Method and apparatus for encoding/decoding multi-channel audio signal, Method and apparatus for decoding downmixed singal to 2 channel signal

The present invention relates to a decoding method and apparatus for outputting the coding / decoding method and apparatus, a multi-channel downmix signal in multi-channel audio signal to 2-channel, a plurality of channel coding method of the audio signal according to the invention generating spatial information indicating a direction of the virtual sound source is formed by a sound source of at least two channels of the respective sources and, to mix down the plurality of channel signals, a plurality of channel decoding method of an audio signal according to the invention a plurality of channels to the each of the space that represents the direction of the virtual sound source information which is formed by the excitation of the at least two channels of the sound source and a plurality of channel signals being input to the downmix signal, the downmix signal using the spatial information It is restored to the signals. According to the present invention may allow the multi-channel audio signal accuracy, regardless of the frequency domain encoding and decoding.