Video processing systems

Video processing wherein a host processor sends a configuration message to a video encoder indicating to the video encoder 3 how to encode a video frame 7 and including information indicating the location of encoding configuration data stored in a memory. Video encoder receives the configuration message, uses the location indicating information to read the encoding configuration data from the memory, and encodes the video frame in accordance with the encoding configuration data read from the memory. The configuration message 41 may include a frame parameter record 32 containing information on how to encode the frame as a whole. Preferably, the configuration data stored in the memory includes data indicating how multiple tiles or sub-regions 9 of the image data 7 should be encoded. In embodiments, the configuration messages uses run-length encoding 44 to communicate a memory location for each frame sub-region 9, allowing efficient messaging of encoding configurations in various regions of interest formed of multiple sub-region tiles. Other independent claims are for video processing in which the host processor sends a configuration message to the encoder including instructions to be executed by the encoder firmware to generate configuration data that is used to encode video frames.