Method and an apparatus for processing an audio signal

The present invention includes receiving a plurality of frame data including first frame data and second frame data encoded by at least one coding schemes, obtaining first flag information indicating whether the first frame data and the second frame data are encoded by frequency domain transform coding scheme, respectively, decoding the first frame data by frequency domain transform coding scheme based on the first flag information when the first frame data is encoded by frequency domain transform coding scheme, obtaining second flag information indicating whether subframe data is encoded by time domain transform coding scheme or time-frequency domain coding scheme when the second frame data is not encoded by frequency domain transform coding scheme, the at least two subframe data being included in the second frame data, decoding the subframe data by time domain transform coding scheme or time-frequency domain transform coding scheme based on the second flag information, and compensating for discontinuity existing between the first frame data decoded by frequency domain transform coding scheme and the subframe data decoded by time domain transform coding scheme, wherein the time-frequency domain coding scheme is time domain coding scheme including frequency domain transform.