The invention relates to low density parity check decoding. A method for decoding an encoded data block is described. Encoded data block comprising data sub-blocks are stored. Decoding is performed in a pipelined manner using an irregular, block- structured parity check matrix, where at least two data sub-block matrices of the parity check matrix are read from and written in each of a plurality of clock cycles. The reading and writing of the data sub-blocks is evenly distributed between at least two area of a memory. The decoding is performed with shift values which eliminate cycles at or below a predetermined threshold length. An apparatus, computer program product and device are also described.