Spatial audio signal decoder

Patent metadata

Field	Value
Publication number	US-10796704-B2
Application number	US-201916543083-A
Country	US
Kind code	B2
Filing date	Aug 16, 2019
Priority date	Aug 17, 2018
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A method to decode audio signals is provided that includes: receiving an input spatial audio signal; determining directions of arrival of directional audio sources represented in the received input spatial audio signal; determining one of an active input spatial audio signal component and a passive spatial audio signal input component, based upon the determined directions of arrival; determining the other of the active input spatial audio signal component and the passive input spatial audio signal component, based upon the determined one of the active input spatial audio signal component and the passive input spatial audio signal component; decoding the active input spatial audio signal component to a first output format; and decoding the passive input spatial audio signal component to a second output format.

First claim

The invention claimed is:

1. An audio signal decoder comprising:
a processor and a non-transitory computer readable medium operably coupled thereto, the non-transitory computer readable medium comprising a plurality of instructions stored in association therewith that are accessible to, and executable by, the processor, where the plurality of instructions comprises:
instructions that, when executed, receive an input spatial audio signal having an input spatial format, the input spatial format comprising multiple channels, each channel having a corresponding directivity pattern, the input spatial audio signal comprising an active spatial audio signal component and a passive spatial audio signal component;
instructions that, when executed, determine a number of directional audio sources represented in the input spatial audio signal having the input spatial format and determine a direction of arrival for each of the determined number of directional audio sources represented in the input spatial audio signal having the input spatial format;
instructions that when executed, determine one of the active input spatial audio signal component and the passive input spatial audio signal component, based upon the number and directions of arrival of the directional audio sources represented in the input spatial audio signal;
instructions that when executed, determine the other of the active input spatial audio signal component and the passive input spatial audio signal component, based upon the one of the active input spatial audio signal component and the passive input spatial audio signal component;
instructions that when executed, decode the active input spatial audio signal component having the input spatial format, to a first output signal having a first output format;
instructions that when executed, decode the passive input spatial audio signal component having the input spatial format, to a second output signal having a second output format.

2. The audio signal decoder of claim 1 ,
wherein the first output format is different from the second output format.

3. The audio signal decoder of claim 1 ,
wherein the first output format matches the second output format.

4. The audio signal decoder of claim 1 ,
wherein the instructions that, when executed, determine the number of directional audio sources and the direction of arrival for each of the determined number of directional audio sources, determine a subspace corresponding to one or more direction vectors of a codebook to represent the input spatial audio signal.

5. The audio signal decoder of claim 1 ,
wherein the instructions that, when executed, determine the number of directional audio sources and the direction of arrival for each of the determined number of directional audio sources, determine a subspace corresponding to one or more direction vectors of a codebook to represent the input spatial audio signal, based upon an optimality metric computed for direction vectors within the codebook.

6. The audio signal decoder of claim 5 ,
wherein the optimality metric includes one or more correlations between direction vectors within the codebook and one or more eigenvectors of a noise subspace of the input spatial audio signal.

7. The audio signal decoder of claim 5 ,
wherein the optimality metric includes a correlation between direction vectors within the codebook and the input spatial audio signal.

8. The audio signal decoder of claim 1 ,
wherein the instructions that, when executed, determine the number of directional audio sources and the direction of arrival for each of the determined number of directional audio sources, determine a subspace corresponding to one or more direction vectors of a codebook to represent the input spatial audio signal; and
wherein the instructions that, when executed, determine one of an active input spatial audio signal component and a passive audio signal input component, determine based upon a mapping of the input signal onto the determined subspace corresponding to the one or more direction vectors of the codebook.

9. The audio signal decoder of claim 1 ,
wherein the instructions that, when executed, determine one of the active input spatial audio signal component and the passive input spatial audio signal component, determine the active input spatial audio signal component;
wherein the instructions that when executed, determine the other of the active input spatial audio signal component and the passive input spatial audio signal component based upon the determined one of the active input spatial audio signal component and the passive input spatial audio signal component, determine the passive input spatial audio signal component.

10. The audio signal decoder of claim 1 further including:
instructions that, when executed, convert the input spatial audio signals having the input spatial format from a time-domain representation to a time-frequency representation; and
instructions that, when executed, convert the first output signal having the first output format and the second output signal having the second output format from the time-frequency representation to the time-domain representation.

11. The audio signal decoder of claim 1 further including:
instructions that, when executed, combine the first output signal having the first output format and the second output signal having the second output format.

12. The audio signal decoder of claim 1 ,
wherein at least one of the first output format and the second output format includes an ambisonic format.

13. A method to decode audio signals comprising:
receiving an input spatial audio signal in an input spatial format, the input spatial format comprising multiple channels, each channel having a corresponding directivity pattern, the input spatial audio signal comprising an active spatial audio signal component and a passive spatial audio signal component;
determining a number of directional audio sources represented in the input spatial audio signal having the input spatial format and determine a direction of arrival for each of the determined number of direction audio sources represented in the input spatial audio signal having the input spatial format;
determining one of an active input spatial audio signal component and the passive spatial audio signal input component, based upon the determined number and directions of arrival of the directional audio sources represented in the input spatial audio signal;
determining the other of the active input spatial audio signal component and the passive input spatial audio signal component, based upon the determined one of the active input spatial audio signal component and the passive input spatial audio signal component;
decoding the active input spatial audio signal component having the input spatial format, to a first output signal having a first output format;
decoding the passive input spatial audio signal component having the input spatial format, to a second output signal having second output format.

14. The method of claim 13 ,
wherein the first output format is different from the second output format.

15. The method of claim 13 ,
wherein the first output format matches the second output format.

16. The method of claim 13 ,
wherein determining the number of directional audio sources and the direction of arrival for each of the determined number of directional audio sources, includes determining a subspace of a codebook to represent the input spatial audio signal.

17. The method of claim 13 ,
wherein determining the number of directional audio sources an

Assignees

• Dts Inc

Inventors

• Goodwin Michael M
• Stein Edward

Classifications

• G10L19/008 Primary

  Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing · CPC title

• H04S2420/11

  Application of ambisonics in stereophonic audio systems · CPC title

• H04S3/02

  of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other · CPC title

• H04S3/008

  in which the audio signals are in digital form, i.e. employing more than two discrete digital channels (data reduction aspects thereof based on psychoacoustics G10L19/02) · CPC title