UPMIXING OF AUDIO SIGNALS

摘要

An audio apparatus comprises a processor (101) for providing a set of audio channels. A prediction circuit (103) generates a predicted signal for a first channel by adaptive filtering of a second channel by an adaptive filter. An adaptation processor (105) adapts the adaptive filter to minimize a cost function indicative of a difference between the predicted signal and the first channel. A compensation processor (107) then generates a non- predicted signal by compensating the first signal for the predicted signal and a distribution processor (109) generates an output set of audio channels by distributing at least the predicted signal and the non-predicted signal over the output set of audio signals where the distribution is different for the predicted signal and the non-predicted signal. The cross-channel predictive filtering provides signal components that represent different spatial characteristics of the originating sound and which are therefore advantageously distributed differently for the output channels.