Abstract: An apparatus for providing VCR-like “trick mode” functions, such as pause, fast-forward, and rewind, in a distributed, video-on-demand program environment. Trick modes are supported by locally altering the viewing speed for each user who requests such functions, without affecting the operation of the central data source in any way. Thus, a virtual unlimited number of viewers are able to enjoy random access to video programming, including virtually continuous trick mode functionality. This is accomplished in a manner that is operable with existing telephone and cable distribution infrastructure.

Abstract: A compressed video playback system which eliminates playback mode transition artifacts. Transitions between various playback modes are effected in such a manner that transition artifacts are eliminated by delaying playback mode transitions until appropriate frames of data are detected for propagation to the compressed video decoder. In addition, compressed video data retrieval methods are improved for supporting multi-speed playback modes in both forward and reverse directions in an optimal manner.

Abstract: An digital home video system providing recording and playback of compressed video programs using an archival storage medium; simultaneous recording and playback using the same archival medium; storage of multiple programs on a single videotape; a full array of trick mode functions; efficient management of the contents of a video tape or other archival storage medium; and real-time random access to video program content, enabling truly interactive playback. These capabilities are provided by combining the best features of an archival storage medium such as digital video tape: namely, potentially large storage capacity, but low tolerance for variable data rate, and essentially linear program access; with the complementary features of a relatively high-access storage device such as a fixed disk drive: namely, tolerance for a highly variable data rate, and random access capability, but relatively lower storage capacity.

Abstract: A system for providing efficient constant bit rate distribution of variable bit-rate encoded video programs while facilitating the distribution of encoded video programs, along with Auxiliary Data of a general character, to one or more receivers. At a particular receiver, a customized augmented video program is created by inserting selected portions of the Auxiliary Data into a selected encoded video program. The encoded video portion of the augmented video program can be transmitted, decoded and displayed in real time, while the Auxiliary Data need not be transmitted in real time but can be stored locally at the receiver for real-time presentation at a later time. Real time presentation might include insertion into the video program while non real-time presentation might include insertion into non-video applications separate from the video program.

Abstract: A method for increasing channel utilization for a data channel transmitting a multiplex of a set of one or more encoded program streams, each program stream in being decodeable by a corresponding decoder, each corresponding decoder including a corresponding decoder buffer, the decoder buffers having a maximum allowable size, the method comprising selecting encoded pictures to be modified, said selecting according to a criterion which includes preventing any underflow of any decoder buffer, modifying each said selected encoded picture to form a corresponding modified encoded picture, said modified encoded picture having less data than said selected encoded picture, and transmitting the corresponding modified encoded pictures through the channel in place of the selected encoded pictures.

Abstract: A compressed video playback system which eliminates playback mode transition artifacts. Transitions between various playback modes are effected in such a manner that transition artifacts are eliminated by delaying playback mode transitions until appropriate frames of data are detected for propagation to the compressed video decoder. In addition, compressed video data retrieval methods are improved for supporting multi-speed playback modes in both forward and reverse directions in an optimal manner.

Abstract: Selective video-on-demand access is provided to a virtually unlimited number of subscribers by partitioning the video program into an ordered sequence of N segments and providing the subscribers concurrent access to each of the N segments. A data stream representative of the video program is partitioned into N subsequences, each representative of one of the N segments. The data of each of the N subsequences is organized as an ordered sequence of elements. The elements of each of the N subsequences are interleaved and the interleaved data stream is continuously transmitted over a video program distribution medium at a rate which renders the data representing each segment concurrently available to any subscriber having a receiver capable of selecting, assembling, and displaying the data of a particular segment.

Abstract: A method and apparatus for reducing the size of data rate fluctuations that occur in forming a multiplex of a set of program streams, each program stream in said set being decodeable by a corresponding decoder, each corresponding decoder including a corresponding decoder buffer, said decoder buffers having a maximum allowable size, said method comprising varying the formation of the different program streams in said set to minimize the memory requirement of the decoder buffers. In one embodiment, for the case of the streams being segments of a program, varying includes varying the segment length. In another embodiment, varying includes adjusting the relative alignment of the program streams. Different embodiments of adjusting include inserting program material such as a pause at selected points in time, causing decoder buffers to underflow at selected points in time, and varying the rate of decoding and display at selected points in time.

Abstract: A method and apparatus multiplexing several encoded program streams into a single multiplex suitable for transmission over a data channel, the streams typically including video and audio. According to one embodiment of the invention, high data channel utilization is achieved by determining the order of sending data packets of program streams into the data channel. According to this embodiment, whenever data is to be sent into the data channel, a determination is made of which packet to send or append to the multiplex, said determination by selecting a channel that has a decoder buffer that is not approaching a full state, and said next packet is appended to said multiplex. The method further includes selecting a channel that substantially balances the decoder buffers of the decoders with which the program streams are decodeable.

Abstract: Virtually random and on-demand access is provided to a virtually unlimited number of subscribers by partitioning the video program into an ordered sequence of n segments and providing the subscribers concurrent access to each of the n subsequences. A data stream representative of the video program is partitioned into n subsequences, each representative of one of the n segments. The data of each of the n subsequences is organized as an ordered sequence of elements. The elements of each of the n subsequences are interleaved and the interleaved data stream is continuously transmitted over a video program distribution medium at a rate which renders the data representing each segment concurrently available to any subscriber having a receiver capable of selecting, assembling, and displaying the data of a particular segment. The data stream can be compressed prior to interleaving using one of many known video data compression standards and techniques.