Methods, apparatus and systems for representation, encoding, and decoding of discrete directivity data
AssigneeDolby International AB
InventorsLeon Terentiv, Christof Fersch, Daniel Fischer
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Abstract
The present disclosure relates to a method of processing audio content including directivity information for at least one sound source, the directivity information comprising a first set of first directivity unit vectors representing directivity directions and associated first directivity gains. The disclosure further relates to corresponding methods of encoding and decoding audio content including directivity information for at least one sound source.
Claims17
A method of processing audio content including directivity information for at least one sound source, the directivity information comprising a first set of first directivity unit vectors representing directivity directions and associated first directivity gains, the method comprising:
- determining, as a count number, a number of unit vectors for arrangement on a surface of a 3D sphere, wherein the number of unit vectors relates to a desired representation accuracy;
- generating a second set of second directivity unit vectors by using a predetermined arrangement algorithm to distribute the determined number of unit vectors on the surface of the 3D sphere, wherein the predetermined arrangement algorithm is an algorithm for approximately uniform spherical distribution of the unit vectors on the surface of the 3D sphere;
- and
- determining, for the second directivity unit vectors, associated second directivity gains based on the first directivity gains of one or more among a group of first directivity unit vectors that are closest to the respective second directivity unit vector.
A method of decoding audio content including directivity information for at least one sound source, the directivity information comprising a number that indicates a number of approximately uniformly distributed unit vectors on a surface of a 3D sphere, and, for each such unit vector, an associated directivity gain, wherein the unit vectors are assumed to be distributed on the surface of the 3D sphere by a predetermined arrangement algorithm, wherein the predetermined arrangement algorithm is an algorithm for approximately uniform spherical distribution of the unit vectors on the surface of the 3D sphere, the method comprising:
- receiving a bitstream including the audio content;
- extracting the number and the directivity gains from the bitstream;
- and
- generating a set of directivity unit vectors by using the predetermined arrangement algorithm to distribute the number of unit vectors on the surface of the 3D sphere.
A method of decoding audio content including directivity information for at least one sound source, the directivity information comprising a first set of first directivity unit vectors representing directivity directions and associated first directivity gains, the method comprising:
- receiving a bitstream including the audio content;
- extracting the first set of directivity unit vectors and the associated first directivity gains from the bitstream;
- determining, as a count number, a number of vectors for arrangement on a surface of a 3D sphere, wherein the number of unit vectors relates to a desired representation accuracy;
- generating a second set of second directivity unit vectors by using a predetermined arrangement algorithm to distribute the determined number of unit vectors on the surface of the 3D sphere, wherein the predetermined arrangement algorithm is an algorithm for approximately uniform spherical distribution of the unit vectors on the surface of the 3D sphere;
- determining, for the second directivity unit vectors, associated second directivity gains based on the first directivity gains of one or more among a group of first directivity unit vectors that are closest to the respective second directivity unit vector;
- and
- for a given target directivity unit vector pointing from the sound source towards a listener position, determining a target directivity gain for the target directivity unit vector based on the associated second directivity gains of one or more among a group of second directivity unit vectors that are closest to the target directivity unit vector.
Dependencies are inferred from the claim text.