Patent ID: 7809579
Filing Date: 2010-10-05
Classification: G10L

Abstract:
1. A method of encoding polyphonic signals in an encoder apparatus, comprising the steps of: the encoder apparatus creating a main signal and a side signal as a first linear combination and a second different linear combination, respectively, of at least a first channel and a second channel, where each of the main signal and the side signal on their own represent a complete audio signal; the side signal being different from the main signal; the encoder apparatus generating a first output signal being encoding parameters representing the main signal; the encoder apparatus generating a second output signal being encoding parameters representing the side signal within an encoding frame; the encoder apparatus providing at least two side signal encoding schemes, each of the at least two side signal encoding schemes being characterized by a different respective set of sub-frames together constituting the encoding frame, wherein the sum of the lengths of the sub-frames in each encoding scheme is equal to the length of the encoding frame; each set of sub-frames including at least one sub-frame; wherein: the at least two side signal encoding schemes each encode the side signal into a set of sub-frames having a different sub-frame pattern; the step of generating the second output signal comprises the step of selecting an encoding scheme from the at least two side signal encoding schemes, having a certain set of sub-frames, depending on a present signal content of the side signal; and the second output signal is encoded in each of the sub-frames of the selected set of sub-frames separately.