Efficient Large Size Transforms for High-Performance Video Coding

This paper describes design of transforms for extended block sizes for video coding. The proposed transforms are orthogonal integer transforms, based on a simple recursive factorization structure, and allow very compact and efficient implementations. We discuss techniques used for finding integer and scale factors in these transforms, and describe our final design. We evaluate efficiency of our proposed transforms in VCEG's H.265/JMKTA framework, and show that they achieve nearly identical performance compared to much more complex transforms in the current test model.