1. A method comprising:
receiving coded pictures of a first scalability layer;
decoding the coded pictures of the first scalability layer;
receiving coded pictures of a second scalability layer, the second scalability layer depending on the first scalability layer;
selecting a layer access picture on the second scalability layer from the coded pictures of the second scalability layer, wherein the selected layer access picture is a step-wise temporal sub-layer access (STSA) picture on a lowest temporal sub-layer, wherein receiving coded pictures of the second scalability layer comprises receiving the STSA [ step-wise temporal sub-layer access ] picture on the lowest sub-layer in a Supplemental Enhancement Information (SEI) [ supplemental enhancement information ] message that also defines a number of sub-layers that are decodable when the decoding starts from the selected layer access picture;
ignoring coded pictures on a [ the ] second scalability layer prior to, in decoding order, the selected layer access picture;
decoding the selected layer access picture; and
starting step-wise decoding of at least one enhancement layer in response to said at least one enhancement layer containing an intra random access point (IRAP) picture or an STSA [ a step-wise temporal sub-layer access ] picture on the lowest sub-layer, wherein starting step-wise decoding comprises:
when the [ a ] current picture is a temporal sub-layer access (TSA) or STSA [ step-wise temporal sub-layer access ] picture at a higher sub-layer than the lowest sub-layer and decoding of the next lower sub-layer in the same layer has been started, and decoding of the same sub-layer of all the reference layers of the TSA [ temporal sub-layer access ] or STSA [ step-wise temporal sub-layer access ] picture has been started, the TSA [ temporal sub-layer access ] or STSA [ step-wise temporal sub-layer access ] picture and all pictures at the same sub-layer following the TSA [ temporal sub-layer access ] or STSA [ step-wise temporal sub-layer access ] picture, in decoding order, in the same layer are decoded.
