Method and system for handling local transitions between listening positions in a virtual reality environment

A virtual reality audio renderer for rendering an audio signal in a virtual reality rendering environment, wherein the audio renderer is configured to

• render an origin audio signal of an audio source from an origin source position on an origin sphere around an origin listening position of a listener;
• determine that the listener moves from the origin listening position to a destination listening position;
• determine a destination source position of the audio source on a destination sphere around the destination listening position based on the origin source position by projecting the origin source position from the origin sphere onto the destination sphere;
• determine a destination audio signal of the audio source based on the origin audio signal;
• and
• render the destination audio signal of the audio source from the destination source position on the destination sphere around the destination listening position,
• wherein the origin source position is projected from the origin sphere onto the destination sphere by a perspective projection with respect to the destination listening position;
• and
• wherein the origin sphere and the destination sphere have the same radius.

An audio encoder configured to generate a bitstream which is indicative of an audio signal to be rendered in a virtual reality environment, wherein the encoder is configured to

• determine an origin audio signal of an audio source;
• determine origin position data regarding an origin source position of the audio source on an origin sphere around an origin listening position of a listener;
• generate a bitstream comprising the origin audio signal and the origin position data;
• receive an indication that the listener moves from the origin listening position to a destination listening position;
• determine a destination audio signal of the audio source based on the origin audio signal;
• determine destination position data regarding a destination source position of the audio source on a destination sphere around the destination listening position based on the origin source position by projecting the origin source position from the origin sphere onto the destination sphere;
• and
• generate a bitstream comprising the destination audio signal and the destination position data,
• wherein the origin source position is projected from the origin sphere onto the destination sphere by a perspective projection with respect to the destination listening position;
• and
• wherein the origin sphere and the destination sphere have the same radius.

A method of generating a bitstream which is indicative of an audio signal to be rendered in a virtual reality environment, the method comprising:

• determining an origin audio signal of an audio source;
• determining origin position data regarding an origin source position of the audio source on an origin sphere around an origin listening position of a listener;
• generating a bitstream comprising the origin audio signal and the origin position data;
• receiving an indication that the listener moves from the origin listening position to a destination listening position;
• determining a destination audio signal of the audio source based on the origin audio signal;
• determining destination position data regarding a destination source position of the audio source on a destination sphere around the destination listening position based on the origin source position by projecting the origin source position from the origin sphere onto the destination sphere;
• and
• generating a bitstream comprising the destination audio signal and the destination position data,
• wherein the origin source position is projected from the origin sphere onto the destination sphere by a perspective projection with respect to the destination listening position;
• and
• wherein the origin sphere and the destination sphere have the same radius.

A virtual reality audio renderer for rendering an audio signal in a virtual reality rendering environment, wherein the audio renderer comprises,

• a 3D audio renderer which is configured to render an audio signal of an audio source from a source position on a sphere around a listening position of a listener within the virtual reality rendering environment;
• a pre-processing unit which is configured to
• determine a new listening position of the listener within the virtual reality rendering environment;
• and
• update the audio signal and the source position of the audio source with respect to a sphere around the new listening position, wherein the source position of the audio source with respect to the sphere around the new listening position is determined by projecting the source position on the sphere around the listening position onto the sphere around the new listening position;
• wherein the 3D audio renderer is configured to render the updated audio signal of the audio source from the updated source position on the sphere around the new listening position;
• wherein the source position is projected from the sphere around the listening position onto the sphere around the new listening position by a perspective projection with respect to the new listening position;
• and wherein the sphere around the listening position and the sphere around the new listening position have the same radius.