DETERMINING THE INTER-CHANNEL TIME DIFFERENCE OF A MULTI-CHANNEL AUDIO SIGNAL

摘要

A method and device are disclosed for determining an inter-channel time difference of a multi-channel audio signal having at least two channels. A determination is made at a number of consecutive time instances, inter-channel correlation based on a cross-correlation function involving at least two different channels of the multi-channel audio signal. Each value of the inter-channel correlation is associated with a corresponding value of the inter-channel time difference. An adaptive inter-channel correlation threshold is adaptively determined based on adaptive smoothing of the inter-channel correlation in time. A current value of the inter-channel correlation is then evaluated in relation to the adaptive inter-channel correlation threshold to determine whether the corresponding current value of the inter-channel time difference is relevant. Based on the result of this evaluation, an updated value of the inter-channel time difference is determined.

主权项

1. A mobile device comprising an apparatus for determining an inter-channel time difference of a multi-channel audio signal having at least two channels, wherein said apparatus comprises:
an inter-channel correlation determiner configured to determine, at a number of consecutive time instances, inter-channel correlation based on a cross-correlation function involving at least two different channels of the multi-channel audio signal, where each value of the inter-channel correlation is associated with a corresponding value of the inter-channel time difference; an adaptive filter configured to perform adaptive smoothing of the inter-channel correlation in time; a threshold determiner configured to adaptively determine an adaptive inter-channel correlation threshold based on the adaptive smoothing of the inter-channel correlation; an inter-channel correlation evaluator configured to evaluate a current value of inter-channel correlation in relation to the adaptive inter-channel correlation threshold to determine whether the corresponding current value of the inter-channel time difference is relevant; an inter-channel time difference determiner is configured to determine an updated value of the inter-channel time difference based on the result of this evaluation; and at least one of: a decoder configured to decode the multi-channel audio signal based on the updated value of the inter-channel time difference to generate a decoded multi-channel audio signal communicated toward speakers; and an encoder configured to encode the multi-channel audio signal based on the updated value of the inter-channel time difference to generate an encoded multi-channel audio signal communicated toward speakers.