A secondary packetized data stream, such as a commercial, is spliced with a primary packetized data stream, such as a network television program. The system does not require decompression of the data in the primary data stream, and is particularly suitable for use at a cable system headend to allow the...http://www.google.co.uk/patents/US5917830?utm_source=gb-gplus-sharePatent US5917830 - Splicing compressed packetized digital video streams
