Video compression with intra/inter mode switching and a dual frame buffer

Video codecs that use motion compensation have achieved performance improvements from the use of intra/inter mode switching decisions within a rate-distortion framework. A separate development has involved the use of multiple frame prediction, in which more than one past reference frame is available for motion estimation. It is shown that using a dual frame buffer, together with intra/inter mode switching improves the compression performance of the coder. Also, the mode switching algorithm is improved with the use of half-pel motion vectors.