Abstract: A system is provided for controlling the transmission of best-effort filed data or programs on channels from one of plural controllers to one or more client nodes. A program is a group of files and has program information indicating to a client node how to use the files of the program. A channel is a virtual path, wherein a client node can receive program files from different channels in a separable fashion. Channels also have channel information. Multiple controllers are provided which self configure in rank order to control the scheduled transmission of programs files on channels. Client nodes receive announcements of programs and channels from the controllers and selectively subscribe to the channels and programs. Client nodes can be instructed to positively acknowledge receipt of programs and also send back negative acknowledgements for ranges of data words in program files not received. The negative acknowledgements can be consolidated to reduce the number of packets on the network.

Abstract: A deblocking/deflickering filter decreases artifacts produced in a block-based image compression system, wherein a plurality of transform coefficients are produced respectively indicative of different frequencies in input signal values. The filter includes a first filter portion for deblocking filtering a first low frequency one of the transform coefficients and a second filter portion for deblocking filtering a second low frequency one of the transform coefficients, the first low frequency being different from the second low frequency. The deblocking filter passes through at least a third one of the transform coefficients having a third frequency higher than both of the first and second frequencies without deblocking filtering.

Abstract: An interactive television (ITV) system transmitting ITV content created and received by different ITV platforms via a single ITV stream. The system provides universal time codes which are embedded into the ITV stream. Each time code is associated with a program identifier which uniquely identifies a particular program. An ITV receiver receives the ITV stream and compares the program identifier and time code with a program held in the receiver's memory. When a match is found, an interactive event indicated by the program is executed. The program may be loaded into the receiver's memory using a back channel.

Abstract: A method and system are provided for remultiplexing program bearing data. The remultiplexing method and system are applicable to MPEG-2 compliant transport streams carrying video programs. Remultiplexing functions may be distributed across a network. The remultiplexer can furthermore optimize the bandwidth of transport streams by replacing null transport packets with transport packet data to be inserted into the output transport stream. Remultiplexing and program specific information can be seamlessly dynamically varied without stopping, or introducing a discontinuity in, the flow-of outputted transport packets.

Abstract: A system and method is provided for revising the time stamp information in an MPEG-2 transport stream after content in the transport stream is modified. According to one method, successive PCR time stamps previously added to the transport stream are used to determine PCRSYNC time stamps for synchronization points in the transport stream by interpolation. The PCRSYNC time stamps are substituted into transport packets within the transport stream. The PCRSYNC is also used to determine modified time of arrival (TOA) stamps to be added to transport packets. According to a second method, PCR interpolation is used to determine the values of PCRSYNC. TOA interpolation of TOA stamps previously added to the transport stream are used to determine modified TOA stamps to be substituted into the transport stream for the previously added TOA stamps.