Video encoder with context switching

Abstract

A context switching method for video encoders that enables higher priority video streams to interrupt lower priority video streams. A high priority frame may be received for processing while another frame is being processed. The pipeline may be signaled to perform a context stop for the current frame. The pipeline stops processing the current frame at an appropriate place, and propagates the stop through the stages of the pipeline and to a transcoder through DMA. The stopping location is recorded. The video encoder may then process the higher-priority frame. When done, a context restart is performed and the pipeline resumes processing the lower-priority frame beginning at the recorded location. The transcoder may process data for the interrupted frame while the higher-priority frame is being processed in the pipeline, and similarly the pipeline may begin processing the lower-priority frame after the context restart while the transcoder completes processing the higher-priority frame.