System and method for transmitting and receiving variable length authorization control for digital services
US5506904A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 1993 |
| Grant date | Apr 9, 1996 |
| Priority date | — |
| Expiry date | Dec 3, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/8355
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Authorization information, such as blackout and spotlight regions, circular blackout and spotlight regions, and tier pointers, may be transmitted from an encoder to a decoder in a plurality of sessions of data frames. By spreading the authorization information over a plurality of sessions, more space may be allocated for the provision of services. In addition, the authorization information may be framed by START and STOP fields so that the length of authorization information may be variable. Calculation of a circular blackout/spotlight region can be simplified by transmitting a distortion factor from the encoder to the decoder. Accordingly, complex calculations need not be performed at a microprocessor in the decoder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.