Abstract: For a given cross-data-store transaction request at a storage service, a coordinator transmits respective voting transition requests to a plurality of log-based transaction managers (LTMs) configured for the respective data stores to which writes are directed in the transaction. The LTMs transmit responses to the coordinator based on data-store-specific conflict detection performed using contents of the voting transition requests and respective data-store-specific state transition logs. The coordinator determines a termination status of the cross-data-store transaction based on the LTMs' responses, and provides an indication of the termination status to the LTMs.

Abstract: Methods and apparatus for private network peering in virtual network environments in which peerings between virtual client private networks on a provider network may be established by clients via an API to a peering service. The peering service and API 104 may allow clients to dynamically establish and manage virtual network transit centers on the provider network at which virtual ports may be established and configured, virtual peerings between private networks may be requested and, if accepted, established, and routing information for the peerings may be specified and exchanged. Once a virtual peering between client private networks is established, packets may be exchanged between the respective client private networks via the peering over the network substrate according to the overlay network technology used by the provider network, for example an encapsulation protocol technology.

Abstract: A control-plane component of a virtual network interface (VNI) multiplexing service assigns one or more VNIs as members of a first interface group. A first VNI of the interface group is attached to a first compute instance. Network traffic directed to a particular endpoint address associated with the first interface group is to be distributed among members of the first interface group by client-side components of the service. The control-plane component propagates membership metadata of the first interface group to the client-side components. In response to a detection of an unhealthy state of the first compute instance, the first VNI is attached to a different compute instance by the control-plane component.

Abstract: Methods and apparatus for private network peering in virtual network environments in which peerings between virtual client private networks on a provider network may be established by clients via an API to a peering service. The peering service and API 104 may allow clients to dynamically establish and manage virtual network transit centers on the provider network at which virtual ports may be established and configured, virtual peerings between private networks may be requested and, if accepted, established, and routing information for the peerings may be specified and exchanged. Once a virtual peering between client private networks is established, packets may be exchanged between the respective client private networks via the peering over the network substrate according to the overlay network technology used by the provider network, for example an encapsulation protocol technology.

Abstract: Methods and apparatus for bandwidth metering in large-scale networks are disclosed. Metadata for a network transmission involving a virtualized resource at a host of a provider network, including endpoint address information and a traffic metric, is determined at a metering component. The metadata is aggregated at another metering component and provided to a traffic classification node. The traffic classification node generates a categorized usage record for the network transmission, based at least in part on network topology information associated with the provider network. The categorized usage record is used to determine a billing amount for the network transmission.

Abstract: A technique for processing instructions in an electronic system is provided. In one embodiment, a processor of the electronic system may submit a unit of work to a queue accessible by a coprocessor, such as a graphics processing unit. The coprocessor may process work from the queue, and write a completion record into a memory accessible by the processor. The electronic system may be configured to switch between a polling mode and an interrupt mode based on progress made by the coprocessor in processing the work. In one embodiment, the processor may switch from an interrupt mode to a polling mode upon completion of a threshold amount of work by the coprocessor. Various additional methods, systems, and computer program products are also provided.

Abstract: Systems and methods are disclosed to enable switching of graphics processing unit (GPU) resources based on different factors. Embodiments include a virtual graphics driver as an interface between GPU drivers and the applications or graphics framework executing on an electronic device. The virtual graphics driver may switch GPU resources from a first GPU to a second GPU by routing function calls to the first GPU or the second GPU. The switching of GPU resources may be based on power management, system events such as hot-plug events, load management, user requests, any other factor, or any combination thereof. In some embodiments, a virtual frame buffer driver is provided that interfaces with the frame buffer of the GPU and provides a virtual view of the frame buffer to manage additional system application programming interfaces (APIs) during the switch.

Abstract: Systems and methods are disclosed to enable switching of graphics processing unit (GPU) resources based on different factors. Embodiments include a virtual graphics driver as an interface between GPU drivers and the applications or graphics framework executing on an electronic device. The virtual graphics driver may switch GPU resources from a first GPU to a second GPU by routing function calls to the first GPU or the second GPU. The switching of GPU resources may be based on power management, system events such as hot-plug events, load management, user requests, any other factor, or any combination thereof. In some embodiments, a virtual frame buffer driver is provided that interfaces with the frame buffer of the GPU and provides a virtual view of the frame buffer to manage additional system application programming interfaces (APIs) during the switch.

Abstract: A method and electronic device employing the method of processing a frame of graphics for display is provided that includes developing a frame in a first software frame processing stage following a first vertical blanking (VBL) heartbeat, issuing a command indicating the first stage is complete, and performing a final software frame processing stage without waiting for a subsequent VBL heartbeat. The method may alternatively include performing the final software frame processing stage regardless as to whether a target framebuffer is available, performing all but final hardware frame processing stages regardless as to whether the target framebuffer is in use, and performing the final hardware processing stage if the target framebuffer is not in use.

Abstract: Techniques are provided for encoding an extended image such that it is backwards compatible with existing decoding devices. An extended image format is defined such that the extended image format is consistent with an existing image format over the full range of the existing image format. Because the extended image format is consistent with the existing image format over the full range of the existing image format, additional image information that is included in an extended image can be extracted from the extended image. A base version of an image (expressed using the existing image format) may be encoded in a payload portion and the extracted additional information may be stored in a metadata portion of a widely supported image file format.

