Patent ID: 9099078
Filing Date: 2015-08-04
Classification: G10L

Abstract:
1. An upmixer for upmixing a downmix audio signal into an upmixed audio signal describing one or more upmixed audio channels, the upmixer comprising: a parameter applier configured to apply upmixing parameters to upmix the downmix audio signal in order to achieve the upmixed audio signal, wherein the parameter applier is configured to apply a phase shift to the downmix audio signal to achieve a phase-shifted version of the downmix audio signal while leaving a decorrelated signal unmodified by the phase shift, and to combine the phase-shifted version of the downmix audio signal with the decorrelated signal to achieve the upmixed audio signal; wherein the upmixer is configured to upmix the downmix audio signal into an upmixed audio signal describing a plurality of upmixed audio channels, wherein the parameter applier is configured to apply the upmixing parameters to upmix the downmix audio signal using the decorrelated signal in order to achieve a first upmixed audio channel signal and a second upmixed audio channel signal, wherein the parameter applier is configured to apply a time-variant phase shift to the downmix audio signal to achieve at least two versions of the downmix audio signal comprising a time-variant phase shift with respect to each other; and wherein the parameter applier is configured to combine the at least two versions of the downmix audio signal with the decorrelated signal to achieve at least two upmixed audio channel signals such that the decorrelated signal remains unaffected by the time-variant phase shift; wherein the upmixer is implemented using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.