Abstract: In some implementations, a method of synchronizing a content generation and delivery architecture to reduce the latency associated with image passthrough. The method includes: determining a temporal offset associated with the content generation and delivery architecture to reduce a photon-to-photon latency across the content generation and delivery architecture; obtaining a first reference rate associated with a portion of the content generation and delivery architecture; generating, via synchronization circuitry, a synchronization signal for the content generation and delivery architecture based at least in part on the first reference rate; and operating the content generation and delivery architecture according to the synchronization signal and the temporal offset.

Abstract: An electronic device includes a wireless transceiver configured to receive content primitives via a wireless communication channel. The electronic device also includes control circuitry control circuitry coupled to the wireless transceiver, and configured to perform content provisioning operations based on the received content primitives, wherein the content provisioning operations comprise generating content image data and transmitting the content image data to the wireless communication channel using the wireless transceiver. In response to a bandwidth condition of the wireless communication channel being less than a threshold, the control circuitry is configured to perform adjusted content provisioning operations that decrease an amount of content image data conveyed by the wireless transceiver to the wireless communication channel.

Abstract: A mobile device includes a display, at least one sensor, and a wireless transceiver. The mobile device also includes control circuitry coupled to the display, the at least one sensor, and the wireless transceiver. The control circuitry is configured to obtain content primitives from the at least one sensor, to perform content provisioning operations to obtain content based at least in part on the content primitives, and to display the obtained content on the display, wherein at least some of the content is virtual content. In response to a bandwidth condition of the wireless communication channel being less than a threshold, the control circuitry is configured to perform adjusted content provisioning operations that involve increasing an amount of image processing operations performed by the mobile device to obtain the content.

Abstract: An electronic device includes a wireless transceiver configured to receive content primitives via a wireless communication channel. The electronic device also includes control circuitry control circuitry coupled to the wireless transceiver, and configured to perform content provisioning operations based on the received content primitives, wherein the content provisioning operations comprise generating content image data and transmitting the content image data to the wireless communication channel using the wireless transceiver. In response to a bandwidth condition of the wireless communication channel being less than a threshold, the control circuitry is configured to perform adjusted content provisioning operations that decrease an amount of content image data conveyed by the wireless transceiver to the wireless communication channel.

Abstract: Various implementations disclosed herein include devices, systems, and methods that dynamically-size zones used in foveated rendering of content that includes text. In some implementations, this involves adjusting the size of a first zone, e.g., a foveated gaze zone (FGZ), based on the apparent size of text from a viewpoint. For example, a FGZ may be increased or decreased in width, height, diameter, or other size attribute based on determining an angle subtended by one or more individual glyphs of the text from the viewpoint. Various implementations disclosed herein include devices, systems, and methods that select a text-rendering algorithm based on a relationship between (a) the rendering resolution of a portion of an image corresponding to a part of a glyph and (b) the size that the part of the glyph will occupy in the image.

Abstract: One exemplary implementation involves performing operations at an electronic device with one or more processors and a computer-readable storage medium. The device establishes a wireless communication link with a host device. The device receives, from the host device, a left eye frame and a right eye frame via a sequence of left eye frame transmissions and right eye frame transmissions. The device switches data transmissions schemes according to wireless commination link quality or eye gaze tracking. Adjusting transmission format based on transmission quality of the wireless communication link allows the devices to take advantage of greater bandwidth when available to save power. An additional transmission format is based on alternately transmitting left eye and right eye frames for very low bandwidth.

Abstract: One exemplary implementation involves performing operations at an electronic device with one or more processors and a computer-readable storage medium. The device establishes a wireless communication link with a host device. The device receives, from the host device, a left eye frame and a right eye frame via a sequence of interleaved left eye frame transmissions and right eye frame transmissions. The device loads the left eye frame into a left eye display device and loads the right eye frame into a right eye display device on the electronic device, where the loading includes sequentially loading left eye frame portions and right eye frame portions as the sequence of interleaved left eye frame transmissions and right eye frame transmissions is received. The device then concurrently displays the left eye frame and the right eye frame at the electronic device. The device switches data transmissions schemes according to wireless communication link quality and eye gaze tracking.

Abstract: Various implementations disclosed herein include devices, systems, and methods that dynamically-size zones used in foveated rendering of content that includes text. In some implementations, this involves adjusting the size of a first zone, e.g., a foveated gaze zone (FGZ), based on the apparent size of text from a viewpoint. For example, a FGZ may be increased or decreased in width, height, diameter, or other size attribute based on determining an angle subtended by one or more individual glyphs of the text from the viewpoint. Various implementations disclosed herein include devices, systems, and methods that select a text-rendering algorithm based on a relationship between (a) the rendering resolution of a portion of an image corresponding to a part of a glyph and (b) the size that the part of the glyph will occupy in the image.

Abstract: An electronic device may have a camera and a display. The display may be configured to display virtual reality content for a user in which no real-world content from the camera is displayed or mixed reality content in which a combination of real-world content from the camera and overlaid virtual reality content is displayed. Control circuitry in the device may adjust the display and camera while transitioning between virtual reality and mixed reality modes. The control circuitry may reconfigure the camera to exhibit a desired frame rate immediately upon transitioning from virtual reality mode to mixed reality mode. Transitions between modes may be accompanied by smooth transitions between frame rates to avoid visible artifacts on the display. The camera frame rate may be synchronized to the display frame rate for at least part of the transition between the virtual reality and mixed reality modes.