Abstract: Systems, methods, and devices for maintaining cache coherence between two or more heterogeneous processors are provided. In accordance with one embodiment, such an electronic device may include memory, a first processing unit having a first characteristic memory usage rate, and a second processing unit having a second characteristic memory usage rate lower than the first. The first and second processing units may share at least a portion of the memory and one or both of the first and second processing units may maintain internal cache coherence at a first granularity, while maintaining cache coherence between the first processing unit and the second processing unit at a second granularity. The first granularity may be finer than the second granularity.

Abstract: Techniques are provided for encoding an extended image such that it is backwards compatible with existing decoding devices. An extended image format is defined such that the extended image format is consistent with an existing image format over the full range of the existing image format. Because the extended image format is consistent with the existing image format over the full range of the existing image format, additional image information that is included in an extended image can be extracted from the extended image. A base version of an image (expressed using the existing image format) may be encoded in a payload portion and the extracted additional information may be stored in a metadata portion of a widely supported image file format.

Abstract: Media is usually encoded using a non-linear transfer function that approximates human perception to more efficiently allocate codes to areas of dynamic range where human observers are more easily able to perceive differences in signal strength. Many common media operations, e.g., scaling, rotating, and gamut converting, must be performed in a linear representation to be correct and artifact-free. The non-linear transfer functions used are often pure-power functions, such as “gamma” functions. To avoid banding after transformation, as many as 17 bits are needed in the linear-space with 8-bit input. Thus, methods, computer readable media, and systems for reducing the number of bits required in the linear domain are described herein that substitute a piecewise linear function (e.g., a line segment followed by an offset curve) for a pure-power gamma function, such that a slope limit is applied to constrain the number of (additional) linear bits required (over the input precision).

Abstract: Techniques are provided for encoding an extended image such that it is backwards compatible with existing decoding devices. An extended image format is defined such that the extended image format is consistent with an existing image format over the full range of the existing image format. Because the extended image format is consistent with the existing image format over the full range of the existing image format, additional image information that is included in an extended image can be extracted from the extended image. A base version of an image (expressed using the existing image format) may be encoded in a payload portion and the extracted additional information may be stored in a metadata portion of a widely supported image file format.

Abstract: Techniques are provided for encoding an extended image such that it is backwards compatible with existing decoding devices. An extended image format is defined such that the extended image format is consistent with an existing image format over the full range of the existing image format. Because the extended image format is consistent with the existing image format over the full range of the existing image format, additional image information that is included in an extended image can be extracted from the extended image. A base version of an image (expressed using the existing image format) may be encoded in a payload portion and the extracted additional information may be stored in a metadata portion of a widely supported image file format.

Abstract: Psychovisual image compression techniques are disclosed that compress pixel data by a fixed compression ratio with little or no perceptual loss of detail. In some implementations, a psychovisual compression process is selected among several psychovisual compression processes based on characteristics of the pixel data. Compression is achieved during encoding by discarding psychovisually unnecessary bits from the pixel data. The psychovisual compression processes can be implemented in hardware and operate on scan lines of pixels captured by the image sensor. The psychovisual compression techniques can be used with image compression techniques to compress further the pixel data.

Abstract: Systems, methods, and devices for dynamically mapping and remapping memory when a portion of memory is activated or deactivated are provided. In accordance with an embodiment, an electronic device may include several memory banks, one or more processors, and a memory controller. The memory banks may store data in hardware memory locations and may be independently deactivated. The processors may request the data using physical memory addresses, and the memory controller may translate the physical addresses to hardware memory locations. The memory controller may use a first memory mapping function when a first number of memory banks is active and a second memory mapping function when a second number is active. When one of the memory banks is to be deactivated, the memory controller may copy data from only the memory bank that is to be deactivated to the active remainder of memory banks.

Abstract: Exemplary embodiments of methods, apparatuses, and systems for seamlessly migrating a user visible display stream sent to a display device from one rendered display stream to another rendered display stream are described. For one embodiment, mirror video display streams are received from both a first graphics processing unit (GPU) and a second GPU, and the video display stream sent to a display device is switched from the video display stream from the first GPU to the video display stream from the second GPU, wherein the switching occurs during a blanking interval for the first GPU that overlaps with a blanking interval for the second GPU.

Abstract: A display mode can be selected by identifying a plurality of display modes supported by a media client, wherein the plurality of display modes comprise safe modes; sequentially selecting a display mode from the plurality of display modes, wherein the plurality of display modes are ordered according to one or more of resolution, timing, and popularity; generating an output signal based on the selected display mode, wherein the generated output signal is provided to a display device; and selectively repeating the sequential selection of a display mode and generating an output signal based on the selected display mode until an input is received from a user indicating that the selected display mode is compatible with the display device. Further, the media client can be configured to utilize the selected display mode. Additionally, the plurality of display modes can be identified based on extended display identification data from the display device.

Abstract: A display mode can be selected by identifying a plurality of display modes supported by a media client, wherein the plurality of display modes comprise safe display modes; generating a user interface including a test image and a plurality of commands in accordance with a selected display mode of the plurality of display modes, wherein the user interface is output to a display device; receiving user input selecting one of the plurality of commands; and configuring an operating display mode of the media client in accordance with the received user input. Configuring an operating display mode further can comprise determining that the received user input confirms the selected display mode and configuring the media client to set the selected display mode as the operating display mode. Further, generating a user interface can comprise presenting a display timer indicating a time remaining until a display mode change.