PARAMETRIC MIXING OF AUDIO SIGNALS

)In an encoding section (100), a downmix section (110) forms first and second channels (L1, L2) of a downmix signal as linear combinations of first and second groups (401, 402) of channels, respectively, of an M-channel audio signal; and an analysis section (120) determines upmix parameters (αLU) for parametric reconstruction of the audio signal, and mixing parameters (αLM). In a decoding section (1200), a decorrelating section (1210) outputs a decorrelated signal (D) based on the downmix signal; and a mixing section (1220) determines mixing coefficients based on the mixing parameters or the upmix parameters, and forms a K-channel output signal (L͂1,...,L͂K) as a linear combination of the downmix signal and the decorrelated signal in accordance with the mixing coefficients. The channels of the output signal approximate linear combinations of K groups (501-502, 1301-1303) of channels, respectively, of the audio signal. The K groups constitute a different partition of the audio signal than the first and second groups, and 2 ≤ K < M.

)In an encoding section (100), a downmix section (110) forms first and second channels (L1, L2) of a downmix signal as linear combinations of first and second groups (401, 402) of channels, respectively, of an M-channel audio signal; and an analysis section (120) determines upmix parameters (αLU) for parametric reconstruction of the audio signal, and mixing parameters (αLM). In a decoding section (1200), a decorrelating section (1210) outputs a decorrelated signal (D) based on the downmix signal; and a mixing section (1220) determines mixing coefficients based on the mixing parameters or the upmix parameters, and forms a K-channel output signal (L͂1,...,L͂K) as a linear combination of the downmix signal and the decorrelated signal in accordance with the mixing coefficients. The channels of the output signal approximate linear combinations of K groups (501-502, 1301-1303) of channels, respectively, of the audio signal. The K groups constitute a different partition of the audio signal than the first and second groups, and 2 ≤ K < M.