Patent ID: 8238561

Claim:
A method of decoding an audio signal performed by an audio coding system, comprising: obtaining a frame of an audio signal including a downmix signal and spatial information, the downmix signal generated by downmixing a multi-channel audio signal, and the spatial information to be used in order to generate an output multi-channel audio signal from the downmix signal; obtaining configuration information from the spatial information being included in the frame, the configuration information including tree configuration information indicating a tree configuration of the downmix signal to generate the output multi-channel audio signal, downmix gain information indicating a gain to be applied to the downmix signal, and channel gain information indicating at least one gain to be applied to at least one channel of the multi-channel audio signal; determining the tree configuration based on the tree configuration information; and generating the output multi-channel audio signal by modifying a gain of the downmix signal and at least one channel of the multi-channel audio signal using the downmix gain information and the channel gain information, respectively, based on the determined tree configuration, wherein the number of channels of the output multi-channel audio signal is greater than the number of channels of the downmix signal.