Switching between coding schemes
US7876966B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 11, 2003 |
| Grant date | Jan 25, 2011 |
| Priority date | — |
| Expiry date | Jun 3, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/22
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods and units are shown for supporting a switching from a first coding scheme to a Modified Discrete Cosine Transform (MDCT) based coding scheme calculating a forward or inverse MDCT with a window (h(n)) of a first type for a respective coding frame, which satisfies constraints of perfect reconstruction. To avoid discontinuities during the switching, it is proposed that for a transient frame immediately after a switching, a sequence of windows (h0(n),h1(n),h2(n)) is provided for the forward and the inverse MDCTs. The windows of the window sequence are shorter than windows of the first type. The window sequence splits the spectrum of a respective first coding frame into nearly uncorrelated spectral components when used as basis for forward MDCTs, and the second half of the last window (h2(n)) of the sequence of windows is identical to the second half of a window of the first type.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.