Abstract: A predictive video coder performs gradient prediction based on previous blocks of image data. For a new block of image data, the prediction determines a horizontal gradient and a vertical gradient from a block diagonally above the new block (vertically above a previous horizontally adjacent block). Based on these gradients, the encoder predicts image information based on image information of either the horizontally adjacent block or a block vertically adjacent to the new block. The encoder determines a residual that is transmitted in an output bitstream. The decoder performs the identical gradient prediction and predicts image information without need for overhead information. The decoder computes the actual information based on the predicted information and the residual from the bitstream.

Abstract: In accordance with the teachings of the present invention, a method and apparatus is presented for alerting an operator of a network problem using a variety of contact devices. A server receives notification of a network problem. The server accesses presence information detailing the current location of an operator. The server then uses push technology to transmit alert information to the operator. As such, the alert information may be communicated directly to a client machine used by the operator. In the case where the operator is communicating through a contact device, which communicates with an interactive system, the alert information is forwarded to the interactive system, which communicates with the contact device.