Patent ID: 8346380

Claim:
A method of processing a signal, comprising: receiving (a) a downmix signal being generated from a plural-channel signal and (b) spatial information indicating attributes of the plural-channel signal in order to upmix the downmix signal and including a phase shift flag indicating whether a phase of a frame of at least one channel of the plural-channel signal is shifted; obtaining an inter-channel phase difference (IPD) coding flag indicating whether an IPD value is used in the spatial information from a header of the spatial information; obtaining an IPD mode flag indicating whether the IPD value is used in a frame of the spatial information from the frame based on the IPD coding flag; obtaining the IPD value corresponding to a parameter band in the frame, based on the IPD mode flag; upmixing the plural-channel signal by applying the IPD value to the downmix signal; and shifting the phase of the frame of the at least one channel of the plural-channel signal based on the phase shift flag, wherein the spatial information includes the header, the frame, and at least one other additional frame, wherein the IPD value indicates a phase difference between two channels of the plural-channel signal, and wherein the parameter band is at least one sub-band of a frequency domain including the IPD value.