Spatial audio rendering and encoding

Abstract

An encoder generates data representing an audio scene by a first downmix and data characterizing audio objects. In addition, a direction dependent diffuseness parameter indicative of a degree of diffuseness of a residual downmix is provided where the residual downmix corresponds to a downmix of audio components of the audio scene with the audio objects being removed. A rendering apparatus comprises a receiver receiving the data from the encoder. A circuit generates signals for a spatial speaker configuration from the audio objects. A transformer generates non-diffuse sound signals for the spatial speaker configuration by applying a first transformation to the residual downmix and another transformer generates signals for the spatial speaker configuration by applying a second transformation to the residual downmix by applying a decorrelation to the residual downmix. The transformations are dependent on the direction dependent diffuseness parameter. The signals are combined to generate an output signal.

1 . A spatial audio encoding apparatus, comprising:
 a first circuit configured to generate encoded data representing an audio scene by a first downmix and data characterizing at least one audio object;   a second circuit configured to generate a direction dependent diffuseness parameter indicative of a degree of diffuseness of a residual downmix, the residual downmix corresponding to a downmix of the audio scene with the at least one audio object being removed; and   an output circuit for generating an output data stream comprising the first downmix, the data characterizing the at least one audio object, and the direction dependent diffuseness parameter.   
     
     
         2 . A method of spatial audio encoding, comprising:
 generating encoded data representing an audio scene by a first downmix and data characterizing at least one audio object;   generating a direction dependent diffuseness parameter indicative of a degree of diffuseness of a residual downmix, the residual downmix corresponding to a downmix of the audio scene with the at least one audio object being removed; and   generating an output data stream comprising the first downmix, the data characterizing the at least one audio object, and the direction dependent diffuseness parameter.