Abstract: A variable length coding system encodes and decodes symbols as uniquely decodable code words using an assignment scheme having a maximum code word length. According to one embodiment, a first bitstream is combined with a second bitstream to provide a resultant bitstream to be sent over a communications channel. The first bitstream represents the code words in a forward direction, and the second bitstream contains the same code words reversed and bit delayed by at least the maximum code word length. A resultant bitstream can be decoded in forward or reverse direction. The scheme is highly efficient for long blocks of data and the reversible aspect of the coding scheme improves the tolerance for errors caused by channel interference.
Abstract: A video unit provides remote activation of appliances and is capable of recording locally captured video data. The video unit includes an infrared transmitter that generates infrared signals to activate and/or control appliances in response to control codes, e.g. received from a remote site by the video arrangement. The video unit also includes a storage element so that locally captured video data can be stored and played back from a remote location.
Abstract: A videoconferencing system includes a videoconferencing arrangement with the capability to automatically determine whether a videoconferencing or conventional telephone call is being initiated. In one embodiment, a portable telephone unit includes a preprogrammed memory storing codes that indicate whether a telephone number input to the telephone unit should be used to initiate a videoconferencing or conventional telephone call. If a conventional telephone call is being initiated, the video processing functions of the videoconferencing unit are not activated and the user proceeds with the conventional telephone call. If a videoconferencing call is being initiated, the videoconferencing unit establishes a data connection with a compatible device at the remote end of the communications channel and proceeds with the videoconference.