Patent ID: 8296156

Claim:
A method for decoding a signal, comprising: receiving a down-mix signal from an input bitstream; receiving spatial information and down-mix identification information from the input bitstream, the down-mix identification information indicating whether the down-mix signal is a compatible down-mix signal optimized for a first multi-channel decoder; if the down-mix identification information indicates that the down-mix signal is the compatible down-mix signal, converting the compatible down-mix signal into a down-mix signal optimized for a second multi-channel decoder by performing a compatibility processing operation on the compatible down-mix signal; and generating a three-dimensional (3D) down-mix signal by performing a 3D rendering operation on the converted down-mix signal using a head related transfer function (HRTF) and the spatial information, wherein the spatial information includes at least one of a channel level difference (CLD) which indicates level differences between two channels, a channel prediction coefficient (CPC) which is a prediction coefficient used to generate a 3-channel signal based on a 2-channel signal, and inter-channel correlation (ICC) which indicates the amount of correlation between two channels.