Combined DCAM and transport demultiplexer
US5602920A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1995 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | May 31, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/4623
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A combined condition access and transport demultiplexer circuit comprises a decryption device receiving a demodulated transport bitstream including a plurality of multiplexed conditional access (CA) and product (e.g. video, audio and data) packets, each CA packet being identified by a CA PID and each product packet by a respective product PID. A comparator is provided for comparing the PID of each received packet with a plurality of stored PID values representing the CA PID and selected product PID's. A routing manager is responsive to the comparator for routing received CA packets from the decryption device to a conditional access circuit which controls the decryption device and for routing received product packets to appropriate output ports for further processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.