Method for obtaining spatial cues in spatial audio coding

The present invention is a spatial information-based audio coding: relates to a method for extracting and applying (SAC Spatial Audio Coding) spatial information (spatial cue) which is used as additional information in the process of encoding and decoding a multi-channel audio signal using a method. According to one aspect of the present invention, a method is provided for extracting each sub-band by the spatial information to the spatial information when the audio coding of multi-channel audio signal. The spatial information extracting method, the left and right that the sum using a window function; and the selection to select the sub-band by a window function to be represented by a certain constant in the portion that is asymmetric and superposed with the window function neighboring said Genie the same maximum value and it characterized by including the step of extracting spatial information. In one embodiment, the spatial information, the inter-channel energy ratio: I (Inter-Channel Level Difference ICLD). A spatial information-based audio coding (spatial audio coding: SAC), (Inter Channel Level Difference) ICLD