Method and apparatus for efficiently transmitting forced updates in a moving picture codec
US5644660A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 9, 1992 |
| Grant date | Jul 1, 1997 |
| Priority date | — |
| Expiry date | Apr 9, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/6377
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for selecting blocks for intraframe encoding in a way which avoids intraframe encoding blocks which have not diverged. An inter-energy value is calculated which represents the approximate number of bits required to encode the block of data using a best interframe encoding technique. An intra-energy value is calculated which represents the approximate number of bits required to encode the block of data using intraframe encoding. The block is transmitted using intraframe encoding if the intra-energy is approximately less than the inter-energy. Otherwise, the block is either a) transmitted using an interframe encoding technique or b) not transmitted, thereby implying that the block from the previous frame in the sequence should be repeated. An encoder determines the number of times K that the block has been interframe encoded since it was last intraframe encoded. A weighting factor w(K) is calculated which decreases with the value of K. A weighted energy value is then calculated by multiplying the intra-energy plus an offset S by the weighting factor w(k). If the weighted energy value is approximately less than the inter-energy value, the block is transmitted us…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.