Patent ID: 8730251

Claim:
A method for driving a display in a computer system, comprising: receiving an input video stream from a graphics source, wherein the input video stream comprises a sequence of video frames; directing the input video stream through a set of two or more memory buffers including a front buffer and a back buffer to produce an output video stream; wherein directing the input video stream through the set of memory buffers involves, writing a video frame from the input video stream into the back buffer, concurrently driving the output video stream from a preceding video frame in the front buffer, and when the writing of the video frame completes, switching buffers so that the back buffer becomes the front buffer, which drives the output video stream, and the front buffer becomes either a spare buffer or the back buffer, which receives a subsequent frame from the input video stream; and using the output video stream to drive the display; if the input video stream goes offline, temporarily halting the switching of the buffers, and continuing to drive the output video stream from the front buffer until the input video stream comes back online, wherein the method further comprises switching input video streams by: receiving a second input video stream from a second graphics source; and performing a switching operation to direct the second input video stream through the set of memory buffers instead of the input video stream, and while the switching operation is in progress, temporarily halting the switching of the buffers and continuing to drive the output video stream from the front buffer until the switching operation completes, wherein after the switching operation completes, if the switching operation introduced a buffering time lag between the input video stream and the output video stream, the method further comprises reducing the time lag during successive video frames until the time lag is eliminated.