. 31, 1995
Filed:
Sep. 25, 1992
Leo M Degen, Menlo Park, CA (US);
Martijn Zwartjes, Utrecht, NL;
Apple Computer, Inc., Cupertino, CA (US);
Abstract
A computer implemented apparatus and method for modifying the playback rate of a previously stored audio or voice data file stored within a computer system without altering the pitch of the audio data file as originally stored. The present invention also maintains a high level of sound quality during playback. The present invention includes a double buffering system in order to perform all of the desired calculations in real time. A time stretching technique is employed upon the audio data file to decrease or increase playback rate which creates audio segments requiring joining processing. Junctions are smoothed by employing a cross-fade amplitude envelope filter and a compressor/limiter is used to maintain filter range. The system may operate on a desktop computer allowing for advantageous playback and audio data management options of stored voice and or sound data.