Abstract: An electronic device may have a camera and a display. The display may be configured to display virtual reality content for a user in which no real-world content from the camera is displayed or mixed reality content in which a combination of real-world content from the camera and overlaid virtual reality content is displayed. Control circuitry in the device may adjust the display and camera while transitioning between virtual reality and mixed reality modes. The control circuitry may reconfigure the camera to exhibit a desired frame rate immediately upon transitioning from virtual reality mode to mixed reality mode. Transitions between modes may be accompanied by smooth transitions between frame rates to avoid visible artifacts on the display. The camera frame rate may be synchronized to the display frame rate for at least part of the transition between the virtual reality and mixed reality modes.

Abstract: An electronic device includes a wireless transceiver configured to receive content primitives via a wireless communication channel. The electronic device also includes control circuitry control circuitry coupled to the wireless transceiver, and configured to perform content provisioning operations based on the received content primitives, wherein the content provisioning operations comprise generating content image data and transmitting the content image data to the wireless communication channel using the wireless transceiver. In response to a bandwidth condition of the wireless communication channel being less than a threshold, the control circuitry is configured to perform adjusted content provisioning operations that decrease an amount of content image data conveyed by the wireless transceiver to the wireless communication channel.

Abstract: A mobile device includes a display, at least one sensor, and a wireless transceiver. The mobile device also includes control circuitry coupled to the display, the at least one sensor, and the wireless transceiver. The control circuitry is configured to obtain content primitives from the at least one sensor, to perform content provisioning operations to obtain content based at least in part on the content primitives, and to display the obtained content on the display, wherein at least some of the content is virtual content. In response to a bandwidth condition of the wireless communication channel being less than a threshold, the control circuitry is configured to perform adjusted content provisioning operations that involve increasing an amount of image processing operations performed by the mobile device to obtain the content.

Abstract: A method and system for message passing which weights messages in a queue by urgency of consumption. A timestamp indicating the urgency of consumption may be assigned to a message, and messages may be automatically re-ordered based on their timestamps, following a first-in-weighted-out (FIWO) logic. Such a schedule-driven auto-reordered message passing system may provide increased efficiency, lower latency and is independent of the configuration of memory types.

Abstract: Ephemeral data stored in a cache is read when needed but is not written to system memory so as to save power and bandwidth. In an embodiment, a no-writeback bit associated with the ephemeral data is set in response to a read-no-writeback instruction. Data in a cache line for which its no-writeback bit has been set is not written back into system memory. Accordingly, when evicting cache lines, if a cache line has a no-writeback bit set, then the data in that cache line is discarded without being written back to system memory.

Abstract: Systems, methods, and computer programs are disclosed for reducing power consumption for static image display refresh in a dynamic random access memory (DRAM) memory system. One such method comprises: prefetching static image frame content from a DRAM memory device into a system cache; during a static display refresh operation, a display processor reads the static image frame content from the system cache while the DRAM memory device is in a power-saving, self-refresh state; and the display processor feeding the static image frame content to a mobile display.

Abstract: Devices and methods for monitoring one or more central processing units in real time are disclosed. The method may include monitoring state data associated with the one or more CPUs in real-time, filtering the state data, and at least partially based on filtered state data, selectively altering one or more system settings. A device may include means for monitoring state data associated with the one or more CPUs in real-time, means for filtering the state data, and means for selectively altering one or more system settings at least partially based on filtered state data. A device may also include a sub-sampling circuit configured to receive a hardware core signal from the central processing unit and output a central processing unit state indication, and an infinite impulse response filter connected to the sub-sampling circuit and configured to receive the central processing unit state indication from the sub-sampling circuit.

Abstract: Devices, systems, methods, and computer-readable mediums for arbitrating bus transactions on a communications bus based on health information are disclosed. Health information of master devices can be used to adjust priorities of bus transactions from master devices to meet quality of service requirements of the master devices. In one embodiment, a bus interconnect is provided and configured to communicate bus transactions from any of a plurality of master devices to slave device(s) coupled the bus interconnect. The bus interconnect is further configured to map health information for each of the plurality of master devices into virtual priority space. The bus interconnect is further configured to translate the virtual priority space into a physical priority level for each of the plurality of master devices. The bus interconnect is further configured to arbitrate bus transactions for the plurality of master devices based on physical priority level for the plurality of master devices.

Abstract: A method and system for message multicasting which provides a programmable persistent header in a message to allow one message to be read by multiple target consumers and to ensure that the message passing mechanism does not delete the message until all target consumers have received it. The persistent header may have information about all target consumers and their priority to consume the message. A message parser may obtain from the persistent header identities of target consumers and the order in which they consume the message and allow target consumers to consume the message following the order. The message parser may have a counter which counts the number of consumers that have consumed the message, and keep the message in the queue until all target consumers have consumed the message.

Abstract: An embodiment of the present invention includes a multi-core processor that processes video data. The control core controls a first processing core to process a first set of data blocks of an image frame according to a stairstep pattern. The control core detects, while the first processing core is processing the first set, that a triggering data block has been processed in the first set. The control core controls, while the first processing core is processing the first set, a second processing core to process a second set of data blocks using information from the triggering data block. By processing data blocks in the stairstep pattern, cache hit rate is improved, resulting in improved video decoder performance.

Abstract: A system including an image data source and a transfer function module. The image data source is configured to provide image data. The transfer function module is configured to generate a transfer function to process the image data, define a first region of the transfer function, wherein a curvature of the transfer function in the first region is less than or equal to a threshold, define a second region of the transfer function, wherein a curvature of the transfer function in the second region is greater than the threshold, allocate a first number of sample inputs to the first region, allocate a second number of the sample inputs to the second region, wherein the second number is greater than the first number, map the sample inputs to sample outputs using the transfer function, and populate entries of a lookup table with the sample outputs.