Encoding apparatus for signaling an extension directional intra-prediction mode within a set of directional intra-prediction modes

Abstract

An encoding apparatus is described for signaling an extension directional intra-prediction mode within a set of directional intra-prediction modes, the set of directional intra-prediction modes comprising predetermined directional intra-prediction modes and the extension directional intra-prediction mode. The encoding apparatus comprises a mode mapping unit selecting a predetermined directional intra-prediction mode, the selected predetermined directional intra-prediction mode being associated with an intra mode index, and mapping the extension directional intra-prediction mode onto the selected predetermined directional intra-prediction mode. A signaling unit generates a signaling indicator comprising at least one of the intra mode index and a flag value. An intra-prediction unit intra-predicts pixel values of pixels of a rectangular video coding block on the basis of the extension directional intra-prediction mode for providing a predicted rectangular video coding block. An encoding unit encodes the rectangular video coding block on the basis of the predicted rectangular video coding block.