Extracting a direct / ambient signal from a downmix signal and spatial parametric information

摘要

An apparatus (100) for extracting a direct and / or ambient signal (125-1, 125-2) from a downmix signal (115) and spatial parametric information (105), the downmix signal (115) and The spatial parametric information (105) represents a multi-channel audio signal (101) that has more channels (Ch1 O ChN) than the downmix signal (115), in which the spatial parametric information (105) comprises inter - channel of the multi-channel audio signal (101), the apparatus comprising (100): a live / environment estimator (110) for estimating a direct level information (113) of a direct portion of the audio signal of multiple channels (101) and / or for estimating an environment level information (113) of a portion of the environment of the multi-channel audio signal (101) based on the spatial parametric information (105); and a direct / ambient extractor (420) for extracting a portion of the direct signal (125-1) and / or a portion of the ambient signal (125-2) from the downstream mixing signal (115) based on the estimated direct level information (113) of the direct portion or based on the estimated ambient level information (113) of the environment portion, in which the direct / environment extractor (420) is configured to mix down the estimated direct level information (113) of the direct portion or the estimated environment level information (113) of the environment portion to obtain level information with descending mix of the direct portion or of the environment portion and extract the direct signal portion (125-1) or the ambient signal portion (125-2) of the downstream mix signal (115) based on the downstream mix level information.