Abstract: A video storage arrangement produces a continuous video signal representing a test pattern. One luminance frame store is provided and two chrominance frame stores. A selection can be made between NTSC, PAL and SECAM modes. Switches are provided for selecting between chrominance frame stores and between inverting and non-inverting mode. Depending upon the selected broadcast standard, these switches are driven from field and line clock signals to generate the required output field sequence in YC or composite form.

Abstract: Apparatus and methods are provided for connecting video components. In one embodiment the apparatus includes a notch filter for filtering frequencies of a first channel from a first video source, the first video source having a plurality of channels, to form a notch filter output having each of the plurality of channels except the frequencies of the first channel, a bandpass filter for filtering a second video source to pass only frequencies in a second channel in the second video source having the same frequencies as the frequencies of the first channel to form a bandpass filter output, and a summer for summing the notch filter output and the bandpass filter output to form a summed output. In another embodiment the apparatus includes a signal splitter for splitting a first input signal and providing a first and second output, the second output coupled to and providing the first video source into the notch filter.

Abstract: A user's personal computer is coupled to a home controller which is, in turn connected to the input cable from a cable television system and to a set top box which determines the channel to be delivered to an associated television. The service provider transmits over a conventional modem communication link the alert message to the user's personal computer. If an acknowledgment by the user is not transmitted to the service provider, a command message is transmitted by the dial-up communication link to the personal computer instructing the personal computer to activate a modulator contained in the home controller to provide an RF encoded signal representing the alert message to be displayed on the television associated with the set top box.

Abstract: A partial response Trellis decoder that performs trellis coded modulation in a high definition television (HDTV) having a specific and detailed configuration and includes a distance mapper for calculating first, second, third and fourth Euclidean distances between the input signal and a reference value; a Viterbi decoder for Viterbi decoding the first, second, third and fourth Euclidean distances calculated by the distance mapper; a first delay for delaying and outputting the Yiterbi decoded data for each Euclidean distance; a ruler selector for selecting a ruler type signal based on the signals output by the first delay; and a slicer for slicing the selected ruler type signal and the input signal.

Abstract: This invention provides a digital color encoder for digitizing color video signals. The encoder forms a digitized color video signal using logic function processing of the digitized luminance signal and color difference signals. The encoder provides an output signal equivalent to the luminance signal added to the color difference signals modulated by triangular wave functions and sampled at the sampling frequency. The sampling frequency is eight times the crominance subcarrier frequency. An analog video signal can easily be recovered from the digital video signal because the fundamental frequency of the triangular wave is easily separated from the higher order harmonics.

Abstract: Compensation for offset errors caused by data truncation is accomplished by adding a compensation value to processed data in systems where the truncation stages are arranged in determinable configurations. More than one compensation value may be selected and applied. The selection of the appropriate value is determined by the number and type of truncation stages used in a given system configuration. The compensation value may be predetermined or measured.

Abstract: An apparatus for providing local programming with direct broadcast satellite transmissions includes a terrestrial transmitter for transmitting converted local channel signals in a first frequency band. The first frequency band is contained within a satellite broadcast frequency band in which the direct broadcast satellite channels are transmitted. The apparatus also includes at each user or subscriber location, a first antenna for receiving the converted local channel signals from the terrestrial transmitter and a second antenna for receiving a direct broadcast satellite channel signals from the satellite. The apparatus further includes a combiner for combining the converted local channel signals and the direct broadcast satellite channel signals on a single propagation path. A signal processor/decoder processes the combined signals on the single propagation path to produce a desired channel output to drive a television set.