Method of partially scrambling a data stream
US7978852B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 2004 |
| Grant date | Jul 12, 2011 |
| Priority date | — |
| Expiry date | Jan 9, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/835
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of partially scrambling a data stream (6) including transport stream packets (7), each transport stream packet (7) having a header (8) and a payload (9), wherein a sequence of transport stream packets (7) has payloads carrying encoded data elements, arranged in units (15), includes: selecting transport stream packets (7) forming a subsequence of the sequence, and scrambling at least part of the payloads (9) of each transport stream packet (7) in the subsequence. The method further includes monitoring the payloads (9) of at least some of the transport stream packets (7) in the sequence for the presence of data (22) indicating a boundary between two subsequent units (15), and, for selected units (15), including at least one of the transport stream packets (7) carrying data forming part of the selected unit (15) in the sub-sequence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.