A method for video coding, comprising: encoding received pictures into coded pictures, the coded pictures being divided into slices comprising an integer number of coding units, encoding a syntax structure for an idle reference picture list, and at least one of a reference picture list 0 and a reference picture list 1, said reference picture lists being constructed from a reference picture list description syntax structure, which includes an idle reference picture list description for any slices including those reference pictures that are not included in either reference picture list 0 or 1 but are still to be kept marked as "used for reference", and at least one of reference picture list 0 description for P and B slices and reference picture list 1 description for B slices, reconstructing the encoded pictures to a memory for storing the reconstructed pictures in the reference picture list 0, the reference picture list 1, or the idle reference picture list, characterised in that the method further comprises marking pictures in any of the reference picture list 0, the reference picture list 1 and the idle reference picture list as "used for reference", wherein those pictures are therefore available as reference pictures for encoding of a subsequent picture, marking reconstructed pictures which are not in any of the reference picture list 0, the reference picture list 1 and the idle reference picture list as "unused for reference", and if a picture is marked as "unused for reference" and has already been encoded, removing the picture from the memory or re-using the memory space used for the picture for another picture, encoding a current picture using one or more reference pictures from the reference picture list 0 or the reference picture list 1, but not from the idle reference picture list. encoding received pictures into coded pictures, the coded pictures being divided into slices comprising an integer number of coding units, encoding a syntax structure for an idle reference picture list, and at least one of a reference picture list 0 and a reference picture list 1, said reference picture lists being constructed from a reference picture list description syntax structure, which includes an idle reference picture list description for any slices including those reference pictures that are not included in either reference picture list 0 or 1 but are still to be kept marked as "used for reference", and at least one of reference picture list 0 description for P and B slices and reference picture list 1 description for B slices, reconstructing the encoded pictures to a memory for storing the reconstructed pictures in the reference picture list 0, the reference picture list 1, or the idle reference picture list, characterised in that the method further comprises marking pictures in any of the reference picture list 0, the reference picture list 1 and the idle reference picture list as "used for reference", wherein those pictures are therefore available as reference pictures for encoding of a subsequent picture, marking reconstructed pictures which are not in any of the reference picture list 0, the reference picture list 1 and the idle reference picture list as "unused for reference", and if a picture is marked as "unused for reference" and has already been encoded, removing the picture from the memory or re-using the memory space used for the picture for another picture, encoding a current picture using one or more reference pictures from the reference picture list 0 or the reference picture list 1, but not from the idle reference picture list.