AUDIO DIRECTIVITY CODING

An apparatus for decoding audio metadata displaced in different directions associated with discrete positions on a unit sphere, which is displaced according to parallel lines from an equatorial line towards a poles, comprises:a bitstream reader reading prediction residual values;a prediction section receiving the audio metadata from prediction residual values of the audio metadata using a plurality of prediction sequences, which include:an initial prediction sequence, along a line of adjacent discrete positions, predicting the audio metadata based on the immediately preceding audio metadata in the same initial predictions sequence; andsubsequent prediction sequences, divided among subsequences, each moving along a parallel line and being adjacent to a previously predicted parallel line, such that audio metadata along a parallel line being processed are predicted based on at least:audio metadata of the adjacent discrete positions in the same subsequence; andinterpolated versions of the already predicted audio metadata.