Method for signaling a step-wise temporal sub-layer access sample

A method for decoding a picture, the method comprising:

• receiving an audio-visual bitstream, the audio-visual bitstream comprising a plurality of samples corresponding to one or more encoded pictures, a sample being assigned to a respective temporal layer, wherein the plurality of samples includes one or more step-wise temporal sub-layer access (STSA) samples, wherein an STSA sample is a sample that represents a point in the audio-visual bitstream at which a decoder is configured to perform a step-wise switch to decoding samples at a temporal layer that is one step higher than the temporal layer to which the STSA sample is assigned, and wherein the temporal layer that is one step higher is a temporal layer with a temporal identifier that is one temporal ID greater than a temporal identifier of the temporal layer to which the STSA sample is assigned;
• obtaining, from the plurality of samples, an STSA sample grouping, wherein the STSA sample grouping is a group of STSA samples from the plurality of samples sent in a sample group description box (SGDP) that includes a next STSA upswitching distance parameter, wherein the next STSA upswitching distance parameter indicates when a next STSA temporal layer switching point will occur in a higher temporal layer from a current sample of the plurality of samples that is assigned to a current temporal layer, wherein the higher temporal layer is a temporal layer with a temporal identifier that is one temporal ID greater than a temporal identifier of the current temporal layer, wherein the next STSA temporal layer switching point in the higher temporal layer is an STSA sample assigned to the higher temporal layer that indicates that the decoder can start decoding samples assigned to a temporal layer that is one step higher than the higher temporal layer;
• decoding the STSA sample grouping;
• and
• determining, based at least on the next STSA upswitching distance parameter, when to switch to a new temporal layer based on the STSA sample grouping.