Method for Decoding and Encoding a Downmix Matrix, Method for Presenting Audio Content, Encoder and Decoder for a Downmix Matrix, Audio Encoder and Audio Decoder

WO15058991A1 [EN] A method is described which decodes a downmix matrix (306) for mapping a plurality of input channels (300) of audio content to a plurality of output channels (302), the input and output channels (300, 302) being associated with respective speakers at predetermined positions relative to a listener position, wherein the downmix matrix (306) is encoded by exploiting the symmetry of speaker pairs (S1-S9) of the plurality of input channels (300) and the symmetry of speaker pairs (S10-S11) of the plurality of output channels (302). Encoded information representing the encoded downmix matrix (306) is received and decoded for obtaining the decoded downmix matrix (306)