Abstract: A method and apparatus forming a user interface for examining and retrieving audio/video/data content from digital video recorders. This includes an improved time period selection mechanism, a rich array of temporal data presentations, such as timelines, lists, and thumbnail images, and a unified method of displaying content from either a direct stream or downloaded files. Summary information is provided relating to undownloaded content based on a selected time period.

Abstract: A system for monitoring broadcast channels, includes a device for receiving a plurality of broadcast channels, a central search engine operable to search the received channels for a match with a pre-stored profile, a central memory connected to the search engine for storing the profile, and a plurality of user terminals connected to the search engine over a network. The search engine is responsive to commands from the user terminals to store the profiles to be searched in the memory in association with the identity of the user terminal from which the command was received. A device sends an alert signal over the network when a match is found with a pre-stored profile to the user terminal associated with the pre-stored profile. The alert signal identifies the broadcast channel matching the pre-stored profile.

Abstract: A method of detecting video sequences involves creating on-the-fly candidate digital signatures uniquely characteristic of successive groups of frames in accordance with a predetermined algorithm. The candidate digital signatures are compared with at least one signature of a stored sequence created in accordance with the predetermined algorithm. A candidate is identified as corresponding to the stored sequence in the event of a positive match.

Abstract: A method of processing a video stream, involves contemporaneously selecting first and second pairs of frames in the video stream with a predetermined period. The second pairs of frames have a longer period than the first pair. For each of the first and second pairs of frames, there is determined a difference value representing the number of pixels whose value has changed between the first and second frames of the pair. A particular logic level is generated depending on whether this difference value exceeds a predetermined threshold.