Methods, apparatus and systems for a pre-rendered signal for audio rendering

A method of generating audio scene content, the method comprising:

• obtaining, by a sound capturing device, sound emitted from one or more audio elements representing captured signals from an audio scene, the audio scene comprising a virtual reality/augmented reality/mixed reality (VR/AR/MR) acoustic environment;
• obtaining effective audio element information including effective audio element positions of one or more effective audio elements to be generated, the effective audio element positions being received as a user input;
• and
• generating the one or more effective audio elements from the captured signals by application of sound attenuation modelling according to distances between a position at which the captured signals have been captured and the effective audio element positions of the one or more effective audio elements, wherein the one or more effective audio elements encapsulate an impact of the VR/AR/MR acoustic environment including one or more of reverberation, echo, direct reflection, or acoustic occlusion, and wherein each effective audio element is a virtual audio object.

A method of encoding audio scene content into a bitstream, the method comprising:

• receiving a description of an audio scene, the audio scene comprising a virtual reality/augmented reality/mixed reality (VR/AR/MR) acoustic environment and one or more audio elements at respective audio element positions;
• determining one or more effective audio elements at respective effective audio element positions from the one or more audio elements, wherein each audio element is an original audio object, and wherein the one or more effective audio elements encapsulate an impact of the VR/AR/MR acoustic environment and wherein each effective audio element is a virtual audio object, wherein determining the one or more effective audio elements comprises:
• rendering the one or more audio elements to a reference position in the VR/AR/MR acoustic environment using a first rendering function, thereby obtaining a reference sound field at the reference position, wherein the first rendering function takes into account the impact of the VR/AR/MR acoustic environment as well as distance attenuation between the audio element positions and the reference position;
• and
• determining, based on the reference sound field at the reference position, the one or more effective audio elements at the respective effective audio element positions in the VR/AR/MR acoustic environment, in such manner that rendering the effective audio elements to the reference position using a second rendering function would yield a sound field at the reference position that approximates the reference sound field, wherein the second rendering function takes into account distance attenuation between the effective audio element positions and the reference position, but does not take into account the impact of the VR/AR/MR acoustic environment;
• generating effective audio element information indicative of the effective audio element positions of the one or more effective audio elements;
• generating a rendering mode indication that indicates that the one or more effective audio elements represent the sound field obtained from pre-rendered audio elements and should be rendered using a predetermined rendering mode that defines a predetermined configuration of rendering tools of a decoder for controlling the impact of the VR/AR/MR acoustic environment on a rendering output at the decoder;
• and
• encoding the one or more audio elements, the audio element positions, the one or more effective audio elements, the effective audio element information, and the rendering mode indication into the bitstream.