Abstract: The technology described herein relates to a method of generating an encoded output video frame for transmission to an electronic display in which an encoded source video frame is decoded to obtain a decoded source video frame 200a, the decoded source video frame 200a is processed to obtain an input video frame 200c, and the input video frame 200c is encoded to obtain an encoded output video frame for transmission.

Abstract: A display controller provides an output frame to a display for display by sending respective output surface regions that together form the output frame, each respective region of the output surface being generated from a respective region or regions of one or more input surfaces, to the display. When a new version of an output surface region is generated, the display controller determines whether the output surface region has been unchanged for a period, and if it has, then stores the generated output surface region in a frame buffer. Then, for the subsequent frame, checks are performed to see if the output surface region could have changed. If there is no change the stored version of the output surface region is reused, but if there is a change in the output surface region, the output surface region is regenerated.

Abstract: In a data processing system, an output surface, such as frame to be displayed, is generated as a plurality of respective regions with each respective region of the output surface being generated from a respective region or regions of one or more input surfaces. When a new version of the output surface is to be generated 80, for each region of the output surface it is determined which region or regions of the input surface or surfaces contribute to the region of the output surface 84 and then checked whether the contributing region or regions of the input surface or surfaces have changed since the previous version of the output surface region was generated 85. If there has been a change in the contributing region or regions of the input surface or surfaces since the previous version of the region in the output surface was generated 86, the region of the output surface is regenerated 87.

Abstract: In a compositing window system, as a respective version of the window for an application is written into a window buffer, a corresponding set of per tile signatures indicative of the content of each respective tile in the window buffer is generated and stored. When an updated version of the window is stored into a window buffer, the set of signature values for the updated version is compared to the set of signature values for the previous version in the window buffer to determine which tiles' content has changed. The set of tiles found to have changed is used to generate a set of regions for a window compositor to write to a window in a display frame buffer to update the window in the display frame buffer to display the new version of the window.