Patent ID: 8611545

Claim:
A surround generation apparatus for generating a multi-channel surround signal from an encoded audio stream, the surround generation apparatus comprising: a decoder configured to decode the encoded audio stream and determine a coding method used to encode the encoded audio stream; a decorrelation unit configured to receive at least two stereo signals decoded by the decoder and decorrelate the at least two stereo signals so as to generate a surround signal having a low-correlation component; an addition unit configured to add, to the surround signal, a high-correlation-component signal extracted from the at least two stereo signals, wherein the addition unit adds, to the surround signal, a signal obtained by eliminating a low-frequency component from the high-correlation-component signal; and a controller configured to control addition of the high-correlation-component signal performed by the addition unit based at least in part on the coding method used to encode the encoded audio stream as determined by the decoder, wherein the controller controls the addition of the high-correlation-component signal performed by the addition unit such that quality of a surround sound generated by the apparatus is enhanced.