Method and apparatus for encoding and decoding a video. A method and an apparatus for encoding a video are disclosed. Such a method comprises, for at least one block having a size N which is not a power of 2 along at least one dimension: —determining (40) a predicted block for said at least one block, —obtaining (41) a residual block from said at least one block and said predicted block, —performing (42) block transform of said residual block, said residual block having a size N, —encoding (43) said transformed residual block. Corresponding method and apparatus for decoding a video are also disclosed.