US Patent 7295613 Early detection of zeros in the transform domain

A method detects blocks that are to be indicated as skipped at an earlier stage of the encoding process, than would be the case with other implementations of the ITU H.263 and H.264 standards. The method includes transforming 4×4 blocks in the macro blocks having a skip vector of zero with a binary-transform function. The blocks having values of the four uppermost left binary-transform coefficients less than a predefined threshold, are defined as skipped, thus, minimizing the need for computationally demanding block transformation or quantization.