Encoding or decoding digital video frames in intra-prediction mode by selecting column reference data locations for blocks adjacent a current block from a column reference data buffer storing column reference data samples for no more than two macro blocks of the frame. In some cases, the column reference data buffer may include a storage size for samples of a first column of data of blocks of one macro block of luminance samples. Encoding and decoding may also include selecting row reference data locations for blocks adjacent a current block from a row reference data buffer storing row reference data samples for at least one row of macro blocks of the frame. In some cases, the row reference data buffer may include storage for samples of a first row of data of fourteen successive blocks spanning two rows. The concept can be applied to various video processing components and standards.