Immersive Audio Delivery Using Joint Object Coding

Immersive audio experiences (3D audio) are an important element of next-generation audio entertainment systems. This paper presents joint object coding techniques that enable the delivery of object-based immersive audio content (e.g. Dolby Atmos) at low bit rates. This is achieved by conveying a multi-channel downmix of the immersive content using perceptual audio coding algorithms together with parametric side information that enables the reconstruction of the audio objects from the downmix in the decoder. An advanced joint object coding tool is part of the AC-4 system recently standardized by ETSI. Joint object coding is also used in a backwards compatible extension of the Dolby Digital Plus system. Listening test results illustrate the performance of joint object coding in these two applications.