Patent ID: 8208641

Claim:
A method of processing a signal, comprising: receiving, by an audio decoding apparatus, spatial information and a downmix signal, wherein the downmix signal corresponding to 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 the audio decoding apparatus, rendering information by using the spatial information and HRTF (Head Related Transfer Function); and generating, by the audio decoding apparatus, a surround signal having a surround effect by applying the rendering information to the downmix signal, wherein: the downmix signal consists of a left input channel and a right input channel, the surround signal consists of a left output channel and a right output channel, 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, the rendering information comprises first rendering information and second rendering information, the first rendering information includes information for generating the left output channel by being applied to the left input channel, and information for generating the right output channel by being applied to the right input channel, and the second rendering information includes information for generating the right output channel by being applied to the left input channel, and information for generating the left output channel by being applied to the right input channel.