Coding, transcoding and iterative filtering methods and apparatus are described wherein a 2D FIFO is used to implement CACLA processing, and wherein the processing methods are block-oriented. A block-by-block processed input image or input coded image, which is delayed in an arbitrary number of lines and columns, is provided such that the output image is produced in a block-by-block schedule at a reduced or minimal memory access and memory size cost. A 2D FIFO which is memory-efficient in image block coding and decoding applications is described. The 2D FIFO has an associated scheduling mechanism for enabling delay of a block-by-block coded input signal, such as an image, in an arbitrary number of lines and columns, such that the output image is produced in a block-by-block schedule.