Abstract: A method of generating a monaural signal (S) comprising a combination of at least two input audio channels (L, R) is disclosed. Corresponding frequency components from respective frequency spectrum representations for each audio channel (L(k), R(k)) are summed (46) to provide a set of summed frequency components (S(k)) for each sequential segment. For each frequency band (i) of each of sequential segment, a correction factor (m(i)) is calculated (45) as function of a sum of energy of the frequency components of the summed signal in the band formula (I) and a sum of components of the input audio channels in the band formula (II). Each summed frequency component is corrected (47) as a function of the correction factor (m(i)) for the frequency band of said component.

Abstract: A multi-channel signal having at least three channels can be reconstructed such, that the reconstructed channels are at least partly de-correlated from each other using a downmixed signal derived from an original multi-channel signal and a set of de-correlated signals provided by a de-correlator (101) that derives the set of de-correlated signals from the down-mix signal, wherein the de-correlated signals within the set of de-correlated signals are mutually mostly orthogonal to each other, i.e. an orthogonality relation between channel pairs is satisfied within an orthogonality tolerance range.

Abstract: In the method of coding the audio signal, the values of first parameters (P1,1), which represent aspects of the audio signal at a first instant (ti), are calculated to obtain first calculated values (A1,i). The values of second parameters P2,i), which represent the aspects of the audio signal at a second, later, instant (t2), are calculated to obtain the second calculated values (A2,i). The number of the first parameters (P1,i) and the number of the second parameters (P2,i) differ. A subset (SUS2,i) of the second parameters (P2,i) is associated with a particular portion (SFRAi) of a frequency range (FR) of the audio signal This frequency range (FR) of the audio signal is preferably selected to cover all the frequencies present in the audio signal.

Abstract: A parametric representation of a multi-channel audio signal having parameters suited to be used together with a monophonic downmix signal to calculate a reconstruction of the multi-channel audio signal can efficiently be derived in a stereo-backwards compatible way when a parameter combiner is used to generate the parametric representation by combining a one or more spatial parameters and a stereo parameter resulting in a parametric representation having a decoder usable stereo parameter and an information on the one or more spatial parameters that represents, together with the decoder usable stereo parameter, the one or more spatial parameters.

Abstract: A method of filtering an information signal (x(t)), the method comprising modifying frequency domain components (X(k,n)) of the information signal according to a desired filter response (F(k,n)); wherein the step of modifying frequency domain components further comprises modifying (105) frequency domain components of a first frame of said information signal according to a first actual filter response (F?(k,n)), the first actual filter response being a function (?) of the desired filter response and information (108) related to a previous frame of the information signal.

Abstract: Multi-channel audio signals are coded into a monaural audio signal and information allowing to recover the multi-channel audio signal from the monaural audio signal and the information. The information is generated by determining a first portion of the information for a first frequency region of the multi-channel audio signal, and by determining a second portion of the information for a second frequency region of the multi-channel audio signal. The second frequency region is a portion of the first frequency region and thus is a sub-range of the first frequency region. The information is multi-layered enabling a scaling of the decoding quality versus bit rate.

Abstract: In binaural stereo coding, only one monaural channel is encoded. An additional layer holds the parameters to retrieve the left and right signal. An encoder is disclosed which links transient information extracted from the mono encoded signal to parametric multi-channel layers to provide increased performance. Transient positions can either be directly derived from the bit-stream or be estimated from other encoded parameters (e.g. window-switching flag in mp3).

Abstract: The invention provides coding (11) of an at least two-channel audio signal (L,R) by determining common frequencies (fcom) in the at least two channels (L,R) of the audio signal, which common frequencies occur in at least two of the at least two channels of the audio signal, and by representing respective sinusoidal components in respective channels at a given common frequency by a representation of the given common frequency (fcom) and a representation of respective amplitudes (A,?A) of the respective sinusoidal components at the given common frequency.

Abstract: Coding a signal is provided, wherein a first set of values is provided related to subsequent times in a first time interval of the signal, a second set of values is provided related to subsequent times in a second time interval of the signal, the first time interval having an overlap with the second time interval, the overlap including at least two subsequent times of the second interval, wherein at least one of the values of the second set related to the at least two subsequent times in the overlap is encoded with reference to a value of the first set which is closer in time to the at least one value of the second set than any other value in the second set.