Patent ID: 7840411

Claim:
A multi-channel audio encoder for encoding an N-channel audio signal, the multi-channel audio encoder comprising: a down-mixer, coupled to receive the N-channel audio signal, for generating a first M-channel signal, M being smaller than N; an encoder, also coupled to receive said N-channel audio signal, for generating first enhancement data for the first M-channel signal relative to the N-channel audio signal; means for generating a second M-channel signal for the N-channel audio signal; a generator coupled to receive the first M-channel signal and the second M-channel signal for generating second enhancement data for the second M-channel signal relative to the first M-channel signal; and an output for supplying an encoded output signal comprising the second M-channel signal, the first enhancement data and the second enhancement data, wherein the generator dynamically selects between generating the second enhancement data as absolute enhancement data or as relative enhancement data relative to the second M-channel signal.