Abstract: A video system is disclosed in which a single generic MPEG standard encoder (107) is used to simultaneously code and compress plural different resolution video signals from a single input video signal; and in which a single generic MPEG standard decoder (402) is used to simultaneously decode plural coded and compressed video signals of different resolutions and form a single composite video signal. The coder converts each frame of pixel data of the input video signal into plural frames having different resolutions, which are then combined into a common frame (106) for input to the generic MPEG encoder. The MPEG encoder produces a single coded and compressed output bitstream in slices of microblocks of pixel data, which output bitstream is demultiplexed (108) into separate resolution bitstreams using Slice Start Code identifiers associated with each slice and Macroblock Address Increments associated with the first macroblock in each slice, to properly route each slice to the appropriate output.

Abstract: Apparatus for and method of sending a video bitstream, including a plurality of high priority segments and associated low priority segments, by transmitting only the low priority segments from a transmitter over a facility to a receiver is disclosed. The transmitter and receiver locations are arranged to use previously agreed-to high priority information (e.g., predefined high priority segments or format for generating same) and, consequently, only the low priority segments of the video bitstream need to be transmitted to the receiver. At the receiver, the high priority segments are obtained (from storage or generated using the agreed-to format) and interleaved in real time with the received low priority segments to recreate an interleaved video bitstream.

Abstract: Apparatus and method of transmitting a video bitstream from a transmitter over a facility to a receiver, the video bitstream including a plurality of high priority segments and associated low priority segments, is disclosed. The transmitter first transmits high priority information, representative of the high priority segments, of the video bitstream over the facility using a first packet delivery mechanism having a first probability of success and subsequently transmits a low priority partition, including the low priority segments, of the video bitstream over the facility using a second packet deliver mechanism having a second probability of success which is substantially lower than that of the first delivery mechanism. At the receiver, the high priority partition is received and used to generate the high priority segments.

Abstract: The described video communication system incorporates multiple window display. One or more video transmission nodes provide macroblocks of video data available in a plurality of resolution levels. The transmission node encodes the macroblocks and assigns macroblock identifiers (IDs) to each macroblock. A receiving node receives a plurality of video sequences from a plurality of transmission nodes through a communication network. The receiving node thereafter eliminates macroblocks of video data that will not be displayed, such as in the case of portions of video that are hidden or overlapped. A macroblock translator also transforms the macroblock ID to a new macroblock ID which reflects the macroblock's position on the display screen as dictated by the user's window configuration. A decoder thereafter decompresses the video data one macroblock at a time, and provides the decompressed macroblock to a frame buffer. The frame buffer provides the window configured video data to a display.

Abstract: A Transform Coder Unit (TCU) to transform an arbitrarily shaped image into optimal transform coefficients (OTC) for data transmission. The TCU comprises a forward transform which transforms the image to transform coefficients, and a TCS generator which generates a transform coefficient set (TCS) from the transform coefficients. The TCU also contains an inverse transform which transforms the TCS to a computed region block having computed pel values. Finally, the TCU comprises a replacer which replaces those computed pel values corresponding to the interior pel set with the original pel values to form a modified computed region block which is re-iterated until optimal transform coefficients are determined. The present invention is also directed at a process for determining optimal transform coefficients using the aforementioned device.

Abstract: An improved technique for decoding wherein the number of coefficients to be included in each sub-block is selectable, and a code indicating the number of coefficients within each layer is inserted in the bitstream at the beginning of each encoded video sequence. This technique allows the original runs of zero coefficients in the highest resolution layer to remain intact by forming a sub-block for each scale from a selected number of coefficients along a continuous scan. These sub-blocks may be decoded in a standard fashion, with an inverse discrete cosine transform applied to square sub-blocks obtained by the appropriate zero padding of and/or discarding of excess coefficients from each of the scales. This technique further improves decoding efficiency by allowing an implicit end of block signal to separate blocks, making it unnecessary to decode an explicit end of block signal in most cases.

Abstract: An improved technique for efficient frequency scaling wherein the number of coefficients to be included in each sub-block is selectable, and a code indicating the number of coefficients within each layer is inserted in the bitstream at the beginning of each encoded video sequence. This technique allows the original runs of zero coefficients in the highest resolution layer to remain intact by forming a sub-block for each scale from a selected number of coefficients along a continuous scan. These sub-blocks may be decoded in a standard fashion, with an inverse discrete cosine transform applied to square sub-blocks obtained by the appropriate zero padding of and/or discarding of excess coefficients from each of the scales. This technique further improves coding efficiency by allowing an implicit end of block signal to separate blocks, making it unnecessary to transmit an explicit end of block signal in most cases.