Abstract: Switched digital television programming for video-on-demand and other interactive television services are combined utilizing a class-based, multi-dimensional decision logic to simultaneously optimize video quality and audio uniformity while minimizing latency during user interactions with the system over managed networks such as cable and satellite television networks. A group of user sessions are assigned to a single modulator. The user sessions include data in a plurality of classes, each class having a respective priority. In response to a determination that an aggregate bandwidth of the group of user sessions for a first frame time exceeds a specified budget, bandwidth is allocated for the group of user sessions during the first frame time in accordance with the class priorities. The group of user sessions is multiplexed onto a channel corresponding to the modulator in accordance with the allocated bandwidth and transmitted over a managed network.

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 method of combining an interactive user interface for generating a blended output that includes the interactive user interface and one or more supplemental images. At a client device remote from a server, a video stream that contains an interactive user interface is received from the server using a first data communications channel configured to communicate video content, and a command that relates to an interactive user interface is transmitted to the server. In response to the transmitting, an updated user interface is received from the server using the first data communications channel, and one or more supplemental images for supplementing the interactive user interface are received using a second data communications channel different from the first data communications channel. The updated user interface and the one or more supplemental images are blended to generate a blended output, which is transmitted toward the display device for display thereon.

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: Systems and methods are provided for reducing and controlling playback latency in an unmanaged, buffered data network. A delay cost function is determined, the function representing the effect of playback latency on end user experience. An encoder transmits audiovisual data through the network to a client device. Network latency is measured, and the delay cost function is evaluated to establish an encoding bitrate for the encoder. The encoding of the audiovisual data is altered in response to dynamic network conditions, thereby controlling end-to-end playback latency of the system, which is represented by the playout length of data buffered between the encoder and the client device.

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: The present invention provides a method for streaming of parallel user sessions, system and computer software server to at least one client device of a number of client devices for representation of the sessions on a monitor that is connectable to a client device, in which the sessions comprise video data and optional additional data, such as audio data, in which the method comprises steps for: defining coded fragments, based on reusable image data, in which the encoded fragments are suitable for assembling of the video data in a predefined data format, such as a video standard or a video codec, and in which the encoded fragments are suitable for application in one or more images and/or one or more sessions, and assembling of a data stream per session, comprising video data in which the encoded fragments are applied.

Abstract: A technique is disclosed that enables latency-tolerant and latency-intolerant applications to intelligently share a shared-communications channel in a manner that seeks to satisfy the needs of all of the applications. In particular, the illustrative embodiment enables each application to be associated with a different class of service, wherein each class of service is associated with one or more quality-of-service parameters (e.g., minimum throughput, maximum latency, etc.). The illustrative embodiment then effectively apportions access to the shared-communications channel by regulating different degrees of bursting (i.e., the transmission of multiple frames at a single transmission opportunity) based on the class of service associated with the application.

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 technique is disclosed that enables latency-tolerant and latency-intolerant applications to intelligently share a shared-communications channel in a manner that seeks to satisfy the needs of all of the applications. In particular, the illustrative embodiment enables each application to be associated with a different class of service, wherein each class of service is associated with one or more quality-of-service parameters (e.g., minimum throughput, maximum latency, etc.). The illustrative embodiment then effectively apportions access to the shared-communications channel by regulating different degrees of bursting (i.e., the transmission of multiple frames at a single transmission opportunity) based on the class of service associated with the application.

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.