Time-domain time/pitch scaling of speech or audio signals with transient handling
US6049766A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 7, 1996 |
| Grant date | Apr 11, 2000 |
| Priority date | — |
| Expiry date | Nov 7, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L21/01
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for time-scaling and/or pitch shifting by discarding and/or repeating segments of a signal. The signal is stored as a series of samples in a memory where it is readable by one or more read pointers. Periodicity of segments of the signal is determined by evaluating normalized cross-correlation over a range of possible periods. Transients are detected by monitoring changes in rms signal value. To achieve time compression or time stretching, a segment is skipped/discarded whenever a maximum time-discrepancy between the current output and an ideal output is reached or a high periodicity is detected, a jump of the optimal length would not make this time discrepancy too high, and no transient is present in the segment to be skipped/discarded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.