Apparatuses for converting an object position of an audio object, audio stream provider, audio content production system, audio playback apparatus, methods and computer programs

Patent metadata

Field	Value
Publication number	US-11653162-B2
Application number	US-202016943778-A
Country	US
Kind code	B2
Filing date	Jul 30, 2020
Priority date	Jan 30, 2018
Publication date	May 16, 2023
Grant date	May 16, 2023

Abstract

An apparatus for converting an object position of an audio object from a Cartesian representation to a spherical representation is described. A basis area of the Cartesian representation is subdivided into a plurality of basis area triangles, and wherein a plurality of spherical-domain triangles are inscribed into a circle of a spherical representation. The apparatus is configured to determine, in which of the basis area triangles a projection of the object position of the audio object into the base area is arranged; and the apparatus is configured to determine a mapped position of the projection of the object position using a linear transform, which maps the base area triangle onto its associated spherical domain triangle. The apparatus is configured to derive an azimuth angle and an intermediate radius value from the mapped position. The apparatus is configured to obtain a spherical domain radius value and an elevation angle in dependence on the intermediate radius value and in dependence on a distance of the object position from the base area. An apparatus for converting an object position of an audio object from a spherical representation to a spherical representation, applications of these apparatuses, methods and computer programs are also described.

First claim

The invention claimed is:

1. An apparatus for converting an object position of an audio object from a Cartesian representation to a spherical representation,
wherein a base area of the Cartesian representation is subdivided into a plurality of base area triangles, and wherein a plurality of associated spherical-domain triangles are inscribed into a circle of the spherical representation,
wherein the apparatus comprises a triangle determinator configured to determine, in which of the base area triangles a projection of the object position of the audio object into the base area is arranged; and
wherein the apparatus comprises a mapped position determinator configured to determine a mapped position of the projection of the object position using a linear transform, which maps the base area triangle onto its associated spherical domain triangle,
wherein the apparatus comprises an azimuth angle derivator configured to derive an azimuth angle and an intermediate radius value from the mapped position;
wherein the apparatus is configured to acquire a spherical domain radius value and an elevation angle in dependence on the intermediate radius value and in dependence on a distance of the object position from the base area.

2. The apparatus according to claim 1 , wherein the apparatus is configured to determine the mapped position {tilde over (P)} of the projection P of the object position using a linear transform described by a transform matrix T according to

P
~

=

(

x
~

y
~

)

=

T
_

⁢

⁢
P

,

wherein the apparatus is configured to acquire the transform matrix in dependence the determined base area triangle, and
wherein {tilde over (x)} represents a first coordinate of the mapped position {tilde over (P)} and {tilde over (y)} represents a second coordinate of the mapped position {tilde over (P)}.

3. The apparatus according to claim 2 , wherein the transform matrix is defined according to

T
_

=

[

t
11

t
12

t
21

t
22

]

=

1

P

1
,
x

⁢

P

2
,
y

-

P

2
,
x

⁢

P

1
,
y

⁡

[

P
~

1
,
x

⁢

P

2
,
y

-

P
~

2
,
x

⁢

P

1
,
y

P

1
,
x

⁢

P
~

2
,
x

Assignees

• Fraunhofer Ges Forschung

Inventors

• Wübbolt Oliver
• Kuntz Achim
• Ertel Christian
• Dick Sascha
• Nagel Frederik
• Neusinger Matthias

Classifications

• H04S3/002 Primary

  Non-adaptive circuits, e.g. manually adjustable or static, for enhancing the sound image or the spatial distribution (control circuits for electronic adaptation of the sound field H04S7/30) · CPC title

• H04S7/302

  Electronic adaptation of stereophonic sound system to listener position or orientation (H04S7/301 takes precedence) · CPC title

• H04S2400/11

  Positioning of individual sound objects, e.g. moving airplane, within a sound field (H04S2420/13 takes precedence) · CPC title

• H04S2400/01

  Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved · CPC title

• H04R5/02 Primary

  Spatial or constructional arrangements of loudspeakers · CPC title