Abstract: System and methods are provided to cache encoded graphical objects that may be subsequently combined with other encoded video data to form a data stream decodable by a client device according to a format specification. Paint instructions relating to a graphical object are sent from a layout engine to a rendering library. A shim intercepts these instructions and determines whether the graphical object already has been rendered and encoded. If so, a cached copy of the object is transmitted to the client device. If not, the shim transparently passes the instructions to the rendering library, and the object is rendered, encoded, and cached. Hash values are used for efficiency. Methods are disclosed to detect and cache animations, and to cut and splice cached objects into encoded video data.

Abstract: Switched digital television programming for video-on-demand and other interactive television services are combined utilizing class-based, multi-dimensional decision logic to simultaneously optimize video quality and audio uniformity while minimizing latency during user interactions with the system over an unmanaged network. For example, a method of adapting content-stream bandwidth includes generating a content stream for transmission over an unmanaged network with varying capacity; sending the content stream, via the unmanaged network, toward a client device; monitoring the capacity of the unmanaged network; determining whether an aggregate bandwidth of an upcoming portion of the content stream fits the capacity, wherein the upcoming portion of the content stream corresponds to a respective frame time and includes video content and user-interface data; and, in response to a determination that the aggregate bandwidth does not fit the capacity, reducing a size of the upcoming portion of the content stream.

Abstract: A system method and computer program product for creating a composited video frame sequence for an application. A current scene state for the application is compared to a previous scene state wherein each scene state includes a plurality of objects. A video construction engine determines if properties of one or more objects have changed based upon a comparison of the scene states. If properties of one or more objects have changed based upon the comparison, the delta between the object's states is determined and this information is used by a fragment encoding module if the fragment has not been encoded before. The information is used to define, for example, the motion vectors for use by the fragment encoding module in construction of the fragments to be used by the stitching module to build the composited video frame sequence.

Abstract: A system method and computer program product for creating a composited video frame sequence for an application. A current scene graph state for the application is compared to a previous scene graph state wherein each scene graph state includes a plurality of hierarchical nodes that represent one or more objects at each node. A video construction engine determines if one or more objects have moved based upon a comparison of the scene graph states. If one or more objects have moved based upon the scene graph comparison, motion information about the objects is determined and the motion information is forwarded to a stitcher module. The motion information is used to define motion vectors for use by the stitcher module in construction of the composited video frame sequence.

Abstract: System and methods are provided to cache encoded graphical objects that may be subsequently combined with other encoded video data to form a data stream decodable by a client device according to a format specification. Paint instructions relating to a graphical object are sent from a layout engine to a rendering library. A shim intercepts these instructions and determines whether the graphical object already has been rendered and encoded. If so, a cached copy of the object is transmitted to the client device. If not, the shim transparently passes the instructions to the rendering library, and the object is rendered, encoded, and cached. Hash values are used for efficiency. Methods are disclosed to detect and cache animations, and to cut and splice cached objects into encoded video data.

Abstract: A technique to allow enhanced stations and legacy stations to work with each other without the inefficiencies of signaling overhead in the prior art is disclosed. An enhanced station transmits an initial, short frame using a modulation compatible with legacy stations. The frame sets the duration for a frame exchange—consisting of a data frame, followed by acknowledgement frame—in which the data frame is transmitted using an enhanced modulation format. The duration specified in the transmitted initial frame covers the time interval of the subsequent frame exchange. All stations, including legacy stations, listen in on the frame exchange and refrain subsequently from transmitting spontaneously for the time interval covered by the duration. Alternatively, the frame exchange can comprise multiple data frames with corresponding acknowledgement frames. The enhanced station can also transmit, during the remaining frame exchange, one or more intermediate frames that indicate duration.

Abstract: A method and apparatus are disclosed for enabling coexistence in a wireless local-area network between legacy stations and stations that can transmit higher-bandwidth signals. The illustrative embodiment employs a transceiver that can transmit and receive higher-bandwidth signals over a combination of two or more shared-communications channels, and an enhanced medium access control (MAC) protocol by which stations progressively reserve channels before transmitting higher-bandwidth signals.

Abstract: A technique to allow enhanced stations and legacy stations to work with each other without the inefficiencies of signaling overhead in the prior art is disclosed. An enhanced station transmits an initial, short frame using a modulation compatible with legacy stations. The frame sets the duration for a frame exchange—consisting of a data frame, followed by acknowledgement frame—in which the data frame is transmitted using an enhanced modulation format. The duration specified in the transmitted initial frame covers the time interval of the subsequent frame exchange. All stations, including legacy stations, listen in on the frame exchange and refrain subsequently from transmitting spontaneously for the time interval covered by the duration. Alternatively, the frame exchange can comprise multiple data frames with corresponding acknowledgement frames. The enhanced station can also transmit, during the remaining frame exchange, one or more intermediate frames that indicate duration.

Abstract: A technique to allow enhanced stations and legacy stations to work with each other without the inefficiencies of signaling overhead in the prior art is disclosed. An enhanced station transmits an initial, short frame using a modulation compatible with legacy stations. The frame sets the duration for a frame exchange—consisting of a data frame, followed by acknowledgement frame—in which the data frame is transmitted using an enhanced modulation format. The duration specified in the transmitted initial frame covers the time interval of the subsequent frame exchange. All stations, including legacy stations, listen in on the frame exchange and refrain subsequently from transmitting spontaneously for the time interval covered by the duration. Alternatively, the frame exchange can comprise multiple data frames with corresponding acknowledgement frames. The enhanced station can also transmit, during the remaining frame exchange, one or more intermediate frames that indicate duration.

Abstract: A method and apparatus are disclosed for enabling coexistence in a wireless local-area network between legacy stations and stations that can transmit higher-bandwidth signals. The illustrative embodiment employs a transceiver that can transmit and receive higher-bandwidth signals over a combination of two or more shared-communications channels, and an enhanced medium access control (MAC) protocol by which stations progressively reserve channels before transmitting higher-bandwidth signals.

Abstract: A technique to allow enhanced stations and legacy stations to work with each other without the inefficiencies of signaling overhead in the prior art is disclosed. An enhanced station transmits an initial, short frame using a modulation compatible with legacy stations. The frame sets the duration for a frame exchange—consisting of a data frame, followed by acknowledgement frame—in which the data frame is transmitted using an enhanced modulation format. The duration specified in the transmitted initial frame covers the time interval of the subsequent frame exchange. All stations, including legacy stations, listen in on the frame exchange and refrain subsequently from transmitting spontaneously for the time interval covered by the duration. Alternatively, the frame exchange can comprise multiple data frames with corresponding acknowledgement frames. The enhanced station can also transmit, during the remaining frame exchange, one or more intermediate frames that indicate duration.