Intra block walk around refresh for H.264

摘要

The disclosed video encoding system provides for a way of correcting divergence of a reference block in a decoder while minimizing the overhead required to update the reference block. The H.264 standard articulates that only macroblocks within the same slice group may be spatially predicted off one another. A map describing which slice group each macroblock in the frame is assigned to may be sent according to H.264. By sending a map placing a small subset of macroblocks in one slice group and the remainder of the macroblocks in one or more other slice groups, one can produce the effect of isolating the refresh blocks of the picture from blocks that exploit image redundancies. Further, by sending a different map for each transmitted frame, each map corresponding with the macroblocks to be intra refreshed in that frame, the effect of gradually refreshing all parts of the image can be achieved. By assigning a different frame index to each transmitted map, the map description only needs to be sent once at the start of the communication. The result is an efficiently transmitted self-correcting video sequence with only the additional channel overhead of sending the plurality of refresh maps at the start of the communication.