Apparatus and method for playing back audio at faster or slower rates without pitch distortion
US5386493A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 1992 |
| Grant date | Jan 31, 1995 |
| Priority date | — |
| Expiry date | Sep 25, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10H1/20
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.