Techniques for block wise encoding and decoding may be applied to encoders, decoders, and methods for encoding or decoding. In one example, there is provided a technique to decode or encode a predetermined block of the picture by assigning, based on a first signalization in the data stream, the predetermined block to a first set or a second set; sorting the assigned set of intra-prediction modes according to intra-prediction modes used for neighboring blocks, neighboring the predetermined block, to obtain a list of intra prediction modes; deriving, for the predetermined block, from the data stream, an index into the list of intra prediction modes; and predicting the predetermined block using an intra prediction mode onto which the index points. The decoder or encoder, if the assigned set is the first set of intra-prediction modes, in sorting the assigned set, uses a second mapping which maps each intra-prediction mode of the second set of prediction modes onto a representative one in the first set of intra-prediction modes.