Audio channel spatial translation

An apparatus for upmixing N audio input channels, each associated with a spatial direction, to M audio output channels, each associated with a spatial direction, wherein M and N are positive whole integers and M is greater than N, comprising:

• one or more audio signal processors, configured to perform:
• deriving the M audio output channels from the N audio input channels;
• determining a specific audio output channel, in the M audio output channels, to which a specific set of three or more audio input channels in the N audio input channels is mapped;
• computing a plurality of pairwise common signal powers for a plurality of distinct pairs of two audio input channels in the specific set of three or more audio input channels in the N audio input channels;
• determining, based at least in part on the plurality of pairwise common signal powers, a specific correlation for all audio input channels in the specific set of three or more audio input channels;
• setting, based at least in part on the specific correlation for all the audio input channels in the specific set of three or more audio input channels, relative output signal levels of the M audio output channels.

A computer program, stored on a non-transitory computer-readable medium for causing a computer to perform:

• deriving the M audio output channels from the N audio input channels;
• determining a specific audio output channel, in the M audio output channels, to which a specific set of three or more audio input channels in the N audio input channels is mapped;
• computing a plurality of pairwise common signal powers for a plurality of distinct pairs of two audio input channels in the specific set of three or more audio input channels in the N audio input channels;
• determining, based at least in part on the plurality of pairwise common signal powers, a specific correlation for all audio input channels in the specific set of three or more audio input channels;
• setting, based at least in part on the specific correlation for all the audio input channels in the specific set of three or more audio input channels, relative output signal levels of the M audio output channels.