Patent ID: 8411869

Claim:
A method of processing signals, comprising: receiving, by an audio decoding apparatus, spatial information and a downmix signal, wherein the downmix signal corresponding to one of a mono signal and a stereo signal is generated by downmixing a multi-channel audio signal, the spatial information is determined when the multi-channel audio signal is downmixed into the downmix signal, the spatial information includes at least one of channel level difference (CLD) and an inter-channel correlation (ICC); generating, by an audio decoding apparatus, rendering information by using the spatial information and HRTF(Head Related Transfer Function); and generating, by an audio decoding apparatus, a surround signal having the surround effect from the downmix signal using a rendering filter corresponding to the rendering information, wherein: the surround signal having the surround effect consists of two output channels, and provides multi-channel impression corresponding to the multi-channel audio signal over two output channels, and, a tab number of the rendering filter is variable.